common/cli_hush.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * sh.c -- a prototype Bourne shell grammar parser
   4  *      Intended to follow the original Thompson and Ritchie
   5  *      "small and simple is beautiful" philosophy, which
   6  *      incidentally is a good match to today's BusyBox.
   7  *
   8  * Copyright (C) 2000,2001  Larry Doolittle  <[email protected]>
   9  *
  10  * Credits:
  11  *      The parser routines proper are all original material, first
  12  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  13  *      The execution engine, the builtins, and much of the underlying
  14  *      support has been adapted from busybox-0.49pre's lash,
  15  *      which is Copyright (C) 2000 by Lineo, Inc., and
  16  *      written by Erik Andersen <[email protected]>, <[email protected]>.
  17  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  18  *      Erik W. Troan, which they placed in the public domain.  I don't know
  19  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  20  * Other credits:
  21  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  22  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  23  *        and many builtins derived from contributions by Erik Andersen
  24  *      miscellaneous bugfixes from Matt Kraai
  25  *
  26  * There are two big (and related) architecture differences between
  27  * this parser and the lash parser.  One is that this version is
  28  * actually designed from the ground up to understand nearly all
  29  * of the Bourne grammar.  The second, consequential change is that
  30  * the parser and input reader have been turned inside out.  Now,
  31  * the parser is in control, and asks for input as needed.  The old
  32  * way had the input reader in control, and it asked for parsing to
  33  * take place as needed.  The new way makes it much easier to properly
  34  * handle the recursion implicit in the various substitutions, especially
  35  * across continuation lines.
  36  *
  37  * Bash grammar not implemented: (how many of these were in original sh?)
  38  *      $@ (those sure look like weird quoting rules)
  39  *      $_
  40  *      ! negation operator for pipes
  41  *      &> and >& redirection of stdout+stderr
  42  *      Brace Expansion
  43  *      Tilde Expansion
  44  *      fancy forms of Parameter Expansion
  45  *      aliases
  46  *      Arithmetic Expansion
  47  *      <(list) and >(list) Process Substitution
  48  *      reserved words: case, esac, select, function
  49  *      Here Documents ( << word )
  50  *      Functions
  51  * Major bugs:
  52  *      job handling woefully incomplete and buggy
  53  *      reserved word execution woefully incomplete and buggy
  54  * to-do:
  55  *      port selected bugfixes from post-0.49 busybox lash - done?
  56  *      finish implementing reserved words: for, while, until, do, done
  57  *      change { and } from special chars to reserved words
  58  *      builtins: break, continue, eval, return, set, trap, ulimit
  59  *      test magic exec
  60  *      handle children going into background
  61  *      clean up recognition of null pipes
  62  *      check setting of global_argc and global_argv
  63  *      control-C handling, probably with longjmp
  64  *      follow IFS rules more precisely, including update semantics
  65  *      figure out what to do with backslash-newline
  66  *      explain why we use signal instead of sigaction
  67  *      propagate syntax errors, die on resource errors?
  68  *      continuation lines, both explicit and implicit - done?
  69  *      memory leak finding and plugging - done?
  70  *      more testing, especially quoting rules and redirection
  71  *      document how quoting rules not precisely followed for variable assignments
  72  *      maybe change map[] to use 2-bit entries
  73  *      (eventually) remove all the printf's
  74  */
  75
  76 #define __U_BOOT__
  77 #ifdef __U_BOOT__
  78 #include <env.h>
  79 #include <malloc.h>         /* malloc, free, realloc*/
  80 #include <linux/ctype.h>    /* isalpha, isdigit */
  81 #include <console.h>
  82 #include <bootretry.h>
  83 #include <cli.h>
  84 #include <cli_hush.h>
  85 #include <command.h>        /* find_cmd */
  86 #include <asm/global_data.h>
  87 #endif
  88 #ifndef __U_BOOT__
  89 #include <ctype.h>     /* isalpha, isdigit */
  90 #include <unistd.h>    /* getpid */
  91 #include <stdlib.h>    /* getenv, atoi */
  92 #include <string.h>    /* strchr */
  93 #include <stdio.h>     /* popen etc. */
  94 #include <glob.h>      /* glob, of course */
  95 #include <stdarg.h>    /* va_list */
  96 #include <errno.h>
  97 #include <fcntl.h>
  98 #include <getopt.h>    /* should be pretty obvious */
  99
 100 #include <sys/stat.h>  /* ulimit */
 101 #include <sys/types.h>
 102 #include <sys/wait.h>
 103 #include <signal.h>
 104
 105 /* #include <dmalloc.h> */
 106
 107 #if 1
 108 #include "busybox.h"
 109 #include "cmdedit.h"
 110 #else
 111 #define applet_name "hush"
 112 #include "standalone.h"
 113 #define hush_main main
 114 #define BB_BANNER
 115 #endif
 116 #endif
 117 #define SPECIAL_VAR_SYMBOL 03
 118 #define SUBSTED_VAR_SYMBOL 04
 119 #ifndef __U_BOOT__
 120 #define FLAG_EXIT_FROM_LOOP 1
 121 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 122 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 123
 124 #endif
 125
 126 #ifdef __U_BOOT__
 127 DECLARE_GLOBAL_DATA_PTR;
 128
 129 #define EXIT_SUCCESS 0
 130 #define EOF -1
 131 #define syntax() syntax_err()
 132 #define xstrdup strdup
 133 #define error_msg printf
 134 #else
 135 typedef enum {
 136         REDIRECT_INPUT     = 1,
 137         REDIRECT_OVERWRITE = 2,
 138         REDIRECT_APPEND    = 3,
 139         REDIRECT_HEREIS    = 4,
 140         REDIRECT_IO        = 5
 141 } redir_type;
 142
 143 /* The descrip member of this structure is only used to make debugging
 144  * output pretty */
 145 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 146         { 0,                         0, "()" },
 147         { O_RDONLY,                  0, "<"  },
 148         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 149         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 150         { O_RDONLY,                 -1, "<<" },
 151         { O_RDWR,                    1, "<>" }
 152 };
 153 #endif
 154
 155 typedef enum {
 156         PIPE_SEQ = 1,
 157         PIPE_AND = 2,
 158         PIPE_OR  = 3,
 159         PIPE_BG  = 4,
 160 } pipe_style;
 161
 162 /* might eventually control execution */
 163 typedef enum {
 164         RES_NONE  = 0,
 165         RES_IF    = 1,
 166         RES_THEN  = 2,
 167         RES_ELIF  = 3,
 168         RES_ELSE  = 4,
 169         RES_FI    = 5,
 170         RES_FOR   = 6,
 171         RES_WHILE = 7,
 172         RES_UNTIL = 8,
 173         RES_DO    = 9,
 174         RES_DONE  = 10,
 175         RES_XXXX  = 11,
 176         RES_IN    = 12,
 177         RES_SNTX  = 13
 178 } reserved_style;
 179 #define FLAG_END   (1<<RES_NONE)
 180 #define FLAG_IF    (1<<RES_IF)
 181 #define FLAG_THEN  (1<<RES_THEN)
 182 #define FLAG_ELIF  (1<<RES_ELIF)
 183 #define FLAG_ELSE  (1<<RES_ELSE)
 184 #define FLAG_FI    (1<<RES_FI)
 185 #define FLAG_FOR   (1<<RES_FOR)
 186 #define FLAG_WHILE (1<<RES_WHILE)
 187 #define FLAG_UNTIL (1<<RES_UNTIL)
 188 #define FLAG_DO    (1<<RES_DO)
 189 #define FLAG_DONE  (1<<RES_DONE)
 190 #define FLAG_IN    (1<<RES_IN)
 191 #define FLAG_START (1<<RES_XXXX)
 192
 193 /* This holds pointers to the various results of parsing */
 194 struct p_context {
 195         struct child_prog *child;
 196         struct pipe *list_head;
 197         struct pipe *pipe;
 198 #ifndef __U_BOOT__
 199         struct redir_struct *pending_redirect;
 200 #endif
 201         reserved_style w;
 202         int old_flag;                           /* for figuring out valid reserved words */
 203         struct p_context *stack;
 204         int type;                       /* define type of parser : ";$" common or special symbol */
 205         /* How about quoting status? */
 206 };
 207
 208 #ifndef __U_BOOT__
 209 struct redir_struct {
 210         redir_type type;                        /* type of redirection */
 211         int fd;                                         /* file descriptor being redirected */
 212         int dup;                                        /* -1, or file descriptor being duplicated */
 213         struct redir_struct *next;      /* pointer to the next redirect in the list */
 214         glob_t word;                            /* *word.gl_pathv is the filename */
 215 };
 216 #endif
 217
 218 struct child_prog {
 219 #ifndef __U_BOOT__
 220         pid_t pid;                                      /* 0 if exited */
 221 #endif
 222         char **argv;                            /* program name and arguments */
 223         /* was quoted when parsed; copy of struct o_string.nonnull field */
 224         int *argv_nonnull;
 225 #ifdef __U_BOOT__
 226         int    argc;                            /* number of program arguments */
 227 #endif
 228         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 229 #ifndef __U_BOOT__
 230         int subshell;                           /* flag, non-zero if group must be forked */
 231         struct redir_struct *redirects; /* I/O redirections */
 232         glob_t glob_result;                     /* result of parameter globbing */
 233         int is_stopped;                         /* is the program currently running? */
 234         struct pipe *family;            /* pointer back to the child's parent pipe */
 235 #endif
 236         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 237         int type;
 238 };
 239
 240 struct pipe {
 241 #ifndef __U_BOOT__
 242         int jobid;                                      /* job number */
 243 #endif
 244         int num_progs;                          /* total number of programs in job */
 245 #ifndef __U_BOOT__
 246         int running_progs;                      /* number of programs running */
 247         char *text;                                     /* name of job */
 248         char *cmdbuf;                           /* buffer various argv's point into */
 249         pid_t pgrp;                                     /* process group ID for the job */
 250 #endif
 251         struct child_prog *progs;       /* array of commands in pipe */
 252         struct pipe *next;                      /* to track background commands */
 253 #ifndef __U_BOOT__
 254         int stopped_progs;                      /* number of programs alive, but stopped */
 255         int job_context;                        /* bitmask defining current context */
 256 #endif
 257         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 258         reserved_style r_mode;          /* supports if, for, while, until */
 259 };
 260
 261 #ifndef __U_BOOT__
 262 struct close_me {
 263         int fd;
 264         struct close_me *next;
 265 };
 266 #endif
 267
 268 struct variables {
 269         char *name;
 270         char *value;
 271         int flg_export;
 272         int flg_read_only;
 273         struct variables *next;
 274 };
 275
 276 /* globals, connect us to the outside world
 277  * the first three support $?, $#, and $1 */
 278 #ifndef __U_BOOT__
 279 char **global_argv;
 280 unsigned int global_argc;
 281 #endif
 282 static unsigned int last_return_code;
 283 #ifndef __U_BOOT__
 284 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 285 #endif
 286
 287 /* "globals" within this file */
 288 static uchar *ifs;
 289 static char map[256];
 290 #ifndef __U_BOOT__
 291 static int fake_mode;
 292 static int interactive;
 293 static struct close_me *close_me_head;
 294 static const char *cwd;
 295 static struct pipe *job_list;
 296 static unsigned int last_bg_pid;
 297 static unsigned int last_jobid;
 298 static unsigned int shell_terminal;
 299 static char *PS1;
 300 static char *PS2;
 301 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 302 struct variables *top_vars = &shell_ver;
 303 #else
 304 static int flag_repeat = 0;
 305 static int do_repeat = 0;
 306 static struct variables *top_vars = NULL ;
 307 #endif /*__U_BOOT__ */
 308
 309 #define B_CHUNK (100)
 310 #define B_NOSPAC 1
 311
 312 typedef struct {
 313         char *data;
 314         int length;
 315         int maxlen;
 316         int quote;
 317         int nonnull;
 318 } o_string;
 319 #define NULL_O_STRING {NULL,0,0,0,0}
 320 /* used for initialization:
 321         o_string foo = NULL_O_STRING; */
 322
 323 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 324  * available?  Where is it documented? */
 325 struct in_str {
 326         const unsigned char *p;
 327 #ifndef __U_BOOT__
 328         char peek_buf[2];
 329 #endif
 330         int __promptme;
 331         int promptmode;
 332 #ifndef __U_BOOT__
 333         FILE *file;
 334 #endif
 335         int (*get) (struct in_str *);
 336         int (*peek) (struct in_str *);
 337 };
 338 #define b_getch(input) ((input)->get(input))
 339 #define b_peek(input) ((input)->peek(input))
 340
 341 #ifndef __U_BOOT__
 342 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 343
 344 struct built_in_command {
 345         char *cmd;                                      /* name */
 346         char *descr;                            /* description */
 347         int (*function) (struct child_prog *);  /* function ptr */
 348 };
 349 #endif
 350
 351 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
 352 #if 0
 353 #define DEBUG_SHELL
 354 #endif
 355
 356 /* This should be in utility.c */
 357 #ifdef DEBUG_SHELL
 358 #ifndef __U_BOOT__
 359 static void debug_printf(const char *format, ...)
 360 {
 361         va_list args;
 362         va_start(args, format);
 363         vfprintf(stderr, format, args);
 364         va_end(args);
 365 }
 366 #else
 367 #define debug_printf(fmt,args...)       printf (fmt ,##args)
 368 #endif
 369 #else
 370 static inline void debug_printf(const char *format, ...) { }
 371 #endif
 372 #define final_printf debug_printf
 373
 374 #ifdef __U_BOOT__
 375 static void syntax_err(void) {
 376          printf("syntax error\n");
 377 }
 378 #else
 379 static void __syntax(char *file, int line) {
 380         error_msg("syntax error %s:%d", file, line);
 381 }
 382 #define syntax() __syntax(__FILE__, __LINE__)
 383 #endif
 384
 385 #ifdef __U_BOOT__
 386 static void *xmalloc(size_t size);
 387 static void *xrealloc(void *ptr, size_t size);
 388 #else
 389 /* Index of subroutines: */
 390 /*   function prototypes for builtins */
 391 static int builtin_cd(struct child_prog *child);
 392 static int builtin_env(struct child_prog *child);
 393 static int builtin_eval(struct child_prog *child);
 394 static int builtin_exec(struct child_prog *child);
 395 static int builtin_exit(struct child_prog *child);
 396 static int builtin_export(struct child_prog *child);
 397 static int builtin_fg_bg(struct child_prog *child);
 398 static int builtin_help(struct child_prog *child);
 399 static int builtin_jobs(struct child_prog *child);
 400 static int builtin_pwd(struct child_prog *child);
 401 static int builtin_read(struct child_prog *child);
 402 static int builtin_set(struct child_prog *child);
 403 static int builtin_shift(struct child_prog *child);
 404 static int builtin_source(struct child_prog *child);
 405 static int builtin_umask(struct child_prog *child);
 406 static int builtin_unset(struct child_prog *child);
 407 static int builtin_not_written(struct child_prog *child);
 408 #endif
 409 /*   o_string manipulation: */
 410 static int b_check_space(o_string *o, int len);
 411 static int b_addchr(o_string *o, int ch);
 412 static void b_reset(o_string *o);
 413 static int b_addqchr(o_string *o, int ch, int quote);
 414 #ifndef __U_BOOT__
 415 static int b_adduint(o_string *o, unsigned int i);
 416 #endif
 417 /*  in_str manipulations: */
 418 static int static_get(struct in_str *i);
 419 static int static_peek(struct in_str *i);
 420 static int file_get(struct in_str *i);
 421 static int file_peek(struct in_str *i);
 422 #ifndef __U_BOOT__
 423 static void setup_file_in_str(struct in_str *i, FILE *f);
 424 #else
 425 static void setup_file_in_str(struct in_str *i);
 426 #endif
 427 static void setup_string_in_str(struct in_str *i, const char *s);
 428 #ifndef __U_BOOT__
 429 /*  close_me manipulations: */
 430 static void mark_open(int fd);
 431 static void mark_closed(int fd);
 432 static void close_all(void);
 433 #endif
 434 /*  "run" the final data structures: */
 435 static char *indenter(int i);
 436 static int free_pipe_list(struct pipe *head, int indent);
 437 static int free_pipe(struct pipe *pi, int indent);
 438 /*  really run the final data structures: */
 439 #ifndef __U_BOOT__
 440 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 441 #endif
 442 static int run_list_real(struct pipe *pi);
 443 #ifndef __U_BOOT__
 444 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 445 #endif
 446 static int run_pipe_real(struct pipe *pi);
 447 /*   extended glob support: */
 448 #ifndef __U_BOOT__
 449 static int globhack(const char *src, int flags, glob_t *pglob);
 450 static int glob_needed(const char *s);
 451 static int xglob(o_string *dest, int flags, glob_t *pglob);
 452 #endif
 453 /*   variable assignment: */
 454 static int is_assignment(const char *s);
 455 /*   data structure manipulation: */
 456 #ifndef __U_BOOT__
 457 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 458 #endif
 459 static void initialize_context(struct p_context *ctx);
 460 static int done_word(o_string *dest, struct p_context *ctx);
 461 static int done_command(struct p_context *ctx);
 462 static int done_pipe(struct p_context *ctx, pipe_style type);
 463 /*   primary string parsing: */
 464 #ifndef __U_BOOT__
 465 static int redirect_dup_num(struct in_str *input);
 466 static int redirect_opt_num(o_string *o);
 467 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 468 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 469 #endif
 470 static char *lookup_param(char *src);
 471 static char *make_string(char **inp, int *nonnull);
 472 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 473 #ifndef __U_BOOT__
 474 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 475 #endif
 476 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 477 /*   setup: */
 478 static int parse_stream_outer(struct in_str *inp, int flag);
 479 #ifndef __U_BOOT__
 480 static int parse_string_outer(const char *s, int flag);
 481 static int parse_file_outer(FILE *f);
 482 #endif
 483 #ifndef __U_BOOT__
 484 /*   job management: */
 485 static int checkjobs(struct pipe* fg_pipe);
 486 static void insert_bg_job(struct pipe *pi);
 487 static void remove_bg_job(struct pipe *pi);
 488 #endif
 489 /*     local variable support */
 490 static char **make_list_in(char **inp, char *name);
 491 static char *insert_var_value(char *inp);
 492 static char *insert_var_value_sub(char *inp, int tag_subst);
 493
 494 #ifndef __U_BOOT__
 495 /* Table of built-in functions.  They can be forked or not, depending on
 496  * context: within pipes, they fork.  As simple commands, they do not.
 497  * When used in non-forking context, they can change global variables
 498  * in the parent shell process.  If forked, of course they can not.
 499  * For example, 'unset foo | whatever' will parse and run, but foo will
 500  * still be set at the end. */
 501 static struct built_in_command bltins[] = {
 502         {"bg", "Resume a job in the background", builtin_fg_bg},
 503         {"break", "Exit for, while or until loop", builtin_not_written},
 504         {"cd", "Change working directory", builtin_cd},
 505         {"continue", "Continue for, while or until loop", builtin_not_written},
 506         {"env", "Print all environment variables", builtin_env},
 507         {"eval", "Construct and run shell command", builtin_eval},
 508         {"exec", "Exec command, replacing this shell with the exec'd process",
 509                 builtin_exec},
 510         {"exit", "Exit from shell()", builtin_exit},
 511         {"export", "Set environment variable", builtin_export},
 512         {"fg", "Bring job into the foreground", builtin_fg_bg},
 513         {"jobs", "Lists the active jobs", builtin_jobs},
 514         {"pwd", "Print current directory", builtin_pwd},
 515         {"read", "Input environment variable", builtin_read},
 516         {"return", "Return from a function", builtin_not_written},
 517         {"set", "Set/unset shell local variables", builtin_set},
 518         {"shift", "Shift positional parameters", builtin_shift},
 519         {"trap", "Trap signals", builtin_not_written},
 520         {"ulimit","Controls resource limits", builtin_not_written},
 521         {"umask","Sets file creation mask", builtin_umask},
 522         {"unset", "Unset environment variable", builtin_unset},
 523         {".", "Source-in and run commands in a file", builtin_source},
 524         {"help", "List shell built-in commands", builtin_help},
 525         {NULL, NULL, NULL}
 526 };
 527
 528 static const char *set_cwd(void)
 529 {
 530         if(cwd==unknown)
 531                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 532         cwd = xgetcwd((char *)cwd);
 533         if (!cwd)
 534                 cwd = unknown;
 535         return cwd;
 536 }
 537
 538 /* built-in 'eval' handler */
 539 static int builtin_eval(struct child_prog *child)
 540 {
 541         char *str = NULL;
 542         int rcode = EXIT_SUCCESS;
 543
 544         if (child->argv[1]) {
 545                 str = make_string(child->argv + 1);
 546                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 547                                         FLAG_PARSE_SEMICOLON);
 548                 free(str);
 549                 rcode = last_return_code;
 550         }
 551         return rcode;
 552 }
 553
 554 /* built-in 'cd <path>' handler */
 555 static int builtin_cd(struct child_prog *child)
 556 {
 557         char *newdir;
 558         if (child->argv[1] == NULL)
 559                 newdir = env_get("HOME");
 560         else
 561                 newdir = child->argv[1];
 562         if (chdir(newdir)) {
 563                 printf("cd: %s: %s\n", newdir, strerror(errno));
 564                 return EXIT_FAILURE;
 565         }
 566         set_cwd();
 567         return EXIT_SUCCESS;
 568 }
 569
 570 /* built-in 'env' handler */
 571 static int builtin_env(struct child_prog *dummy)
 572 {
 573         char **e = environ;
 574         if (e == NULL) return EXIT_FAILURE;
 575         for (; *e; e++) {
 576                 puts(*e);
 577         }
 578         return EXIT_SUCCESS;
 579 }
 580
 581 /* built-in 'exec' handler */
 582 static int builtin_exec(struct child_prog *child)
 583 {
 584         if (child->argv[1] == NULL)
 585                 return EXIT_SUCCESS;   /* Really? */
 586         child->argv++;
 587         pseudo_exec(child);
 588         /* never returns */
 589 }
 590
 591 /* built-in 'exit' handler */
 592 static int builtin_exit(struct child_prog *child)
 593 {
 594         if (child->argv[1] == NULL)
 595                 exit(last_return_code);
 596         exit (atoi(child->argv[1]));
 597 }
 598
 599 /* built-in 'export VAR=value' handler */
 600 static int builtin_export(struct child_prog *child)
 601 {
 602         int res = 0;
 603         char *name = child->argv[1];
 604
 605         if (name == NULL) {
 606                 return (builtin_env(child));
 607         }
 608
 609         name = strdup(name);
 610
 611         if(name) {
 612                 char *value = strchr(name, '=');
 613
 614                 if (!value) {
 615                         char *tmp;
 616                         /* They are exporting something without an =VALUE */
 617
 618                         value = get_local_var(name);
 619                         if (value) {
 620                                 size_t ln = strlen(name);
 621
 622                                 tmp = realloc(name, ln+strlen(value)+2);
 623                                 if(tmp==NULL)
 624                                         res = -1;
 625                                 else {
 626                                         sprintf(tmp+ln, "=%s", value);
 627                                         name = tmp;
 628                                 }
 629                         } else {
 630                                 /* bash does not return an error when trying to export
 631                                  * an undefined variable.  Do likewise. */
 632                                 res = 1;
 633                         }
 634                 }
 635         }
 636         if (res<0)
 637                 perror_msg("export");
 638         else if(res==0)
 639                 res = set_local_var(name, 1);
 640         else
 641                 res = 0;
 642         free(name);
 643         return res;
 644 }
 645
 646 /* built-in 'fg' and 'bg' handler */
 647 static int builtin_fg_bg(struct child_prog *child)
 648 {
 649         int i, jobnum;
 650         struct pipe *pi=NULL;
 651
 652         if (!interactive)
 653                 return EXIT_FAILURE;
 654         /* If they gave us no args, assume they want the last backgrounded task */
 655         if (!child->argv[1]) {
 656                 for (pi = job_list; pi; pi = pi->next) {
 657                         if (pi->jobid == last_jobid) {
 658                                 break;
 659                         }
 660                 }
 661                 if (!pi) {
 662                         error_msg("%s: no current job", child->argv[0]);
 663                         return EXIT_FAILURE;
 664                 }
 665         } else {
 666                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 667                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 668                         return EXIT_FAILURE;
 669                 }
 670                 for (pi = job_list; pi; pi = pi->next) {
 671                         if (pi->jobid == jobnum) {
 672                                 break;
 673                         }
 674                 }
 675                 if (!pi) {
 676                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 677                         return EXIT_FAILURE;
 678                 }
 679         }
 680
 681         if (*child->argv[0] == 'f') {
 682                 /* Put the job into the foreground.  */
 683                 tcsetpgrp(shell_terminal, pi->pgrp);
 684         }
 685
 686         /* Restart the processes in the job */
 687         for (i = 0; i < pi->num_progs; i++)
 688                 pi->progs[i].is_stopped = 0;
 689
 690         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 691                 if (i == ESRCH) {
 692                         remove_bg_job(pi);
 693                 } else {
 694                         perror_msg("kill (SIGCONT)");
 695                 }
 696         }
 697
 698         pi->stopped_progs = 0;
 699         return EXIT_SUCCESS;
 700 }
 701
 702 /* built-in 'help' handler */
 703 static int builtin_help(struct child_prog *dummy)
 704 {
 705         struct built_in_command *x;
 706
 707         printf("\nBuilt-in commands:\n");
 708         printf("-------------------\n");
 709         for (x = bltins; x->cmd; x++) {
 710                 if (x->descr==NULL)
 711                         continue;
 712                 printf("%s\t%s\n", x->cmd, x->descr);
 713         }
 714         printf("\n\n");
 715         return EXIT_SUCCESS;
 716 }
 717
 718 /* built-in 'jobs' handler */
 719 static int builtin_jobs(struct child_prog *child)
 720 {
 721         struct pipe *job;
 722         char *status_string;
 723
 724         for (job = job_list; job; job = job->next) {
 725                 if (job->running_progs == job->stopped_progs)
 726                         status_string = "Stopped";
 727                 else
 728                         status_string = "Running";
 729
 730                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 731         }
 732         return EXIT_SUCCESS;
 733 }
 734
 735
 736 /* built-in 'pwd' handler */
 737 static int builtin_pwd(struct child_prog *dummy)
 738 {
 739         puts(set_cwd());
 740         return EXIT_SUCCESS;
 741 }
 742
 743 /* built-in 'read VAR' handler */
 744 static int builtin_read(struct child_prog *child)
 745 {
 746         int res;
 747
 748         if (child->argv[1]) {
 749                 char string[BUFSIZ];
 750                 char *var = 0;
 751
 752                 string[0] = 0;  /* In case stdin has only EOF */
 753                 /* read string */
 754                 fgets(string, sizeof(string), stdin);
 755                 chomp(string);
 756                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 757                 if(var) {
 758                         sprintf(var, "%s=%s", child->argv[1], string);
 759                         res = set_local_var(var, 0);
 760                 } else
 761                         res = -1;
 762                 if (res)
 763                         fprintf(stderr, "read: %m\n");
 764                 free(var);      /* So not move up to avoid breaking errno */
 765                 return res;
 766         } else {
 767                 do res=getchar(); while(res!='\n' && res!=EOF);
 768                 return 0;
 769         }
 770 }
 771
 772 /* built-in 'set VAR=value' handler */
 773 static int builtin_set(struct child_prog *child)
 774 {
 775         char *temp = child->argv[1];
 776         struct variables *e;
 777
 778         if (temp == NULL)
 779                 for(e = top_vars; e; e=e->next)
 780                         printf("%s=%s\n", e->name, e->value);
 781         else
 782                 set_local_var(temp, 0);
 783
 784                 return EXIT_SUCCESS;
 785 }
 786
 787
 788 /* Built-in 'shift' handler */
 789 static int builtin_shift(struct child_prog *child)
 790 {
 791         int n=1;
 792         if (child->argv[1]) {
 793                 n=atoi(child->argv[1]);
 794         }
 795         if (n>=0 && n<global_argc) {
 796                 /* XXX This probably breaks $0 */
 797                 global_argc -= n;
 798                 global_argv += n;
 799                 return EXIT_SUCCESS;
 800         } else {
 801                 return EXIT_FAILURE;
 802         }
 803 }
 804
 805 /* Built-in '.' handler (read-in and execute commands from file) */
 806 static int builtin_source(struct child_prog *child)
 807 {
 808         FILE *input;
 809         int status;
 810
 811         if (child->argv[1] == NULL)
 812                 return EXIT_FAILURE;
 813
 814         /* XXX search through $PATH is missing */
 815         input = fopen(child->argv[1], "r");
 816         if (!input) {
 817                 error_msg("Couldn't open file '%s'", child->argv[1]);
 818                 return EXIT_FAILURE;
 819         }
 820
 821         /* Now run the file */
 822         /* XXX argv and argc are broken; need to save old global_argv
 823          * (pointer only is OK!) on this stack frame,
 824          * set global_argv=child->argv+1, recurse, and restore. */
 825         mark_open(fileno(input));
 826         status = parse_file_outer(input);
 827         mark_closed(fileno(input));
 828         fclose(input);
 829         return (status);
 830 }
 831
 832 static int builtin_umask(struct child_prog *child)
 833 {
 834         mode_t new_umask;
 835         const char *arg = child->argv[1];
 836         char *end;
 837         if (arg) {
 838                 new_umask=strtoul(arg, &end, 8);
 839                 if (*end!='\0' || end == arg) {
 840                         return EXIT_FAILURE;
 841                 }
 842         } else {
 843                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 844         }
 845         umask(new_umask);
 846         return EXIT_SUCCESS;
 847 }
 848
 849 /* built-in 'unset VAR' handler */
 850 static int builtin_unset(struct child_prog *child)
 851 {
 852         /* bash returned already true */
 853         unset_local_var(child->argv[1]);
 854         return EXIT_SUCCESS;
 855 }
 856
 857 static int builtin_not_written(struct child_prog *child)
 858 {
 859         printf("builtin_%s not written\n",child->argv[0]);
 860         return EXIT_FAILURE;
 861 }
 862 #endif
 863
 864 static int b_check_space(o_string *o, int len)
 865 {
 866         /* It would be easy to drop a more restrictive policy
 867          * in here, such as setting a maximum string length */
 868         if (o->length + len > o->maxlen) {
 869                 char *old_data = o->data;
 870                 /* assert (data == NULL || o->maxlen != 0); */
 871                 o->maxlen += max(2*len, B_CHUNK);
 872                 o->data = realloc(o->data, 1 + o->maxlen);
 873                 if (o->data == NULL) {
 874                         free(old_data);
 875                 }
 876         }
 877         return o->data == NULL;
 878 }
 879
 880 static int b_addchr(o_string *o, int ch)
 881 {
 882         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 883         if (b_check_space(o, 1)) return B_NOSPAC;
 884         o->data[o->length] = ch;
 885         o->length++;
 886         o->data[o->length] = '\0';
 887         return 0;
 888 }
 889
 890 static void b_reset(o_string *o)
 891 {
 892         o->length = 0;
 893         o->nonnull = 0;
 894         if (o->data != NULL) *o->data = '\0';
 895 }
 896
 897 static void b_free(o_string *o)
 898 {
 899         b_reset(o);
 900         free(o->data);
 901         o->data = NULL;
 902         o->maxlen = 0;
 903 }
 904
 905 /* My analysis of quoting semantics tells me that state information
 906  * is associated with a destination, not a source.
 907  */
 908 static int b_addqchr(o_string *o, int ch, int quote)
 909 {
 910         if (quote && strchr("*?[\\",ch)) {
 911                 int rc;
 912                 rc = b_addchr(o, '\\');
 913                 if (rc) return rc;
 914         }
 915         return b_addchr(o, ch);
 916 }
 917
 918 #ifndef __U_BOOT__
 919 static int b_adduint(o_string *o, unsigned int i)
 920 {
 921         int r;
 922         char *p = simple_itoa(i);
 923         /* no escape checking necessary */
 924         do r=b_addchr(o, *p++); while (r==0 && *p);
 925         return r;
 926 }
 927 #endif
 928
 929 static int static_get(struct in_str *i)
 930 {
 931         int ch = *i->p++;
 932         if (ch=='\0') return EOF;
 933         return ch;
 934 }
 935
 936 static int static_peek(struct in_str *i)
 937 {
 938         return *i->p;
 939 }
 940
 941 #ifndef __U_BOOT__
 942 static inline void cmdedit_set_initial_prompt(void)
 943 {
 944 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 945         PS1 = NULL;
 946 #else
 947         PS1 = env_get("PS1");
 948         if(PS1==0)
 949                 PS1 = "\\w \\$ ";
 950 #endif
 951 }
 952
 953 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 954 {
 955         debug_printf("setup_prompt_string %d ",promptmode);
 956 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 957         /* Set up the prompt */
 958         if (promptmode == 1) {
 959                 free(PS1);
 960                 PS1=xmalloc(strlen(cwd)+4);
 961                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 962                 *prompt_str = PS1;
 963         } else {
 964                 *prompt_str = PS2;
 965         }
 966 #else
 967         *prompt_str = (promptmode==1)? PS1 : PS2;
 968 #endif
 969         debug_printf("result %s\n",*prompt_str);
 970 }
 971 #endif
 972
 973 #ifdef __U_BOOT__
 974 static int uboot_cli_readline(struct in_str *i)
 975 {
 976         char *prompt;
 977         char __maybe_unused *ps_prompt = NULL;
 978
 979         if (i->promptmode == 1)
 980                 prompt = CONFIG_SYS_PROMPT;
 981         else
 982                 prompt = CONFIG_SYS_PROMPT_HUSH_PS2;
 983
 984 #ifdef CONFIG_CMDLINE_PS_SUPPORT
 985         if (i->promptmode == 1)
 986                 ps_prompt = env_get("PS1");
 987         else
 988                 ps_prompt = env_get("PS2");
 989         if (ps_prompt)
 990                 prompt = ps_prompt;
 991 #endif
 992
 993         return cli_readline(prompt);
 994 }
 995 #endif
 996
 997 static void get_user_input(struct in_str *i)
 998 {
 999 #ifndef __U_BOOT__
1000         char *prompt_str;
1001         static char the_command[BUFSIZ];
1002
1003         setup_prompt_string(i->promptmode, &prompt_str);
1004 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1005         /*
1006          ** enable command line editing only while a command line
1007          ** is actually being read; otherwise, we'll end up bequeathing
1008          ** atexit() handlers and other unwanted stuff to our
1009          ** child processes ([email protected])
1010          */
1011         cmdedit_read_input(prompt_str, the_command);
1012 #else
1013         fputs(prompt_str, stdout);
1014         fflush(stdout);
1015         the_command[0]=fgetc(i->file);
1016         the_command[1]='\0';
1017 #endif
1018         fflush(stdout);
1019         i->p = the_command;
1020 #else
1021         int n;
1022         static char the_command[CONFIG_SYS_CBSIZE + 1];
1023
1024         bootretry_reset_cmd_timeout();
1025         i->__promptme = 1;
1026         n = uboot_cli_readline(i);
1027
1028 #ifdef CONFIG_BOOT_RETRY_TIME
1029         if (n == -2) {
1030           puts("\nTimeout waiting for command\n");
1031 #  ifdef CONFIG_RESET_TO_RETRY
1032           do_reset(NULL, 0, 0, NULL);
1033 #  else
1034 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1035 #  endif
1036         }
1037 #endif
1038         if (n == -1 ) {
1039                 flag_repeat = 0;
1040                 i->__promptme = 0;
1041         }
1042         n = strlen(console_buffer);
1043         console_buffer[n] = '\n';
1044         console_buffer[n+1]= '\0';
1045         if (had_ctrlc()) flag_repeat = 0;
1046         clear_ctrlc();
1047         do_repeat = 0;
1048         if (i->promptmode == 1) {
1049                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1050                         strcpy(the_command,console_buffer);
1051                 }
1052                 else {
1053                         if (console_buffer[0] != '\n') {
1054                                 strcpy(the_command,console_buffer);
1055                                 flag_repeat = 1;
1056                         }
1057                         else {
1058                                 do_repeat = 1;
1059                         }
1060                 }
1061                 i->p = the_command;
1062         }
1063         else {
1064                 if (console_buffer[0] != '\n') {
1065                         if (strlen(the_command) + strlen(console_buffer)
1066                             < CONFIG_SYS_CBSIZE) {
1067                                 n = strlen(the_command);
1068                                 the_command[n-1] = ' ';
1069                                 strcpy(&the_command[n],console_buffer);
1070                         }
1071                         else {
1072                                 the_command[0] = '\n';
1073                                 the_command[1] = '\0';
1074                                 flag_repeat = 0;
1075                         }
1076                 }
1077                 if (i->__promptme == 0) {
1078                         the_command[0] = '\n';
1079                         the_command[1] = '\0';
1080                 }
1081                 i->p = console_buffer;
1082         }
1083 #endif
1084 }
1085
1086 /* This is the magic location that prints prompts
1087  * and gets data back from the user */
1088 static int file_get(struct in_str *i)
1089 {
1090         int ch;
1091
1092         ch = 0;
1093         /* If there is data waiting, eat it up */
1094         if (i->p && *i->p) {
1095                 ch = *i->p++;
1096         } else {
1097                 /* need to double check i->file because we might be doing something
1098                  * more complicated by now, like sourcing or substituting. */
1099 #ifndef __U_BOOT__
1100                 if (i->__promptme && interactive && i->file == stdin) {
1101                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1102 #else
1103                         while(! i->p  || strlen(i->p)==0 ) {
1104 #endif
1105                                 get_user_input(i);
1106                         }
1107                         i->promptmode=2;
1108 #ifndef __U_BOOT__
1109                         i->__promptme = 0;
1110 #endif
1111                         if (i->p && *i->p) {
1112                                 ch = *i->p++;
1113                         }
1114 #ifndef __U_BOOT__
1115                 } else {
1116                         ch = fgetc(i->file);
1117                 }
1118
1119 #endif
1120                 debug_printf("b_getch: got a %d\n", ch);
1121         }
1122 #ifndef __U_BOOT__
1123         if (ch == '\n') i->__promptme=1;
1124 #endif
1125         return ch;
1126 }
1127
1128 /* All the callers guarantee this routine will never be
1129  * used right after a newline, so prompting is not needed.
1130  */
1131 static int file_peek(struct in_str *i)
1132 {
1133 #ifndef __U_BOOT__
1134         if (i->p && *i->p) {
1135 #endif
1136                 return *i->p;
1137 #ifndef __U_BOOT__
1138         } else {
1139                 i->peek_buf[0] = fgetc(i->file);
1140                 i->peek_buf[1] = '\0';
1141                 i->p = i->peek_buf;
1142                 debug_printf("b_peek: got a %d\n", *i->p);
1143                 return *i->p;
1144         }
1145 #endif
1146 }
1147
1148 #ifndef __U_BOOT__
1149 static void setup_file_in_str(struct in_str *i, FILE *f)
1150 #else
1151 static void setup_file_in_str(struct in_str *i)
1152 #endif
1153 {
1154         i->peek = file_peek;
1155         i->get = file_get;
1156         i->__promptme=1;
1157         i->promptmode=1;
1158 #ifndef __U_BOOT__
1159         i->file = f;
1160 #endif
1161         i->p = NULL;
1162 }
1163
1164 static void setup_string_in_str(struct in_str *i, const char *s)
1165 {
1166         i->peek = static_peek;
1167         i->get = static_get;
1168         i->__promptme=1;
1169         i->promptmode=1;
1170         i->p = s;
1171 }
1172
1173 #ifndef __U_BOOT__
1174 static void mark_open(int fd)
1175 {
1176         struct close_me *new = xmalloc(sizeof(struct close_me));
1177         new->fd = fd;
1178         new->next = close_me_head;
1179         close_me_head = new;
1180 }
1181
1182 static void mark_closed(int fd)
1183 {
1184         struct close_me *tmp;
1185         if (close_me_head == NULL || close_me_head->fd != fd)
1186                 error_msg_and_die("corrupt close_me");
1187         tmp = close_me_head;
1188         close_me_head = close_me_head->next;
1189         free(tmp);
1190 }
1191
1192 static void close_all(void)
1193 {
1194         struct close_me *c;
1195         for (c=close_me_head; c; c=c->next) {
1196                 close(c->fd);
1197         }
1198         close_me_head = NULL;
1199 }
1200
1201 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1202  * and stderr if they are redirected. */
1203 static int setup_redirects(struct child_prog *prog, int squirrel[])
1204 {
1205         int openfd, mode;
1206         struct redir_struct *redir;
1207
1208         for (redir=prog->redirects; redir; redir=redir->next) {
1209                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1210                         /* something went wrong in the parse.  Pretend it didn't happen */
1211                         continue;
1212                 }
1213                 if (redir->dup == -1) {
1214                         mode=redir_table[redir->type].mode;
1215                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1216                         if (openfd < 0) {
1217                         /* this could get lost if stderr has been redirected, but
1218                            bash and ash both lose it as well (though zsh doesn't!) */
1219                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1220                                 return 1;
1221                         }
1222                 } else {
1223                         openfd = redir->dup;
1224                 }
1225
1226                 if (openfd != redir->fd) {
1227                         if (squirrel && redir->fd < 3) {
1228                                 squirrel[redir->fd] = dup(redir->fd);
1229                         }
1230                         if (openfd == -3) {
1231                                 close(openfd);
1232                         } else {
1233                                 dup2(openfd, redir->fd);
1234                                 if (redir->dup == -1)
1235                                         close (openfd);
1236                         }
1237                 }
1238         }
1239         return 0;
1240 }
1241
1242 static void restore_redirects(int squirrel[])
1243 {
1244         int i, fd;
1245         for (i=0; i<3; i++) {
1246                 fd = squirrel[i];
1247                 if (fd != -1) {
1248                         /* No error checking.  I sure wouldn't know what
1249                          * to do with an error if I found one! */
1250                         dup2(fd, i);
1251                         close(fd);
1252                 }
1253         }
1254 }
1255
1256 /* never returns */
1257 /* XXX no exit() here.  If you don't exec, use _exit instead.
1258  * The at_exit handlers apparently confuse the calling process,
1259  * in particular stdin handling.  Not sure why? */
1260 static void pseudo_exec(struct child_prog *child)
1261 {
1262         int i, rcode;
1263         char *p;
1264         struct built_in_command *x;
1265         if (child->argv) {
1266                 for (i=0; is_assignment(child->argv[i]); i++) {
1267                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1268                         p = insert_var_value(child->argv[i]);
1269                         putenv(strdup(p));
1270                         if (p != child->argv[i]) free(p);
1271                 }
1272                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1273                                         to exit, and therefore don't need to keep data
1274                                         structures consistent for free() use. */
1275                 /* If a variable is assigned in a forest, and nobody listens,
1276                  * was it ever really set?
1277                  */
1278                 if (child->argv[0] == NULL) {
1279                         _exit(EXIT_SUCCESS);
1280                 }
1281
1282                 /*
1283                  * Check if the command matches any of the builtins.
1284                  * Depending on context, this might be redundant.  But it's
1285                  * easier to waste a few CPU cycles than it is to figure out
1286                  * if this is one of those cases.
1287                  */
1288                 for (x = bltins; x->cmd; x++) {
1289                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1290                                 debug_printf("builtin exec %s\n", child->argv[0]);
1291                                 rcode = x->function(child);
1292                                 fflush(stdout);
1293                                 _exit(rcode);
1294                         }
1295                 }
1296
1297                 /* Check if the command matches any busybox internal commands
1298                  * ("applets") here.
1299                  * FIXME: This feature is not 100% safe, since
1300                  * BusyBox is not fully reentrant, so we have no guarantee the things
1301                  * from the .bss are still zeroed, or that things from .data are still
1302                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1303                  * really dislike relying on /proc for things.  We could exec ourself
1304                  * from global_argv[0], but if we are in a chroot, we may not be able
1305                  * to find ourself... */
1306 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1307                 {
1308                         int argc_l;
1309                         char** argv_l=child->argv;
1310                         char *name = child->argv[0];
1311
1312 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1313                         /* Following discussions from November 2000 on the busybox mailing
1314                          * list, the default configuration, (without
1315                          * get_last_path_component()) lets the user force use of an
1316                          * external command by specifying the full (with slashes) filename.
1317                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1318                          * _aways_ override external commands, so if you want to run
1319                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1320                          * filesystem and is _not_ busybox.  Some systems may want this,
1321                          * most do not.  */
1322                         name = get_last_path_component(name);
1323 #endif
1324                         /* Count argc for use in a second... */
1325                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1326                         optind = 1;
1327                         debug_printf("running applet %s\n", name);
1328                         run_applet_by_name(name, argc_l, child->argv);
1329                 }
1330 #endif
1331                 debug_printf("exec of %s\n",child->argv[0]);
1332                 execvp(child->argv[0],child->argv);
1333                 perror_msg("couldn't exec: %s",child->argv[0]);
1334                 _exit(1);
1335         } else if (child->group) {
1336                 debug_printf("runtime nesting to group\n");
1337                 interactive=0;    /* crucial!!!! */
1338                 rcode = run_list_real(child->group);
1339                 /* OK to leak memory by not calling free_pipe_list,
1340                  * since this process is about to exit */
1341                 _exit(rcode);
1342         } else {
1343                 /* Can happen.  See what bash does with ">foo" by itself. */
1344                 debug_printf("trying to pseudo_exec null command\n");
1345                 _exit(EXIT_SUCCESS);
1346         }
1347 }
1348
1349 static void insert_bg_job(struct pipe *pi)
1350 {
1351         struct pipe *thejob;
1352
1353         /* Linear search for the ID of the job to use */
1354         pi->jobid = 1;
1355         for (thejob = job_list; thejob; thejob = thejob->next)
1356                 if (thejob->jobid >= pi->jobid)
1357                         pi->jobid = thejob->jobid + 1;
1358
1359         /* add thejob to the list of running jobs */
1360         if (!job_list) {
1361                 thejob = job_list = xmalloc(sizeof(*thejob));
1362         } else {
1363                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1364                 thejob->next = xmalloc(sizeof(*thejob));
1365                 thejob = thejob->next;
1366         }
1367
1368         /* physically copy the struct job */
1369         memcpy(thejob, pi, sizeof(struct pipe));
1370         thejob->next = NULL;
1371         thejob->running_progs = thejob->num_progs;
1372         thejob->stopped_progs = 0;
1373         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1374
1375         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1376         {
1377                 char *bar=thejob->text;
1378                 char **foo=pi->progs[0].argv;
1379                 while(foo && *foo) {
1380                         bar += sprintf(bar, "%s ", *foo++);
1381                 }
1382         }
1383
1384         /* we don't wait for background thejobs to return -- append it
1385            to the list of backgrounded thejobs and leave it alone */
1386         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1387         last_bg_pid = thejob->progs[0].pid;
1388         last_jobid = thejob->jobid;
1389 }
1390
1391 /* remove a backgrounded job */
1392 static void remove_bg_job(struct pipe *pi)
1393 {
1394         struct pipe *prev_pipe;
1395
1396         if (pi == job_list) {
1397                 job_list = pi->next;
1398         } else {
1399                 prev_pipe = job_list;
1400                 while (prev_pipe->next != pi)
1401                         prev_pipe = prev_pipe->next;
1402                 prev_pipe->next = pi->next;
1403         }
1404         if (job_list)
1405                 last_jobid = job_list->jobid;
1406         else
1407                 last_jobid = 0;
1408
1409         pi->stopped_progs = 0;
1410         free_pipe(pi, 0);
1411         free(pi);
1412 }
1413
1414 /* Checks to see if any processes have exited -- if they
1415    have, figure out why and see if a job has completed */
1416 static int checkjobs(struct pipe* fg_pipe)
1417 {
1418         int attributes;
1419         int status;
1420         int prognum = 0;
1421         struct pipe *pi;
1422         pid_t childpid;
1423
1424         attributes = WUNTRACED;
1425         if (fg_pipe==NULL) {
1426                 attributes |= WNOHANG;
1427         }
1428
1429         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1430                 if (fg_pipe) {
1431                         int i, rcode = 0;
1432                         for (i=0; i < fg_pipe->num_progs; i++) {
1433                                 if (fg_pipe->progs[i].pid == childpid) {
1434                                         if (i==fg_pipe->num_progs-1)
1435                                                 rcode=WEXITSTATUS(status);
1436                                         (fg_pipe->num_progs)--;
1437                                         return(rcode);
1438                                 }
1439                         }
1440                 }
1441
1442                 for (pi = job_list; pi; pi = pi->next) {
1443                         prognum = 0;
1444                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1445                                 prognum++;
1446                         }
1447                         if (prognum < pi->num_progs)
1448                                 break;
1449                 }
1450
1451                 if(pi==NULL) {
1452                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1453                         continue;
1454                 }
1455
1456                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1457                         /* child exited */
1458                         pi->running_progs--;
1459                         pi->progs[prognum].pid = 0;
1460
1461                         if (!pi->running_progs) {
1462                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1463                                 remove_bg_job(pi);
1464                         }
1465                 } else {
1466                         /* child stopped */
1467                         pi->stopped_progs++;
1468                         pi->progs[prognum].is_stopped = 1;
1469
1470 #if 0
1471                         /* Printing this stuff is a pain, since it tends to
1472                          * overwrite the prompt an inconveinient moments.  So
1473                          * don't do that.  */
1474                         if (pi->stopped_progs == pi->num_progs) {
1475                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1476                         }
1477 #endif
1478                 }
1479         }
1480
1481         if (childpid == -1 && errno != ECHILD)
1482                 perror_msg("waitpid");
1483
1484         /* move the shell to the foreground */
1485         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1486         /*      perror_msg("tcsetpgrp-2"); */
1487         return -1;
1488 }
1489
1490 /* Figure out our controlling tty, checking in order stderr,
1491  * stdin, and stdout.  If check_pgrp is set, also check that
1492  * we belong to the foreground process group associated with
1493  * that tty.  The value of shell_terminal is needed in order to call
1494  * tcsetpgrp(shell_terminal, ...); */
1495 void controlling_tty(int check_pgrp)
1496 {
1497         pid_t curpgrp;
1498
1499         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1500                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1501                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1502                 goto shell_terminal_error;
1503
1504         if (check_pgrp && curpgrp != getpgid(0))
1505                 goto shell_terminal_error;
1506
1507         return;
1508
1509 shell_terminal_error:
1510                 shell_terminal = -1;
1511                 return;
1512 }
1513 #endif
1514
1515 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1516  * to finish.  See checkjobs().
1517  *
1518  * return code is normally -1, when the caller has to wait for children
1519  * to finish to determine the exit status of the pipe.  If the pipe
1520  * is a simple builtin command, however, the action is done by the
1521  * time run_pipe_real returns, and the exit code is provided as the
1522  * return value.
1523  *
1524  * The input of the pipe is always stdin, the output is always
1525  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1526  * because it tries to avoid running the command substitution in
1527  * subshell, when that is in fact necessary.  The subshell process
1528  * now has its stdout directed to the input of the appropriate pipe,
1529  * so this routine is noticeably simpler.
1530  */
1531 static int run_pipe_real(struct pipe *pi)
1532 {
1533         int i;
1534 #ifndef __U_BOOT__
1535         int nextin, nextout;
1536         int pipefds[2];                         /* pipefds[0] is for reading */
1537         struct child_prog *child;
1538         struct built_in_command *x;
1539         char *p;
1540 # if __GNUC__
1541         /* Avoid longjmp clobbering */
1542         (void) &i;
1543         (void) &nextin;
1544         (void) &nextout;
1545         (void) &child;
1546 # endif
1547 #else
1548         int nextin;
1549         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1550         struct child_prog *child;
1551         char *p;
1552 # if __GNUC__
1553         /* Avoid longjmp clobbering */
1554         (void) &i;
1555         (void) &nextin;
1556         (void) &child;
1557 # endif
1558 #endif  /* __U_BOOT__ */
1559
1560         nextin = 0;
1561 #ifndef __U_BOOT__
1562         pi->pgrp = -1;
1563 #endif
1564
1565         /* Check if this is a simple builtin (not part of a pipe).
1566          * Builtins within pipes have to fork anyway, and are handled in
1567          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1568          */
1569         if (pi->num_progs == 1) child = & (pi->progs[0]);
1570 #ifndef __U_BOOT__
1571         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1572                 int squirrel[] = {-1, -1, -1};
1573                 int rcode;
1574                 debug_printf("non-subshell grouping\n");
1575                 setup_redirects(child, squirrel);
1576                 /* XXX could we merge code with following builtin case,
1577                  * by creating a pseudo builtin that calls run_list_real? */
1578                 rcode = run_list_real(child->group);
1579                 restore_redirects(squirrel);
1580 #else
1581                 if (pi->num_progs == 1 && child->group) {
1582                 int rcode;
1583                 debug_printf("non-subshell grouping\n");
1584                 rcode = run_list_real(child->group);
1585 #endif
1586                 return rcode;
1587         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1588                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1589                 if (i!=0 && child->argv[i]==NULL) {
1590                         /* assignments, but no command: set the local environment */
1591                         for (i=0; child->argv[i]!=NULL; i++) {
1592
1593                                 /* Ok, this case is tricky.  We have to decide if this is a
1594                                  * local variable, or an already exported variable.  If it is
1595                                  * already exported, we have to export the new value.  If it is
1596                                  * not exported, we need only set this as a local variable.
1597                                  * This junk is all to decide whether or not to export this
1598                                  * variable. */
1599                                 int export_me=0;
1600                                 char *name, *value;
1601                                 name = xstrdup(child->argv[i]);
1602                                 debug_printf("Local environment set: %s\n", name);
1603                                 value = strchr(name, '=');
1604                                 if (value)
1605                                         *value=0;
1606 #ifndef __U_BOOT__
1607                                 if ( get_local_var(name)) {
1608                                         export_me=1;
1609                                 }
1610 #endif
1611                                 free(name);
1612                                 p = insert_var_value(child->argv[i]);
1613                                 set_local_var(p, export_me);
1614                                 if (p != child->argv[i]) free(p);
1615                         }
1616                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1617                 }
1618                 for (i = 0; is_assignment(child->argv[i]); i++) {
1619                         p = insert_var_value(child->argv[i]);
1620 #ifndef __U_BOOT__
1621                         putenv(strdup(p));
1622 #else
1623                         set_local_var(p, 0);
1624 #endif
1625                         if (p != child->argv[i]) {
1626                                 child->sp--;
1627                                 free(p);
1628                         }
1629                 }
1630                 if (child->sp) {
1631                         char * str = NULL;
1632
1633                         str = make_string(child->argv + i,
1634                                           child->argv_nonnull + i);
1635                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1636                         free(str);
1637                         return last_return_code;
1638                 }
1639 #ifndef __U_BOOT__
1640                 for (x = bltins; x->cmd; x++) {
1641                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1642                                 int squirrel[] = {-1, -1, -1};
1643                                 int rcode;
1644                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1645                                         debug_printf("magic exec\n");
1646                                         setup_redirects(child,NULL);
1647                                         return EXIT_SUCCESS;
1648                                 }
1649                                 debug_printf("builtin inline %s\n", child->argv[0]);
1650                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1651                                  * This is perfect for work that comes after exec().
1652                                  * Is it really safe for inline use?  Experimentally,
1653                                  * things seem to work with glibc. */
1654                                 setup_redirects(child, squirrel);
1655
1656                                 child->argv += i;  /* XXX horrible hack */
1657                                 rcode = x->function(child);
1658                                 /* XXX restore hack so free() can work right */
1659                                 child->argv -= i;
1660                                 restore_redirects(squirrel);
1661                         }
1662                         return rcode;
1663                 }
1664 #else
1665                 /* check ";", because ,example , argv consist from
1666                  * "help;flinfo" must not execute
1667                  */
1668                 if (strchr(child->argv[i], ';')) {
1669                         printf("Unknown command '%s' - try 'help' or use "
1670                                         "'run' command\n", child->argv[i]);
1671                         return -1;
1672                 }
1673                 /* Process the command */
1674                 return cmd_process(flag, child->argc - i, child->argv + i,
1675                                    &flag_repeat, NULL);
1676 #endif
1677         }
1678 #ifndef __U_BOOT__
1679
1680         for (i = 0; i < pi->num_progs; i++) {
1681                 child = & (pi->progs[i]);
1682
1683                 /* pipes are inserted between pairs of commands */
1684                 if ((i + 1) < pi->num_progs) {
1685                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1686                         nextout = pipefds[1];
1687                 } else {
1688                         nextout=1;
1689                         pipefds[0] = -1;
1690                 }
1691
1692                 /* XXX test for failed fork()? */
1693                 if (!(child->pid = fork())) {
1694                         /* Set the handling for job control signals back to the default.  */
1695                         signal(SIGINT, SIG_DFL);
1696                         signal(SIGQUIT, SIG_DFL);
1697                         signal(SIGTERM, SIG_DFL);
1698                         signal(SIGTSTP, SIG_DFL);
1699                         signal(SIGTTIN, SIG_DFL);
1700                         signal(SIGTTOU, SIG_DFL);
1701                         signal(SIGCHLD, SIG_DFL);
1702
1703                         close_all();
1704
1705                         if (nextin != 0) {
1706                                 dup2(nextin, 0);
1707                                 close(nextin);
1708                         }
1709                         if (nextout != 1) {
1710                                 dup2(nextout, 1);
1711                                 close(nextout);
1712                         }
1713                         if (pipefds[0]!=-1) {
1714                                 close(pipefds[0]);  /* opposite end of our output pipe */
1715                         }
1716
1717                         /* Like bash, explicit redirects override pipes,
1718                          * and the pipe fd is available for dup'ing. */
1719                         setup_redirects(child,NULL);
1720
1721                         if (interactive && pi->followup!=PIPE_BG) {
1722                                 /* If we (the child) win the race, put ourselves in the process
1723                                  * group whose leader is the first process in this pipe. */
1724                                 if (pi->pgrp < 0) {
1725                                         pi->pgrp = getpid();
1726                                 }
1727                                 if (setpgid(0, pi->pgrp) == 0) {
1728                                         tcsetpgrp(2, pi->pgrp);
1729                                 }
1730                         }
1731
1732                         pseudo_exec(child);
1733                 }
1734
1735
1736                 /* put our child in the process group whose leader is the
1737                    first process in this pipe */
1738                 if (pi->pgrp < 0) {
1739                         pi->pgrp = child->pid;
1740                 }
1741                 /* Don't check for errors.  The child may be dead already,
1742                  * in which case setpgid returns error code EACCES. */
1743                 setpgid(child->pid, pi->pgrp);
1744
1745                 if (nextin != 0)
1746                         close(nextin);
1747                 if (nextout != 1)
1748                         close(nextout);
1749
1750                 /* If there isn't another process, nextin is garbage
1751                    but it doesn't matter */
1752                 nextin = pipefds[0];
1753         }
1754 #endif
1755         return -1;
1756 }
1757
1758 static int run_list_real(struct pipe *pi)
1759 {
1760         char *save_name = NULL;
1761         char **list = NULL;
1762         char **save_list = NULL;
1763         struct pipe *rpipe;
1764         int flag_rep = 0;
1765 #ifndef __U_BOOT__
1766         int save_num_progs;
1767 #endif
1768         int rcode=0, flag_skip=1;
1769         int flag_restore = 0;
1770         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1771         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1772         /* check syntax for "for" */
1773         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1774                 if ((rpipe->r_mode == RES_IN ||
1775                     rpipe->r_mode == RES_FOR) &&
1776                     (rpipe->next == NULL)) {
1777                                 syntax();
1778 #ifdef __U_BOOT__
1779                                 flag_repeat = 0;
1780 #endif
1781                                 return 1;
1782                 }
1783                 if ((rpipe->r_mode == RES_IN &&
1784                         (rpipe->next->r_mode == RES_IN &&
1785                         rpipe->next->progs->argv != NULL))||
1786                         (rpipe->r_mode == RES_FOR &&
1787                         rpipe->next->r_mode != RES_IN)) {
1788                                 syntax();
1789 #ifdef __U_BOOT__
1790                                 flag_repeat = 0;
1791 #endif
1792                                 return 1;
1793                 }
1794         }
1795         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1796                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1797                         pi->r_mode == RES_FOR) {
1798 #ifdef __U_BOOT__
1799                                 /* check Ctrl-C */
1800                                 ctrlc();
1801                                 if ((had_ctrlc())) {
1802                                         return 1;
1803                                 }
1804 #endif
1805                                 flag_restore = 0;
1806                                 if (!rpipe) {
1807                                         flag_rep = 0;
1808                                         rpipe = pi;
1809                                 }
1810                 }
1811                 rmode = pi->r_mode;
1812                 debug_printf("rmode=%d  if_code=%d  next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1813                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1814                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1815                         continue;
1816                 }
1817                 flag_skip = 1;
1818                 skip_more_in_this_rmode = RES_XXXX;
1819                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1820                 if (rmode == RES_THEN &&  if_code) continue;
1821                 if (rmode == RES_ELSE && !if_code) continue;
1822                 if (rmode == RES_ELIF && !if_code) break;
1823                 if (rmode == RES_FOR && pi->num_progs) {
1824                         if (!list) {
1825                                 /* if no variable values after "in" we skip "for" */
1826                                 if (!pi->next->progs->argv) continue;
1827                                 /* create list of variable values */
1828                                 list = make_list_in(pi->next->progs->argv,
1829                                         pi->progs->argv[0]);
1830                                 save_list = list;
1831                                 save_name = pi->progs->argv[0];
1832                                 pi->progs->argv[0] = NULL;
1833                                 flag_rep = 1;
1834                         }
1835                         if (!(*list)) {
1836                                 free(pi->progs->argv[0]);
1837                                 free(save_list);
1838                                 list = NULL;
1839                                 flag_rep = 0;
1840                                 pi->progs->argv[0] = save_name;
1841 #ifndef __U_BOOT__
1842                                 pi->progs->glob_result.gl_pathv[0] =
1843                                         pi->progs->argv[0];
1844 #endif
1845                                 continue;
1846                         } else {
1847                                 /* insert new value from list for variable */
1848                                 free(pi->progs->argv[0]);
1849                                 pi->progs->argv[0] = *list++;
1850 #ifndef __U_BOOT__
1851                                 pi->progs->glob_result.gl_pathv[0] =
1852                                         pi->progs->argv[0];
1853 #endif
1854                         }
1855                 }
1856                 if (rmode == RES_IN) continue;
1857                 if (rmode == RES_DO) {
1858                         if (!flag_rep) continue;
1859                 }
1860                 if (rmode == RES_DONE) {
1861                         if (flag_rep) {
1862                                 flag_restore = 1;
1863                         } else {
1864                                 rpipe = NULL;
1865                         }
1866                 }
1867                 if (pi->num_progs == 0) continue;
1868 #ifndef __U_BOOT__
1869                 save_num_progs = pi->num_progs; /* save number of programs */
1870 #endif
1871                 rcode = run_pipe_real(pi);
1872                 debug_printf("run_pipe_real returned %d\n",rcode);
1873 #ifndef __U_BOOT__
1874                 if (rcode!=-1) {
1875                         /* We only ran a builtin: rcode was set by the return value
1876                          * of run_pipe_real(), and we don't need to wait for anything. */
1877                 } else if (pi->followup==PIPE_BG) {
1878                         /* XXX check bash's behavior with nontrivial pipes */
1879                         /* XXX compute jobid */
1880                         /* XXX what does bash do with attempts to background builtins? */
1881                         insert_bg_job(pi);
1882                         rcode = EXIT_SUCCESS;
1883                 } else {
1884                         if (interactive) {
1885                                 /* move the new process group into the foreground */
1886                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1887                                         perror_msg("tcsetpgrp-3");
1888                                 rcode = checkjobs(pi);
1889                                 /* move the shell to the foreground */
1890                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1891                                         perror_msg("tcsetpgrp-4");
1892                         } else {
1893                                 rcode = checkjobs(pi);
1894                         }
1895                         debug_printf("checkjobs returned %d\n",rcode);
1896                 }
1897                 last_return_code=rcode;
1898 #else
1899                 if (rcode < -1) {
1900                         last_return_code = -rcode - 2;
1901                         return -2;      /* exit */
1902                 }
1903                 last_return_code = rcode;
1904 #endif
1905 #ifndef __U_BOOT__
1906                 pi->num_progs = save_num_progs; /* restore number of programs */
1907 #endif
1908                 if ( rmode == RES_IF || rmode == RES_ELIF )
1909                         next_if_code=rcode;  /* can be overwritten a number of times */
1910                 if (rmode == RES_WHILE)
1911                         flag_rep = !last_return_code;
1912                 if (rmode == RES_UNTIL)
1913                         flag_rep = last_return_code;
1914                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1915                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1916                         skip_more_in_this_rmode=rmode;
1917 #ifndef __U_BOOT__
1918                 checkjobs(NULL);
1919 #endif
1920         }
1921         return rcode;
1922 }
1923
1924 /* broken, of course, but OK for testing */
1925 static char *indenter(int i)
1926 {
1927         static char blanks[]="                                    ";
1928         return &blanks[sizeof(blanks)-i-1];
1929 }
1930
1931 /* return code is the exit status of the pipe */
1932 static int free_pipe(struct pipe *pi, int indent)
1933 {
1934         char **p;
1935         struct child_prog *child;
1936 #ifndef __U_BOOT__
1937         struct redir_struct *r, *rnext;
1938 #endif
1939         int a, i, ret_code=0;
1940         char *ind = indenter(indent);
1941
1942 #ifndef __U_BOOT__
1943         if (pi->stopped_progs > 0)
1944                 return ret_code;
1945         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1946 #endif
1947         for (i=0; i<pi->num_progs; i++) {
1948                 child = &pi->progs[i];
1949                 final_printf("%s  command %d:\n",ind,i);
1950                 if (child->argv) {
1951                         for (a=0,p=child->argv; *p; a++,p++) {
1952                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1953                         }
1954 #ifndef __U_BOOT__
1955                         globfree(&child->glob_result);
1956 #else
1957                         for (a = 0; a < child->argc; a++) {
1958                                 free(child->argv[a]);
1959                         }
1960                         free(child->argv);
1961                         free(child->argv_nonnull);
1962                         child->argc = 0;
1963 #endif
1964                         child->argv=NULL;
1965                 } else if (child->group) {
1966 #ifndef __U_BOOT__
1967                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1968 #endif
1969                         ret_code = free_pipe_list(child->group,indent+3);
1970                         final_printf("%s   end group\n",ind);
1971                 } else {
1972                         final_printf("%s   (nil)\n",ind);
1973                 }
1974 #ifndef __U_BOOT__
1975                 for (r=child->redirects; r; r=rnext) {
1976                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1977                         if (r->dup == -1) {
1978                                 /* guard against the case >$FOO, where foo is unset or blank */
1979                                 if (r->word.gl_pathv) {
1980                                         final_printf(" %s\n", *r->word.gl_pathv);
1981                                         globfree(&r->word);
1982                                 }
1983                         } else {
1984                                 final_printf("&%d\n", r->dup);
1985                         }
1986                         rnext=r->next;
1987                         free(r);
1988                 }
1989                 child->redirects=NULL;
1990 #endif
1991         }
1992         free(pi->progs);   /* children are an array, they get freed all at once */
1993         pi->progs=NULL;
1994         return ret_code;
1995 }
1996
1997 static int free_pipe_list(struct pipe *head, int indent)
1998 {
1999         int rcode=0;   /* if list has no members */
2000         struct pipe *pi, *next;
2001         char *ind = indenter(indent);
2002         for (pi=head; pi; pi=next) {
2003                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2004                 rcode = free_pipe(pi, indent);
2005                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2006                 next=pi->next;
2007                 pi->next=NULL;
2008                 free(pi);
2009         }
2010         return rcode;
2011 }
2012
2013 /* Select which version we will use */
2014 static int run_list(struct pipe *pi)
2015 {
2016         int rcode=0;
2017 #ifndef __U_BOOT__
2018         if (fake_mode==0) {
2019 #endif
2020                 rcode = run_list_real(pi);
2021 #ifndef __U_BOOT__
2022         }
2023 #endif
2024         /* free_pipe_list has the side effect of clearing memory
2025          * In the long run that function can be merged with run_list_real,
2026          * but doing that now would hobble the debugging effort. */
2027         free_pipe_list(pi,0);
2028         return rcode;
2029 }
2030
2031 /* The API for glob is arguably broken.  This routine pushes a non-matching
2032  * string into the output structure, removing non-backslashed backslashes.
2033  * If someone can prove me wrong, by performing this function within the
2034  * original glob(3) api, feel free to rewrite this routine into oblivion.
2035  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2036  * XXX broken if the last character is '\\', check that before calling.
2037  */
2038 #ifndef __U_BOOT__
2039 static int globhack(const char *src, int flags, glob_t *pglob)
2040 {
2041         int cnt=0, pathc;
2042         const char *s;
2043         char *dest;
2044         for (cnt=1, s=src; s && *s; s++) {
2045                 if (*s == '\\') s++;
2046                 cnt++;
2047         }
2048         dest = malloc(cnt);
2049         if (!dest) return GLOB_NOSPACE;
2050         if (!(flags & GLOB_APPEND)) {
2051                 pglob->gl_pathv=NULL;
2052                 pglob->gl_pathc=0;
2053                 pglob->gl_offs=0;
2054                 pglob->gl_offs=0;
2055         }
2056         pathc = ++pglob->gl_pathc;
2057         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2058         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2059         pglob->gl_pathv[pathc-1]=dest;
2060         pglob->gl_pathv[pathc]=NULL;
2061         for (s=src; s && *s; s++, dest++) {
2062                 if (*s == '\\') s++;
2063                 *dest = *s;
2064         }
2065         *dest='\0';
2066         return 0;
2067 }
2068
2069 /* XXX broken if the last character is '\\', check that before calling */
2070 static int glob_needed(const char *s)
2071 {
2072         for (; *s; s++) {
2073                 if (*s == '\\') s++;
2074                 if (strchr("*[?",*s)) return 1;
2075         }
2076         return 0;
2077 }
2078
2079 #if 0
2080 static void globprint(glob_t *pglob)
2081 {
2082         int i;
2083         debug_printf("glob_t at %p:\n", pglob);
2084         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2085                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2086         for (i=0; i<pglob->gl_pathc; i++)
2087                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2088                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2089 }
2090 #endif
2091
2092 static int xglob(o_string *dest, int flags, glob_t *pglob)
2093 {
2094         int gr;
2095
2096         /* short-circuit for null word */
2097         /* we can code this better when the debug_printf's are gone */
2098         if (dest->length == 0) {
2099                 if (dest->nonnull) {
2100                         /* bash man page calls this an "explicit" null */
2101                         gr = globhack(dest->data, flags, pglob);
2102                         debug_printf("globhack returned %d\n",gr);
2103                 } else {
2104                         return 0;
2105                 }
2106         } else if (glob_needed(dest->data)) {
2107                 gr = glob(dest->data, flags, NULL, pglob);
2108                 debug_printf("glob returned %d\n",gr);
2109                 if (gr == GLOB_NOMATCH) {
2110                         /* quote removal, or more accurately, backslash removal */
2111                         gr = globhack(dest->data, flags, pglob);
2112                         debug_printf("globhack returned %d\n",gr);
2113                 }
2114         } else {
2115                 gr = globhack(dest->data, flags, pglob);
2116                 debug_printf("globhack returned %d\n",gr);
2117         }
2118         if (gr == GLOB_NOSPACE)
2119                 error_msg_and_die("out of memory during glob");
2120         if (gr != 0) { /* GLOB_ABORTED ? */
2121                 error_msg("glob(3) error %d",gr);
2122         }
2123         /* globprint(glob_target); */
2124         return gr;
2125 }
2126 #endif
2127
2128 #ifdef __U_BOOT__
2129 static char *get_dollar_var(char ch);
2130 #endif
2131
2132 /* This is used to get/check local shell variables */
2133 char *get_local_var(const char *s)
2134 {
2135         struct variables *cur;
2136
2137         if (!s)
2138                 return NULL;
2139
2140 #ifdef __U_BOOT__
2141         if (*s == '$')
2142                 return get_dollar_var(s[1]);
2143 #endif
2144
2145         for (cur = top_vars; cur; cur=cur->next)
2146                 if(strcmp(cur->name, s)==0)
2147                         return cur->value;
2148         return NULL;
2149 }
2150
2151 /* This is used to set local shell variables
2152    flg_export==0 if only local (not exporting) variable
2153    flg_export==1 if "new" exporting environ
2154    flg_export>1  if current startup environ (not call putenv()) */
2155 int set_local_var(const char *s, int flg_export)
2156 {
2157         char *name, *value;
2158         int result=0;
2159         struct variables *cur;
2160
2161 #ifdef __U_BOOT__
2162         /* might be possible! */
2163         if (!isalpha(*s))
2164                 return -1;
2165 #endif
2166
2167         name=strdup(s);
2168
2169         /* Assume when we enter this function that we are already in
2170          * NAME=VALUE format.  So the first order of business is to
2171          * split 's' on the '=' into 'name' and 'value' */
2172         value = strchr(name, '=');
2173         if (!value) {
2174                 free(name);
2175                 return -1;
2176         }
2177         *value++ = 0;
2178
2179         if (!*value) {
2180                 unset_local_var(name);
2181                 free(name);
2182                 return 0;
2183         }
2184
2185         for(cur = top_vars; cur; cur = cur->next) {
2186                 if(strcmp(cur->name, name)==0)
2187                         break;
2188         }
2189
2190         if(cur) {
2191                 if(strcmp(cur->value, value)==0) {
2192                         if(flg_export>0 && cur->flg_export==0)
2193                                 cur->flg_export=flg_export;
2194                         else
2195                                 result++;
2196                 } else {
2197                         if(cur->flg_read_only) {
2198                                 error_msg("%s: readonly variable", name);
2199                                 result = -1;
2200                         } else {
2201                                 if(flg_export>0 || cur->flg_export>1)
2202                                         cur->flg_export=1;
2203                                 free(cur->value);
2204
2205                                 cur->value = strdup(value);
2206                         }
2207                 }
2208         } else {
2209                 cur = malloc(sizeof(struct variables));
2210                 if(!cur) {
2211                         result = -1;
2212                 } else {
2213                         cur->name = strdup(name);
2214                         if (cur->name == NULL) {
2215                                 free(cur);
2216                                 result = -1;
2217                         } else {
2218                                 struct variables *bottom = top_vars;
2219                                 cur->value = strdup(value);
2220                                 cur->next = NULL;
2221                                 cur->flg_export = flg_export;
2222                                 cur->flg_read_only = 0;
2223                                 while(bottom->next) bottom=bottom->next;
2224                                 bottom->next = cur;
2225                         }
2226                 }
2227         }
2228
2229 #ifndef __U_BOOT__
2230         if(result==0 && cur->flg_export==1) {
2231                 *(value-1) = '=';
2232                 result = putenv(name);
2233         } else {
2234 #endif
2235                 free(name);
2236 #ifndef __U_BOOT__
2237                 if(result>0)            /* equivalent to previous set */
2238                         result = 0;
2239         }
2240 #endif
2241         return result;
2242 }
2243
2244 void unset_local_var(const char *name)
2245 {
2246         struct variables *cur;
2247
2248         if (name) {
2249                 for (cur = top_vars; cur; cur=cur->next) {
2250                         if(strcmp(cur->name, name)==0)
2251                                 break;
2252                 }
2253                 if (cur != NULL) {
2254                         struct variables *next = top_vars;
2255                         if(cur->flg_read_only) {
2256                                 error_msg("%s: readonly variable", name);
2257                                 return;
2258                         } else {
2259 #ifndef __U_BOOT__
2260                                 if(cur->flg_export)
2261                                         unenv_set(cur->name);
2262 #endif
2263                                 free(cur->name);
2264                                 free(cur->value);
2265                                 while (next->next != cur)
2266                                         next = next->next;
2267                                 next->next = cur->next;
2268                         }
2269                         free(cur);
2270                 }
2271         }
2272 }
2273
2274 static int is_assignment(const char *s)
2275 {
2276         if (s == NULL)
2277                 return 0;
2278
2279         if (!isalpha(*s)) return 0;
2280         ++s;
2281         while(isalnum(*s) || *s=='_') ++s;
2282         return *s=='=';
2283 }
2284
2285 #ifndef __U_BOOT__
2286 /* the src parameter allows us to peek forward to a possible &n syntax
2287  * for file descriptor duplication, e.g., "2>&1".
2288  * Return code is 0 normally, 1 if a syntax error is detected in src.
2289  * Resource errors (in xmalloc) cause the process to exit */
2290 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2291         struct in_str *input)
2292 {
2293         struct child_prog *child=ctx->child;
2294         struct redir_struct *redir = child->redirects;
2295         struct redir_struct *last_redir=NULL;
2296
2297         /* Create a new redir_struct and drop it onto the end of the linked list */
2298         while(redir) {
2299                 last_redir=redir;
2300                 redir=redir->next;
2301         }
2302         redir = xmalloc(sizeof(struct redir_struct));
2303         redir->next=NULL;
2304         redir->word.gl_pathv=NULL;
2305         if (last_redir) {
2306                 last_redir->next=redir;
2307         } else {
2308                 child->redirects=redir;
2309         }
2310
2311         redir->type=style;
2312         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2313
2314         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2315
2316         /* Check for a '2>&1' type redirect */
2317         redir->dup = redirect_dup_num(input);
2318         if (redir->dup == -2) return 1;  /* syntax error */
2319         if (redir->dup != -1) {
2320                 /* Erik had a check here that the file descriptor in question
2321                  * is legit; I postpone that to "run time"
2322                  * A "-" representation of "close me" shows up as a -3 here */
2323                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2324         } else {
2325                 /* We do _not_ try to open the file that src points to,
2326                  * since we need to return and let src be expanded first.
2327                  * Set ctx->pending_redirect, so we know what to do at the
2328                  * end of the next parsed word.
2329                  */
2330                 ctx->pending_redirect = redir;
2331         }
2332         return 0;
2333 }
2334 #endif
2335
2336 static struct pipe *new_pipe(void)
2337 {
2338         struct pipe *pi;
2339         pi = xmalloc(sizeof(struct pipe));
2340         pi->num_progs = 0;
2341         pi->progs = NULL;
2342         pi->next = NULL;
2343         pi->followup = 0;  /* invalid */
2344         pi->r_mode = RES_NONE;
2345         return pi;
2346 }
2347
2348 static void initialize_context(struct p_context *ctx)
2349 {
2350         ctx->pipe=NULL;
2351 #ifndef __U_BOOT__
2352         ctx->pending_redirect=NULL;
2353 #endif
2354         ctx->child=NULL;
2355         ctx->list_head=new_pipe();
2356         ctx->pipe=ctx->list_head;
2357         ctx->w=RES_NONE;
2358         ctx->stack=NULL;
2359 #ifdef __U_BOOT__
2360         ctx->old_flag=0;
2361 #endif
2362         done_command(ctx);   /* creates the memory for working child */
2363 }
2364
2365 /* normal return is 0
2366  * if a reserved word is found, and processed, return 1
2367  * should handle if, then, elif, else, fi, for, while, until, do, done.
2368  * case, function, and select are obnoxious, save those for later.
2369  */
2370 struct reserved_combo {
2371         char *literal;
2372         int code;
2373         long flag;
2374 };
2375 /* Mostly a list of accepted follow-up reserved words.
2376  * FLAG_END means we are done with the sequence, and are ready
2377  * to turn the compound list into a command.
2378  * FLAG_START means the word must start a new compound list.
2379  */
2380 static struct reserved_combo reserved_list[] = {
2381         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2382         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2383         { "elif",  RES_ELIF,  FLAG_THEN },
2384         { "else",  RES_ELSE,  FLAG_FI   },
2385         { "fi",    RES_FI,    FLAG_END  },
2386         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2387         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2388         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2389         { "in",    RES_IN,    FLAG_DO   },
2390         { "do",    RES_DO,    FLAG_DONE },
2391         { "done",  RES_DONE,  FLAG_END  }
2392 };
2393 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2394
2395 static int reserved_word(o_string *dest, struct p_context *ctx)
2396 {
2397         struct reserved_combo *r;
2398         for (r=reserved_list;
2399                 r<reserved_list+NRES; r++) {
2400                 if (strcmp(dest->data, r->literal) == 0) {
2401                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2402                         if (r->flag & FLAG_START) {
2403                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2404                                 debug_printf("push stack\n");
2405                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2406                                         syntax();
2407                                         free(new);
2408                                         ctx->w = RES_SNTX;
2409                                         b_reset(dest);
2410                                         return 1;
2411                                 }
2412                                 *new = *ctx;   /* physical copy */
2413                                 initialize_context(ctx);
2414                                 ctx->stack=new;
2415                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2416                                 syntax();
2417                                 ctx->w = RES_SNTX;
2418                                 b_reset(dest);
2419                                 return 1;
2420                         }
2421                         ctx->w=r->code;
2422                         ctx->old_flag = r->flag;
2423                         if (ctx->old_flag & FLAG_END) {
2424                                 struct p_context *old;
2425                                 debug_printf("pop stack\n");
2426                                 done_pipe(ctx,PIPE_SEQ);
2427                                 old = ctx->stack;
2428                                 old->child->group = ctx->list_head;
2429 #ifndef __U_BOOT__
2430                                 old->child->subshell = 0;
2431 #endif
2432                                 *ctx = *old;   /* physical copy */
2433                                 free(old);
2434                         }
2435                         b_reset (dest);
2436                         return 1;
2437                 }
2438         }
2439         return 0;
2440 }
2441
2442 /* normal return is 0.
2443  * Syntax or xglob errors return 1. */
2444 static int done_word(o_string *dest, struct p_context *ctx)
2445 {
2446         struct child_prog *child=ctx->child;
2447 #ifndef __U_BOOT__
2448         glob_t *glob_target;
2449         int gr, flags = 0;
2450 #else
2451         char *str, *s;
2452         int argc, cnt;
2453 #endif
2454
2455         debug_printf("done_word: %s %p\n", dest->data, child);
2456         if (dest->length == 0 && !dest->nonnull) {
2457                 debug_printf("  true null, ignored\n");
2458                 return 0;
2459         }
2460 #ifndef __U_BOOT__
2461         if (ctx->pending_redirect) {
2462                 glob_target = &ctx->pending_redirect->word;
2463         } else {
2464 #endif
2465                 if (child->group) {
2466                         syntax();
2467                         return 1;  /* syntax error, groups and arglists don't mix */
2468                 }
2469                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2470                         debug_printf("checking %s for reserved-ness\n",dest->data);
2471                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2472                 }
2473 #ifndef __U_BOOT__
2474                 glob_target = &child->glob_result;
2475                 if (child->argv) flags |= GLOB_APPEND;
2476 #else
2477                 for (cnt = 1, s = dest->data; s && *s; s++) {
2478                         if (*s == '\\') s++;
2479                         cnt++;
2480                 }
2481                 str = malloc(cnt);
2482                 if (!str) return 1;
2483                 if ( child->argv == NULL) {
2484                         child->argc=0;
2485                 }
2486                 argc = ++child->argc;
2487                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2488                 if (child->argv == NULL) {
2489                         free(str);
2490                         return 1;
2491                 }
2492                 child->argv_nonnull = realloc(child->argv_nonnull,
2493                                         (argc+1)*sizeof(*child->argv_nonnull));
2494                 if (child->argv_nonnull == NULL) {
2495                         free(str);
2496                         return 1;
2497                 }
2498                 child->argv[argc-1]=str;
2499                 child->argv_nonnull[argc-1] = dest->nonnull;
2500                 child->argv[argc]=NULL;
2501                 child->argv_nonnull[argc] = 0;
2502                 for (s = dest->data; s && *s; s++,str++) {
2503                         if (*s == '\\') s++;
2504                         *str = *s;
2505                 }
2506                 *str = '\0';
2507 #endif
2508 #ifndef __U_BOOT__
2509         }
2510         gr = xglob(dest, flags, glob_target);
2511         if (gr != 0) return 1;
2512 #endif
2513
2514         b_reset(dest);
2515 #ifndef __U_BOOT__
2516         if (ctx->pending_redirect) {
2517                 ctx->pending_redirect=NULL;
2518                 if (glob_target->gl_pathc != 1) {
2519                         error_msg("ambiguous redirect");
2520                         return 1;
2521                 }
2522         } else {
2523                 child->argv = glob_target->gl_pathv;
2524         }
2525 #endif
2526         if (ctx->w == RES_FOR) {
2527                 done_word(dest,ctx);
2528                 done_pipe(ctx,PIPE_SEQ);
2529         }
2530         return 0;
2531 }
2532
2533 /* The only possible error here is out of memory, in which case
2534  * xmalloc exits. */
2535 static int done_command(struct p_context *ctx)
2536 {
2537         /* The child is really already in the pipe structure, so
2538          * advance the pipe counter and make a new, null child.
2539          * Only real trickiness here is that the uncommitted
2540          * child structure, to which ctx->child points, is not
2541          * counted in pi->num_progs. */
2542         struct pipe *pi=ctx->pipe;
2543         struct child_prog *prog=ctx->child;
2544
2545         if (prog && prog->group == NULL
2546                  && prog->argv == NULL
2547 #ifndef __U_BOOT__
2548                  && prog->redirects == NULL) {
2549 #else
2550                                                                                 ) {
2551 #endif
2552                 debug_printf("done_command: skipping null command\n");
2553                 return 0;
2554         } else if (prog) {
2555                 pi->num_progs++;
2556                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2557         } else {
2558                 debug_printf("done_command: initializing\n");
2559         }
2560         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2561
2562         prog = pi->progs + pi->num_progs;
2563 #ifndef __U_BOOT__
2564         prog->redirects = NULL;
2565 #endif
2566         prog->argv = NULL;
2567         prog->argv_nonnull = NULL;
2568 #ifndef __U_BOOT__
2569         prog->is_stopped = 0;
2570 #endif
2571         prog->group = NULL;
2572 #ifndef __U_BOOT__
2573         prog->glob_result.gl_pathv = NULL;
2574         prog->family = pi;
2575 #endif
2576         prog->sp = 0;
2577         ctx->child = prog;
2578         prog->type = ctx->type;
2579
2580         /* but ctx->pipe and ctx->list_head remain unchanged */
2581         return 0;
2582 }
2583
2584 static int done_pipe(struct p_context *ctx, pipe_style type)
2585 {
2586         struct pipe *new_p;
2587         done_command(ctx);  /* implicit closure of previous command */
2588         debug_printf("done_pipe, type %d\n", type);
2589         ctx->pipe->followup = type;
2590         ctx->pipe->r_mode = ctx->w;
2591         new_p=new_pipe();
2592         ctx->pipe->next = new_p;
2593         ctx->pipe = new_p;
2594         ctx->child = NULL;
2595         done_command(ctx);  /* set up new pipe to accept commands */
2596         return 0;
2597 }
2598
2599 #ifndef __U_BOOT__
2600 /* peek ahead in the in_str to find out if we have a "&n" construct,
2601  * as in "2>&1", that represents duplicating a file descriptor.
2602  * returns either -2 (syntax error), -1 (no &), or the number found.
2603  */
2604 static int redirect_dup_num(struct in_str *input)
2605 {
2606         int ch, d=0, ok=0;
2607         ch = b_peek(input);
2608         if (ch != '&') return -1;
2609
2610         b_getch(input);  /* get the & */
2611         ch=b_peek(input);
2612         if (ch == '-') {
2613                 b_getch(input);
2614                 return -3;  /* "-" represents "close me" */
2615         }
2616         while (isdigit(ch)) {
2617                 d = d*10+(ch-'0');
2618                 ok=1;
2619                 b_getch(input);
2620                 ch = b_peek(input);
2621         }
2622         if (ok) return d;
2623
2624         error_msg("ambiguous redirect");
2625         return -2;
2626 }
2627
2628 /* If a redirect is immediately preceded by a number, that number is
2629  * supposed to tell which file descriptor to redirect.  This routine
2630  * looks for such preceding numbers.  In an ideal world this routine
2631  * needs to handle all the following classes of redirects...
2632  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2633  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2634  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2635  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2636  * A -1 output from this program means no valid number was found, so the
2637  * caller should use the appropriate default for this redirection.
2638  */
2639 static int redirect_opt_num(o_string *o)
2640 {
2641         int num;
2642
2643         if (o->length==0) return -1;
2644         for(num=0; num<o->length; num++) {
2645                 if (!isdigit(*(o->data+num))) {
2646                         return -1;
2647                 }
2648         }
2649         /* reuse num (and save an int) */
2650         num=atoi(o->data);
2651         b_reset(o);
2652         return num;
2653 }
2654
2655 FILE *generate_stream_from_list(struct pipe *head)
2656 {
2657         FILE *pf;
2658 #if 1
2659         int pid, channel[2];
2660         if (pipe(channel)<0) perror_msg_and_die("pipe");
2661         pid=fork();
2662         if (pid<0) {
2663                 perror_msg_and_die("fork");
2664         } else if (pid==0) {
2665                 close(channel[0]);
2666                 if (channel[1] != 1) {
2667                         dup2(channel[1],1);
2668                         close(channel[1]);
2669                 }
2670 #if 0
2671 #define SURROGATE "surrogate response"
2672                 write(1,SURROGATE,sizeof(SURROGATE));
2673                 _exit(run_list(head));
2674 #else
2675                 _exit(run_list_real(head));   /* leaks memory */
2676 #endif
2677         }
2678         debug_printf("forked child %d\n",pid);
2679         close(channel[1]);
2680         pf = fdopen(channel[0],"r");
2681         debug_printf("pipe on FILE *%p\n",pf);
2682 #else
2683         free_pipe_list(head,0);
2684         pf=popen("echo surrogate response","r");
2685         debug_printf("started fake pipe on FILE *%p\n",pf);
2686 #endif
2687         return pf;
2688 }
2689
2690 /* this version hacked for testing purposes */
2691 /* return code is exit status of the process that is run. */
2692 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2693 {
2694         int retcode;
2695         o_string result=NULL_O_STRING;
2696         struct p_context inner;
2697         FILE *p;
2698         struct in_str pipe_str;
2699         initialize_context(&inner);
2700
2701         /* recursion to generate command */
2702         retcode = parse_stream(&result, &inner, input, subst_end);
2703         if (retcode != 0) return retcode;  /* syntax error or EOF */
2704         done_word(&result, &inner);
2705         done_pipe(&inner, PIPE_SEQ);
2706         b_free(&result);
2707
2708         p=generate_stream_from_list(inner.list_head);
2709         if (p==NULL) return 1;
2710         mark_open(fileno(p));
2711         setup_file_in_str(&pipe_str, p);
2712
2713         /* now send results of command back into original context */
2714         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2715         /* XXX In case of a syntax error, should we try to kill the child?
2716          * That would be tough to do right, so just read until EOF. */
2717         if (retcode == 1) {
2718                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2719         }
2720
2721         debug_printf("done reading from pipe, pclose()ing\n");
2722         /* This is the step that wait()s for the child.  Should be pretty
2723          * safe, since we just read an EOF from its stdout.  We could try
2724          * to better, by using wait(), and keeping track of background jobs
2725          * at the same time.  That would be a lot of work, and contrary
2726          * to the KISS philosophy of this program. */
2727         mark_closed(fileno(p));
2728         retcode=pclose(p);
2729         free_pipe_list(inner.list_head,0);
2730         debug_printf("pclosed, retcode=%d\n",retcode);
2731         /* XXX this process fails to trim a single trailing newline */
2732         return retcode;
2733 }
2734
2735 static int parse_group(o_string *dest, struct p_context *ctx,
2736         struct in_str *input, int ch)
2737 {
2738         int rcode, endch=0;
2739         struct p_context sub;
2740         struct child_prog *child = ctx->child;
2741         if (child->argv) {
2742                 syntax();
2743                 return 1;  /* syntax error, groups and arglists don't mix */
2744         }
2745         initialize_context(&sub);
2746         switch(ch) {
2747                 case '(': endch=')'; child->subshell=1; break;
2748                 case '{': endch='}'; break;
2749                 default: syntax();   /* really logic error */
2750         }
2751         rcode=parse_stream(dest,&sub,input,endch);
2752         done_word(dest,&sub); /* finish off the final word in the subcontext */
2753         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2754         child->group = sub.list_head;
2755         return rcode;
2756         /* child remains "open", available for possible redirects */
2757 }
2758 #endif
2759
2760 /* basically useful version until someone wants to get fancier,
2761  * see the bash man page under "Parameter Expansion" */
2762 static char *lookup_param(char *src)
2763 {
2764         char *p;
2765         char *sep;
2766         char *default_val = NULL;
2767         int assign = 0;
2768         int expand_empty = 0;
2769
2770         if (!src)
2771                 return NULL;
2772
2773         sep = strchr(src, ':');
2774
2775         if (sep) {
2776                 *sep = '\0';
2777                 if (*(sep + 1) == '-')
2778                         default_val = sep+2;
2779                 if (*(sep + 1) == '=') {
2780                         default_val = sep+2;
2781                         assign = 1;
2782                 }
2783                 if (*(sep + 1) == '+') {
2784                         default_val = sep+2;
2785                         expand_empty = 1;
2786                 }
2787         }
2788
2789         p = env_get(src);
2790         if (!p)
2791                 p = get_local_var(src);
2792
2793         if (!p || strlen(p) == 0) {
2794                 p = default_val;
2795                 if (assign) {
2796                         char *var = malloc(strlen(src)+strlen(default_val)+2);
2797                         if (var) {
2798                                 sprintf(var, "%s=%s", src, default_val);
2799                                 set_local_var(var, 0);
2800                         }
2801                         free(var);
2802                 }
2803         } else if (expand_empty) {
2804                 p += strlen(p);
2805         }
2806
2807         if (sep)
2808                 *sep = ':';
2809
2810         return p;
2811 }
2812
2813 #ifdef __U_BOOT__
2814 static char *get_dollar_var(char ch)
2815 {
2816         static char buf[40];
2817
2818         buf[0] = '\0';
2819         switch (ch) {
2820                 case '?':
2821                         sprintf(buf, "%u", (unsigned int)last_return_code);
2822                         break;
2823                 default:
2824                         return NULL;
2825         }
2826         return buf;
2827 }
2828 #endif
2829
2830 /* return code: 0 for OK, 1 for syntax error */
2831 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2832 {
2833 #ifndef __U_BOOT__
2834         int i, advance=0;
2835 #else
2836         int advance=0;
2837 #endif
2838 #ifndef __U_BOOT__
2839         char sep[]=" ";
2840 #endif
2841         int ch = input->peek(input);  /* first character after the $ */
2842         debug_printf("handle_dollar: ch=%c\n",ch);
2843         if (isalpha(ch)) {
2844                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2845                 ctx->child->sp++;
2846                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2847                         b_getch(input);
2848                         b_addchr(dest,ch);
2849                 }
2850                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2851 #ifndef __U_BOOT__
2852         } else if (isdigit(ch)) {
2853                 i = ch-'0';  /* XXX is $0 special? */
2854                 if (i<global_argc) {
2855                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2856                 }
2857                 advance = 1;
2858 #endif
2859         } else switch (ch) {
2860 #ifndef __U_BOOT__
2861                 case '$':
2862                         b_adduint(dest,getpid());
2863                         advance = 1;
2864                         break;
2865                 case '!':
2866                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2867                         advance = 1;
2868                         break;
2869 #endif
2870                 case '?':
2871 #ifndef __U_BOOT__
2872                         b_adduint(dest,last_return_code);
2873 #else
2874                         ctx->child->sp++;
2875                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2876                         b_addchr(dest, '$');
2877                         b_addchr(dest, '?');
2878                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2879 #endif
2880                         advance = 1;
2881                         break;
2882 #ifndef __U_BOOT__
2883                 case '#':
2884                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2885                         advance = 1;
2886                         break;
2887 #endif
2888                 case '{':
2889                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2890                         ctx->child->sp++;
2891                         b_getch(input);
2892                         /* XXX maybe someone will try to escape the '}' */
2893                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2894                                 b_addchr(dest,ch);
2895                         }
2896                         if (ch != '}') {
2897                                 syntax();
2898                                 return 1;
2899                         }
2900                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2901                         break;
2902 #ifndef __U_BOOT__
2903                 case '(':
2904                         b_getch(input);
2905                         process_command_subs(dest, ctx, input, ')');
2906                         break;
2907                 case '*':
2908                         sep[0]=ifs[0];
2909                         for (i=1; i<global_argc; i++) {
2910                                 parse_string(dest, ctx, global_argv[i]);
2911                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2912                         }
2913                         break;
2914                 case '@':
2915                 case '-':
2916                 case '_':
2917                         /* still unhandled, but should be eventually */
2918                         error_msg("unhandled syntax: $%c",ch);
2919                         return 1;
2920                         break;
2921 #endif
2922                 default:
2923                         b_addqchr(dest,'$',dest->quote);
2924         }
2925         /* Eat the character if the flag was set.  If the compiler
2926          * is smart enough, we could substitute "b_getch(input);"
2927          * for all the "advance = 1;" above, and also end up with
2928          * a nice size-optimized program.  Hah!  That'll be the day.
2929          */
2930         if (advance) b_getch(input);
2931         return 0;
2932 }
2933
2934 #ifndef __U_BOOT__
2935 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2936 {
2937         struct in_str foo;
2938         setup_string_in_str(&foo, src);
2939         return parse_stream(dest, ctx, &foo, '\0');
2940 }
2941 #endif
2942
2943 /* return code is 0 for normal exit, 1 for syntax error */
2944 static int parse_stream(o_string *dest, struct p_context *ctx,
2945                         struct in_str *input, int end_trigger)
2946 {
2947         unsigned int ch, m;
2948 #ifndef __U_BOOT__
2949         int redir_fd;
2950         redir_type redir_style;
2951 #endif
2952         int next;
2953
2954         /* Only double-quote state is handled in the state variable dest->quote.
2955          * A single-quote triggers a bypass of the main loop until its mate is
2956          * found.  When recursing, quote state is passed in via dest->quote. */
2957
2958         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2959         while ((ch=b_getch(input))!=EOF) {
2960                 m = map[ch];
2961 #ifdef __U_BOOT__
2962                 if (input->__promptme == 0) return 1;
2963 #endif
2964                 next = (ch == '\n') ? 0 : b_peek(input);
2965
2966                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2967                         ch >= ' ' ? ch : '.', ch, m,
2968                         dest->quote, ctx->stack == NULL ? '*' : '.');
2969
2970                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2971                         b_addqchr(dest, ch, dest->quote);
2972                 } else {
2973                         if (m==2) {  /* unquoted IFS */
2974                                 if (done_word(dest, ctx)) {
2975                                         return 1;
2976                                 }
2977                                 /* If we aren't performing a substitution, treat a newline as a
2978                                  * command separator.  */
2979                                 if (end_trigger != '\0' && ch=='\n')
2980                                         done_pipe(ctx,PIPE_SEQ);
2981                         }
2982                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2983                                 debug_printf("leaving parse_stream (triggered)\n");
2984                                 return 0;
2985                         }
2986 #if 0
2987                         if (ch=='\n') {
2988                                 /* Yahoo!  Time to run with it! */
2989                                 done_pipe(ctx,PIPE_SEQ);
2990                                 run_list(ctx->list_head);
2991                                 initialize_context(ctx);
2992                         }
2993 #endif
2994                         if (m!=2) switch (ch) {
2995                 case '#':
2996                         if (dest->length == 0 && !dest->quote) {
2997                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2998                         } else {
2999                                 b_addqchr(dest, ch, dest->quote);
3000                         }
3001                         break;
3002                 case '\\':
3003                         if (next == EOF) {
3004                                 syntax();
3005                                 return 1;
3006                         }
3007                         b_addqchr(dest, '\\', dest->quote);
3008                         b_addqchr(dest, b_getch(input), dest->quote);
3009                         break;
3010                 case '$':
3011                         if (handle_dollar(dest, ctx, input)!=0) return 1;
3012                         break;
3013                 case '\'':
3014                         dest->nonnull = 1;
3015                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3016 #ifdef __U_BOOT__
3017                                 if(input->__promptme == 0) return 1;
3018 #endif
3019                                 b_addchr(dest,ch);
3020                         }
3021                         if (ch==EOF) {
3022                                 syntax();
3023                                 return 1;
3024                         }
3025                         break;
3026                 case '"':
3027                         dest->nonnull = 1;
3028                         dest->quote = !dest->quote;
3029                         break;
3030 #ifndef __U_BOOT__
3031                 case '`':
3032                         process_command_subs(dest, ctx, input, '`');
3033                         break;
3034                 case '>':
3035                         redir_fd = redirect_opt_num(dest);
3036                         done_word(dest, ctx);
3037                         redir_style=REDIRECT_OVERWRITE;
3038                         if (next == '>') {
3039                                 redir_style=REDIRECT_APPEND;
3040                                 b_getch(input);
3041                         } else if (next == '(') {
3042                                 syntax();   /* until we support >(list) Process Substitution */
3043                                 return 1;
3044                         }
3045                         setup_redirect(ctx, redir_fd, redir_style, input);
3046                         break;
3047                 case '<':
3048                         redir_fd = redirect_opt_num(dest);
3049                         done_word(dest, ctx);
3050                         redir_style=REDIRECT_INPUT;
3051                         if (next == '<') {
3052                                 redir_style=REDIRECT_HEREIS;
3053                                 b_getch(input);
3054                         } else if (next == '>') {
3055                                 redir_style=REDIRECT_IO;
3056                                 b_getch(input);
3057                         } else if (next == '(') {
3058                                 syntax();   /* until we support <(list) Process Substitution */
3059                                 return 1;
3060                         }
3061                         setup_redirect(ctx, redir_fd, redir_style, input);
3062                         break;
3063 #endif
3064                 case ';':
3065                         done_word(dest, ctx);
3066                         done_pipe(ctx,PIPE_SEQ);
3067                         break;
3068                 case '&':
3069                         done_word(dest, ctx);
3070                         if (next=='&') {
3071                                 b_getch(input);
3072                                 done_pipe(ctx,PIPE_AND);
3073                         } else {
3074 #ifndef __U_BOOT__
3075                                 done_pipe(ctx,PIPE_BG);
3076 #else
3077                                 syntax_err();
3078                                 return 1;
3079 #endif
3080                         }
3081                         break;
3082                 case '|':
3083                         done_word(dest, ctx);
3084                         if (next=='|') {
3085                                 b_getch(input);
3086                                 done_pipe(ctx,PIPE_OR);
3087                         } else {
3088                                 /* we could pick up a file descriptor choice here
3089                                  * with redirect_opt_num(), but bash doesn't do it.
3090                                  * "echo foo 2| cat" yields "foo 2". */
3091 #ifndef __U_BOOT__
3092                                 done_command(ctx);
3093 #else
3094                                 syntax_err();
3095                                 return 1;
3096 #endif
3097                         }
3098                         break;
3099 #ifndef __U_BOOT__
3100                 case '(':
3101                 case '{':
3102                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3103                         break;
3104                 case ')':
3105                 case '}':
3106                         syntax();   /* Proper use of this character caught by end_trigger */
3107                         return 1;
3108                         break;
3109 #endif
3110                 case SUBSTED_VAR_SYMBOL:
3111                         dest->nonnull = 1;
3112                         while (ch = b_getch(input), ch != EOF &&
3113                             ch != SUBSTED_VAR_SYMBOL) {
3114                                 debug_printf("subst, pass=%d\n", ch);
3115                                 if (input->__promptme == 0)
3116                                         return 1;
3117                                 b_addchr(dest, ch);
3118                         }
3119                         debug_printf("subst, term=%d\n", ch);
3120                         if (ch == EOF) {
3121                                 syntax();
3122                                 return 1;
3123                         }
3124                         break;
3125                 default:
3126                         syntax();   /* this is really an internal logic error */
3127                         return 1;
3128                         }
3129                 }
3130         }
3131         /* complain if quote?  No, maybe we just finished a command substitution
3132          * that was quoted.  Example:
3133          * $ echo "`cat foo` plus more"
3134          * and we just got the EOF generated by the subshell that ran "cat foo"
3135          * The only real complaint is if we got an EOF when end_trigger != '\0',
3136          * that is, we were really supposed to get end_trigger, and never got
3137          * one before the EOF.  Can't use the standard "syntax error" return code,
3138          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3139         debug_printf("leaving parse_stream (EOF)\n");
3140         if (end_trigger != '\0') return -1;
3141         return 0;
3142 }
3143
3144 static void mapset(const unsigned char *set, int code)
3145 {
3146         const unsigned char *s;
3147         for (s=set; *s; s++) map[*s] = code;
3148 }
3149
3150 static void update_ifs_map(void)
3151 {
3152         /* char *ifs and char map[256] are both globals. */
3153         ifs = (uchar *)env_get("IFS");
3154         if (ifs == NULL) ifs=(uchar *)" \t\n";
3155         /* Precompute a list of 'flow through' behavior so it can be treated
3156          * quickly up front.  Computation is necessary because of IFS.
3157          * Special case handling of IFS == " \t\n" is not implemented.
3158          * The map[] array only really needs two bits each, and on most machines
3159          * that would be faster because of the reduced L1 cache footprint.
3160          */
3161         memset(map,0,sizeof(map)); /* most characters flow through always */
3162 #ifndef __U_BOOT__
3163         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3164         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3165 #else
3166         {
3167                 uchar subst[2] = {SUBSTED_VAR_SYMBOL, 0};
3168                 mapset(subst, 3);       /* never flow through */
3169         }
3170         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3171         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3172 #endif
3173         mapset(ifs, 2);            /* also flow through if quoted */
3174 }
3175
3176 /* most recursion does not come through here, the exeception is
3177  * from builtin_source() */
3178 static int parse_stream_outer(struct in_str *inp, int flag)
3179 {
3180
3181         struct p_context ctx;
3182         o_string temp=NULL_O_STRING;
3183         int rcode;
3184 #ifdef __U_BOOT__
3185         int code = 1;
3186 #endif
3187         do {
3188                 ctx.type = flag;
3189                 initialize_context(&ctx);
3190                 update_ifs_map();
3191                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3192                 inp->promptmode=1;
3193                 rcode = parse_stream(&temp, &ctx, inp,
3194                                      flag & FLAG_CONT_ON_NEWLINE ? -1 : '\n');
3195 #ifdef __U_BOOT__
3196                 if (rcode == 1) flag_repeat = 0;
3197 #endif
3198                 if (rcode != 1 && ctx.old_flag != 0) {
3199                         syntax();
3200 #ifdef __U_BOOT__
3201                         flag_repeat = 0;
3202 #endif
3203                 }
3204                 if (rcode != 1 && ctx.old_flag == 0) {
3205                         done_word(&temp, &ctx);
3206                         done_pipe(&ctx,PIPE_SEQ);
3207 #ifndef __U_BOOT__
3208                         run_list(ctx.list_head);
3209 #else
3210                         code = run_list(ctx.list_head);
3211                         if (code == -2) {       /* exit */
3212                                 b_free(&temp);
3213                                 code = 0;
3214                                 /* XXX hackish way to not allow exit from main loop */
3215                                 if (inp->peek == file_peek) {
3216                                         printf("exit not allowed from main input shell.\n");
3217                                         continue;
3218                                 }
3219                                 /*
3220                                  * DANGER
3221                                  * Return code -2 is special in this context,
3222                                  * it indicates exit from inner pipe instead
3223                                  * of return code itself, the return code is
3224                                  * stored in 'last_return_code' variable!
3225                                  * DANGER
3226                                  */
3227                                 return -2;
3228                         }
3229                         if (code == -1)
3230                             flag_repeat = 0;
3231 #endif
3232                 } else {
3233                         if (ctx.old_flag != 0) {
3234                                 free(ctx.stack);
3235                                 b_reset(&temp);
3236                         }
3237 #ifdef __U_BOOT__
3238                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3239                         inp->__promptme = 1;
3240 #endif
3241                         temp.nonnull = 0;
3242                         temp.quote = 0;
3243                         inp->p = NULL;
3244                         free_pipe_list(ctx.list_head,0);
3245                 }
3246                 b_free(&temp);
3247         /* loop on syntax errors, return on EOF */
3248         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP) &&
3249                 (inp->peek != static_peek || b_peek(inp)));
3250 #ifndef __U_BOOT__
3251         return 0;
3252 #else
3253         return (code != 0) ? 1 : 0;
3254 #endif /* __U_BOOT__ */
3255 }
3256
3257 #ifndef __U_BOOT__
3258 static int parse_string_outer(const char *s, int flag)
3259 #else
3260 int parse_string_outer(const char *s, int flag)
3261 #endif  /* __U_BOOT__ */
3262 {
3263         struct in_str input;
3264         int rcode;
3265 #ifdef __U_BOOT__
3266         char *p = NULL;
3267         if (!s)
3268                 return 1;
3269         if (!*s)
3270                 return 0;
3271         if (!(p = strchr(s, '\n')) || *++p) {
3272                 p = xmalloc(strlen(s) + 2);
3273                 strcpy(p, s);
3274                 strcat(p, "\n");
3275                 setup_string_in_str(&input, p);
3276                 rcode = parse_stream_outer(&input, flag);
3277                 free(p);
3278                 return rcode == -2 ? last_return_code : rcode;
3279         } else {
3280 #endif
3281         setup_string_in_str(&input, s);
3282         rcode = parse_stream_outer(&input, flag);
3283         return rcode == -2 ? last_return_code : rcode;
3284 #ifdef __U_BOOT__
3285         }
3286 #endif
3287 }
3288
3289 #ifndef __U_BOOT__
3290 static int parse_file_outer(FILE *f)
3291 #else
3292 int parse_file_outer(void)
3293 #endif
3294 {
3295         int rcode;
3296         struct in_str input;
3297 #ifndef __U_BOOT__
3298         setup_file_in_str(&input, f);
3299 #else
3300         setup_file_in_str(&input);
3301 #endif
3302         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3303         return rcode == -2 ? last_return_code : rcode;
3304 }
3305
3306 #ifdef __U_BOOT__
3307 int u_boot_hush_start(void)
3308 {
3309         if (top_vars == NULL) {
3310                 top_vars = malloc(sizeof(struct variables));
3311                 top_vars->name = "HUSH_VERSION";
3312                 top_vars->value = "0.01";
3313                 top_vars->next = NULL;
3314                 top_vars->flg_export = 0;
3315                 top_vars->flg_read_only = 1;
3316         }
3317         return 0;
3318 }
3319
3320 static void *xmalloc(size_t size)
3321 {
3322         void *p = NULL;
3323
3324         if (!(p = malloc(size))) {
3325             printf("ERROR : xmalloc failed\n");
3326             for(;;);
3327         }
3328         return p;
3329 }
3330
3331 static void *xrealloc(void *ptr, size_t size)
3332 {
3333         void *p = NULL;
3334
3335         if (!(p = realloc(ptr, size))) {
3336             printf("ERROR : xrealloc failed\n");
3337             for(;;);
3338         }
3339         return p;
3340 }
3341 #endif /* __U_BOOT__ */
3342
3343 #ifndef __U_BOOT__
3344 /* Make sure we have a controlling tty.  If we get started under a job
3345  * aware app (like bash for example), make sure we are now in charge so
3346  * we don't fight over who gets the foreground */
3347 static void setup_job_control(void)
3348 {
3349         static pid_t shell_pgrp;
3350         /* Loop until we are in the foreground.  */
3351         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3352                 kill (- shell_pgrp, SIGTTIN);
3353
3354         /* Ignore interactive and job-control signals.  */
3355         signal(SIGINT, SIG_IGN);
3356         signal(SIGQUIT, SIG_IGN);
3357         signal(SIGTERM, SIG_IGN);
3358         signal(SIGTSTP, SIG_IGN);
3359         signal(SIGTTIN, SIG_IGN);
3360         signal(SIGTTOU, SIG_IGN);
3361         signal(SIGCHLD, SIG_IGN);
3362
3363         /* Put ourselves in our own process group.  */
3364         setsid();
3365         shell_pgrp = getpid ();
3366         setpgid (shell_pgrp, shell_pgrp);
3367
3368         /* Grab control of the terminal.  */
3369         tcsetpgrp(shell_terminal, shell_pgrp);
3370 }
3371
3372 int hush_main(int argc, char * const *argv)
3373 {
3374         int opt;
3375         FILE *input;
3376         char **e = environ;
3377
3378         /* XXX what should these be while sourcing /etc/profile? */
3379         global_argc = argc;
3380         global_argv = argv;
3381
3382         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3383          * hush_main(), therefore we cannot rely on the BSS to zero out this
3384          * stuff.  Reset these to 0 every time. */
3385         ifs = NULL;
3386         /* map[] is taken care of with call to update_ifs_map() */
3387         fake_mode = 0;
3388         interactive = 0;
3389         close_me_head = NULL;
3390         last_bg_pid = 0;
3391         job_list = NULL;
3392         last_jobid = 0;
3393
3394         /* Initialize some more globals to non-zero values */
3395         set_cwd();
3396 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3397         cmdedit_set_initial_prompt();
3398 #else
3399         PS1 = NULL;
3400 #endif
3401         PS2 = "> ";
3402
3403         /* initialize our shell local variables with the values
3404          * currently living in the environment */
3405         if (e) {
3406                 for (; *e; e++)
3407                         set_local_var(*e, 2);   /* without call putenv() */
3408         }
3409
3410         last_return_code=EXIT_SUCCESS;
3411
3412
3413         if (argv[0] && argv[0][0] == '-') {
3414                 debug_printf("\nsourcing /etc/profile\n");
3415                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3416                         mark_open(fileno(input));
3417                         parse_file_outer(input);
3418                         mark_closed(fileno(input));
3419                         fclose(input);
3420                 }
3421         }
3422         input=stdin;
3423
3424         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3425                 switch (opt) {
3426                         case 'c':
3427                                 {
3428                                         global_argv = argv+optind;
3429                                         global_argc = argc-optind;
3430                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3431                                         goto final_return;
3432                                 }
3433                                 break;
3434                         case 'i':
3435                                 interactive++;
3436                                 break;
3437                         case 'f':
3438                                 fake_mode++;
3439                                 break;
3440                         default:
3441 #ifndef BB_VER
3442                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3443                                                 "   or: sh -c command [args]...\n\n");
3444                                 exit(EXIT_FAILURE);
3445 #else
3446                                 show_usage();
3447 #endif
3448                 }
3449         }
3450         /* A shell is interactive if the `-i' flag was given, or if all of
3451          * the following conditions are met:
3452          *        no -c command
3453          *    no arguments remaining or the -s flag given
3454          *    standard input is a terminal
3455          *    standard output is a terminal
3456          *    Refer to Posix.2, the description of the `sh' utility. */
3457         if (argv[optind]==NULL && input==stdin &&
3458                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3459                 interactive++;
3460         }
3461
3462         debug_printf("\ninteractive=%d\n", interactive);
3463         if (interactive) {
3464                 /* Looks like they want an interactive shell */
3465 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3466                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3467                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3468 #endif
3469                 setup_job_control();
3470         }
3471
3472         if (argv[optind]==NULL) {
3473                 opt=parse_file_outer(stdin);
3474                 goto final_return;
3475         }
3476
3477         debug_printf("\nrunning script '%s'\n", argv[optind]);
3478         global_argv = argv+optind;
3479         global_argc = argc-optind;
3480         input = xfopen(argv[optind], "r");
3481         opt = parse_file_outer(input);
3482
3483 #ifdef CONFIG_FEATURE_CLEAN_UP
3484         fclose(input);
3485         if (cwd && cwd != unknown)
3486                 free((char*)cwd);
3487         {
3488                 struct variables *cur, *tmp;
3489                 for(cur = top_vars; cur; cur = tmp) {
3490                         tmp = cur->next;
3491                         if (!cur->flg_read_only) {
3492                                 free(cur->name);
3493                                 free(cur->value);
3494                                 free(cur);
3495                         }
3496                 }
3497         }
3498 #endif
3499
3500 final_return:
3501         return(opt?opt:last_return_code);
3502 }
3503 #endif
3504
3505 static char *insert_var_value(char *inp)
3506 {
3507         return insert_var_value_sub(inp, 0);
3508 }
3509
3510 static char *insert_var_value_sub(char *inp, int tag_subst)
3511 {
3512         int res_str_len = 0;
3513         int len;
3514         int done = 0;
3515         char *p, *p1, *res_str = NULL;
3516
3517         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3518                 /* check the beginning of the string for normal characters */
3519                 if (p != inp) {
3520                         /* copy any characters to the result string */
3521                         len = p - inp;
3522                         res_str = xrealloc(res_str, (res_str_len + len));
3523                         strncpy((res_str + res_str_len), inp, len);
3524                         res_str_len += len;
3525                 }
3526                 inp = ++p;
3527                 /* find the ending marker */
3528                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3529                 *p = '\0';
3530                 /* look up the value to substitute */
3531                 if ((p1 = lookup_param(inp))) {
3532                         if (tag_subst)
3533                                 len = res_str_len + strlen(p1) + 2;
3534                         else
3535                                 len = res_str_len + strlen(p1);
3536                         res_str = xrealloc(res_str, (1 + len));
3537                         if (tag_subst) {
3538                                 /*
3539                                  * copy the variable value to the result
3540                                  * string
3541                                  */
3542                                 strcpy((res_str + res_str_len + 1), p1);
3543
3544                                 /*
3545                                  * mark the replaced text to be accepted as
3546                                  * is
3547                                  */
3548                                 res_str[res_str_len] = SUBSTED_VAR_SYMBOL;
3549                                 res_str[res_str_len + 1 + strlen(p1)] =
3550                                         SUBSTED_VAR_SYMBOL;
3551                         } else
3552                                 /*
3553                                  * copy the variable value to the result
3554                                  * string
3555                                  */
3556                                 strcpy((res_str + res_str_len), p1);
3557
3558                         res_str_len = len;
3559                 }
3560                 *p = SPECIAL_VAR_SYMBOL;
3561                 inp = ++p;
3562                 done = 1;
3563         }
3564         if (done) {
3565                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3566                 strcpy((res_str + res_str_len), inp);
3567                 while ((p = strchr(res_str, '\n'))) {
3568                         *p = ' ';
3569                 }
3570         }
3571         return (res_str == NULL) ? inp : res_str;
3572 }
3573
3574 static char **make_list_in(char **inp, char *name)
3575 {
3576         int len, i;
3577         int name_len = strlen(name);
3578         int n = 0;
3579         char **list;
3580         char *p1, *p2, *p3;
3581
3582         /* create list of variable values */
3583         list = xmalloc(sizeof(*list));
3584         for (i = 0; inp[i]; i++) {
3585                 p3 = insert_var_value(inp[i]);
3586                 p1 = p3;
3587                 while (*p1) {
3588                         if (*p1 == ' ') {
3589                                 p1++;
3590                                 continue;
3591                         }
3592                         if ((p2 = strchr(p1, ' '))) {
3593                                 len = p2 - p1;
3594                         } else {
3595                                 len = strlen(p1);
3596                                 p2 = p1 + len;
3597                         }
3598                         /* we use n + 2 in realloc for list,because we add
3599                          * new element and then we will add NULL element */
3600                         list = xrealloc(list, sizeof(*list) * (n + 2));
3601                         list[n] = xmalloc(2 + name_len + len);
3602                         strcpy(list[n], name);
3603                         strcat(list[n], "=");
3604                         strncat(list[n], p1, len);
3605                         list[n++][name_len + len + 1] = '\0';
3606                         p1 = p2;
3607                 }
3608                 if (p3 != inp[i]) free(p3);
3609         }
3610         list[n] = NULL;
3611         return list;
3612 }
3613
3614 /*
3615  * Make new string for parser
3616  * inp     - array of argument strings to flatten
3617  * nonnull - indicates argument was quoted when originally parsed
3618  */
3619 static char *make_string(char **inp, int *nonnull)
3620 {
3621         char *p;
3622         char *str = NULL;
3623         int n;
3624         int len = 2;
3625         char *noeval_str;
3626         int noeval = 0;
3627
3628         noeval_str = get_local_var("HUSH_NO_EVAL");
3629         if (noeval_str != NULL && *noeval_str != '0' && *noeval_str != '\0')
3630                 noeval = 1;
3631         for (n = 0; inp[n]; n++) {
3632                 p = insert_var_value_sub(inp[n], noeval);
3633                 str = xrealloc(str, (len + strlen(p) + (2 * nonnull[n])));
3634                 if (n) {
3635                         strcat(str, " ");
3636                 } else {
3637                         *str = '\0';
3638                 }
3639                 if (nonnull[n])
3640                         strcat(str, "'");
3641                 strcat(str, p);
3642                 if (nonnull[n])
3643                         strcat(str, "'");
3644                 len = strlen(str) + 3;
3645                 if (p != inp[n]) free(p);
3646         }
3647         len = strlen(str);
3648         *(str + len) = '\n';
3649         *(str + len + 1) = '\0';
3650         return str;
3651 }
3652
3653 #ifdef __U_BOOT__
3654 static int do_showvar(struct cmd_tbl *cmdtp, int flag, int argc,
3655                       char *const argv[])
3656 {
3657         int i, k;
3658         int rcode = 0;
3659         struct variables *cur;
3660
3661         if (argc == 1) {                /* Print all env variables      */
3662                 for (cur = top_vars; cur; cur = cur->next) {
3663                         printf ("%s=%s\n", cur->name, cur->value);
3664                         if (ctrlc ()) {
3665                                 puts ("\n ** Abort\n");
3666                                 return 1;
3667                         }
3668                 }
3669                 return 0;
3670         }
3671         for (i = 1; i < argc; ++i) {    /* print single env variables   */
3672                 char *name = argv[i];
3673
3674                 k = -1;
3675                 for (cur = top_vars; cur; cur = cur->next) {
3676                         if(strcmp (cur->name, name) == 0) {
3677                                 k = 0;
3678                                 printf ("%s=%s\n", cur->name, cur->value);
3679                         }
3680                         if (ctrlc ()) {
3681                                 puts ("\n ** Abort\n");
3682                                 return 1;
3683                         }
3684                 }
3685                 if (k < 0) {
3686                         printf ("## Error: \"%s\" not defined\n", name);
3687                         rcode ++;
3688                 }
3689         }
3690         return rcode;
3691 }
3692
3693 U_BOOT_CMD(
3694         showvar, CONFIG_SYS_MAXARGS, 1, do_showvar,
3695         "print local hushshell variables",
3696         "\n    - print values of all hushshell variables\n"
3697         "showvar name ...\n"
3698         "    - print value of hushshell variable 'name'"
3699 );
3700
3701 #endif
3702 /****************************************************************************/