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