[J-u-boot.git] / tools / getline.c

// SPDX-License-Identifier: GPL-2.0+
/* getline.c -- Replacement for GNU C library function getline
 *
 * Copyright (C) 1993, 1996, 2001, 2002 Free Software Foundation, Inc.
 */

/* Written by Jan Brittenson, [email protected].  */

#include <assert.h>
#include <stdio.h>

/* Always add at least this many bytes when extending the buffer.  */
#define MIN_CHUNK 64

/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
   + OFFSET (and null-terminate it). *LINEPTR is a pointer returned from
   malloc (or NULL), pointing to *N characters of space.  It is realloc'd
   as necessary.  Return the number of characters read (not including the
   null terminator), or -1 on error or EOF.
   NOTE: There is another getstr() function declared in <curses.h>.  */
static int getstr(char **lineptr, size_t *n, FILE *stream,
		  char terminator, size_t offset)
{
	int nchars_avail;	/* Allocated but unused chars in *LINEPTR.  */
	char *read_pos;		/* Where we're reading into *LINEPTR. */
	int ret;

	if (!lineptr || !n || !stream)
		return -1;

	if (!*lineptr) {
		*n = MIN_CHUNK;
		*lineptr = malloc(*n);
		if (!*lineptr)
			return -1;
	}

	nchars_avail = *n - offset;
	read_pos = *lineptr + offset;

	for (;;) {
		register int c = getc(stream);

		/* We always want at least one char left in the buffer, since we
		   always (unless we get an error while reading the first char)
		   NUL-terminate the line buffer.  */

		assert(*n - nchars_avail == read_pos - *lineptr);
		if (nchars_avail < 2) {
			if (*n > MIN_CHUNK)
				*n *= 2;
			else
				*n += MIN_CHUNK;

			nchars_avail = *n + *lineptr - read_pos;
			*lineptr = realloc(*lineptr, *n);
			if (!*lineptr)
				return -1;
			read_pos = *n - nchars_avail + *lineptr;
			assert(*n - nchars_avail == read_pos - *lineptr);
		}

		if (c == EOF || ferror (stream)) {
			/* Return partial line, if any.  */
			if (read_pos == *lineptr)
				return -1;
			else
				break;
		}

		*read_pos++ = c;
		nchars_avail--;

		if (c == terminator)
			/* Return the line.  */
			break;
	}

	/* Done - NUL terminate and return the number of chars read.  */
	*read_pos = '\0';

	ret = read_pos - (*lineptr + offset);
	return ret;
}

int getline (char **lineptr, size_t *n, FILE *stream)
{
	return getstr(lineptr, n, stream, '\n', 0);
}
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
64b15021	2	/* getline.c -- Replacement for GNU C library function getline
1a459660 WD	3	*
1a459660 WD	4	* Copyright (C) 1993, 1996, 2001, 2002 Free Software Foundation, Inc.
1a459660	5	*/
64b15021 MF	6
	7	/* Written by Jan Brittenson, [email protected]. */
	8
	9	#include <assert.h>
	10	#include <stdio.h>
	11
	12	/* Always add at least this many bytes when extending the buffer. */
	13	#define MIN_CHUNK 64
	14
	15	/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
	16	+ OFFSET (and null-terminate it). *LINEPTR is a pointer returned from
	17	malloc (or NULL), pointing to *N characters of space. It is realloc'd
	18	as necessary. Return the number of characters read (not including the
	19	null terminator), or -1 on error or EOF.
	20	NOTE: There is another getstr() function declared in <curses.h>. */
	21	static int getstr(char *lineptr, size_t n, FILE *stream,
	22	char terminator, size_t offset)
	23	{
	24	int nchars_avail; /* Allocated but unused chars in LINEPTR. /
	25	char read_pos; / Where we're reading into LINEPTR. /
	26	int ret;
	27
	28	if (!lineptr \|\| !n \|\| !stream)
	29	return -1;
	30
	31	if (!*lineptr) {
	32	*n = MIN_CHUNK;
	33	lineptr = malloc(n);
	34	if (!*lineptr)
	35	return -1;
	36	}
	37
	38	nchars_avail = *n - offset;
	39	read_pos = *lineptr + offset;
	40
	41	for (;;) {
	42	register int c = getc(stream);
	43
	44	/* We always want at least one char left in the buffer, since we
	45	always (unless we get an error while reading the first char)
	46	NUL-terminate the line buffer. */
	47
	48	assert(n - nchars_avail == read_pos - lineptr);
	49	if (nchars_avail < 2) {
	50	if (*n > MIN_CHUNK)
	51	n = 2;
	52	else
	53	*n += MIN_CHUNK;
	54
	55	nchars_avail = n + lineptr - read_pos;
	56	lineptr = realloc(lineptr, *n);
	57	if (!*lineptr)
	58	return -1;
	59	read_pos = n - nchars_avail + lineptr;
	60	assert(n - nchars_avail == read_pos - lineptr);
	61	}
	62
	63	if (c == EOF \|\| ferror (stream)) {
	64	/* Return partial line, if any. */
	65	if (read_pos == *lineptr)
	66	return -1;
	67	else
	68	break;
	69	}
70
71	*read_pos++ = c;
72	nchars_avail--;
73
74	if (c == terminator)
75	/* Return the line. */
76	break;
77	}
78
79	/* Done - NUL terminate and return the number of chars read. */
80	*read_pos = '\0';
81
82	ret = read_pos - (*lineptr + offset);
83	return ret;
84	}
85
86	int getline (char *lineptr, size_t n, FILE *stream)
87	{
88	return getstr(lineptr, n, stream, '\n', 0);
89	}