hush/libbb/fgets_str.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) many different people.
* If you wrote this, please acknowledge your work.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
static char *xmalloc_fgets_internal(FILE *file, const char *terminating_string, int chop_off, size_t *maxsz_p)
{
char *linebuf = NULL;
const int term_length = strlen(terminating_string);
int end_string_offset;
int linebufsz = 0;
int idx = 0;
int ch;
size_t maxsz = *maxsz_p;
while (1) {
ch = fgetc(file);
if (ch == EOF) {
if (idx == 0)
return linebuf; /* NULL */
break;
}
if (idx >= linebufsz) {
linebufsz += 200;
linebuf = xrealloc(linebuf, linebufsz);
if (idx >= maxsz) {
linebuf[idx] = ch;
idx++;
break;
}
}
linebuf[idx] = ch;
idx++;
/* Check for terminating string */
end_string_offset = idx - term_length;
if (end_string_offset >= 0
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&& memcmp(&linebuf[end_string_offset], terminating_string, term_length) == 0
) {
if (chop_off)
idx -= term_length;
break;
}
}
/* Grow/shrink *first*, then store NUL */
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linebuf = xrealloc(linebuf, idx + 1);
linebuf[idx] = '\0';
*maxsz_p = idx;
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return linebuf;
}
/* Read up to TERMINATING_STRING from FILE and return it,
* including terminating string.
* Non-terminated string can be returned if EOF is reached.
* Return NULL if EOF is reached immediately. */
char* FAST_FUNC xmalloc_fgets_str(FILE *file, const char *terminating_string)
{
size_t maxsz = INT_MAX - 4095;
return xmalloc_fgets_internal(file, terminating_string, 0, &maxsz);
}
char* FAST_FUNC xmalloc_fgets_str_len(FILE *file, const char *terminating_string, size_t *maxsz_p)
{
size_t maxsz;
if (!maxsz_p) {
maxsz = INT_MAX - 4095;
maxsz_p = &maxsz;
}
return xmalloc_fgets_internal(file, terminating_string, 0, maxsz_p);
}
char* FAST_FUNC xmalloc_fgetline_str(FILE *file, const char *terminating_string)
{
size_t maxsz = INT_MAX - 4095;
return xmalloc_fgets_internal(file, terminating_string, 1, &maxsz);
}