busybox/libbb/get_line_from_file.c
Denis Vlasenko ab24e18c7a passwd: rework:
* do not make backup copy by copying (just retain old file)
* correctly fall back to /etc/passwd if user is not in shadow
* fix bug with overlong passwd entries
* be permissive on some kinds of failures
* reduce stack usage
* code size: -500 bytes
2006-11-30 16:41:15 +00:00

69 lines
1.5 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 2005, 2006 Rob Landley <rob@landley.net>
* Copyright (C) 2004 Erik Andersen <andersen@codepoet.org>
* Copyright (C) 2001 Matt Krai
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#include "libbb.h"
/* This function reads an entire line from a text file,
* up to a newline or NUL byte. It returns a malloc'ed char * which must be
* stored and free'ed by the caller. If end is null '\n' isn't considered
* end of line. If end isn't null, length of the chunk read is stored in it. */
char *bb_get_chunk_from_file(FILE * file, int *end)
{
int ch;
int idx = 0;
char *linebuf = NULL;
int linebufsz = 0;
while ((ch = getc(file)) != EOF) {
/* grow the line buffer as necessary */
if (idx > linebufsz - 2) {
linebuf = xrealloc(linebuf, linebufsz += 80);
}
linebuf[idx++] = (char) ch;
if (!ch || (end && ch == '\n'))
break;
}
if (end)
*end = idx;
if (linebuf) {
// huh, is fgets discards prior data on error like this?
// I don't think so....
//if (ferror(file)) {
// free(linebuf);
// return NULL;
//}
linebuf = xrealloc(linebuf, idx+1);
linebuf[idx] = 0;
}
return linebuf;
}
/* Get line, including trailing \n if any */
char *xmalloc_fgets(FILE * file)
{
int i;
return bb_get_chunk_from_file(file, &i);
}
/* Get line. Remove trailing \n */
char *xmalloc_getline(FILE * file)
{
int i;
char *c = bb_get_chunk_from_file(file, &i);
if (i && c[--i] == '\n')
c[i] = 0;
return c;
}