1/* vi: set sw=4 ts=4: */
2/*
3 * xgetcwd.c -- return current directory with unlimited length
4 * Copyright (C) 1992, 1996 Free Software Foundation, Inc.
5 * Written by David MacKenzie <djm@gnu.ai.mit.edu>.
6 *
7 * Special function for busybox written by Vladimir Oleynik <dzo@simtreas.ru>
8 *
9 * Licensed under GPLv2, see file LICENSE in this tarball for details.
10 */
11
12#include "libbb.h"
13
14/* Return the current directory, newly allocated, arbitrarily long.
15   Return NULL and set errno on error.
16   If argument is not NULL (previous usage allocate memory), call free()
17*/
18
19char* FAST_FUNC
20xrealloc_getcwd_or_warn(char *cwd)
21{
22#define PATH_INCR 64
23
24	char *ret;
25	unsigned path_max;
26
27	path_max = 128;	/* 128 + 64 should be enough for 99% of cases */
28
29	while (1) {
30		path_max += PATH_INCR;
31		cwd = xrealloc(cwd, path_max);
32		ret = getcwd(cwd, path_max);
33		if (ret == NULL) {
34			if (errno == ERANGE)
35				continue;
36			free(cwd);
37			bb_perror_msg("getcwd");
38			return NULL;
39		}
40		cwd = xrealloc(cwd, strlen(cwd) + 1);
41		return cwd;
42	}
43}
44