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
10#include "libbb.h"
11
12/* Amount to increase buffer size by in each try. */
13#define PATH_INCR 32
14
15/* Return the current directory, newly allocated, arbitrarily long.
16   Return NULL and set errno on error.
17   If argument is not NULL (previous usage allocate memory), call free()
18*/
19
20char *
21xrealloc_getcwd_or_warn(char *cwd)
22{
23	char *ret;
24	unsigned path_max;
25
26	path_max = (unsigned) PATH_MAX;
27	path_max += 2;                /* The getcwd docs say to do this. */
28
29	if (cwd == NULL)
30		cwd = xmalloc(path_max);
31
32	while ((ret = getcwd(cwd, path_max)) == NULL && errno == ERANGE) {
33		path_max += PATH_INCR;
34		cwd = xrealloc(cwd, path_max);
35	}
36
37	if (ret == NULL) {
38		free(cwd);
39		bb_perror_msg("getcwd");
40		return NULL;
41	}
42
43	return cwd;
44}
45