hush/libbb/xgetcwd.c

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/* vi: set sw=4 ts=4: */
/*
* xgetcwd.c -- return current directory with unlimited length
* Copyright (C) 1992, 1996 Free Software Foundation, Inc.
* Written by David MacKenzie <djm@gnu.ai.mit.edu>.
*
2003-05-26 14:07:50 +00:00
* Special function for busybox written by Vladimir Oleynik <dzo@simtreas.ru>
*/
#include "libbb.h"
/* Amount to increase buffer size by in each try. */
#define PATH_INCR 32
/* Return the current directory, newly allocated, arbitrarily long.
Return NULL and set errno on error.
If argument is not NULL (previous usage allocate memory), call free()
*/
char *
xrealloc_getcwd_or_warn(char *cwd)
{
char *ret;
unsigned path_max;
path_max = (unsigned) PATH_MAX;
path_max += 2; /* The getcwd docs say to do this. */
if (cwd == NULL)
cwd = xmalloc(path_max);
while ((ret = getcwd(cwd, path_max)) == NULL && errno == ERANGE) {
path_max += PATH_INCR;
cwd = xrealloc(cwd, path_max);
}
if (ret == NULL) {
free(cwd);
bb_perror_msg("getcwd");
return NULL;
}
return cwd;
}