NetBSD/gnu/dist/cvs/lib/xgetwd.c

68 lines
1.6 KiB
C

/* xgetwd.c -- return current directory with unlimited length
Copyright (C) 1992, 1997 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details. */
/* Derived from xgetcwd.c in e.g. the GNU sh-utils. */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "system.h"
#include <stdio.h>
#include <errno.h>
#ifndef errno
extern int errno;
#endif
#include <sys/types.h>
/* Amount by which to increase buffer size when allocating more space. */
#define PATH_INCR 32
char *xmalloc ();
char *xrealloc ();
/* Return the current directory, newly allocated, arbitrarily long.
Return NULL and set errno on error. */
char *
xgetwd ()
{
char *cwd;
char *ret;
unsigned path_max;
errno = 0;
path_max = (unsigned) PATH_MAX;
path_max += 2; /* The getcwd docs say to do this. */
cwd = xmalloc (path_max);
errno = 0;
while ((ret = getcwd (cwd, path_max)) == NULL && errno == ERANGE)
{
path_max += PATH_INCR;
cwd = xrealloc (cwd, path_max);
errno = 0;
}
if (ret == NULL)
{
int save_errno = errno;
free (cwd);
errno = save_errno;
return NULL;
}
return cwd;
}