Tag
Hash :
4f796b14
Author :
Date :
2000-06-21T20:16:03
(xgetcwd): If the required pathname length is smaller than 1024, return a memory chunk of least possible size, instead of size PATH_MAX + 2. In the loop, increment the size proportionally. Use free/xmalloc instead of xrealloc to avoid copying for very long paths.
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/* xgetcwd.c -- return current directory with unlimited length
Copyright (C) 1992, 1996, 2000 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.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
#if HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <errno.h>
#ifndef errno
extern int errno;
#endif
#include <sys/types.h>
#include "pathmax.h"
#if HAVE_GETCWD
char *getcwd ();
#else
char *getwd ();
# define getcwd(Buf, Max) getwd (Buf)
#endif
extern void *xmalloc ();
extern char *xstrdup ();
extern void free ();
/* Return the current directory, newly allocated, arbitrarily long.
Return NULL and set errno on error. */
char *
xgetcwd ()
{
char *ret;
unsigned path_max;
char buf[1024];
errno = 0;
ret = getcwd (buf, sizeof (buf));
if (ret != NULL)
return xstrdup (buf);
if (errno != ERANGE)
return NULL;
path_max = (unsigned) PATH_MAX;
path_max += 2; /* The getcwd docs say to do this. */
for (;;)
{
char *cwd = (char *) xmalloc (path_max);
errno = 0;
ret = getcwd (cwd, path_max);
if (ret != NULL)
return ret;
if (errno != ERANGE)
{
int save_errno = errno;
free (cwd);
errno = save_errno;
return NULL;
}
free (cwd);
path_max += path_max / 16;
path_max += 32;
}
}