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978bf5f750
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.
86 lines
1.9 KiB
C
86 lines
1.9 KiB
C
/* xgetcwd.c -- return current directory with unlimited length
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Copyright (C) 1992, 1996, 2000 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* Written by David MacKenzie <djm@gnu.ai.mit.edu>. */
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <stdio.h>
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#include <errno.h>
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#ifndef errno
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extern int errno;
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#endif
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#include <sys/types.h>
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#include "pathmax.h"
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#if HAVE_GETCWD
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char *getcwd ();
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#else
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char *getwd ();
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# define getcwd(Buf, Max) getwd (Buf)
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#endif
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extern void *xmalloc ();
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extern char *xstrdup ();
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extern void free ();
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/* Return the current directory, newly allocated, arbitrarily long.
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Return NULL and set errno on error. */
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char *
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xgetcwd ()
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{
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char *ret;
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unsigned path_max;
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char buf[1024];
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errno = 0;
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ret = getcwd (buf, sizeof (buf));
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if (ret != NULL)
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return xstrdup (buf);
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if (errno != ERANGE)
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return NULL;
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path_max = (unsigned) PATH_MAX;
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path_max += 2; /* The getcwd docs say to do this. */
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for (;;)
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{
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char *cwd = (char *) xmalloc (path_max);
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errno = 0;
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ret = getcwd (cwd, path_max);
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if (ret != NULL)
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return ret;
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if (errno != ERANGE)
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{
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int save_errno = errno;
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free (cwd);
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errno = save_errno;
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return NULL;
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}
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free (cwd);
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path_max += path_max / 16;
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path_max += 32;
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}
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}
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