154 lines
3.5 KiB
C
154 lines
3.5 KiB
C
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/* save-cwd.c -- Save and restore current working directory.
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Copyright (C) 1995, 1997, 1998 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 Jim Meyering <meyering@na-net.ornl.gov>. */
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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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#ifdef STDC_HEADERS
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# include <stdlib.h>
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#endif
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#if HAVE_UNISTD_H
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# include <unistd.h>
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#endif
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#if HAVE_FCNTL_H
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# include <fcntl.h>
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#else
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# include <sys/file.h>
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#endif
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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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#ifndef O_DIRECTORY
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# define O_DIRECTORY 0
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#endif
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#include "save-cwd.h"
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#include "error.h"
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char *xgetcwd PARAMS ((void));
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/* Record the location of the current working directory in CWD so that
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the program may change to other directories and later use restore_cwd
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to return to the recorded location. This function may allocate
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space using malloc (via xgetcwd) or leave a file descriptor open;
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use free_cwd to perform the necessary free or close. Upon failure,
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no memory is allocated, any locally opened file descriptors are
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closed; return non-zero -- in that case, free_cwd need not be
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called, but doing so is ok. Otherwise, return zero. */
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int
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save_cwd (struct saved_cwd *cwd)
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{
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static int have_working_fchdir = 1;
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cwd->desc = -1;
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cwd->name = NULL;
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if (have_working_fchdir)
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{
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#if HAVE_FCHDIR
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cwd->desc = open (".", O_RDONLY | O_DIRECTORY);
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if (cwd->desc < 0)
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{
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error (0, errno, "cannot open current directory");
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return 1;
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}
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# if __sun__ || sun
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/* On SunOS 4, fchdir returns EINVAL if accounting is enabled,
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so we have to fall back to chdir. */
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if (fchdir (cwd->desc))
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{
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if (errno == EINVAL)
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{
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close (cwd->desc);
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cwd->desc = -1;
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have_working_fchdir = 0;
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}
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else
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{
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error (0, errno, "current directory");
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close (cwd->desc);
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cwd->desc = -1;
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return 1;
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}
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}
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# endif /* __sun__ || sun */
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#else
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# define fchdir(x) (abort (), 0)
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have_working_fchdir = 0;
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#endif
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}
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if (!have_working_fchdir)
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{
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cwd->name = xgetcwd ();
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if (cwd->name == NULL)
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{
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error (0, errno, "cannot get current directory");
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return 1;
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}
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}
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return 0;
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}
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/* Change to recorded location, CWD, in directory hierarchy.
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If "saved working directory", NULL))
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*/
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int
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restore_cwd (const struct saved_cwd *cwd, const char *dest, const char *from)
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{
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int fail = 0;
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if (cwd->desc >= 0)
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{
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if (fchdir (cwd->desc))
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{
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error (0, errno, "cannot return to %s%s%s",
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(dest ? dest : "saved working directory"),
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(from ? " from " : ""),
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(from ? from : ""));
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fail = 1;
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}
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}
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else if (chdir (cwd->name) < 0)
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{
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error (0, errno, "%s", cwd->name);
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fail = 1;
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}
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return fail;
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}
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void
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free_cwd (struct saved_cwd *cwd)
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{
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if (cwd->desc >= 0)
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close (cwd->desc);
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if (cwd->name)
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free (cwd->name);
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}
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