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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:29:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:29:51 +0000 |
commit | 6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e (patch) | |
tree | 32451fa3cdd9321fb2591fada9891b2cb70a9cd1 /grub-core/lib/gnulib/save-cwd.c | |
parent | Initial commit. (diff) | |
download | grub2-6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e.tar.xz grub2-6e7a315eb67cb6c113cf37e1d66c4f11a51a2b3e.zip |
Adding upstream version 2.06.upstream/2.06upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'grub-core/lib/gnulib/save-cwd.c')
-rw-r--r-- | grub-core/lib/gnulib/save-cwd.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/grub-core/lib/gnulib/save-cwd.c b/grub-core/lib/gnulib/save-cwd.c new file mode 100644 index 0000000..a67d95d --- /dev/null +++ b/grub-core/lib/gnulib/save-cwd.c @@ -0,0 +1,97 @@ +/* save-cwd.c -- Save and restore current working directory. + + Copyright (C) 1995, 1997-1998, 2003-2006, 2009-2019 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 3 of the License, 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, see <https://www.gnu.org/licenses/>. */ + +/* Written by Jim Meyering. */ + +#include <config.h> + +#include "save-cwd.h" + +#include <errno.h> +#include <fcntl.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> + +#include "chdir-long.h" +#include "unistd--.h" + +#if GNULIB_FCNTL_SAFER +# include "fcntl--.h" +#else +# define GNULIB_FCNTL_SAFER 0 +#endif + +/* Record the location of the current working directory in CWD so that + the program may change to other directories and later use restore_cwd + to return to the recorded location. This function may allocate + space using malloc (via getcwd) or leave a file descriptor open; + use free_cwd to perform the necessary free or close. Upon failure, + no memory is allocated, any locally opened file descriptors are + closed; return non-zero -- in that case, free_cwd need not be + called, but doing so is ok. Otherwise, return zero. + + The _raison d'etre_ for this interface is that the working directory + is sometimes inaccessible, and getcwd is not robust or as efficient. + So, we prefer to use the open/fchdir approach, but fall back on + getcwd if necessary. This module works for most cases with just + the getcwd-lgpl module, but to be truly robust, use the getcwd module. + + Some systems lack fchdir altogether: e.g., OS/2, pre-2001 Cygwin, + SCO Xenix. Also, SunOS 4 and Irix 5.3 provide the function, yet it + doesn't work for partitions on which auditing is enabled. If + you're still using an obsolete system with these problems, please + send email to the maintainer of this code. */ + +int +save_cwd (struct saved_cwd *cwd) +{ + cwd->name = NULL; + + cwd->desc = open (".", O_SEARCH | O_CLOEXEC); + if (!GNULIB_FCNTL_SAFER) + cwd->desc = fd_safer_flag (cwd->desc, O_CLOEXEC); + if (cwd->desc < 0) + { + cwd->name = getcwd (NULL, 0); + return cwd->name ? 0 : -1; + } + + return 0; +} + +/* Change to recorded location, CWD, in directory hierarchy. + Upon failure, return -1 (errno is set by chdir or fchdir). + Upon success, return zero. */ + +int +restore_cwd (const struct saved_cwd *cwd) +{ + if (0 <= cwd->desc) + return fchdir (cwd->desc); + else + return chdir_long (cwd->name); +} + +void +free_cwd (struct saved_cwd *cwd) +{ + if (cwd->desc >= 0) + close (cwd->desc); + free (cwd->name); +} |