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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 16:11:47 +0000 |
commit | 758f820bcc0f68aeebac1717e537ca13a320b909 (patch) | |
tree | 48111ece75cf4f98316848b37a7e26356e00669e /lib/symlinkat.c | |
parent | Initial commit. (diff) | |
download | coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.tar.xz coreutils-758f820bcc0f68aeebac1717e537ca13a320b909.zip |
Adding upstream version 9.1.upstream/9.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/symlinkat.c')
-rw-r--r-- | lib/symlinkat.c | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/lib/symlinkat.c b/lib/symlinkat.c new file mode 100644 index 0000000..1346da8 --- /dev/null +++ b/lib/symlinkat.c @@ -0,0 +1,101 @@ +/* Create a symlink relative to an open directory. + Copyright (C) 2009-2022 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 Eric Blake */ + +#include <config.h> + +/* Specification. */ +#include <unistd.h> + +#include <errno.h> +#include <stdlib.h> + +#if HAVE_SYMLINKAT +# undef symlinkat + +#include <fcntl.h> +#include <sys/stat.h> +#include <string.h> + +/* Create a symlink, but reject trailing slash. */ +int +rpl_symlinkat (char const *contents, int fd, char const *name) +{ + size_t len = strlen (name); + if (len && name[len - 1] == '/') + { + struct stat st; + if (fstatat (fd, name, &st, AT_SYMLINK_NOFOLLOW) == 0 + || errno == EOVERFLOW) + errno = EEXIST; + return -1; + } + return symlinkat (contents, fd, name); +} + +#elif !HAVE_SYMLINK +/* Mingw lacks symlink, and it is more efficient to provide a trivial + wrapper than to go through at-func.c to call rpl_symlink. */ + +int +symlinkat (_GL_UNUSED char const *path1, _GL_UNUSED int fd, + _GL_UNUSED char const *path2) +{ + errno = ENOSYS; + return -1; +} + +#else /* HAVE_SYMLINK */ + +/* Our openat helper functions expect the directory parameter first, + not second. These shims make life easier. */ + +/* Like symlink, but with arguments reversed. */ +static int +symlink_reversed (char const *file, char const *contents) +{ + return symlink (contents, file); +} + +/* Like symlinkat, but with arguments reversed. */ + +static int +symlinkat_reversed (int fd, char const *file, char const *contents); + +# define AT_FUNC_NAME symlinkat_reversed +# define AT_FUNC_F1 symlink_reversed +# define AT_FUNC_POST_FILE_PARAM_DECLS , char const *contents +# define AT_FUNC_POST_FILE_ARGS , contents +# include "at-func.c" +# undef AT_FUNC_NAME +# undef AT_FUNC_F1 +# undef AT_FUNC_POST_FILE_PARAM_DECLS +# undef AT_FUNC_POST_FILE_ARGS + +/* Create a symlink FILE, in the directory open on descriptor FD, + holding CONTENTS. If possible, do it without changing the + working directory. Otherwise, resort to using save_cwd/fchdir, + then symlink/restore_cwd. If either the save_cwd or the restore_cwd + fails, then give a diagnostic and exit nonzero. */ + +int +symlinkat (char const *contents, int fd, char const *file) +{ + return symlinkat_reversed (fd, file, contents); +} + +#endif /* HAVE_SYMLINK */ |