2020-09-02 16:47:03 +08:00
|
|
|
/* areadlinkat.c -- readlinkat wrapper to return malloc'd link name
|
|
|
|
|
Unlike xreadlinkat, only call exit on failure to change directory.
|
|
|
|
|
|
2022-07-28 14:16:50 +08:00
|
|
|
Copyright (C) 2001, 2003-2007, 2009-2022 Free Software Foundation, Inc.
|
2020-09-02 16:47:03 +08:00
|
|
|
|
|
|
|
|
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
|
2022-07-28 14:16:50 +08:00
|
|
|
the Free Software Foundation, either version 3 of the License, or
|
2020-09-02 16:47:03 +08:00
|
|
|
(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 <jim@meyering.net>,
|
|
|
|
|
and Bruno Haible <bruno@clisp.org>,
|
|
|
|
|
and Eric Blake <ebb9@byu.net>. */
|
|
|
|
|
|
|
|
|
|
#include <config.h>
|
|
|
|
|
|
|
|
|
|
/* Specification. */
|
|
|
|
|
#include "areadlink.h"
|
|
|
|
|
|
|
|
|
|
#include <stdlib.h>
|
|
|
|
|
|
|
|
|
|
#include "careadlinkat.h"
|
|
|
|
|
|
|
|
|
|
#if HAVE_READLINKAT
|
|
|
|
|
|
|
|
|
|
/* Call readlinkat to get the symbolic link value of FILENAME relative to FD.
|
|
|
|
|
Return a pointer to that NUL-terminated string in malloc'd storage.
|
|
|
|
|
If readlinkat fails, return NULL and set errno (although failure to
|
|
|
|
|
change directory will issue a diagnostic and exit).
|
|
|
|
|
If allocation fails, or if the link value is longer than SIZE_MAX :-),
|
|
|
|
|
return NULL and set errno to ENOMEM. */
|
|
|
|
|
|
|
|
|
|
char *
|
|
|
|
|
areadlinkat (int fd, char const *filename)
|
|
|
|
|
{
|
|
|
|
|
return careadlinkat (fd, filename, NULL, 0, NULL, readlinkat);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#else /* !HAVE_READLINKAT */
|
|
|
|
|
|
|
|
|
|
/* It is more efficient to change directories only once and call
|
|
|
|
|
areadlink, rather than repeatedly call the replacement
|
|
|
|
|
readlinkat. */
|
|
|
|
|
|
|
|
|
|
# define AT_FUNC_NAME areadlinkat
|
|
|
|
|
# define AT_FUNC_F1 areadlink
|
|
|
|
|
# define AT_FUNC_POST_FILE_PARAM_DECLS /* empty */
|
|
|
|
|
# define AT_FUNC_POST_FILE_ARGS /* empty */
|
|
|
|
|
# define AT_FUNC_RESULT char *
|
|
|
|
|
# define AT_FUNC_FAIL NULL
|
|
|
|
|
# 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
|
|
|
|
|
# undef AT_FUNC_RESULT
|
|
|
|
|
# undef AT_FUNC_FAIL
|
|
|
|
|
|
|
|
|
|
#endif /* !HAVE_READLINKAT */
|
