mirror of
git://git.sv.gnu.org/emacs.git
synced 2026-01-04 02:51:31 -08:00
68 lines
2.1 KiB
C
68 lines
2.1 KiB
C
/* Test whether a file is a symbolic link.
|
|
Copyright (C) 2025-2026 Free Software Foundation, Inc.
|
|
|
|
This file is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU Lesser General Public License as
|
|
published by the Free Software Foundation; either version 2.1 of the
|
|
License, or (at your option) any later version.
|
|
|
|
This file 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 Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with this program. If not, see <https://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef _ISSYMLINKAT_H
|
|
#define _ISSYMLINKAT_H
|
|
|
|
/* This file uses _GL_ARG_NONNULL, _GL_INLINE. */
|
|
#if !_GL_CONFIG_H_INCLUDED
|
|
#error "Please include config.h first."
|
|
#endif
|
|
|
|
#include <errno.h>
|
|
#include <unistd.h> /* for readlinkat */
|
|
|
|
|
|
_GL_INLINE_HEADER_BEGIN
|
|
|
|
#ifndef _GL_ISSYMLINKAT_INLINE
|
|
# define _GL_ISSYMLINKAT_INLINE _GL_INLINE
|
|
#endif
|
|
|
|
/* Tests whether FILENAME represents a symbolic link.
|
|
This function is more reliable than lstat() / fstatat() followed by S_ISLNK,
|
|
because it avoids possible EOVERFLOW errors.
|
|
If FILENAME is a relative file name, it is interpreted as relative to the
|
|
directory referred to by FD (where FD = AT_FDCWD denotes the current
|
|
directory).
|
|
Returns
|
|
1 if FILENAME is a symbolic link,
|
|
0 if FILENAME exists and is not a symbolic link,
|
|
-1 with errno set if determination failed, in particular
|
|
-1 with errno = ENOENT or ENOTDIR if FILENAME does not exist. */
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif
|
|
_GL_ISSYMLINKAT_INLINE int issymlinkat (int fd, const char *filename)
|
|
_GL_ARG_NONNULL ((2));
|
|
_GL_ISSYMLINKAT_INLINE int
|
|
issymlinkat (int fd, const char *filename)
|
|
{
|
|
char linkbuf[1];
|
|
if (readlinkat (fd, filename, linkbuf, sizeof (linkbuf)) >= 0)
|
|
return 1;
|
|
if (errno == EINVAL)
|
|
return 0;
|
|
else
|
|
return -1;
|
|
}
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
_GL_INLINE_HEADER_END
|
|
|
|
#endif /* _ISSYMLINKAT_H */
|