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65 lines
1.9 KiB
C
65 lines
1.9 KiB
C
/* Test whether a file is a symbolic link.
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Copyright (C) 2025-2026 Free Software Foundation, Inc.
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This file is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as
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published by the Free Software Foundation; either version 2.1 of the
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License, or (at your option) any later version.
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This file 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 Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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#ifndef _ISSYMLINK_H
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#define _ISSYMLINK_H
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/* This file uses _GL_ARG_NONNULL, _GL_INLINE. */
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#if !_GL_CONFIG_H_INCLUDED
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#error "Please include config.h first."
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#endif
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#include <errno.h>
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#include <unistd.h> /* for readlink */
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_GL_INLINE_HEADER_BEGIN
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#ifndef _GL_ISSYMLINK_INLINE
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# define _GL_ISSYMLINK_INLINE _GL_INLINE
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#endif
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/* Tests whether FILENAME represents a symbolic link.
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This function is more reliable than lstat() / fstatat() followed by S_ISLNK,
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because it avoids possible EOVERFLOW errors.
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Returns
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1 if FILENAME is a symbolic link,
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0 if FILENAME exists and is not a symbolic link,
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-1 with errno set if determination failed, in particular
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-1 with errno = ENOENT or ENOTDIR if FILENAME does not exist. */
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#ifdef __cplusplus
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extern "C" {
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#endif
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_GL_ISSYMLINK_INLINE int issymlink (const char *filename)
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_GL_ARG_NONNULL ((1));
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_GL_ISSYMLINK_INLINE int
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issymlink (const char *filename)
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{
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char linkbuf[1];
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if (readlink (filename, linkbuf, sizeof (linkbuf)) >= 0)
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return 1;
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if (errno == EINVAL)
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return 0;
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else
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return -1;
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}
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#ifdef __cplusplus
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}
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#endif
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_GL_INLINE_HEADER_END
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#endif /* _ISSYMLINK_H */
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