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READLINK(2) | System Calls Manual | READLINK(2) |
NAME¶
readlink
,
readlinkat
—
read value of a symbolic link
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include
<unistd.h>
ssize_t
readlink
(const
char *restrict path,
char *restrict
buf, size_t
bufsiz);
ssize_t
readlinkat
(int
fd, const char *restrict path,
char *restrict buf,
size_t bufsize);
DESCRIPTION¶
Thereadlink
() system call places the
contents of the symbolic link path in the
buffer buf, which has size
bufsiz. The
readlink
() system call does not append a
NUL
character to
buf.
The readlinkat
() system call is equivalent to
readlink
() except in the case where
path specifies a relative path. In this case
the symbolic link whose content is read relative to the directory associated
with the file descriptor fd instead of the
current working directory. If readlinkat
()
is passed the special value AT_FDCWD
in the
fd parameter, the current working directory
is used and the behavior is identical to a call to
readlink
().
RETURN VALUES¶
The call returns the count of characters placed in the buffer if it succeeds, or a -1 if an error occurs, placing the error code in the global variable errno.ERRORS¶
Thereadlink
() system call will fail if:
- [
ENOTDIR
] - A component of the path prefix is not a directory.
- [
ENAMETOOLONG
] - A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters.
- [
ENOENT
] - The named file does not exist.
- [
EACCES
] - Search permission is denied for a component of the path prefix.
- [
ELOOP
] - Too many symbolic links were encountered in translating the pathname.
- [
EINVAL
] - The named file is not a symbolic link.
- [
EIO
] - An I/O error occurred while reading from the file system.
- [
EFAULT
] - The buf argument extends outside the process's allocated address space.
readlink
(), the
readlinkat
() may fail if:
- [
EBADF
] - The path argument does not specify an
absolute path and the fd argument is
neither
AT_FDCWD
nor a valid file descriptor open for searching. - [
ENOTDIR
] - The path argument is not an absolute path
and fd is neither
AT_FDCWD
nor a file descriptor associated with a directory.
SEE ALSO¶
lstat(2), stat(2), symlink(2), symlink(7)STANDARDS¶
Thereadlinkat
() system call follows The Open
Group Extended API Set 2 specification.
HISTORY¶
Thereadlink
() system call appeared in
4.2BSD. The
readlinkat
() system call appeared in
FreeBSD 8.0.April 10, 2008 | Debian |