readlink(2) - Linux man page

Name

readlink - read value of a symbolic link

Synopsis

#include <unistd.h>

ssize_t readlink(const char *path, char *buf, size_t bufsiz);

Description

readlink() places the contents of the symbolic link path in the buffer buf, which has size bufsiz. readlink() does not append a null byte to buf. It will truncate the contents (to a length of bufsiz characters), in case the buffer is too small to hold all of the contents.

Return Value

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 errno.

Errors

EACCES: Search permission is denied for a component of the path prefix. (See also path_resolution(2).)
EFAULT: buf extends outside the process's allocated address space.
EINVAL: bufsiz is not positive.
EINVAL: The named file is not a symbolic link.
EIO: An I/O error occurred while reading from the file system.
ELOOP: Too many symbolic links were encountered in translating the pathname.
ENAMETOOLONG: A pathname, or a component of a pathname, was too long.
ENOENT: The named file does not exist.
ENOMEM: Insufficient kernel memory was available.
ENOTDIR: A component of the path prefix is not a directory.

Conforming to

4.4BSD (the readlink() function call appeared in 4.2BSD), POSIX.1-2001.

History

In versions of glibc up to and including glibc 2.4, the return type of readlink() was declared as int. Nowadays, the return type is declared as ssize_t, as (newly) required in POSIX.1-2001.

Referenced By

fstat(2), kpsereadlink(1), lslk(8), lsof(8), open_by_handle(3), proc(5), read(2), realpath(3), rpm(8), star(1), syscalls(2)