readlink() - Unix, Linux System Call

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

Tag	Description
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.