readlink

READLINK(2)                  BSD 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
     The readlink() 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
     The readlink() 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.

     In addition to the errors returned by the 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
     The readlinkat() system call follows The Open Group Extended API Set 2
     specification.

HISTORY
     The readlink() system call appeared in 4.2BSD.  The readlinkat() system
     call appeared in FreeBSD 8.0.

BSD                              April 10, 2008                              BSD