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.

       [EINTEGRITY]       Corrupted data was detected 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.

Debian                                           March 30, 2020                                      READLINK(2)