READLINKAT(2)                                       Linux Programmer's Manual                                      READLINKAT(2)



NAME
       readlinkat - read value of a symbolic link relative to a directory file descriptor

SYNOPSIS
       #include <fcntl.h> /* Definition of AT_* constants */
       #include <unistd.h>

       int readlinkat(int dirfd, const char *pathname,
                      char *buf, size_t bufsiz);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       readlinkat():
       Since glibc 2.10: _XOPEN_SOURCE >= 700 || _POSIX_C_SOURCE >= 200809L
       Before glibc 2.10: _ATFILE_SOURCE

DESCRIPTION
       The  readlinkat()  system  call  operates in exactly the same way as readlink(2), except for the differences described in
       this manual page.

       If the pathname given in pathname is relative, then it is interpreted relative to the directory referred to by  the  file
       descriptor dirfd (rather than relative to the current working directory of the calling process, as is done by readlink(2)
       for a relative pathname).

       If pathname is relative and dirfd is the special value AT_FDCWD, then pathname is interpreted  relative  to  the  current
       working directory of the calling process (like readlink(2)).

       If pathname is absolute, then dirfd is ignored.

RETURN VALUE
       On  success,  readlinkat() returns the number of bytes placed in buf.  On error, -1 is returned and errno is set to indi-
       cate the error.

ERRORS
       The same errors that occur for readlink(2) can also occur for readlinkat().  The following additional  errors  can  occur
       for readlinkat():

       EBADF  dirfd is not a valid file descriptor.

       ENOTDIR
              pathname is relative and dirfd is a file descriptor referring to a file other than a directory.

VERSIONS
       readlinkat() was added to Linux in kernel 2.6.16.

CONFORMING TO
       POSIX.1-2008.

NOTES
       See openat(2) for an explanation of the need for readlinkat().

SEE ALSO
       openat(2), readlink(2), path_resolution(7)

COLOPHON
       This  page  is  part of release 3.25 of the Linux man-pages project.  A description of the project, and information about
       reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.



Linux                                                      2009-12-13                                              READLINKAT(2)