linkat

linkat - create a file link relative to directory file descriptors

#define _ATFILE_SOURCE
#include <unistd.h>
 I int linkat(int  olddirfd , const char * oldpath ,
I            int  newdirfd , const char * newpath , int  flags );

The R linkat () system call operates in exactly the same way as link(2), except for the differences described in this manual page. If the pathname given in oldpath is relative, then it is interpreted relative to the directory referred to by the file descriptor R olddirfd (rather than relative to the current working directory of the calling process, as is done by link(2) for a relative pathname). If oldpath is relative and olddirfd is the special value R AT_FDCWD , then oldpath is interpreted relative to the current working directory of the calling process (like link(2)). If R oldpath is absolute, then olddirfd is ignored. The interpretation of newpath is as for R oldpath , except that a relative pathname is interpreted relative to the directory referred to by the file descriptor R newdirfd . By default, linkat(2), does not dereference oldpath if it is a symbolic link (like link(2)). Since Linux 2.6.18, the flag AT_SYMLINK_FOLLOW can be specified in flags to cause oldpath to be dereferenced if it is a symbolic link. Before kernel 2.6.18, the flags argument was unused, and had to be specified as 0.

On success, R linkat () returns 0. On error, -1 is returned and errno is set to indicate the error.

The same errors that occur for link(2) can also occur for R linkat (). The following additional errors can occur for R linkat ():

EBADF

ENOTDIR

R linkat () was added to Linux in kernel 2.6.16.

This system call is non-standard but is proposed for inclusion in a future revision of POSIX.1.

See openat(2) for an explanation of the need for R linkat ().

link(2), openat(2), path_resolution(7)