readlinkat() System Call in Linux

NAME

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

SYNOPSIS

#include <unistd.h> 

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

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

If the pathname given in path is absolute, then dirfd is ignored.

RETURN VALUE

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

ERRORS

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

Tag	Description
EBADF	dirfd is not a valid file descriptor.
ENOTDIR
	path is a relative path and dirfd is a file descriptor referring to a file other than a directory.

NOTES

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

CONFORMING TO

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

VERSIONS

readlinkat() was added to Linux in kernel 2.6.16.