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# linkat() - Unix, Linux System Call

# NAME

linkat - create a file link relative to directory file descriptors

# SYNOPSIS

    #include <unistd.h>

    int linkat(int olddirfd, const char *oldpath,
               int newdirfd, const char *newpath, int flags);

# DESCRIPTION

The 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 olddirfd (rather than relative to the current working directory of the calling process, as is done by link(2) for a relative pathname).

If the pathname given in oldpath is relative and olddirfd is the special value AT_FDCWD, then oldpath is interpreted relative to the current working directory of the calling process (like link(2)).

If the pathname given in oldpath is absolute, then olddirfd is ignored.

The interpretation of newpath is as for oldpath, except that a relative pathname is interpreted relative to the directory referred to by the file descriptor newdirfd.

The flags argument is currently unused, and must be specified as 0.

# RETURN VALUE

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

# ERRORS

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

Tag | Description
--- | ---
EBADF | olddirfd or newdirfd is not a valid file descriptor.
ENOTDIR
| oldpath is a relative path and olddirfd is a file descriptor referring to a file other than a directory; or similar for newpath and newdirfd

# NOTES

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

# CONFORMING TO

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

# VERSIONS

linkat() was added to Linux in kernel 2.6.16.

# SEE ALSO

- link (2)

- openat (2)

- path_resolution (2)

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