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.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" This manpage is Copyright (C) 1992 Drew Eckhardt;
.\" 1993 Michael Haardt, Ian Jackson.
.\"
.\" Permission is granted to make and distribute verbatim copies of this
.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
.\" permission notice identical to this one
.\"
.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date. The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein. The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
.\" professionally.
.\"
.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" Modified Fri Jul 23 22:01:51 1993 Rik Faith <faith@cs.unc.edu>
.\" Modified Sun Aug 21 18:18:14 1994: Michael Haardt's NFS diffs were
.\" applied by hand <faith@cs.unc.edu>
.\"
.TH LINK 2 "10 December 1997" "Linux 2.0.30" "Linux Programmer's Manual"
.SH NAME
link \- make a new name for a file
.SH SYNOPSIS
.B #include <unistd.h>
.sp
.BI "int link(const char *" oldpath ", const char *" newpath );
.SH DESCRIPTION
.B link
creates a new link (also known as a hard link) to an existing file.
If
.I newpath
exists it will
.I not
be overwritten.
This new name may be used exactly as the old one for any operation;
both names refer to the same file (and so have the same permissions
and ownership) and it is impossible to tell which name was the
`original'.
.SH "RETURN VALUE"
On success, zero is returned. On error, \-1 is returned, and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EXDEV
.IR oldpath " and " newpath
are not on the same filesystem.
.TP
.B EPERM
The filesystem containing
.IR oldpath " and " newpath
does not support the creation of hard links.
.TP
.B EFAULT
.IR oldpath " or " newpath " points outside your accessible address space."
.TP
.B EACCES
Write access to the directory containing
.I newpath
is not allowed for the process's effective uid, or one of the
directories in
.IR oldpath " or " newpath
did not allow search (execute) permission.
.TP
.B ENAMETOOLONG
.IR oldpath " or " newpath " was too long."
.TP
.B ENOENT
A directory component in
.IR oldpath " or " newpath
does not exist or is a dangling symbolic link.
.TP
.B ENOTDIR
A component used as a directory in
.IR oldpath " or " newpath
is not, in fact, a directory.
.TP
.B ENOMEM
Insufficient kernel memory was available.
.TP
.B EROFS
The file is on a read-only filesystem.
.TP
.B EEXIST
.I newpath
already exists.
.TP
.B EMLINK
The file referred to by
.I oldpath
already has the maximum number of links to it.
.TP
.B ELOOP
Too many symbolic links were encountered in resolving
.IR oldpath " or " newpath .
.TP
.B ENOSPC
The device containing the file has no room for the new directory
entry.
.TP
.B EPERM
.I oldpath
is a directory.
.TP
.B EIO
An I/O error occurred.
.SH NOTES
Hard links, as created by
.BR link ,
cannot span filesystems. Use
.B symlink
if this is required.
.SH "CONFORMING TO"
SVr4, SVID, POSIX, BSD 4.3, X/OPEN. SVr4 documents additional ENOLINK and
EMULTIHOP error conditions; POSIX.1 does not document ELOOP.
X/OPEN does not document EFAULT, ENOMEM or EIO.
.SH BUGS
On NFS file systems, the return code may be wrong in case the NFS server
performs the link creation and dies before it can say so. Use
.BR stat (2)
to find out if the link got created.
.SH "SEE ALSO"
.BR symlink (2),
.BR unlink (2),
.BR rename (2),
.BR open (2),
.BR stat (2),
.BR ln (1)
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