LINK(2) Linux Programmer's Manual LINK(2)
NAME
link(1,2) - make a new name for a file(1,n)
SYNOPSIS
#include <unistd.h>
int link(1,2)(const char *oldpath, const char *newpath);
DESCRIPTION
link(1,2) creates a new link(1,2) (also known as a hard link(1,2)) to an existing
file.
If newpath exists it will not be overwritten.
This new name may be used exactly as the old one for any operation;
both names refer to the same file(1,n) (and so have the same permissions and
ownership) and it is impossible to tell which name was the `original'.
RETURN VALUE
On success, zero is returned. On error(8,n), -1 is returned, and errno is
set(7,n,1 builtins) appropriately.
ERRORS
EACCES Write access(2,5) to the directory containing newpath is denied, or
search permission is denied for one of the directories in(1,8) the
path prefix of oldpath or newpath. (See also path_resolu-
tion(2).)
EEXIST newpath already exists.
EFAULT oldpath or newpath points outside your accessible address space.
EIO An I/O error(8,n) occurred.
ELOOP Too many symbolic links were encountered in(1,8) resolving oldpath or
newpath.
EMLINK The file(1,n) referred to by oldpath already has the maximum number
of links to it.
ENAMETOOLONG
oldpath or newpath was too long.
ENOENT A directory component in(1,8) oldpath or newpath does not exist or is
a dangling symbolic link.
ENOMEM Insufficient kernel memory was available.
ENOSPC The device containing the file(1,n) has no room for the new directory
entry.
ENOTDIR
A component used as a directory in(1,8) oldpath or newpath is not, in(1,8)
fact, a directory.
EPERM oldpath is a directory.
EPERM The filesystem containing oldpath and newpath does not support
the creation of hard links.
EROFS The file(1,n) is on a read-only filesystem.
EXDEV oldpath and newpath are not on the same filesystem.
NOTES
Hard links, as created by link(1,2), cannot span filesystems. Use symlink if(3,n)
this is required.
CONFORMING TO
SVr4, SVID, POSIX, BSD 4.3, X/OPEN. SVr4 documents additional ENOLINK
and EMULTIHOP error(8,n) conditions; POSIX.1 does not document ELOOP.
X/OPEN does not document EFAULT, ENOMEM or EIO.
BUGS
On NFS file(1,n) systems, the return code may be wrong in(1,8) case the NFS
server performs the link(1,2) creation and dies before it can say so. Use
stat(1,2)(2) to find out if(3,n) the link(1,2) got created.
SEE ALSO
ln(1), open(2,3,n)(2), path_resolution(2), rename(1,2,n)(2), stat(1,2)(2), symlink(2),
unlink(1,2)(2)
Linux 2.6.7 2004-06-23 LINK(2)