Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

link(2) [centos man page]

LINK(2) 						     Linux Programmer's Manual							   LINK(2)

NAME
link - make a new name for a file SYNOPSIS
#include <unistd.h> int link(const char *oldpath, const char *newpath); DESCRIPTION
link() creates a new link (also known as a hard link) 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 (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, -1 is returned, and errno is set appropriately. ERRORS
EACCES Write access to the directory containing newpath is denied, or search permission is denied for one of the directories in the path prefix of oldpath or newpath. (See also path_resolution(7).) EDQUOT The user's quota of disk blocks on the file system has been exhausted. EEXIST newpath already exists. EFAULT oldpath or newpath points outside your accessible address space. EIO An I/O error occurred. ELOOP Too many symbolic links were encountered in resolving oldpath or newpath. EMLINK The file 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 oldpath or newpath does not exist or is a dangling symbolic link. ENOMEM Insufficient kernel memory was available. ENOSPC The device containing the file has no room for the new directory entry. ENOTDIR A component used as a directory in oldpath or newpath is not, in fact, a directory. EPERM oldpath is a directory. EPERM The file system containing oldpath and newpath does not support the creation of hard links. EPERM (since Linux 3.6) The caller does not have permission to create a hard link to this file (see the description of /proc/sys/fs/protected_hardlink in proc(5)). EROFS The file is on a read-only file system. EXDEV oldpath and newpath are not on the same mounted file system. (Linux permits a file system to be mounted at multiple points, but link() does not work across different mount points, even if the same file system is mounted on both.) CONFORMING TO
SVr4, 4.3BSD, POSIX.1-2001 (but see NOTES). NOTES
Hard links, as created by link(), cannot span file systems. Use symlink(2) if this is required. POSIX.1-2001 says that link() should dereference oldpath if it is a symbolic link. However, since kernel 2.0, Linux does not do so: if oldpath is a symbolic link, then newpath is created as a (hard) link to the same symbolic link file (i.e., newpath becomes a symbolic link to the same file that oldpath refers to). Some other implementations behave in the same manner as Linux. POSIX.1-2008 changes the speci- fication of link(), making it implementation-dependent whether or not oldpath is dereferenced if it is a symbolic link. For precise con- trol over the treatment of symbolic links when creating a link, see linkat(2). 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 stat(2) to find out if the link got created. SEE ALSO
ln(1), linkat(2), open(2), rename(2), stat(2), symlink(2), unlink(2), path_resolution(7), symlink(7) COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2013-01-27 LINK(2)

Check Out this Related Man Page

SYMLINK(2)						     Linux Programmer's Manual							SYMLINK(2)

NAME
symlink - make a new name for a file SYNOPSIS
#include <unistd.h> int symlink(const char *oldpath, const char *newpath); DESCRIPTION
symlink creates a symbolic link named newpath which contains the string oldpath. Symbolic links are interpreted at run-time as if the contents of the link had been substituted into the path being followed to find a file or directory. Symbolic links may contain .. path components, which (if used at the start of the link) refer to the parent directories of that in which the link resides. A symbolic link (also known as a soft link) may point to an existing file or to a nonexistent one; the latter case is known as a dangling link. The permissions of a symbolic link are irrelevant; the ownership is ignored when following the link, but is checked when removal or renam- ing of the link is requested and the link is in a directory with the sticky bit set. If newpath exists it will not be overwritten. RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is set appropriately. ERRORS
EPERM The filesystem containing newpath does not support the creation of symbolic links. EFAULT oldpath or newpath points outside your accessible address space. EACCES Write access to the directory containing newpath is not allowed for the process's effective uid, or one of the directories in new- path did not allow search (execute) permission. ENAMETOOLONG oldpath or newpath was too long. ENOENT A directory component in newpath does not exist or is a dangling symbolic link, or oldpath is the empty string. ENOTDIR A component used as a directory in newpath is not, in fact, a directory. ENOMEM Insufficient kernel memory was available. EROFS newpath is on a read-only filesystem. EEXIST newpath already exists. ELOOP Too many symbolic links were encountered in resolving newpath. ENOSPC The device containing the file has no room for the new directory entry. EIO An I/O error occurred. NOTES
No checking of oldpath is done. Deleting the name referred to by a symlink will actually delete the file (unless it also has other hard links). If this behaviour is not desired, use link. CONFORMING TO
SVr4, SVID, POSIX, BSD 4.3. SVr4 documents additional error codes SVr4, SVID, BSD 4.3, X/OPEN. SVr4 documents additional error codes EDQUOT and ENOSYS. See open(2) re multiple files with the same name, and NFS. SEE ALSO
readlink(2), link(2), unlink(2), rename(2), open(2), lstat(2), ln(1) Linux 2.0.30 1997-08-21 SYMLINK(2)
Man Page

Featured Tech Videos