link(2) System Calls link(2)
NAME
link - link to a file
SYNOPSIS
#include <unistd.h>
int link(const char *existing, const char *new);
DESCRIPTION
The link() function creates a new link (directory entry) for the existing file and increments its link count by one. The existing argument
points to a path name naming an existing file. The new argument points to a pathname naming the new directory entry to be created.
To create hard links, both files must be on the same file system. Both the old and the new link share equal access and rights to the under-
lying object. Privileged processes can make multiple links to a directory. Unless the caller is privileged, the file named by existing must
not be a directory.
Upon successful completion, link() marks for update the st_ctime field of the file. Also, the st_ctime and st_mtime fields of the directory
that contains the new entry are marked for update.
RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is returned, no link is created, and errno is set to indicate the error.
ERRORS
The link() function will fail if:
EACCES A component of either path prefix denies search permission, or the requested link requires writing in a directory with a
mode that denies write permission.
EDQUOT The directory where the entry for the new link is being placed cannot be extended because the user's quota of disk blocks
on that file system has been exhausted.
EEXIST The link named by new exists.
EFAULT The existing or new argument points to an illegal address.
EINTR A signal was caught during the execution of the link() function.
ELOOP Too many symbolic links were encountered in translating path.
EMLINK The maximum number of links to a file would be exceeded.
ENAMETOOLONG The length of the existing or new argument exceeds PATH_MAX, or the length of a existing or new component exceeds NAME_MAX
while _POSIX_NO_TRUNC is in effect.
ENOENT The existing or new argument is a null pathname; a component of either path prefix does not exist; or the file named by
existing does not exist.
ENOLINK The existing or new argument points to a remote machine and the link to that machine is no longer active.
ENOSPC The directory that would contain the link cannot be extended.
ENOTDIR A component of either path prefix is not a directory.
EPERM The file named by existing is a directory and the {PRIV_SYS_LINKDIR} privilege is not asserted in the effective set of the
calling process.
The effective user ID does not match the owner of the file and the {PRIV_FILE_LINK_ANY} privilege is not asserted in the
effective set of the calling process.
EROFS The requested link requires writing in a directory on a read-only file system.
EXDEV The link named by new and the file named by existing are on different logical devices (file systems).
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |Async-Signal-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
symlink(2), unlink(2), attributes(5), privileges(5), standards(5)
SunOS 5.10 20 Jan 2003 link(2)