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link(2) [osx man page]

LINK(2) 						      BSD System Calls Manual							   LINK(2)

NAME
link -- make a hard file link SYNOPSIS
#include <unistd.h> int link(const char *path1, const char *path2); DESCRIPTION
The link() function call atomically creates the specified directory entry (hard link) path2 with the attributes of the underlying object pointed at by path1. If the link is successful, the link count of the underlying object is incremented; path1 and path2 share equal access and rights to the underlying object. If path1 is removed, the file path2 is not deleted and the link count of the underlying object is decremented. In order for the system call to succeed, path1 must exist and both path1 and path2 must be in the same file system. As mandated by POSIX.1, path1 may not be a directory. link() will resolve and follow symbolic links contained within both path1 and path2. If the last component of path1 is a symbolic link, link() will point the hard link, path2, to the underlying object pointed to by path1, not to the symbolic link itself. RETURN VALUES
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error. ERRORS
Link() will fail and no link will be created if: [EACCES] A component of either path prefix denies search permission. [EACCES] The requested link requires writing in a directory with a mode that denies write permission. [EACCES] The current process cannot access the existing file. [EDQUOT] The directory in which the entry for the new link is being placed cannot be extended because the user's quota of disk blocks on the file system containing the directory has been exhausted. [EEXIST] The link named by path2 already exists. [EFAULT] One of the pathnames specified is outside the process's allocated address space. [EIO] An I/O error occurs while reading from or writing to the file system to make the directory entry. [ELOOP] Too many symbolic links are encountered in translating one of the pathnames. This is taken to be indicative of a looping symbolic link. [EMLINK] The file already has {LINK_MAX} links. [ENAMETOOLONG] A component of a pathname exceeds {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters. [ENOENT] A component of either path prefix does not exist, or is a dangling symbolic link. [ENOENT] The file named by path1 does not exist, or is a dangling symbolic link. [ENOSPC] The directory in which the entry for the new link is being placed cannot be extended because there is no space left on the file system containing the directory. [ENOTDIR] A component of either path prefix is not a directory. [EPERM] The file named by path1 is a directory. [EROFS] The requested link requires writing in a directory on a read-only file system. [EXDEV] The link named by path2 and the file named by path1 are on different file systems. SEE ALSO
symlink(2), unlink(2) STANDARDS
The link() function is expected to conform to IEEE Std 1003.1-1988 (``POSIX.1''). 4th Berkeley Distribution October 29, 2008 4th Berkeley Distribution

Check Out this Related Man Page

symlink(2)							System Calls Manual							symlink(2)

NAME
symlink - make symbolic link to a file SYNOPSIS
DESCRIPTION
The function creates a symbolic link. Its name is the pathname pointed to by path2, which must be a pathname that does not name an existing file or symbolic link. The contents of the symbolic link are the string pointed to by path1. RETURN VALUE
Upon successful completion, returns 0. Otherwise, it returns -1 and sets to indicate the error. ERRORS
If fails, is set to one of the following values: [EACCES] Write permission is denied in the directory where the symbolic link is being created, or search permission is denied for a component of the path prefix of path2. [EEXIST] The path2 argument names an existing file or symbolic link. [EFAULT] path1 or path2 points outside the process's allocated address space. The reliable detection of this error is implementation-dependent. [EIO] An I/O error occurred while reading from path1, making the directory entry for path2, allocating the inode for path2, or writing out the link contents of path2. [ELOOP] Too many symbolic links were encountered in resolving path2. [ENAMETOOLONG] The length of the path2 argument exceeds or pathname resolution of a symbolic link produced an intermediate result that exceeds or a pathname component is longer than [ENOENT] A component of path2 does not name an existing file or path2 is an empty string. [ENOSPC] The directory in which the entry for the new symbolic link is being placed cannot be extended because no space is left on the file system containing the directory, or the new symbolic link cannot be created because no space is left on the file system which will contain the link, or the file system is out of file- allocation resources. [ENOTDIR] A component of the path prefix of path2 is not a directory. [EROFS] The new symbolic link would reside on a read-only file system. APPLICATION USAGE
Like a hard link, a symbolic link allows a file to have multiple logical names. The presence of a hard link guarantees the existence of a file, even after the original name has been removed. A symbolic link provides no such assurance; in fact, the file named by the path1 argu- ment need not exist when the link is created. A symbolic link can cross file system boundaries. Normal permission checks are made on each component of the symbolic link pathname during its resolution. AUTHOR
was developed by the University of California, Berkeley. SEE ALSO
cp(1), chown(2), link(2), lstat(2), open(2), readlink(2), unlink(2), symlink(4), <unistd.h>. STANDARDS CONFORMANCE
CHANGE HISTORY
First released in Issue 4, Version 2. symlink(2)

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