SYMLINK(2) System Calls Manual SYMLINK(2)

symlink, symlinkat — make symbolic link to a file

Standard C Library (libc, -lc)

#include <unistd.h>

int
symlink(const char *name1, const char *name2);

int
symlinkat(const char *name1, int fd, const char *name2);

A symbolic link name2 is created to name1 (name2 is the name of the file created, name1 is the string used in creating the symbolic link). Either name may be an arbitrary path name; the files need neither to be on the same file system nor to exist.

() works the same way as () except if path2 is relative. In that case, it is looked up from a directory whose file descriptor was passed as fd. Search permission is required on this directory. fd can be set to AT_FDCWD in order to specify the current directory.

The symlink() and symlinkat() functions return the value 0 if successful; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

symlink() and symlinkat() will fail and no link will be created if:

[]
A component of the name2 path prefix denies search permission.
[]
The directory in which the entry for the new symbolic 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. Or, the new symbolic link cannot be created because the user's quota of disk blocks on the file system that will contain the symbolic link has been exhausted. Or, the user's quota of inodes on the file system on which the symbolic link is being created has been exhausted.
[]
name2 already exists.
[]
name1 or name2 points outside the process's allocated address space.
[]
An I/O error occurred while making the directory entry for name2, or allocating the inode for name2, or writing out the link contents of name2. Or, an I/O error occurred while making the directory entry or allocating the inode.
[]
Too many symbolic links were encountered in translating the pathname.
[]
A component of a pathname exceeded {NAME_MAX} characters, or an entire path name exceeded {PATH_MAX} characters.
[]
A component of the name2 path does not exist.
[]
The directory in which the entry for the new symbolic link is being placed cannot be extended because there is no space left on the file system containing the directory. Or, the new symbolic link cannot be created because there there is no space left on the file system that will contain the symbolic link. Or, there are no free inodes on the file system on which the symbolic link is being created.
[]
A component of the name2 prefix is not a directory.
[]
The file name2 would reside on a read-only file system.

In addition, symlinkat() will fail if:

[]
name2 does not specify an absolute path and fd is neither AT_FDCWD nor a valid file descriptor open for reading or searching.
[]
name2 is not an absolute path and fd is a file descriptor associated with a non-directory file.

ln(1), link(2), readlink(2), unlink(2), symlink(7)

The symlink() function conforms to IEEE Std 1003.1-1990 (“POSIX.1”). symlinkat() conforms to IEEE Std 1003.1-2008 (“POSIX.1”).

The symlink() function call appeared in 4.2BSD.

July 29, 2013 NetBSD 11.0