symlink(2)

symlink -- make a symbolic link to a file

Synopsis

   #include <unistd.h>
   
   int symlink(const char *name1, const char *name2);

Description

symlink creates a symbolic link name2 to the file name1. Either name may be an arbitrary pathname, the files need not be on the same file system, and name1 may be nonexistent.

The file to which the symbolic link points is used when an open(2) operation is performed on the link. A stat(2) on a symbolic link returns the linked-to file, while an lstat returns information about the link itself. This can lead to surprising results when a symbolic link is made to a directory. To avoid confusion in programs, the readlink(2) call can be used to read the contents of a symbolic link.

If the file named by name2 does not exist, it is created. The permission mode of name2 is 777 [see creat(2)].

For security reasons, if the sticky bit is set on the directory in which the link is being created, the directory must be owned by the calling user ID.

Return values

On success, symlink returns 0. On failure, symlink returns -1 and sets errno to identify the error.

Errors

In the following conditions, symlink fails and sets errno to:

EACCES: Search permission is denied for a component of the path prefix of name2.
EACCES: Write access is denied on the directory in which the new file is to be created.
EACCES: The level of the new file is not within the file system's level range, and the calling process does not have appropriate privilege (P_FSYSRANGE).
EDQUOT: 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.
EDQUOT: The new symbolic link cannot be created because the user's quota of disk blocks on the file system which will contain the link has been exhausted.
EDQUOT: The user's quota of inodes on the file system on which the file is being created has been exhausted.
EEXIST: The file referred to by name2 already exists.
EFAULT: name1 or name2 points outside the allocated address space for the process.
EIO: An I/O error occurs while reading from or writing to the file system.
ELOOP: Too many symbolic links are encountered in translating name2.
ENAMETOOLONG: The length of the name1 or name2 argument exceeds {PATH_MAX}, or the length of a name1 or name2 component exceeds {NAME_MAX} while (_POSIX_NO_TRUNC) is in effect.
ENOENT: A component of the path prefix of name2 does not exist.
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.
ENOSPC: The new symbolic link cannot be created because no space is left on the file system which will contain the link.
ENOSPC: There are no free inodes on the file system on which the file is being created.
ENOSYS: The file system does not support symbolic links
ENOTDIR: A component of the path prefix of name2 is not a directory.
EPERM: The sticky bit is set on the directory in which the link is being created and the directory is not owned by the calling user ID. The P_OWNER privilege is required to override this restriction.
EROFS: The file name2 would reside on a read-only file system.

References

cp(1), link(2), readlink(2), realpath(3C), unlink(2)