NAME

unlink – remove directory entry

SYNOPSIS

#include <unistd.h>

int unlink(const char *path );

DESCRIPTION

unlink() removes the directory entry named by the path name pointed to by path and decrements the link count of the file referenced by the directory entry. When all links to a file have been removed and no thread has the file open, the space occupied by the file is freed and the file ceases to exist. If one or more threads have the file open when the last link is removed, space occupied by the file is not released until all references to the file have been closed. If path is a symbolic link, the symbolic link is removed. path should not name a directory unless the process has appropriate privileges. The rmdir() function should be used to remove directories.

Upon successful completion unlink() marks for update the st_ctime and st_mtime fields of the parent directory. Also, if the file’s link count is not zero, the st_ctime field of the file is marked for update.

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

This function is a member of Unison’s IOLIB family of functions. IOLIB is implemented as a message passing and generalized interface layer. Each Unison I/O server is responsible for its own error reporting.

For an exact list of error codes returned by a particular server, refer to that server’s documentation in the Unison Programmer’s Guide for each specific platform.

Servers may implement these errors codes in response to this function.

The named file is unlinked unless one or more of the following are true:

EACCES

Search permission is denied for a component of the path prefix. Or, write permission is denied on the directory containing the link to be removed.

EBUSY

The entry to be unlinked is the mount point for a mounted file system.

EFAULT

path points to an illegal address.

EMULTIHOP

Components of path require hopping to multiple remote machines and the file system does not allow it.

ENAMETOOLONG

The length of the path argument exceeds {PATH_MAX}, or the length of a path component exceeds {NAME_MAX} while {_POSIX_NO_TRUNC} is in effect.

ENOENT

The named file does not exist or is a null pathname.

ENOTDIR

A component of the path prefix is not a directory.

EROFS

The directory entry to be unlinked is part of a read-only file system.

SEE ALSO

close(), link(), open(), rmdir()