Linux and UNIX Man Pages

Test Your Knowledge in Computers #546
Difficulty: Medium
In computer science, an operator takes the values of its operands and combines them in some way to produce a new value.
True or False?
Linux & Unix Commands - Search Man Pages

unlink(2) [osx man page]

UNLINK(2)						      BSD System Calls Manual							 UNLINK(2)

NAME
unlink -- remove directory entry SYNOPSIS
#include <unistd.h> int unlink(const char *path); DESCRIPTION
The unlink() function removes the link named by path from its directory and decrements the link count of the file which was referenced by the link. If that decrement reduces the link count of the file to zero, and no process has the file open, then all resources associated with the file are reclaimed. If one or more process have the file open when the last link is removed, the link is removed, but the removal of the file is delayed until all references to it have been closed. 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
The unlink() system call will fail if: [EACCES] Search permission is denied for a component of the path prefix. [EACCES] 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. [EBUSY] The file named by the path argument cannot be unlinked because it is being used by the system or by another process. [EFAULT] Path points outside the process's allocated address space. [EIO] An I/O error occurs while deleting the directory entry or deallocating the inode. [ELOOP] Too many symbolic links are encountered in translating the pathname. This is taken to be indicative of a looping symbolic link. [ENAMETOOLONG] A component of a pathname exceeds {NAME_MAX} characters, or an entire path name exceeds {PATH_MAX} characters (possibly as a result of expanding a symlink). [ENOENT] The named file does not exist. [ENOTDIR] A component of the path prefix is not a directory. [EPERM] The named file is a directory and the effective user ID of the process is not the super-user. [EPERM] The directory containing the file is marked sticky, and neither the containing directory nor the file to be removed are owned by the effective user ID. [EROFS] The named file resides on a read-only file system. SEE ALSO
close(2), link(2), rmdir(2), symlink(7) HISTORY
An unlink() function call appeared in Version 6 AT&T UNIX. 4th Berkeley Distribution June 4, 1993 4th Berkeley Distribution

Check Out this Related Man Page

unlink(2)							System Calls Manual							 unlink(2)

Name
       unlink - remove directory entry

Syntax
       unlink(path)
       char *path;

Description
       The  system  call  removes the entry for the file path from its directory.  If this entry was the last link to the file, and no process has
       the file open, then all resources associated with the file are reclaimed.  If, however, the file  was  open  in	any  process,  the  actual
       resource reclamation is delayed until it is closed, even though the directory entry has disappeared.

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.

Diagnostics
       The system call succeeds unless:

       [ENOTDIR]      A component of the path prefix is not a directory.

       [ENOENT]       The named file does not exist or path points to an empty string and the environment defined is POSIX or SYSTEM_FIVE.

       [EACCES]       Search permission is denied for a component of the path prefix.

       [EACCES]       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.

       [EROFS]	      The named file resides on a read-only file system.

       [EFAULT]       The path points outside the process's allocated address space.

       [ELOOP]	      Too many symbolic links were encountered in translating the pathname.

       [ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an entire pathname exceeded 1023 characters.

       [EPERM]	      The named file is a directory and the effective user ID of the process is not the superuser.

       [EPERM]	      The named file is a directory and the environment is defined is POSIX.

       [EPERM]	      The  directory  containing  the  file  is marked sticky, and neither the containing directory nor the file to be removed are
		      owned by the effective user ID.

       [EIO]	      An I/O error occurred while deleting the directory entry or deallocating the inode.

       [ETIMEDOUT]    A connect request or remote file operation failed, because the connected party did not properly respond after  a	period	of
		      time that is dependent on the communications protocol.

       [ETXTBSY]      The named file is the last link to a shared text executable and the environment defined is POSIX or SYSTEM_FIVE.

Environment
       Differs from the System V definition in that ELOOP is a possible error condition.

See Also
       close(2), link(2), rmdir(2)

																	 unlink(2)

Featured Tech Videos