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

     unlink -- remove directory entry

     #include <unistd.h>

     unlink(const char *path);

     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.

     Upon successful completion, a value of 0 is returned.  Otherwise, a value of -1 is returned and errno
     is set to indicate the error.

     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

     [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.

     close(2), link(2), rmdir(2), symlink(7)

     An unlink() function call appeared in Version 6 AT&T UNIX.

4th Berkeley Distribution        June 4, 1993        4th Berkeley Distribution

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