v7 man page for unlink

UNLINK(2)							System Calls Manual							 UNLINK(2)

NAME
       unlink - remove directory entry

SYNOPSIS
       unlink(name)
       char *name;

DESCRIPTION
       Name  points  to a null-terminated string.  Unlink removes the entry for the file pointed to by name from its directory.  If this entry was
       the last link to the file, the contents of the file are freed and the file is destroyed.  If, however, the file was open  in  any  process,
       the actual destruction is delayed until it is closed, even though the directory entry has disappeared.

SEE ALSO
       rm(1), link(2)

DIAGNOSTICS
       Zero  is normally returned; -1 indicates that the file does not exist, that its directory cannot be written, or that the file contains pure
       procedure text that is currently in use.  Write permission is not required on the file itself.  It is also illegal to  unlink  a  directory
       (except for the super-user).

ASSEMBLER
       (unlink = 10.)
       sys unlink; name

																	 UNLINK(2)