11/3/71 SYS UNLINK (II)
NAME unlink -- remove directory entry
SYNOPSIS sys unlink; name / unlink = 10.
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 de-
struction is delayed until it is closed, even
though the directory entry has disappeared.
FILES --
SEE ALSO link
DIAGNOSTICS The error bit (c-bit) is set to indicate that the
file does not exist or that its directory cannot
be written. Write permission is not required on
the file itself. It is also illegal to unlink a
directory (except for the super-user).
BUGS Probably write permission should be required to
remove the last link to a file, but this gets in
other problems (namely, one can donate an un-
deletable file to someone else).
If the system crashes while a file is waiting to
be deleted because it is open, the space is lost.
OWNER ken, dmr