xref: /csrg-svn/usr.bin/pascal/libpc/NIL.c (revision 1668)
1*1668Smckusick /* Copyright (c) 1979 Regents of the University of California */
2*1668Smckusick 
3*1668Smckusick static char sccsid[] = "@(#)NIL.c 1.1 10/30/80";
4*1668Smckusick 
5*1668Smckusick #include "h00vars.h"
6*1668Smckusick #include "h01errs.h"
7*1668Smckusick 
8*1668Smckusick char *
9*1668Smckusick NIL(ptr)
10*1668Smckusick 
11*1668Smckusick 	char	*ptr;		/* pointer to struct */
12*1668Smckusick {
13*1668Smckusick 	if (ptr > _maxptr || ptr < _minptr) {
14*1668Smckusick 		ERROR(ENILPTR, 0);
15*1668Smckusick 		return;
16*1668Smckusick 	}
17*1668Smckusick 	return ptr;
18*1668Smckusick }
19