Remove several casts to (char *) 0 and replace them by NULL

Prompted and OK by tb@

10 files changed, 28 insertions, 28 deletions

diff --git a/games/hack/hack.apply.c b/games/hack/hack.apply.c
index 32a862b028e..c85f0310267 100644
--- a/games/hack/hack.apply.c
+++ b/games/hack/hack.apply.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.apply.c,v 1.7 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.apply.c,v 1.8 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -481,7 +481,7 @@ use_pick_axe(struct obj *obj)
 		     && !sobj_at(ENORMOUS_ROCK, rx, ry)) {
 			/* ACCESSIBLE or POOL */
 			pline("You swing your %s through thin air.",
-				aobjnam(obj, (char *) 0));
+				aobjnam(obj, NULL));
 		} else {
 			if(dig_pos.x != rx || dig_pos.y != ry
 			    || dig_level != dlevel || dig_down) {
diff --git a/games/hack/hack.eat.c b/games/hack/hack.eat.c
index beb97494ed5..79ab4217991 100644
--- a/games/hack/hack.eat.c
+++ b/games/hack/hack.eat.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.eat.c,v 1.10 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.eat.c,v 1.11 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -207,7 +207,7 @@ gotit:
 				goto no_opener;
 			}
 			pline("Using your %s you try to open the tin.",
-				aobjnam(uwep, (char *) 0));
+				aobjnam(uwep, NULL));
 		} else {
 		no_opener:
 			pline("It is not so easy to open this tin.");
diff --git a/games/hack/hack.end.c b/games/hack/hack.end.c
index 421dc2a6d19..e4d4c4c5f18 100644
--- a/games/hack/hack.end.c
+++ b/games/hack/hack.end.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.end.c,v 1.15 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.end.c,v 1.16 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -203,7 +203,7 @@ done(char *st1)
 			outrip();
 	}
 	if(*st1 == 'c') killer = st1;		/* after outrip() */
-	settty((char *) 0);	/* does a clr_screen() */
+	settty(NULL);	/* does a clr_screen() */
 	if(!done_stopprint)
 		printf("Goodbye %s %s...\n\n", pl_character, plname);
 	{ long int tmp;
diff --git a/games/hack/hack.engrave.c b/games/hack/hack.engrave.c
index f48c871ce90..e9085ca0b82 100644
--- a/games/hack/hack.engrave.c
+++ b/games/hack/hack.engrave.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.engrave.c,v 1.8 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.engrave.c,v 1.9 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -228,7 +228,7 @@ doengrave(void)
 			if(uwep && uwep->cursed) {
 			    /* Andreas Bormann */
 			    pline("Since your weapon is welded to your hand,");
-			    pline("you use the %s.", aobjnam(uwep, (char *) 0));
+			    pline("you use the %s.", aobjnam(uwep, NULL));
 			    otmp = uwep;
 			} else {
 			    if(!otmp)
diff --git a/games/hack/hack.invent.c b/games/hack/hack.invent.c
index b5a4a564ae2..c949a613a9b 100644
--- a/games/hack/hack.invent.c
+++ b/games/hack/hack.invent.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.invent.c,v 1.13 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.invent.c,v 1.14 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -469,7 +469,7 @@ getobj(char *let, char *word)
 			if(!(ilet = morc)) continue;
 			/* he typed a letter (not a space) to more() */
 		} else if(ilet == '*') {
-			doinv((char *) 0);
+			doinv(NULL);
 			if(!(ilet = morc)) continue;
 			/* ... */
 		}
@@ -667,7 +667,7 @@ xprname(struct obj *obj, char let)
 int
 ddoinv(void)
 {
-	doinv((char *) 0);
+	doinv(NULL);
 	return(0);
 }
 
@@ -688,7 +688,7 @@ doinv(char *lets)
 		return;
 	}
 
-	cornline(0, (char *) 0);
+	cornline(0, NULL);
 	ilet = 'a';
 	for(otmp = invent; otmp; otmp = otmp->nobj) {
 	    if(flags.invlet_constant) ilet = otmp->invlet;
@@ -827,10 +827,10 @@ dolook(void)
 
     if(ct == 1 && !gold) {
 	pline("You %s here %s.", verb, doname(otmp0));
-	cornline(3, (char *) 0);
+	cornline(3, NULL);
     }
     if(ct > 1)
-	cornline(2, (char *) 0);
+	cornline(2, NULL);
     return(!!Blind);
 }
 
diff --git a/games/hack/hack.ioctl.c b/games/hack/hack.ioctl.c
index 6c69a5d191c..30da45629e2 100644
--- a/games/hack/hack.ioctl.c
+++ b/games/hack/hack.ioctl.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.ioctl.c,v 1.9 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.ioctl.c,v 1.10 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -90,7 +90,7 @@ dosuspend(void)
 {
 #ifdef SIGTSTP
 	if(signal(SIGTSTP, SIG_IGN) == SIG_DFL) {
-		settty((char *) 0);
+		settty(NULL);
 		(void) signal(SIGTSTP, SIG_DFL);
 		(void) kill(0, SIGTSTP);
 		gettty();
diff --git a/games/hack/hack.main.c b/games/hack/hack.main.c
index b9d81efd9cc..c879206b4da 100644
--- a/games/hack/hack.main.c
+++ b/games/hack/hack.main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.main.c,v 1.21 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.main.c,v 1.22 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -452,7 +452,7 @@ not_recovered:
 #ifdef MAIL
 			ckmailstatus();
 #endif
-			rhack((char *) 0);
+			rhack(NULL);
 		}
 		if(multi && multi%7 == 0)
 			(void) fflush(stdout);
diff --git a/games/hack/hack.o_init.c b/games/hack/hack.o_init.c
index 3e31aa93549..cb01e1c90b4 100644
--- a/games/hack/hack.o_init.c
+++ b/games/hack/hack.o_init.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.o_init.c,v 1.7 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.o_init.c,v 1.8 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -220,9 +220,9 @@ dodiscovered(void)				/* free after Robert Viduya */
     }
     if (ct == 0) {
 	pline ("You haven't discovered anything yet...");
-	cornline(3, (char *) 0);
+	cornline(3, NULL);
     } else
-	cornline(2, (char *) 0);
+	cornline(2, NULL);
 
     return(0);
 }
diff --git a/games/hack/hack.pager.c b/games/hack/hack.pager.c
index 1a2789268a4..748599a3519 100644
--- a/games/hack/hack.pager.c
+++ b/games/hack/hack.pager.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.pager.c,v 1.22 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.pager.c,v 1.23 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -383,7 +383,7 @@ page_file(char *fnam, boolean silent)
 		if(dup(fd)) {
 			if(!silent) printf("Cannot open %s as stdin.\n", fnam);
 		} else {
-			execlp(catmore, basename(catmore), (char *) 0);
+			execlp(catmore, basename(catmore), NULL);
 			if(!silent) printf("Cannot exec %s.\n", catmore);
 		}
 		exit(1);
@@ -417,9 +417,9 @@ dosh(void)
 
 	if(child(0)) {
 		if ((str = getenv("SHELL")))
-			execlp(str, str, (char *) 0);
+			execlp(str, str, NULL);
 		else
-			execl("/bin/sh", "sh", (char *) 0);
+			execl("/bin/sh", "sh", NULL);
 		pline("sh: cannot execute.");
 		exit(1);
 	}
@@ -439,7 +439,7 @@ child(int wt)
 
 	f = fork();
 	if(f == 0){		/* child */
-		settty((char *) 0);		/* also calls end_screen() */
+		settty(NULL);		/* also calls end_screen() */
 		/* revoke privs */
 		gid = getgid();
 		setresgid(gid, gid, gid);
diff --git a/games/hack/hack.unix.c b/games/hack/hack.unix.c
index 9d4afb2750d..c53003bd1b9 100644
--- a/games/hack/hack.unix.c
+++ b/games/hack/hack.unix.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: hack.unix.c,v 1.17 2016/01/09 18:33:15 mestre Exp $	*/
+/*	$OpenBSD: hack.unix.c,v 1.18 2016/01/09 21:54:11 mestre Exp $	*/
 
 /*
  * Copyright (c) 1985, Stichting Centrum voor Wiskunde en Informatica,
@@ -471,7 +471,7 @@ readmail(void)
 	if(!(mr = getenv("MAILREADER")))
 		mr = DEF_MAILREADER;
 	if(child(1)){
-		execl(mr, mr, (char *) 0);
+		execl(mr, mr, NULL);
 		exit(1);
 	}
 #else /* DEF_MAILREADER */