Fix the type of the NULL arg to execl()

Idea from: Theo de Raadt <deraadt@openbsd.org>

3 files changed, 6 insertions, 4 deletions

diff --git a/bin/mv/mv.c b/bin/mv/mv.c
index fe1d10d..3c4695e 100644
--- a/bin/mv/mv.c
+++ b/bin/mv/mv.c
@@ -331,7 +331,8 @@ copy(from, to)
 	int pid, status;
 
 	if ((pid = fork()) == 0) {
-		execl(_PATH_CP, "mv", vflg ? "-PRpv" : "-PRp", from, to, NULL);
+		execl(_PATH_CP, "mv", vflg ? "-PRpv" : "-PRp", from, to,
+		    (char *)NULL);
 		warn("%s", _PATH_CP);
 		_exit(1);
 	}
@@ -349,7 +350,7 @@ copy(from, to)
 		return (1);
 	}
 	if (!(pid = vfork())) {
-		execl(_PATH_RM, "mv", "-rf", from, NULL);
+		execl(_PATH_RM, "mv", "-rf", from, (char *)NULL);
 		warn("%s", _PATH_RM);
 		_exit(1);
 	}
diff --git a/bin/pax/ar_io.c b/bin/pax/ar_io.c
index 12fe522..3651ca0 100644
--- a/bin/pax/ar_io.c
+++ b/bin/pax/ar_io.c
@@ -1345,7 +1345,8 @@ ar_start_gzip(int fd, const char *gzip_program, int wr)
 		}
 		close(fds[0]);
 		close(fds[1]);
-		if (execlp(gzip_program, gzip_program, gzip_flags, NULL) < 0)
+		if (execlp(gzip_program, gzip_program, gzip_flags,
+		    (char *)NULL) < 0)
 			err(1, "could not exec");
 		/* NOTREACHED */
 	}
diff --git a/bin/rcp/util.c b/bin/rcp/util.c
index 55c474f..8f6f123 100644
--- a/bin/rcp/util.c
+++ b/bin/rcp/util.c
@@ -123,7 +123,7 @@ susystem(s, userid)
 
 	case 0:
 		(void)setuid(userid);
-		execl(_PATH_BSHELL, "sh", "-c", s, NULL);
+		execl(_PATH_BSHELL, "sh", "-c", s, (char *)NULL);
 		_exit(127);
 	}
 	istat = signal(SIGINT, SIG_IGN);