use EARGF; add usage

Reference: /n/atom/patch/applied/ptx1argc
Date: Tue Mar 11 20:00:26 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/lib/man/permind/ptx1.c	Tue Mar 11 20:00:14 2014
+++ /sys/lib/man/permind/ptx1.c	Tue Mar 11 20:00:14 2014
@@ -112,6 +112,13 @@
 char *cmds;
 
 void
+usage(void)
+{
+	fprint(2, "ptx1 [-rf] [-w width] [-g gitwid] [-h hol] [-c cmd] [-i ignore] [-b brkfile] file\n");
+	exits("usage");
+}
+
+void
 main(int argc, char **argv)
 {
 	int c;
@@ -133,44 +140,44 @@
 	case 'w':
 		if(lenarg)
 			extra(ARGC());
-		lenarg = ARGF();
+		lenarg = EARGF(usage());
 		break;
 	case 'c':
 		if(cmds)
 			extra(ARGC());
-		cmds = ARGF();
+		cmds = EARGF(usage());
 	case 't':
 		roff = troff;
 		break;
 	case 'g':
 		if(gutarg)
 			extra(ARGC());
-		gutarg =  ARGF();
+		gutarg =  EARGF(usage());
 		break;
 	case 'h':
 		if(holarg)
 			extra(ARGC());
-		holarg =  ARGF();
+		holarg =  EARGF(usage());
 		break;
 
 	case 'i':
 		if(only|ignore)
 			extra(ARGC());
 		ignore++;
-		xfile = ARGF();
+		xfile = EARGF(usage());
 		break;
 
 	case 'o':
 		if(only|ignore)
 			extra(ARGC());
 		only++;
-		xfile = ARGF();
+		xfile = EARGF(usage());
 		break;
 
 	case 'b':
 		if(bfile)
 			extra(ARGC());
-		bfile = ARGF();
+		bfile = EARGF(usage());
 		break;
 
 	default: