Sync getopt with getopt

[Anthony J. Bentley]

Hi,

This brings /usr/share/misc/getopt in sync with the example in getopt(3).

ok?

Index: getopt
===================================================================
RCS file: /cvs/src/share/misc/getopt,v
retrieving revision 1.8
diff -u -p -r1.8 getopt
--- getopt      1 Feb 2006 09:27:28 -0000       1.8
+++ getopt      4 Sep 2016 17:43:54 -0000
@@ -5,6 +5,8 @@
  *     from: @(#)getopt        5.3 (Berkeley) 3/28/94
  */
 
+#include <err.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -14,23 +16,22 @@ __dead void usage(void);
 int
 main(int argc, char *argv[])
 {
-       int bflag, ch;
-       char *file;
+       int bflag, ch, fd;
 
        bflag = 0;
-       file = NULL;
-       while ((ch = getopt(argc, argv, "bf:")) != -1)
+       while ((ch = getopt(argc, argv, "bf:")) != -1) {
                switch (ch) {
                case 'b':
                        bflag = 1;
                        break;
                case 'f':
-                       file = optarg;
+                       if ((fd = open(optarg, O_RDONLY, 0)) == -1)
+                               err(1, "%s", optarg);
                        break;
                default:
                        usage();
-                       /* NOTREACHED */
                }
+       }
        argc -= optind;
        argv += optind;