[common] fix getopt license to be compatible

vendor/getopt/README.txt

@@ -1 +1 @@
-This source comes from: https://gist.github.com/superwills/5815344
+This source comes from: https://github.com/Stichting-MINIX-Research-Foundation/minix

vendor/getopt/getopt.c

@@ -1,4 +1,4 @@
-#include "getopt.h"
+/*	$NetBSD: getopt.c,v 1.29 2014/06/05 22:00:22 christos Exp $	*/
 
 /*
 * Copyright (c) 1987, 1993, 1994
@@ -12,11 +12,7 @@
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
-* 3. All advertising materials mentioning features or use of this software
-*    must display the following acknowledgement:
-*      This product includes software developed by the University of
-*      California, Berkeley and its contributors.
-* 4. Neither the name of the University nor the names of its contributors
+* 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
@@ -33,8 +29,9 @@
 * SUCH DAMAGE.
 */
 
-#include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 int	opterr = 1,		/* if error message should be printed */
 optind = 1,		/* index into parent argv vector */
@@ -50,57 +47,83 @@ char    *optarg;                /* argument associated with option */
                   * getopt --
                   *	Parse argc/argv argument vector.
                   */
-int getopt(int nargc, char * const nargv[], const char *ostr)
+int
+getopt(int nargc, char * const nargv[], const char *ostr)
 {
   static char *place = EMSG;	/* option letter processing */
-  const char *oli;                              /* option letter list index */
+  char *oli;				/* option letter list index */
 
-  if (optreset || !*place) {              /* update scanning pointer */
+  if (optreset || *place == 0) {		/* update scanning pointer */
     optreset = 0;
-    if (optind >= nargc || *(place = nargv[optind]) != '-') {
+    place = nargv[optind];
+    if (optind >= nargc || *place++ != '-') {
+      /* Argument is absent or is not an option */
       place = EMSG;
       return (-1);
     }
-    if (place[1] && *++place == '-') {      /* found "--" */
+    optopt = *place++;
+    if (optopt == '-' && *place == 0) {
+      /* "--" => end of options */
       ++optind;
       place = EMSG;
       return (-1);
     }
-  }                                       /* option letter okay? */
-  if ((optopt = (int)*place++) == (int)':' ||
-    !(oli = strchr(ostr, optopt))) {
-    /*
-    * if the user didn't specify '-' as an option,
-    * assume it means -1.
-    */
-    if (optopt == (int)'-')
-      return (-1);
-    if (!*place)
+    if (optopt == 0) {
+      /* Solitary '-', treat as a '-' option
+      if the program (eg su) is looking for it. */
+      place = EMSG;
+      if (strchr(ostr, '-') == NULL)
+        return -1;
+      optopt = '-';
+    }
+  }
+  else
+    optopt = *place++;
+
+  /* See if option letter is one the caller wanted... */
+  if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
+    if (*place == 0)
       ++optind;
     if (opterr && *ostr != ':')
-      (void)printf("illegal option -- %c\n", optopt);
+      (void)fprintf(stderr,
+        "unknown option -- %c\n",
+        optopt);
     return (BADCH);
   }
-  if (*++oli != ':') {                    /* don't need argument */
+
+  /* Does this option need an argument? */
+  if (oli[1] != ':') {
+    /* don't need argument */
     optarg = NULL;
-    if (!*place)
+    if (*place == 0)
       ++optind;
   }
-  else {                                  /* need an argument */
-    if (*place)                     /* no white space */
+  else {
+    /* Option-argument is either the rest of this argument or the
+    entire next argument. */
+    if (*place)
       optarg = place;
-    else if (nargc <= ++optind) {   /* no arg */
+    else if (oli[2] == ':')
+      /*
+      * GNU Extension, for optional arguments if the rest of
+      * the argument is empty, we return NULL
+      */
+      optarg = NULL;
+    else if (nargc > ++optind)
+      optarg = nargv[optind];
+    else {
+      /* option-argument absent */
       place = EMSG;
       if (*ostr == ':')
         return (BADARG);
       if (opterr)
-        (void)printf("option requires an argument -- %c\n", optopt);
+        (void)fprintf(stderr,
+          "option requires an argument -- %c\n",
+          optopt);
       return (BADCH);
     }
-    else                            /* white space */
-      optarg = nargv[optind];
     place = EMSG;
     ++optind;
   }
-  return (optopt);                        /* dump back option letter */
+  return (optopt);			/* return option letter */
 }