[libvirt] [PATCH v2] virsh: fix incorrect argument errors for long options

[Ján Tomko]

For long options, print:
* the option as specified by the user if it's unknown
* the cannoncial long option if its argument is  not
  a number (and should be)

And for missing arguments, print both the short and
the long option name.
(Doing only one of those would require either parsing
argv ourselves or let getopt print the errors, since
we can't tell long and short options apart by optopt
or longindex)

https://bugzilla.redhat.com/show_bug.cgi?id=949373
---
v1: https://www.redhat.com/archives/libvir-list/2013-April/msg01653.html

 tools/virsh.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/tools/virsh.c b/tools/virsh.c
index 6ec2f7b..ac86608 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -2978,7 +2978,8 @@ vshAllowedEscapeChar(char c)
 static bool
 vshParseArgv(vshControl *ctl, int argc, char **argv)
 {
-    int arg, len, debug;
+    int arg, len, debug, i;
+    int longindex = -1;
     struct option opt[] = {
         {"debug", required_argument, NULL, 'd'},
         {"help", no_argument, NULL, 'h'},
@@ -2995,11 +2996,12 @@ vshParseArgv(vshControl *ctl, int argc, char **argv)
     /* Standard (non-command) options. The leading + ensures that no
      * argument reordering takes place, so that command options are
      * not confused with top-level virsh options. */
-    while ((arg = getopt_long(argc, argv, "+:d:hqtc:vVrl:e:", opt, NULL)) != -1) {
+    while ((arg = getopt_long(argc, argv, "+:d:hqtc:vVrl:e:", opt, &longindex)) != -1) {
         switch (arg) {
         case 'd':
             if (virStrToLong_i(optarg, NULL, 10, &debug) < 0) {
-                vshError(ctl, "%s", _("option -d takes a numeric argument"));
+                vshError(ctl, _("option %s takes a numeric argument"),
+                         longindex == -1 ? "-d" : "--debug");
                 exit(EXIT_FAILURE);
             }
             if (debug < VSH_ERR_DEBUG || debug > VSH_ERR_ERROR)
@@ -3050,15 +3052,24 @@ vshParseArgv(vshControl *ctl, int argc, char **argv)
             }
             break;
         case ':':
-            vshError(ctl, _("option '-%c' requires an argument"), optopt);
-            exit(EXIT_FAILURE);
+            for (i = 0; opt[i].name != NULL; i++) {
+                if (opt[i].val == optopt) {
+                    vshError(ctl, _("option '-%c'/'--%s' requires an argument"),
+                             optopt, opt[i].name);
+                    exit(EXIT_FAILURE);
+                }
+            }
         case '?':
-            vshError(ctl, _("unsupported option '-%c'. See --help."), optopt);
+            if (optopt)
+                vshError(ctl, _("unsupported option '-%c'. See --help."), optopt);
+            else
+                vshError(ctl, _("unsupported option '%s'. See --help."), argv[optind - 1]);
             exit(EXIT_FAILURE);
         default:
             vshError(ctl, _("unknown option"));
             exit(EXIT_FAILURE);
         }
+        longindex = -1;
     }
 
     if (argc > optind) {
-- 
1.8.1.5