virsh: fix incorrect argument errors for long options

For long options, print:
* the option as specified by the user if it's unknown
* the canonical 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

Unsupported long option:

$ virsh --pm
Before:
error: unsupported option '-
After:
error: unsupported option '--pm'. See --help.

Missing parameter:

$ virsh --deb
Before:
error: option '-d' requires an argument
After:
error: option '-d'/'--debug' requires an argument

$ virsh -rd
Before:
error: option '-d' requires an argument
After:
error: option '-d'/'--debug' requires an argument

Non-numeric parameter:

$ virsh --deb duck
Before:
error: option -d takes a numeric argument
After:
error: option --debug takes a numeric argument

diff --git a/tools/virsh.c b/tools/virsh.c
index 6ec2f7b8072292cd1d31be10ab56a9a1ddbada97..ac86608a1a99798e01efb3e81322b71cda39684b 100644 (file)
--- 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) {