zonename-i.diff

diff --git a/usr/src/cmd/zonename/zonename.c b/usr/src/cmd/zonename/zonename.c
index 2ab2f1f520..eebadcfbc6 100644
--- a/usr/src/cmd/zonename/zonename.c
+++ b/usr/src/cmd/zonename/zonename.c
@@ -40,6 +40,7 @@
 
 /*
  * -t prints "shared" vs. "exclusive"
+ * -i prints the Zone ID number.
  */
 int
 main(int argc, char *argv[])
@@ -48,21 +49,34 @@ main(int argc, char *argv[])
        char zonename[ZONENAME_MAX];
        FILE *fp;
        int arg;
-       boolean_t stacktype = B_FALSE;
+       boolean_t stacktype = B_FALSE, printzoneid = B_FALSE;
 
        (void) setlocale(LC_ALL, "");
        (void) textdomain(TEXT_DOMAIN);
 
        opterr = 0;
-       while ((arg = getopt(argc, argv, "t")) != EOF) {
+       while ((arg = getopt(argc, argv, "it")) != EOF) {
                switch (arg) {
                case 't':
                        stacktype = B_TRUE;
                        break;
+               case 'i':
+                       printzoneid = B_TRUE;
+                       break;
                }
        }
 
+       if (printzoneid && stacktype) {
+               (void) fputs(gettext("Must select only one of -i or -t.\n"),
+                   stderr);
+               return (1);
+       }
+
        zoneid = getzoneid();
+       if (printzoneid) {
+               (void) printf("%d\n", zoneid);
+               return (0);
+       }
 
        if (stacktype) {
                ushort_t flags;