virsh: pool-list: introduce --uuid for printing pool's UUID only

This patch will introduce option --uuid.
If specified, only UUID of pools will be printed out.
Signed-off-by: NChen Hanxiao <chenhanxiao@gmail.com>

tools/virsh-pool.c

@@ -1060,6 +1060,10 @@ static const vshCmdOptDef opts_pool_list[] = {
      .type = VSH_OT_BOOL,
      .help = N_("display extended details for pools")
     },
+    {.name = "uuid",
+     .type = VSH_OT_BOOL,
+     .help = N_("list UUID of active pools only")
+    },
     {.name = NULL}
 };
 
@@ -1087,6 +1091,7 @@ cmdPoolList(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
     const char *type = NULL;
     bool details = vshCommandOptBool(cmd, "details");
     bool inactive, all;
+    bool uuid = false;
     char *outputStr = NULL;
 
     inactive = vshCommandOptBool(cmd, "inactive");
@@ -1111,9 +1116,14 @@ cmdPoolList(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
     if (vshCommandOptBool(cmd, "transient"))
         flags |= VIR_CONNECT_LIST_STORAGE_POOLS_TRANSIENT;
 
+    if (vshCommandOptBool(cmd, "uuid"))
+        uuid = true;
+
     if (vshCommandOptStringReq(ctl, cmd, "type", &type) < 0)
         return false;
 
+    VSH_EXCLUSIVE_OPTIONS("details", "uuid");
+
     if (type) {
         int poolType = -1;
         char **poolTypes = NULL;
@@ -1297,6 +1307,16 @@ cmdPoolList(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
 
     /* Output basic info then return if --details option not selected */
     if (!details) {
+        if (uuid) {
+            for (i = 0; i < list->npools; i++) {
+                char uuid_str[VIR_UUID_STRING_BUFLEN];
+                virStoragePoolGetUUIDString(list->pools[i], uuid_str);
+                vshPrint(ctl, "%-36s\n", uuid_str);
+            }
+            ret = true;
+            goto cleanup;
+        }
+
         /* Output old style header */
         vshPrintExtra(ctl, " %-20s %-10s %-10s\n", _("Name"), _("State"),
                       _("Autostart"));

tools/virsh.pod

@@ -3621,7 +3621,7 @@ of basic info are not converted to human friendly units.
 =item B<pool-list> [I<--inactive>] [I<--all>]
                    [I<--persistent>] [I<--transient>]
                    [I<--autostart>] [I<--no-autostart>]
-                   [[I<--details>] [<type>]
+                   [[I<--details>] [I<--uuid>] [<type>]
 
 List pool objects known to libvirt.  By default, only active pools
 are listed; I<--inactive> lists just the inactive pools, and I<--all>
@@ -3630,7 +3630,7 @@ lists all pools.
 In addition, there are several sets of filtering flags. I<--persistent> is to
 list the persistent pools, I<--transient> is to list the transient pools.
 I<--autostart> lists the autostarting pools, I<--no-autostart> lists the pools
-with autostarting disabled.
+with autostarting disabled. If I<--uuid> is specified only pool's UUIDs are printed.
 
 You may also want to list pools with specified types using I<type>, the
 pool types must be separated by comma, e.g. --type dir,disk. The valid pool