fish: New command: 'supported'

This checks all available optional groups and prints out which
ones are supported by the daemon.  Note you must launch the appliance
first.

Example:

><fs> supported
      augeas yes
     inotify yes
 linuxfsuuid yes
linuxmodules yes
 linuxxattrs yes
        lvm2 yes
       mknod yes
      ntfs3g yes
   ntfsprogs yes
    realpath yes
       scrub yes
     selinux yes
          xz yes
    zerofree yes

fish/Makefile.am

@@ -49,6 +49,7 @@ guestfish_SOURCES = \
 	prep.c \
 	rc.c \
 	reopen.c \
+	supported.c \
 	tilde.c \
 	time.c
 

fish/fish.c

@@ -992,6 +992,8 @@ issue_command (const char *cmd, char *argv[], const char *pipecmd)
     r = do_reopen (cmd, argc, argv);
   else if (STRCASEEQ (cmd, "sparse"))
     r = do_sparse (cmd, argc, argv);
+  else if (STRCASEEQ (cmd, "supported"))
+    r = do_supported (cmd, argc, argv);
   else if (STRCASEEQ (cmd, "time"))
     r = do_time (cmd, argc, argv);
   else
@@ -1048,6 +1050,8 @@ list_builtin_commands (void)
           "reopen", _("close and reopen libguestfs handle"));
   printf ("%-20s %s\n",
           "sparse", _("allocate a sparse image file"));
+  printf ("%-20s %s\n",
+          "supported", _("list supported groups of commands"));
   printf ("%-20s %s\n",
           "time", _("measure time taken to run command"));
 
@@ -1162,6 +1166,16 @@ display_builtin_command (const char *cmd)
               "\n"
               "    Size can be specified using standard suffixes, eg. '1M'.\n"
               ));
+  else if (STRCASEEQ (cmd, "supported"))
+    printf (_("supported - list supported groups of commands\n"
+              "     supported\n"
+              "\n"
+              "    This command returns a list of the optional groups\n"
+              "    known to the daemon, and indicates which ones are\n"
+              "    supported by this build of the libguestfs appliance.\n"
+              "\n"
+              "    See also guestfs(3) section AVAILABILITY.\n"
+              ));
   else if (STRCASEEQ (cmd, "time"))
     printf (_("time - measure time taken to run command\n"
               "    time <command> [<args> ...]\n"

fish/fish.h

@@ -121,6 +121,9 @@ extern int rc_remote (int pid, const char *cmd, int argc, char *argv[],
 /* in reopen.c */
 extern int do_reopen (const char *cmd, int argc, char *argv[]);
 
+/* in supported.c */
+extern int do_supported (const char *cmd, int argc, char *argv[]);
+
 /* in time.c */
 extern int do_time (const char *cmd, int argc, char *argv[]);
 
@@ -142,6 +145,7 @@ extern char *try_tilde_expansion (char *path);
   "more", "less",			\
   "reopen",				\
   "sparse",                             \
+  "supported",                          \
   "time"
 
 static inline char *

fish/guestfish.pod

@@ -785,6 +785,16 @@ For more advanced image creation, see L<qemu-img(1)> utility.
 
 Size can be specified using standard suffixes, eg. C<1M>.
 
+=head2 supported
+
+ supported
+
+This command returns a list of the optional groups
+known to the daemon, and indicates which ones are
+supported by this build of the libguestfs appliance.
+
+See also L<guestfs(3)/AVAILABILITY>.
+
 =head2 time
 
  time command args...

fish/supported.c

@@ -0,0 +1,81 @@
+/* guestfish - the filesystem interactive shell
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "fish.h"
+
+int
+do_supported (const char *cmd, int argc, char *argv[])
+{
+  char **groups;
+
+  /* As a side-effect this also checks that we've called 'launch'. */
+  groups = guestfs_available_all_groups (g);
+  if (groups == NULL)
+    return -1;
+
+  /* Temporarily replace the error handler so that messages don't get
+   * printed to stderr while we are issuing commands.
+   */
+  guestfs_error_handler_cb old_error_cb;
+  void *old_error_cb_data;
+  old_error_cb = guestfs_get_error_handler (g, &old_error_cb_data);
+  guestfs_set_error_handler (g, NULL, NULL);
+
+  /* Work out the max string length of any group name. */
+  size_t i;
+  size_t len = 0;
+  for (i = 0; groups[i] != NULL; ++i) {
+    size_t l = strlen (groups[i]);
+    if (l > len)
+      len = l;
+  }
+
+  for (i = 0; groups[i] != NULL; ++i) {
+    size_t l = strlen (groups[i]);
+    size_t j;
+    for (j = 0; j < len-l; ++j)
+      putchar (' ');
+    printf ("%s", groups[i]);
+    putchar (' ');
+
+    char *gg[] = { groups[i], NULL };
+    int r = guestfs_available (g, gg);
+    if (r == 0)
+      printf ("%s", _("yes"));
+    else
+      printf ("%s", _("no"));
+    putchar ('\n');
+  }
+
+  /* Free groups list. */
+  for (i = 0; groups[i] != NULL; ++i)
+    free (groups[i]);
+  free (groups);
+
+  /* Restore error handler. */
+  guestfs_set_error_handler (g, old_error_cb, old_error_cb_data);
+
+  return 0;
+}

po/POTFILES.in

@@ -79,6 +79,7 @@ fish/more.c
 fish/prep.c
 fish/rc.c
 fish/reopen.c
+fish/supported.c
 fish/tilde.c
 fish/time.c
 fuse/dircache.c

src/guestfs.pod

@@ -801,6 +801,13 @@ supports the functionality.
 
 @AVAILABILITY@
 
+=head2 GUESTFISH supported COMMAND
+
+In L<guestfish(3)> there is a handy interactive command
+C<supported> which prints out the available groups and
+whether they are supported by this build of libguestfs.
+Note however that you have to do C<run> first.
+
 =head2 SINGLE CALLS AT COMPILE TIME
 
 If you need to test whether a single libguestfs function is