[Libguestfs] [libnbd PATCH v4 15/25] info: Add --has alias for --can

[Eric Blake]

'nbdinfo --has structured-reply' reads a bit more naturally than
'nbdinfo --can structured-reply'.  Even though the latter mirrors the
API name, it is not hard to add another alias to make our command-line
usage easier.

Suggested-by: Richard W.M. Jones <rjones at redhat.com>
Signed-off-by: Eric Blake <eblake at redhat.com>
---

v4: new patch
---
 info/nbdinfo.pod | 29 +++++++++++++++++++----------
 info/can.c       |  2 +-
 info/info-can.sh |  6 +++---
 info/main.c      |  4 +++-
 4 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/info/nbdinfo.pod b/info/nbdinfo.pod
index 7eb3c1a0..72193c24 100644
--- a/info/nbdinfo.pod
+++ b/info/nbdinfo.pod
@@ -160,9 +160,9 @@ Test if we can connect to the NBD URI.

 Test if the NBD URI connection is using TLS.

-=item nbdinfo --can structured-reply URI
+=item nbdinfo --has structured-reply URI

-Test if server can respond with structured replies (a prerequisite
+Test if server has support for structured replies (a prerequisite
 for supporting block status commands).

 =item nbdinfo --is rotational URI
@@ -322,26 +322,23 @@ Display brief command line help and exit.

 =item B<--can read>

-=item B<--can structured-reply>
-
 =item B<--can trim>

 =item B<--can write>

 =item B<--can zero>

-Test properties of the NBD server export or the connection itself.
-The command does not print anything.  Instead it exits with success
-(S<exit code 0>) if true, or failure (S<exit code 2>) if false.
-(Other exit codes indicate an error querying the flag).
+Test properties of the NBD server export.  The command does not print
+anything.  Instead it exits with success (S<exit code 0>) if true, or
+failure (S<exit code 2>) if false.  (Other exit codes indicate an
+error querying the flag).

 For further information see the L<NBD
 protocol|https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md>
 and the following libnbd functions: L<nbd_can_cache(3)>,
 L<nbd_can_df(3)>, L<nbd_can_fast_zero(3)>, L<nbd_can_flush(3)>,
 L<nbd_can_fua(3)>, L<nbd_can_multi_conn(3)>, L<nbd_can_trim(3)>,
-L<nbd_can_zero(3)>, L<nbd_is_read_only(3)>,
-L<nbd_get_structured_replies_negotiated(3)>.
+L<nbd_can_zero(3)>, L<nbd_is_read_only(3)>.

 =item B<--color>

@@ -370,6 +367,18 @@ When using I<--list>, the default is I<--no-content> (since
 downloading from each export is expensive).  To enable content probing
 use I<--list --content>.

+=item B<--has structured-reply>
+
+Test properties of the NBD server connection.  The command does not
+print anything.  Instead it exits with success (S<exit code 0>) if
+true, or failure (S<exit code 2>) if false.  (Other exit codes
+indicate an error querying the flag).
+
+For further information see the L<NBD
+protocol|https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md>
+and the following libnbd functions:
+L<nbd_get_structured_replies_negotiated(3)>.
+
 =item B<--is read-only>

 =item B<--is rotational>
diff --git a/info/can.c b/info/can.c
index 01ab4806..8514fd5a 100644
--- a/info/can.c
+++ b/info/can.c
@@ -92,7 +92,7 @@ do_can (void)
     feature = nbd_can_zero (nbd);

   else {
-    fprintf (stderr, "%s: unknown --can or --is option: %s\n",
+    fprintf (stderr, "%s: unknown --can/--is/--has option: %s\n",
              progname, can);
     exit (EXIT_FAILURE);
   }
diff --git a/info/info-can.sh b/info/info-can.sh
index 6cc8cbf4..13ef1032 100755
--- a/info/info-can.sh
+++ b/info/info-can.sh
@@ -38,11 +38,11 @@ requires bash -c "nbdkit sh --dump-plugin | grep has_can_cache=1"
 # and oldstyle never, but that feels like depending a bit too much on
 # the implementation.

-# --can structured-reply is not a per-export setting, but rather
+# --has structured-reply is not a per-export setting, but rather
 # something set on the server as a whole.

 nbdkit -v -U - sh - \
-       --run '$VG nbdinfo --can structured-reply "nbd+unix:///?socket=$unixsocket"' <<'EOF'
+       --run '$VG nbdinfo --has structured-reply "nbd+unix:///?socket=$unixsocket"' <<'EOF'
 case "$1" in
   get_size) echo 1024 ;;
   pread) ;;
@@ -52,7 +52,7 @@ EOF

 st=0
 nbdkit -v -U - --no-sr sh - \
-       --run '$VG nbdinfo --can structured-reply "nbd+unix:///?socket=$unixsocket"' <<'EOF' || st=$?
+       --run '$VG nbdinfo --has structured-reply "nbd+unix:///?socket=$unixsocket"' <<'EOF' || st=$?
 case "$1" in
   get_size) echo 1024 ;;
   pread) ;;
diff --git a/info/main.c b/info/main.c
index c6b3fca0..dbcc5a14 100644
--- a/info/main.c
+++ b/info/main.c
@@ -119,6 +119,8 @@ main (int argc, char *argv[])
     { "no-colours",         no_argument,       NULL, NO_COLOUR_OPTION },
     { "content",            no_argument,       NULL, CONTENT_OPTION },
     { "no-content",         no_argument,       NULL, NO_CONTENT_OPTION },
+    { "has",                required_argument, NULL, CAN_OPTION },
+    { "have",               required_argument, NULL, CAN_OPTION },
     { "is",                 required_argument, NULL, CAN_OPTION },
     { "json",               no_argument,       NULL, JSON_OPTION },
     { "list",               no_argument,       NULL, 'L' },
@@ -296,7 +298,7 @@ main (int argc, char *argv[])

   if (size_only)                /* --size (!list_all) */
     do_size ();
-  else if (can)                 /* --is/--can (!list_all) */
+  else if (can)                 /* --is/--can/--has (!list_all) */
     do_can ();
   else if (map)                 /* --map (!list_all) */
     do_map ();
-- 
2.41.0