[Qemu-devel] [PATCH] qmp-shell: fix pretty printing of JSON responses

[Daniel P. Berrange]

Pretty printing of JSON responses is important to be able
to understand large responses from query commands in
particular, eg

(QEMU) query-chardev
{   u'return': [   {   u'filename': u'vc',
                       u'frontend-open': False,
                       u'label': u'parallel0'},
                   {   u'filename': u'vc',
                       u'frontend-open': True,
                       u'label': u'serial0'},
                   {   u'filename': u'unix:/tmp/qemp,server',
                       u'frontend-open': True,
                       u'label': u'compat_monitor0'}]}

Unfortunately this was broken during the addition of
the verbose flag in

  commit 1ceca07e48ead0dd2e41576c81d40e6a91cafefd
  Author: John Snow <address@hidden>
  Date:   Wed Apr 29 15:14:04 2015 -0400

    scripts: qmp-shell: Add verbose flag

This is because that change turned the python data
structure into a formatted JSON string before the
pretty print was given it. So we're just pretty
printing a string, which is a no-op.

This fixes pretty printing of the command responses
and as an added benefit it will also pretty print
command arguments in verbose mode

(QEMU) object-add qom-type=secret id=sec0 props={"data":"123456"}
{   'arguments': {   'id': 'sec0',
                     'props': {   u'data': u'123456'},
                     'qom-type': 'secret'},
                     'execute': 'object-add'}
                 {   u'return': {   }}

Signed-off-by: Daniel P. Berrange <address@hidden>
---
 scripts/qmp/qmp-shell | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
index 7a402ed..15bbc5e 100755
--- a/scripts/qmp/qmp-shell
+++ b/scripts/qmp/qmp-shell
@@ -231,10 +231,10 @@ class QMPShell(qmp.QEMUMonitorProtocol):
         return qmpcmd
 
     def _print(self, qmp):
-        jsobj = json.dumps(qmp)
         if self._pp is not None:
-            self._pp.pprint(jsobj)
+            self._pp.pprint(qmp)
         else:
+            jsobj = json.dumps(qmp)
             print str(jsobj)
 
     def _execute_cmd(self, cmdline):
-- 
2.5.0