Add support for pretty-printing response in qmp-shell

From: "Daniel P. Berrange" <berrange@redhat.com>

Add a '-p' arg to the QMP/qmp-shell test program, which uses
the python pprint module to pretty-print the dictionary
returned from a command

  $ qmp-shell -p /tmp/qemu
  Welcome to the QMP low-level shell!
  Connected to QEMU 1.1.50

  (QEMU) query-cpus
  {   u'return': [   {   u'CPU': 0,
                         u'current': True,
                         u'halted': True,
                         u'pc': 1048556,
                         u'thread_id': 7108}]}

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 QMP/qmp-shell | 46 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 13 deletions(-)

On 15 August 2012 11:33, Daniel P. Berrange <berrange@redhat.com> wrote:
>  class QMPShell(qmp.QEMUMonitorProtocol):
> -    def __init__(self, address):
> +    def __init__(self, address, pp=None):
>          qmp.QEMUMonitorProtocol.__init__(self, self.__get_address(address))
>          self._greeting = None
>          self._completer = None
> +        self._pp = pp
>
>      def __get_address(self, arg):
>          """
> @@ -114,7 +116,11 @@ class QMPShell(qmp.QEMUMonitorProtocol):
>          if resp is None:
>              print 'Disconnected'
>              return False
> -        print resp
> +
> +        if self._pp is not None:
> +            self._pp.pprint(resp)
> +        else:
> +            print resp

If not pretty printing, you could initialise self._pp to a dummy object
with a pprint method that just does "print", which would let you avoid
the conditional here and just always do "self._pp.pprint(resp)".

Dunno whether that's worth the effort -- probably depends whether
there are likely to be other places in the code in future that want
to pretty-print an object.

-- PMM

On Wed, 15 Aug 2012 11:33:47 +0100
"Daniel P. Berrange" <berrange@redhat.com> wrote:

> From: "Daniel P. Berrange" <berrange@redhat.com>
> 
> Add a '-p' arg to the QMP/qmp-shell test program, which uses
> the python pprint module to pretty-print the dictionary
> returned from a command
> 
>   $ qmp-shell -p /tmp/qemu
>   Welcome to the QMP low-level shell!
>   Connected to QEMU 1.1.50
> 
>   (QEMU) query-cpus
>   {   u'return': [   {   u'CPU': 0,
>                          u'current': True,
>                          u'halted': True,
>                          u'pc': 1048556,
>                          u'thread_id': 7108}]}
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

Applied to the qmp branch, thanks.

> ---
>  QMP/qmp-shell | 46 +++++++++++++++++++++++++++++++++-------------
>  1 file changed, 33 insertions(+), 13 deletions(-)
> 
> diff --git a/QMP/qmp-shell b/QMP/qmp-shell
> index 42dabc8..24b665c 100755
> --- a/QMP/qmp-shell
> +++ b/QMP/qmp-shell
> @@ -33,6 +33,7 @@
>  import qmp
>  import readline
>  import sys
> +import pprint
>  
>  class QMPCompleter(list):
>      def complete(self, text, state):
> @@ -52,10 +53,11 @@ class QMPShellBadPort(QMPShellError):
>  # TODO: QMPShell's interface is a bit ugly (eg. _fill_completion() and
>  #       _execute_cmd()). Let's design a better one.
>  class QMPShell(qmp.QEMUMonitorProtocol):
> -    def __init__(self, address):
> +    def __init__(self, address, pp=None):
>          qmp.QEMUMonitorProtocol.__init__(self, self.__get_address(address))
>          self._greeting = None
>          self._completer = None
> +        self._pp = pp
>  
>      def __get_address(self, arg):
>          """
> @@ -114,7 +116,11 @@ class QMPShell(qmp.QEMUMonitorProtocol):
>          if resp is None:
>              print 'Disconnected'
>              return False
> -        print resp
> +
> +        if self._pp is not None:
> +            self._pp.pprint(resp)
> +        else:
> +            print resp
>          return True
>  
>      def connect(self):
> @@ -222,22 +228,36 @@ def die(msg):
>  def fail_cmdline(option=None):
>      if option:
>          sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
> -    sys.stderr.write('qemu-shell [ -H ] < UNIX socket path> | < TCP address:port >\n')
> +    sys.stderr.write('qemu-shell [ -p ] [ -H ] < UNIX socket path> | < TCP address:port >\n')
>      sys.exit(1)
>  
>  def main():
>      addr = ''
> +    qemu = None
> +    hmp = False
> +    pp = None
> +
>      try:
> -        if len(sys.argv) == 2:
> -            qemu = QMPShell(sys.argv[1])
> -            addr = sys.argv[1]
> -        elif len(sys.argv) == 3:
> -            if sys.argv[1] != '-H':
> -                fail_cmdline(sys.argv[1])
> -            qemu = HMPShell(sys.argv[2])
> -            addr = sys.argv[2]
> -        else:
> -                fail_cmdline()
> +        for arg in sys.argv[1:]:
> +            if arg == "-H":
> +                if qemu is not None:
> +                    fail_cmdline(arg)
> +                hmp = True
> +            elif arg == "-p":
> +                if pp is not None:
> +                    fail_cmdline(arg)
> +                pp = pprint.PrettyPrinter(indent=4)
> +            else:
> +                if qemu is not None:
> +                    fail_cmdline(arg)
> +                if hmp:
> +                    qemu = HMPShell(arg)
> +                else:
> +                    qemu = QMPShell(arg, pp)
> +                addr = arg
> +
> +        if qemu is None:
> +            fail_cmdline()
>      except QMPShellBadPort:
>          die('bad port number in command-line')
>