On Fri, Mar 3, 2017 at 8:54 PM, John Snow <js...@redhat.com> wrote:
> Use the existing readline history function we are utilizing
> to provide persistent command history across instances of qmp-shell.
>
> This assists entering debug commands across sessions that may be
> interrupted by QEMU sessions terminating, where the qmp-shell has
> to be relaunched.
>
> Signed-off-by: John Snow <js...@redhat.com>
> ---
>
> v2: Adjusted the errors to whine about non-ENOENT errors, but still
> intercept all errors as non-fatal.
> Save history atexit() to match bash standard behavior
>
> scripts/qmp/qmp-shell | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/scripts/qmp/qmp-shell b/scripts/qmp/qmp-shell
> index 0373b24..55a8285 100755
> --- a/scripts/qmp/qmp-shell
> +++ b/scripts/qmp/qmp-shell
> @@ -70,6 +70,9 @@ import json
> import ast
> import readline
> import sys
> +import os
> +import errno
> +import atexit
>
> class QMPCompleter(list):
> def complete(self, text, state):
> @@ -109,6 +112,7 @@ class QMPShell(qmp.QEMUMonitorProtocol):
> self._pretty = pretty
> self._transmode = False
> self._actions = list()
> + self._histfile = os.path.join(os.path.expanduser('~'),
> '.qmp_history')
>
> def __get_address(self, arg):
> """
> @@ -137,6 +141,21 @@ class QMPShell(qmp.QEMUMonitorProtocol):
> # XXX: default delimiters conflict with some command names (eg.
> query-),
> # clearing everything as it doesn't seem to matter
> readline.set_completer_delims('')
> + try:
> + readline.read_history_file(self._histfile)
> + except Exception as e:
> + if isinstance(e, IOError) and e.errno == errno.ENOENT:
> + # File not found. No problem.
> + pass
> + else:
> + print "Failed to read history '%s'; %s" % (self._histfile, e)
I would handle only IOError, since any other error means a bug in this code
or in the underlying readline library, and the best way to handle this is to
let it fail loudly.
> + atexit.register(self.__save_history)
> +
> + def __save_history(self):
> + try:
> + readline.write_history_file(self._histfile)
> + except Exception as e:
> + print "Failed to save history file '%s'; %s" % (self._histfile,
> e)
>
> def __parse_value(self, val):
> try:
But I think this is good enough and useful as is.
Reviewed-by: Nir Soffer <nir...@gmail.com>
