filter: added --enable-only & --disabled-only

- Added new arguments to the 'filter' command allowing including or excluding
  stanzas based on the boolean value of the 'disabled' attribute

docs/source/changelog.rst

@@ -21,9 +21,16 @@ Ksconf 0.9
    This new option can be used to control the level of detail in the output.
 
 
+Ksconf v0.9.2 (2022-03-04)
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+-  The ``filter`` command can now include/exclude stanzas based on the boolean value of ``disabled`` using the new ``--enabled-only`` or ``--disabled-only`` arguments.
+   The default behavior remains the same, that is, the ``disabled`` attribute is compleelty ignored.
+   Thanks to John B Splunker for inspiring this feature!
+
+
 Ksconf v0.9.1 (2022-03-03)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
--  Ksconf now tries harder to preserve file modification times.  This is supported in ``merge``, ``combine``` and ``pacakge`` commands.
+-  Ksconf now tries harder to preserve file modification times.  This is supported in ``merge``, ``combine``` and ``package`` commands.
    Specifically, merged ``.conf`` files and concatenated files will keep the most recent modification time in the destination.
    This should make the output of ``combine`` and ``package`` (by extention) more deterministic in many scenarios.
 

docs/source/dyn/cli.rst

@@ -313,7 +313,7 @@ ksconf filter
                          [--match {regex,wildcard,string}] [--ignore-case]
                          [--invert-match] [--files-with-matches]
                          [--count | --brief] [--stanza PATTERN]
-                         [--attr-present ATTR] [--keep-attrs WC-ATTR]
+                         [--attr-present ATTR] [-e | -d] [--keep-attrs WC-ATTR]
                          [--reject-attrs WC-ATTR]
                          CONF [CONF ...]
     
@@ -364,6 +364,11 @@ ksconf filter
       --attr-present ATTR   Match any stanza that includes the ATTR attribute.
                             ATTR supports bulk attribute patterns via the
                             'file://' prefix.
+      -e, --enabled-only    Keep only enabled stanzas. Any stanza containing
+                            'disabled = 1' will be removed. The value of
+                            'disabled' is assumed to be false by default.
+      -d, --disabled-only   Keep disabled stanzas only. The value of the
+                            `disabled` attribute is interpreted as a boolean.
     
     Attribute selection:
       Include or exclude attributes passed through. By default, all attributes

ksconf/commands/filter.py

@@ -21,12 +21,17 @@
 import sys
 
 from ksconf.commands import ConfFileType, KsconfCmd, dedent
-from ksconf.conf.parser import PARSECONF_MID_NC, write_conf_stream
+from ksconf.conf.parser import PARSECONF_MID_NC, conf_attr_boolean, write_conf_stream
 from ksconf.consts import EXIT_CODE_SUCCESS
 from ksconf.filter import FilteredList, FilteredListWildcard, create_filtered_list
 from ksconf.util.completers import conf_files_completer
 
 
+def is_disabled(attributes):
+    # type: (dict) -> bool
+    return conf_attr_boolean(attributes.get("disabled", False))
+
+
 class FilterCmd(KsconfCmd):
     help = "A stanza-aware GREP tool for conf files"
     description = dedent("""
@@ -121,6 +126,18 @@ def register_args(self, parser):
             PATTERN supports the special ``file://`` syntax.""")
         '''
 
+        pg_eod = pg_sel.add_mutually_exclusive_group()
+        pg_eod.add_argument("-e", "--enabled-only", action="store_true",
+                            help=dedent("""
+            Keep only enabled stanzas.  Any stanza containing ``disabled = 1`` will be removed.
+            The value of ``disabled`` is assumed to be false by default.
+            """))
+
+        pg_eod.add_argument("-d", "--disabled-only", action="store_true",
+                            help=dedent("""
+            Keep disabled stanzas only.
+            The value of the `disabled` attribute is interpreted as a boolean. """))
+
         pg_con = parser.add_argument_group("Attribute selection", dedent("""\
             Include or exclude attributes passed through.
             By default, all attributes are preserved.
@@ -149,6 +166,13 @@ def prep_filters(self, args):
         self.attr_presence_filters = create_filtered_list(args.match, flags)
         self.attr_presence_filters.feedall(args.attr_present)
 
+        if args.enabled_only:
+            self.disabled_filter = lambda attrs: not is_disabled(attrs)
+        elif args.disabled_only:
+            self.disabled_filter = is_disabled
+        else:
+            self.disabled_filter = lambda attrs: True
+
         if args.keep_attrs or args.reject_attrs:
             self.attrs_keep_filter = FilteredListWildcard(flags)
             for attrs in args.keep_attrs:
@@ -162,6 +186,10 @@ def prep_filters(self, args):
 
     def _test_stanza(self, stanza, attributes):
         if self.stanza_filters.match_stanza(stanza):
+            # Exclude based on value of 'disabled' attribute
+            if not self.disabled_filter(attributes):
+                return False
+
             # If there are no attribute level filters, automatically keep (preserves empty stanzas)
             if not self.attr_presence_filters.has_rules:
                 return True