Add a new output mode to stdout #1168

NEWS

@@ -20,6 +20,7 @@ Enhancements and new features:
     * Take advantage of the PSUtil issue #1025 (Add process_iter(attrs, ad_value)) #1105
     * Nice Process Priority Configuration #1218
     * Display debug message if dep lib is not found #1224
+    * Add a new output mode to stdout #1168
 
 Bugs corrected:
 
@@ -56,6 +57,8 @@ News command line options:
                      Disable a list of comma separated plugins
     --export exporter1,exporter2
                      Export stats to a comma separated exporters
+    --stdout plugin1,plugin2.attribute
+                     Display stats to stdout
 
 News configuration keys in the glances.conf file:
 

docs/cmds.rst

@@ -30,6 +30,10 @@ Command-Line Options
 
     disable PLUGIN (comma separed list)
 
+.. option:: --stdout PLUGINS_STATS
+
+    display stats to stdout (comma separated list of plugins/plugins.attribute)
+
 .. option:: --export EXPORT
 
     enable EXPORT module (comma separed list)

docs/man/glances.1

 .\" Man page generated from reStructuredText.
 .
-.TH "GLANCES" "1" "Jan 18, 2018" "3.0_DEV" "Glances"
+.TH "GLANCES" "1" "Feb 11, 2018" "3.0.dev0" "Glances"
 .SH NAME
 glances \- An eye on your system
 .
@@ -78,6 +78,11 @@ disable PLUGIN (comma separed list)
 .UNINDENT
 .INDENT 0.0
 .TP
+.B \-\-stdout PLUGINS_STATS
+display stats to stdout (comma separated list of plugins/plugins.attribute)
+.UNINDENT
+.INDENT 0.0
+.TP
 .B \-\-export EXPORT
 enable EXPORT module (comma separed list)
 .UNINDENT

docs/quickstart.rst

@@ -24,6 +24,19 @@ Glances should start (press 'q' or 'ESC' to exit):
 
 .. image:: _static/screenshot-wide.png
 
+It is also possible to display stats directly to stdout using:
+
+.. code-block:: console
+
+    $ glances --stdout cpu.user,mem.used,load
+    cpu.user: 30.7
+    mem.used: 3278204928
+    load: {'cpucore': 4, 'min1': 0.21, 'min5': 0.4, 'min15': 0.27}
+    cpu.user: 3.4
+    mem.used: 3275251712
+    load: {'cpucore': 4, 'min1': 0.19, 'min5': 0.39, 'min15': 0.27}
+    ...
+
 Client/Server Mode
 ------------------
 

glances/main.py

@@ -91,6 +91,9 @@ Examples of use:
   Start the client browser (browser mode):
     $ glances --browser
 
+  Display stats to stdout:
+    $ glances --stdout cpu.user,mem.used,load
+
   Disable some plugins (any modes):
     $ glances --disable-plugin network,ports
 """
@@ -210,6 +213,8 @@ Examples of use:
                             dest='process_filter', help='set the process filter pattern (regular expression)')
         parser.add_argument('--process-short-name', action='store_true', default=False,
                             dest='process_short_name', help='force short name for processes name')
+        parser.add_argument('--stdout', default=None,
+                            dest='stdout', help='display stats to stdout (comma separated list of plugins / plugins.attribute)')
         if not WINDOWS:
             parser.add_argument('--hide-kernel-threads', action='store_true', default=False,
                                 dest='no_kernel_threads', help='hide kernel threads in process list (not available on Windows)')

glances/outputs/glances_stdout.py

+# -*- coding: utf-8 -*-
+#
+# This file is part of Glances.
+#
+# Copyright (C) 2018 Nicolargo <nicolas@nicolargo.com>
+#
+# Glances is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Glances is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+"""Stdout interface class."""
+
+import time
+
+from glances.logger import logger
+
+
+class GlancesStdout(object):
+
+    """
+    This class manages the Stdout display.
+    """
+
+    def __init__(self, config=None, args=None):
+        # Init
+        self.config = config
+        self.args = args
+
+        # Build the list of plugin and/or plugin.attribute to display
+        self.plugins_list = self.build_list()
+
+    def build_list(self):
+        """Return a list of tuples taken from self.args.stdout
+        [(plugin, attribute), ... ]"""
+        ret = []
+        for p in self.args.stdout.split(','):
+            if '.' in p:
+                p, a = p.split('.')
+            else:
+                a = None
+            ret.append((p, a))
+        return ret
+
+    def end(self):
+        pass
+
+    def update(self,
+               stats,
+               duration=3):
+        """Display stats to stdout.
+        Refresh every duration second.
+        """
+        for plugin, attribute in self.plugins_list:
+            # Check if the plugin exist and is enable
+            if plugin in stats.getPluginsList() and \
+               stats.get_plugin(plugin).is_enable():
+                stat = stats.get_plugin(plugin).get_export()
+            else:
+                continue
+            # Display stats
+            if attribute is not None:
+                # With attribute
+                try:
+                    print("{}.{}: {}".format(plugin, attribute,
+                                             stat[attribute]))
+                except KeyError as err:
+                    logger.error("Can not display stat {}.{} ({})".format(plugin, attribute, err))
+            else:
+                # Without attribute
+                print("{}: {}".format(plugin, stat))
+
+        # Wait until next refresh
+        time.sleep(duration)

glances/standalone.py

@@ -26,6 +26,7 @@ from glances.logger import logger
 from glances.processes import glances_processes
 from glances.stats import GlancesStats
 from glances.outputs.glances_curses import GlancesCursesStandalone
+from glances.outputs.glances_stdout import GlancesStdout
 from glances.outdated import Outdated
 from glances.timer import Counter
 
@@ -68,9 +69,13 @@ class GlancesStandalone(object):
         self.stats.update()
 
         if self.quiet:
-            logger.info("Quiet mode is ON: Nothing will be displayed")
+            logger.info("Quiet mode is ON, nothing will be displayed")
             # In quiet mode, nothing is displayed
             glances_processes.max_processes = 0
+        elif args.stdout:
+            logger.info("Stdout mode is ON, following stats will be displayed: {}".format(args.stdout))
+            # Init screen
+            self.screen = GlancesStdout(config=config, args=args)
         else:
             # Default number of processes to displayed is set to 50
             glances_processes.max_processes = 50