add systemctl parser

docs/parsers/systemctl.md

@@ -0,0 +1,76 @@
+# jc.parsers.systemctl
+jc - JSON CLI output utility systemctl Parser
+
+Usage:
+    specify --systemctl as the first argument if the piped input is coming from systemctl
+
+Examples:
+
+    $ systemctl -a | jc --systemctl -p
+    [
+      {
+        "unit": "proc-sys-fs-binfmt_misc.automount",
+        "load": "loaded",
+        "active": "active",
+        "sub": "waiting",
+        "description": "Arbitrary Executable File Formats File System Automount Point"
+      },
+      {
+        "unit": "dev-block-8:2.device",
+        "load": "loaded",
+        "active": "active",
+        "sub": "plugged",
+        "description": "LVM PV 3klkIj-w1qk-DkJi-0XBJ-y3o7-i2Ac-vHqWBM on /dev/sda2 2"
+      },
+      {
+        "unit": "dev-cdrom.device",
+        "load": "loaded",
+        "active": "active",
+        "sub": "plugged",
+        "description": "VMware_Virtual_IDE_CDROM_Drive"
+      },
+      ...
+    ]
+
+## process
+```python
+process(proc_data)
+```
+
+Final processing to conform to the schema.
+
+Parameters:
+
+    proc_data:   (dictionary) raw structured data to process
+
+Returns:
+
+    dictionary   structured data with the following schema:
+
+    [
+      {
+        "unit":          string,
+        "load":          string,
+        "active":        string,
+        "sub":           string,
+        "description":   string
+      }
+    ]
+
+## parse
+```python
+parse(data, raw=False, quiet=False)
+```
+
+Main text parsing function
+
+Parameters:
+
+    data:        (string)  text data to parse
+    raw:         (boolean) output preprocessed JSON if True
+    quiet:       (boolean) suppress warning messages if True
+
+Returns:
+
+    dictionary   raw or processed structured data
+