add /etc/gshadow parser

docs/parsers/gshadow.md

@@ -0,0 +1,109 @@
+# jc.parsers.gshadow
+jc - JSON CLI output utility /etc/gshadow file Parser
+
+Usage:
+
+    specify --gshadow as the first argument if the piped input is coming from /etc/gshadow
+
+Compatibility:
+
+    'linux', 'aix', 'freebsd'
+
+Examples:
+
+    $ cat /etc/gshadow | jc --gshadow -p
+    [
+      {
+        "group_name": "root",
+        "password": "*",
+        "administrators": [],
+        "members": []
+      },
+      {
+        "group_name": "adm",
+        "password": "*",
+        "administrators": [],
+        "members": [
+          "syslog",
+          "joeuser"
+        ]
+      },
+      ...
+    ]
+
+    $ cat /etc/gshadow | jc --gshadow -p -r
+    [
+      {
+        "group_name": "root",
+        "password": "*",
+        "administrators": [
+          ""
+        ],
+        "members": [
+          ""
+        ]
+      },
+      {
+        "group_name": "adm",
+        "password": "*",
+        "administrators": [
+          ""
+        ],
+        "members": [
+          "syslog",
+          "joeuser"
+        ]
+      },
+      ...
+    ]
+
+## info
+```python
+info(self, /, *args, **kwargs)
+```
+
+## process
+```python
+process(proc_data)
+```
+
+Final processing to conform to the schema.
+
+Parameters:
+
+    proc_data:   (dictionary) raw structured data to process
+
+Returns:
+
+    List of dictionaries. Structured data with the following schema:
+
+    [
+      {
+        "group_name":       string,
+        "password":         string,
+        "administrators": [
+                            string
+        ],
+        "members": [
+                            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:
+
+    List of dictionaries. Raw or processed structured data.
+