jc/jc/parsers/w.py

"""jc - JSON CLI output utility w Parser

Usage:
    specify --w as the first argument if the piped input is coming from w

Examples:

    $ w | jc --w -p
    [
      {
        "user": "root",
        "tty": "tty1",
        "from": null,
        "login_at": "07:49",
        "idle": "1:15m",
        "jcpu": "0.00s",
        "pcpu": "0.00s",
        "what": "-bash"
      },
      {
        "user": "root",
        "tty": "ttyS0",
        "from": null,
        "login_at": "06:24",
        "idle": "0.00s",
        "jcpu": "0.43s",
        "pcpu": "0.00s",
        "what": "w"
      },
      {
        "user": "root",
        "tty": "pts/0",
        "from": "192.168.71.1",
        "login_at": "06:29",
        "idle": "2:35m",
        "jcpu": "0.00s",
        "pcpu": "0.00s",
        "what": "-bash"
      }
    ]

    $ w | jc --w -p -r
    [
      {
        "user": "kbrazil",
        "tty": "tty1",
        "from": "-",
        "login_at": "07:49",
        "idle": "1:16m",
        "jcpu": "0.00s",
        "pcpu": "0.00s",
        "what": "-bash"
      },
      {
        "user": "kbrazil",
        "tty": "ttyS0",
        "from": "-",
        "login_at": "06:24",
        "idle": "2.00s",
        "jcpu": "0.46s",
        "pcpu": "0.00s",
        "what": "w"
      },
      {
        "user": "kbrazil",
        "tty": "pts/0",
        "from": "192.168.71.1",
        "login_at": "06:29",
        "idle": "2:36m",
        "jcpu": "0.00s",
        "pcpu": "0.00s",
        "what": "-bash"
      }
    ]
"""
import string
import jc.utils


def process(proc_data):
    """
    schema:
    
        [
          {
            "user":     string,     # '-'' = null
            "tty":      string,     # '-'' = null
            "from":     string,     # '-'' = null
            "login_at": string,     # '-'' = null
            "idle":     string,     # '-'' = null
            "jcpu":     string,
            "pcpu":     string,
            "what":     string      # '-'' = null
          }
        ]
    """
    for entry in proc_data:
        null_list = ['user', 'tty', 'from', 'login_at', 'idle', 'what']
        for key in null_list:
            if key in entry:
                if entry[key] == '-':
                    entry[key] = None

    return proc_data


def parse(data, raw=False, quiet=False):
    """
    Main parsing function

    Arguments:

        raw:    (boolean) output preprocessed JSON if True
        quiet:  (boolean) suppress warning messages if True
    """
    
    # compatible options: linux, darwin, cygwin, win32, aix, freebsd
    compatible = ['linux', 'darwin', 'cygwin', 'aix', 'freebsd']

    if not quiet:
        jc.utils.compatibility(__name__, compatible)

    cleandata = data.splitlines()[1:]
    header_text = cleandata[0].lower()
    # fixup for 'from' column that can be blank
    from_col = header_text.find('from')
    # clean up 'login@' header
    # even though @ in a key is valid json, it can make things difficult
    header_text = header_text.replace('login@', 'login_at')
    headers = [h for h in ' '.join(header_text.strip().split()).split() if h]

    # parse lines
    raw_output = []
    if cleandata:
        for entry in cleandata[1:]:
            output_line = {}

            # normalize data by inserting Null for missing data
            temp_line = entry.split(maxsplit=len(headers) - 1)

            # fix from column, always at column 2
            if 'from' in headers:
                if entry[from_col] in string.whitespace:
                    temp_line.insert(2, '-')

            output_line = dict(zip(headers, temp_line))
            raw_output.append(output_line)

    if raw:
        return raw_output
    else:
        return process(raw_output)