lsdisks

#! /usr/bin/env python

import logging
import os
import os.path
import sys


## auxiliary functions

try:
    from collections import defaultdict
except ImportError:
    class defaultdict(dict):
        """
        A backport of `defaultdict` to Python 2.4
        See http://docs.python.org/library/collections.html

        >>> dl = defaultdict(list)
        >>> dl['emptylist']
        []
        >>> di = defaultdict(int)
        >>> di['zero']
        0
        >>> ds = defaultdict(str)
        >>> ds['empty']
        ''

        """
        def __new__(cls, default_factory=None):
            return dict.__new__(cls)
        def __init__(self, default_factory):
            self.default_factory = default_factory
        def __missing__(self, key):
            try:
                return self.default_factory()
            except:
                raise KeyError("Key '%s' not in dictionary" % key)
        def __getitem__(self, key):
            if not dict.__contains__(self, key):
                dict.__setitem__(self, key, self.__missing__(key))
            return dict.__getitem__(self, key)


## main

from optparse import OptionParser

def main():
    parser = OptionParser(
        version="%prog 1.0",
        usage="""Usage: %prog [options]

Print a table with Linux disk device name, serial number /
manufacturer ID, UUID and PCI bus address of all attached disk
devices.
        """)
    parser.add_option("-s", "--short",
                      action="store_true",
                      dest="short",
                      default=False,
                      help="Only print disk device name and serial number.")
    (options, args) = parser.parse_args()

    # gather disk information from the `/dev/` filesystem
    disks = defaultdict(lambda: defaultdict(lambda: ''))
    widths = defaultdict(lambda: 0)
    if options.short:
        columns = ["id"]
    else:
        columns = ["id", "uuid", "label", "path"]

    for col in columns:
        devdir = ("/dev/disk/by-%s" % col)
        devnames = os.listdir(devdir)
        for devname in devnames:
            disk = os.path.basename(os.readlink(os.path.join(devdir, devname)))
            devname = devname.replace(r'\x2f', '/')
            disks[disk][col] = devname
            widths[col] = max(widths[col], len(devname))

    # print disk information
    fmt = "%-6s" + str.join(" ", [("%%-%ds" % widths[col]) for col in columns])

    for disk in disks:
        print (fmt % tuple([ disk ] + [ disks[disk][col] for col in columns]))


if __name__ == '__main__':
    main()