bacon

#!/usr/bin/env python
import re
import sys
import getopt

def main(argv):
    if not argv:
        print("Syntax: bacon [option] <value>")

        print("\nOptions:")
        print("\t-k --kb:  output in kb")
        print("\t-m --mb:  output in mb")
        print("\t-g --gb:  output in gb")
        print("\t-t --tb:  output in tb")

        print("\nValue should be a numeric string")
        print("optionally followed by k, m, g to specify unit.")
        print("If no unit is given bytes is assumed.")
        sys.exit(1)

    try:
        opts, args = getopt.getopt(argv,"kmgt", ["kb","mb","gb", "tb"])
    except getopt.GetoptError:
        print("u crazy?")
        sys.exit(2)

    to = "g"
    for opt, arg in opts:
        if opt in ("-k", "--kb"):
            to = "k"
        elif opt in ("-m", "--mb"):
            to = "m"
        elif opt in ("-g", "--gb"):
            to = "g"
        elif opt in ("-t", "--tb"):
            to = "t"

    bytes = args[0]

    a = {'k' : 1, 'm': 2, 'g' : 3, 't' : 4}
    b = a[to]

    m = re.match(r"^(\d+)([bkmgtp]?)$", bytes)
    if m is None:
        print("Invalid input...")
        sys.exit()

    bytes = m.group(1)
    if m.group(2):
        b -= a[m.group(2)]

    r = float(bytes)
    for i in range(b):
        r = r / 1024

    output = str(int(r)) + to + "b"
    print(output)

if __name__ == "__main__":
    main(sys.argv[1:])