Application: gvSIG desktop

#! /usr/bin/env python

"""Conversions to/from base64 transport encoding as per RFC-1521."""

# Modified 04-Oct-95 by Jack to use binascii module

import binascii

__all__ = ["encode","decode","encodestring","decodestring"]

MAXLINESIZE = 76 # Excluding the CRLF

MAXBINSIZE = (MAXLINESIZE/4)*3

def encode(input, output):

    """Encode a file."""

    while 1:

        s = input.read(MAXBINSIZE)

        if not s: break

        while len(s) < MAXBINSIZE:

            ns = input.read(MAXBINSIZE-len(s))

            if not ns: break

            s = s + ns

        line = binascii.b2a_base64(s)

        output.write(line)

def decode(input, output):

    """Decode a file."""

    while 1:

        line = input.readline()

        if not line: break

        s = binascii.a2b_base64(line)

        output.write(s)

def encodestring(s):

    """Encode a string."""

    import StringIO

    f = StringIO.StringIO(s)

    g = StringIO.StringIO()

    encode(f, g)

    return g.getvalue()

def decodestring(s):

    """Decode a string."""

    import StringIO

    f = StringIO.StringIO(s)

    g = StringIO.StringIO()

    decode(f, g)

    return g.getvalue()

def test():

    """Small test program"""

    import sys, getopt

    try:

        opts, args = getopt.getopt(sys.argv[1:], 'deut')

    except getopt.error, msg:

        sys.stdout = sys.stderr

        print msg

        print """usage: %s [-d|-e|-u|-t] [file|-]

        -d, -u: decode

        -e: encode (default)

        -t: encode and decode string 'Aladdin:open sesame'"""%sys.argv[0]

        sys.exit(2)

    func = encode

    for o, a in opts:

        if o == '-e': func = encode

        if o == '-d': func = decode

        if o == '-u': func = decode

        if o == '-t': test1(); return

    if args and args[0] != '-':

        func(open(args[0], 'rb'), sys.stdout)

    else:

        func(sys.stdin, sys.stdout)

def test1():

    s0 = "Aladdin:open sesame"

    s1 = encodestring(s0)

    s2 = decodestring(s1)

    print s0, `s1`, s2

if __name__ == '__main__':

    test()