spnconv

#!/usr/bin/env python

import sys

def read(filename):
    data = []
    with open(filename, 'rb') as f:
        byte = f.read(1)
        while byte:
            data.append(byte)
            byte = f.read(1)
    return ''.join(data)

def write(data, filename):
    with open(filename, 'wb') as f:
        for b in data:
            f.write(b)

def is_spn(data):
    return '\x00' in data

def remove_delimiter(data):
    return filter(lambda x: x != '\x00', data)

def add_delimiter(data):
    delimited_data = []
    for d in data:
        delimited_data.append(d)
        delimited_data.append('\x00')
    return ''.join(delimited_data)

def unix_to_dos(data):
    isUnix = ('\n' in data) and not ('\r\n' in data)
    if isUnix:
        return data.replace('\n', '\r\n')
    return data

def new_filename(filename):
    suffix = 'asm' if filename.endswith('spn') else 'spn'
    return filename[0:-3] + suffix

def usage():
    print "Usage:"
    print "  Extract text  : %s file.spn" % __file__
    print "  Convert to spn: %s file.asm" % __file__
    sys.exit(0)

if __name__ == '__main__':
    if len(sys.argv) == 1:
        usage()
    filename = sys.argv[1]
    data = read(filename)
    if is_spn(data):
        write(remove_delimiter(data), new_filename(filename))
    else:
        write(add_delimiter(unix_to_dos(data)), new_filename(filename))