import sys
from optparse import OptionParser

def unwrap(column, infile, outfile):
    lines = infile.readlines()
    if lines[0].startswith('\xef\xbb\xbf'): # UTF-8 BOM
        lines[0] = lines[0][3:]

    for counter in range(len(lines)):
        line = lines[counter]

        if counter < len(lines) - 1: nextline = lines[counter+1]
        else: nextline = ''

        if line.strip() == '' or nextline.strip() == '':
            outfile.write(line) # Don't unwrap if there's a blank line
        elif len(line) >= column: # Use >= instead of > since there's also a newline character
            outfile.write(line.rstrip() + ' ')
        else:
            outfile.write(line + '\n') # Add blank line

def main(argv):
    """%prog [options] input.txt [output.txt]"""
    parser = OptionParser(usage=main.__doc__)
    parser.add_option('-c', '--column', type='int', default=72,
                      help='Lines exceeding this width will be unwrapped with next [default %default]')
    (options, parms) = parser.parse_args(argv[1:])

    if len(parms) == 1:
        return unwrap(options.column, open(parms[0], 'r'), sys.stdout)
    elif len(parms) == 2:
        return unwrap(options.column, open(parms[0], 'r'), open(parms[1], 'w'))
    else:
        print >> sys.stderr, "Syntax: %s" % main.__doc__.replace('%prog', argv[0])
        return 1


if __name__=='__main__':
    sys.exit(main(sys.argv))