patch_args.py

def str_to_args_windows(args):
    # see http:#msdn.microsoft.com/en-us/library/a1y7w461.aspx
    result = []

    DEFAULT = 0
    ARG = 1
    IN_DOUBLE_QUOTE = 2

    state = DEFAULT
    backslashes = 0
    buf = ''

    args_len = len(args)
    for i in xrange(args_len):
        ch = args[i]
        if (ch == '\\'):
            backslashes += 1
            continue
        elif (backslashes != 0):
            if ch == '"':
                while backslashes >= 2:
                    backslashes -= 2
                    buf += '\\'
                if (backslashes == 1):
                    if (state == DEFAULT):
                        state = ARG

                    buf += '"'
                    backslashes = 0
                    continue
                    # else fall through to switch
            else:
                # false alarm, treat passed backslashes literally...
                if (state == DEFAULT):
                    state = ARG

                while backslashes > 0:
                    backslashes -= 1
                    buf += '\\'
                    # fall through to switch
        if ch in (' ', '\t'):
            if (state == DEFAULT):
                # skip
                continue
            elif (state == ARG):
                state = DEFAULT
                result.append(buf)
                buf = ''
                continue

        if state in (DEFAULT, ARG):
            if ch == '"':
                state = IN_DOUBLE_QUOTE
            else:
                state = ARG
                buf += ch

        elif state == IN_DOUBLE_QUOTE:
            if ch == '"':
                if (i + 1 < args_len and args[i + 1] == '"'):
                    # Undocumented feature in Windows:
                    # Two consecutive double quotes inside a double-quoted argument are interpreted as
                    # a single double quote.
                    buf += '"'
                    i += 1
                elif len(buf) == 0:
                    # empty string on Windows platform. Account for bug in constructor of
                    # JDK's java.lang.ProcessImpl.
                    result.append("\"\"")
                    state = DEFAULT
                else:
                    state = ARG
            else:
                buf += ch

        else:
            raise RuntimeError('Illegal condition')

    if len(buf) > 0 or state != DEFAULT:
        result.append(buf)

    return result