def _strip_prefix(cmd_line):
    """Strip an OS operating prefix from a command line.
    """
    if cmd_line.startswith('cmd.exe /c '):
        return cmd_line[11:].strip('"')
    if cmd_line.startswith('cmd /c '):
        return cmd_line[7:].strip('"')
    if cmd_line.startswith('/bin/bash -c '):
        return cmd_line[13:]
    if cmd_line.startswith('/bin/sh -c '):
        return cmd_line[11:]
    return cmd_line