Print a short usage message listing only some few of all available options, then exit successfully.
Print an extended usage message listing all available options, then exit successfully. If an argument is given and it is a valid long-style option name, an extended help text related to the given long-style option name is displayed only, e.g.:
displays the extended help text for the long option --long-help.
If the argument only consists of the single ‘?’ character or is no valid long-style option name, a list of all valid long-style option names is displayed.
Print the software license message, then exit successfully.
Print the version number and compilation options, then exit successfully.
Set the exit state of program to 127 instead to 0, if one of the other options of the common option class is used.