argp_help FunctionWhen calling argp_help (see Argp Help) or
argp_state_help (see Argp Helper Functions) the exact output
is determined by the flags argument. This should consist of any of
the following flags, or’d together:
ARGP_HELP_USAGE
A unix ‘Usage:’ message that explicitly lists all options.
ARGP_HELP_SHORT_USAGE
A unix ‘Usage:’ message that displays an appropriate placeholder to indicate where the options go; useful for showing the non-option argument syntax.
ARGP_HELP_SEE
A ‘Try … for more help’ message; ‘…’ contains the program name and ‘--help’.
ARGP_HELP_LONG
A verbose option help message that gives each option available along with its documentation string.
ARGP_HELP_PRE_DOC
The part of the argp parser doc string preceding the verbose option help.
ARGP_HELP_POST_DOC
The part of the argp parser doc string that following the verbose option help.
ARGP_HELP_DOC
(ARGP_HELP_PRE_DOC | ARGP_HELP_POST_DOC)
ARGP_HELP_BUG_ADDR
A message that prints where to report bugs for this program, if the
argp_program_bug_address variable contains this information.
ARGP_HELP_LONG_ONLY
This will modify any output to reflect the ARGP_LONG_ONLY mode.
The following flags are only understood when used with
argp_state_help. They control whether the function returns after
printing its output, or terminates the program:
ARGP_HELP_EXIT_ERR
This will terminate the program with exit (argp_err_exit_status).
ARGP_HELP_EXIT_OK
This will terminate the program with exit (0).
The following flags are combinations of the basic flags for printing standard messages:
ARGP_HELP_STD_ERR
Assuming that an error message for a parsing error has printed, this prints a message on how to get help, and terminates the program with an error.
ARGP_HELP_STD_USAGE
This prints a standard usage message and terminates the program with an error. This is used when no other specific error messages are appropriate or available.
ARGP_HELP_STD_HELP
This prints the standard response for a ‘--help’ option, and terminates the program successfully.