25.3.10 Flags for the argp_help Function

When 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.