Argp Help (The GNU C Library)

#### 26.3.9 The `argp_help` Function ¶

Normally programs using argp need not be written with particular printing argument-usage-type help messages in mind as the standard ‘`--help`’ option is handled automatically by argp. Typical error cases can be handled using `argp_usage` and `argp_error`. See Functions For Use in Argp Parsers. However, if it’s desirable to print a help message in some context other than parsing the program options, argp offers the `argp_help` interface.

Function: `void` argp_help `(const struct argp *argp, FILE *stream, unsigned flags, char *name)` ¶

  Preliminary: | MT-Unsafe race:argpbuf env locale | AS-Unsafe heap i18n corrupt | AC-Unsafe mem corrupt lock | See POSIX Safety Concepts.

  This outputs a help message for the argp parser argp to stream. The type of messages printed will be determined by flags.

  Any options such as ‘`--help`’ that are implemented automatically by argp itself will not be present in the help output; for this reason it is best to use `argp_state_help` if calling from within an argp parser function. See Functions For Use in Argp Parsers.