![[tokkee]](http://tokkee.org/images/avatar.png){kind=avatar}
diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt
index 539863b1f920f8f34ad9272907cbacbd35a7fcbd..50f9e9ac1708f3f754023c1bb60416adc9c73c74 100644 (file)
. in `cmd_foo(int argc, const char **argv, const char *prefix)`
call
- argc = parse_options(argc, argv, builtin_foo_options, builtin_foo_usage, flags);
+ argc = parse_options(argc, argv, prefix, builtin_foo_options, builtin_foo_usage, flags);
+
`parse_options()` will filter out the processed options of `argv[]` and leave the
non-option arguments in `argv[]`.
`argc` is updated appropriately because of the assignment.
+
+You can also pass NULL instead of a usage array as the fifth parameter of
+parse_options(), to avoid displaying a help screen with usage info and
+option list. This should only be done if necessary, e.g. to implement
+a limited parser for only a subset of the options that needs to be run
+before the full parser, which in turn shows the full help message.
++
Flags are the bitwise-or of:
`PARSE_OPT_KEEP_DASHDASH`::
Using this flag, processing is stopped at the first non-option
argument.
+`PARSE_OPT_KEEP_ARGV0`::
+ Keep the first argument, which contains the program name. It's
+ removed from argv[] by default.
+
+`PARSE_OPT_KEEP_UNKNOWN`::
+ Keep unknown arguments instead of erroring out. This doesn't
+ work for all combinations of arguments as users might expect
+ it to do. E.g. if the first argument in `--unknown --known`
+ takes a value (which we can't know), the second one is
+ mistakenly interpreted as a known option. Similarly, if
+ `PARSE_OPT_STOP_AT_NON_OPTION` is set, the second argument in
+ `--unknown value` will be mistakenly interpreted as a
+ non-option, not as a value belonging to the unknown option,
+ the parser early. That's why parse_options() errors out if
+ both options are set.
+
+`PARSE_OPT_NO_INTERNAL_HELP`::
+ By default, parse_options() handles `-h`, `--help` and
+ `--help-all` internally, by showing a help screen. This option
+ turns it off and allows one to add custom handlers for these
+ options, or to just leave them unknown.
+
Data Structure
--------------
Introduce a boolean option.
If used, `int_var` is bitwise-ored with `mask`.
+`OPT_NEGBIT(short, long, &int_var, description, mask)`::
+ Introduce a boolean option.
+ If used, `int_var` is bitwise-anded with the inverted `mask`.
+
`OPT_SET_INT(short, long, &int_var, description, integer)`::
Introduce a boolean option.
If used, set `int_var` to `integer`.
and the result will be put into `var`.
See 'Option Callbacks' below for a more elaborate description.
+`OPT_FILENAME(short, long, &var, description)`::
+ Introduce an option with a filename argument.
+ The filename will be prefixed by passing the filename along with
+ the prefix argument of `parse_options()` to `prefix_filename()`.
+
`OPT_ARGUMENT(long, description)`::
Introduce a long-option argument that will be kept in `argv[]`.
+`OPT_NUMBER_CALLBACK(&var, description, func_ptr)`::
+ Recognize numerical options like -123 and feed the integer as
+ if it was an argument to the function given by `func_ptr`.
+ The result will be put into `var`. There can be only one such
+ option definition. It cannot be negated and it takes no
+ arguments. Short options that happen to be digits take
+ precedence over it.
+
The last element of the array must be `OPT_END()`.
The callback mechanism is as follows:
-* Inside `funct`, the only interesting member of the structure
+* Inside `func`, the only interesting member of the structure
given by `opt` is the void pointer `opt->value`.
`\*opt->value` will be the value that is saved into `var`, if you
use `OPT_CALLBACK()`.