commander.c - C option parser
Every time I write a C program I end up rolling my own option parsing with a loop and strcmp(), so I figured it was time to port over commander.c from the original ruby commander, and there’s also a node.js port.
Commander.c is a super simple script that makes defining options declarative and does the dirty work for you, its usage looks like this:
#include <stdio.h>
#include "commander.h"
static void
verbose(command_t *self) {
printf("verbose: enabled\n");
}
static void
required(command_t *self) {
printf("required: %s\n", self->arg);
}
static void
optional(command_t *self) {
printf("optional: %s\n", self->arg);
}
int
main(int argc, const char **argv){
command_t cmd;
command_init(&cmd, argv[0], "0.0.1");
command_option(&cmd, "-v", "--verbose", "enable verbose stuff", verbose);
command_option(&cmd, "-r", "--required <arg>", "required arg", required);
command_option(&cmd, "-o", "--optional [arg]", "optional arg", optional);
command_parse(&cmd, argc, argv);
printf("additional args:\n");
for (int i = 0; i < cmd.argc; ++i) {
printf(" - '%s'\n", cmd.argv[i]);
}
return 0;
}
As a bonus it generates the --help from what it already knows about your program:
Usage: example [options]
Options:
-V, --version output program version
-h, --help output help information
-v, --verbose enable verbose stuff
-r, --required <arg> required arg
-o, --optional [arg] optional arg
Commander handles optional and required args:
$ mon --sleep
--sleep requires an argument
Warns about unrecognized flags:
$ ./test --foo
unrecognized flag --foo
Unparsed arguments are then provided as cmd.argv and of course its companion cmd.argc, which of course includes -- support to flag subsequent args as literals:
$ ./test foo -- --foo
additional args:
- 'foo'
- '--bar'
If you have a struct that you want to access within each callback just assign to cmd.data, a void *.
That’s it for now, I’ll be adding a few more things in the near future so check it out on github.
