The Fugue Counterpoint by Hans Fugal

opg ftw

Few things about programming (in most languages) are less enjoyable than
writing option parsing code. On the other hand, few things are more irritating
to users than no -h and no options where options are needed (or
underdeveloped option parsers). In few languages is it more painful to do
option parsing than it is in C.

So I did what any sane lunatic would do. I wrote an option parser generator. I think it's quite nice. This input:

usage: foo [options] other stuff
-f --foo          bool     Short name, long name, type, help text.
-b --bar=name     char*    This has a required string argument.
-z --baz=decibels int?     Optional integer argument
-q --quux=MACH    float    char*, int, and float are the recognized types

Any line not starting with a dash is copied into the help message verbatim.

becomes this output (a header and source file):

/* This file is automatically generated by opg */
#ifndef _OPG_H
#define _OPG_H

struct options {
    int   f; /* foo */
    char* b; /* bar */
    int   z; /* baz */
    float q; /* quux */
};

/* Print usage and exit(1) */
void usage(void);

/* Parse options, populate opts, adjust argc/argv */
void parse_options(int *argc, char * const *argv, struct options *opts);

#endif

/* This file is automatically generated by opg */
#include "opts.h"

...

void usage(void)
{
    puts("usage: foo [options] other stuff");
    puts("  -f  --foo             Short name, long name, type, help text.");
    puts("  -b  --bar=name        This has a required string argument.");
    puts("  -z  --baz[=decibels]  Optional integer argument");
    puts("  -q  --quux=MACH       char*, int, and float are the recognized types");
    puts("");
    puts("Any line not starting with a dash is copied to the help message verbatim.");

    exit(1);
}

void parse_options(int *argc, char * const *argv, struct options *opts)
{
    ...
}

http://hans.fugal.net/src/opg. Enjoy.