gopt.h

/* gopt.h version 8.1: tom.viza@gmail.com PUBLIC DOMAIN 2003-8 */
/*
I, Tom Vajzovic, am the author of this software and its documentation and
permanently abandon all copyright and other intellectual property rights in
them, including the right to be identified as the author.

I am fairly certain that this software does what the documentation says it
does, but I cannot guarantee that it does, or that it does what you think it
should, and I cannot guarantee that it will not have undesirable side effects.

You are free to use, modify and distribute this software as you please, but
you do so at your own risk.  If you remove or hide this warning then you are
responsible for any problems encountered by people that you make the software
available to.

Before modifying or distributing this software I ask that you would please
read http://www.purposeful.co.uk/tfl/
*/

#ifndef GOPT_H_INCLUDED
#define GOPT_H_INCLUDED

#define GOPT_ONCE   0
#define GOPT_REPEAT 1
#define GOPT_NOARG  0
#define GOPT_ARG    2

#define gopt_start(...)  (const void*)( const struct { int k; int f; const char *s; const char*const*l; }[]){ __VA_ARGS__, {0}}
#define gopt_option(k,f,s,l)    { k, f, s, l }
#define gopt_shorts( ... )      (const char*)(const char[]){ __VA_ARGS__, 0 }
#define gopt_longs( ... )       (const char**)(const char*[]){ __VA_ARGS__, NULL }


void *gopt_sort( int *argc, const char **argv, const void *opt_specs );
/* returns a pointer for use in the following calls
 * prints to stderr and call exit() on error
 */
size_t gopt( const void *opts, int key );
/* returns the number of times the option was specified
 * which will be 0 or 1 unless GOPT_REPEAT was used
 */
size_t gopt_arg( const void *opts, int key, const char **arg );
/* returns the number of times the option was specified
 * writes a pointer to the option argument from the first (or only) occurance to *arg
 */
const char *gopt_arg_i( const void *opts, int key, size_t i );
/* returns a pointer to the ith (starting at zero) occurance
 * of the option, or NULL if it was not specified that many times
 */
size_t gopt_args( const void *opts, int key, const char **args, size_t args_len );
/* returns the number of times the option was specified
 * writes pointers to the option arguments in the order of occurance to args[].
 * writes at most args_len pointers
 * if the return value is less than args_len, also writes a null pointer
 */
void gopt_free( void *opts );
/* releases memory allocated in the corresponding call to gopt_sort()
 * opts can no longer be used
 */
#endif /* GOPT_H_INCLUDED */