#define __STDC_WANT_LIB_EXT1__ 1
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static const char *keywords[] = {
        "auto",
        "break",
        "case",
        "char",
        /* . */
        /* . */
        /* . */
        "while"
};
static void * context = NULL;

#define NUM_KW  sizeof(keywords) / sizeof(char *)

int kw_compare( const void *p1, const void *p2, void *context )
{
    const char *p1c = (const char *) p1;
    const char **p2c = (const char **) p2;
    return( strcmp( p1c, *p2c ) );
}

int keyword_lookup( const char *name )
{
    const char **key;
    key = (char const **) bsearch_s( name, keywords, NUM_KW,
                   sizeof( char * ),  kw_compare, context );
    if( key == NULL ) return( -1 );
    return key - keywords;
}

int main()
{
    printf( "%d\n", keyword_lookup( "case" ) );
    printf( "%d\n", keyword_lookup( "crigger" ) );
    printf( "%d\n", keyword_lookup( "auto" ) );
    return 0;
}