bsearch.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 40 行

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

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

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

int kw_compare( const void *p1, const void *p2 )
  {
    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( name, keywords, NUM_KW,
                   sizeof( char * ),  kw_compare );
    if( key == NULL ) return( -1 );
    return key - keywords;
  }

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