代码:

---

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

     struct info {                   /* This is the info stored in the table */
             int age, room;          /* other than the key. */
     };

     #define NUM_EMPL        5000    /* # of elements in search table. */

     int
     main(void)
     {
             char str[BUFSIZ]; /* Space to read string */
             struct info info_space[NUM_EMPL]; /* Space to store employee info. */
             struct info *info_ptr = info_space; /* Next space in info_space. */
             ENTRY item;
             ENTRY *found_item; /* Name to look for in table. */
             char name_to_find[30];
             int i = 0;

             /* Create table; no error checking is performed. */
             (void) hcreate(NUM_EMPL);

             while (scanf("%s%d%d", str, &info_ptr->age,
                 &info_ptr->room) != EOF && i++ < NUM_EMPL) {
                     /* Put information in structure, and structure in item. */
                     item.key = strdup(str);
                     item.data = info_ptr;
                     info_ptr++;
                     /* Put item into table. */
                     (void) hsearch(item, ENTER);
             }

             /* Access table. */
             item.key = name_to_find;
             while (scanf("%s", item.key) != EOF) {
                     if ((found_item = hsearch(item, FIND)) != NULL) {
                             /* If item is in the table. */
                             (void)printf("found %s, age = %d, room = %d\n",
                                 found_item->key,
                                 ((struct info *)found_item->data)->age,
                                 ((struct info *)found_item->data)->room);
                     } else
                             (void)printf("no such employee %s\n", name_to_find);
             }
             hdestroy();
             return 0;
     }

---

代码:

---

/*
 * Written by J.T. Conklin <jtc@netbsd.org>
 * Public domain.
 */

#ifndef _SEARCH_H_
#define _SEARCH_H_

#include <sys/cdefs.h>
#include <machine/ansi.h>

#ifdef	_BSD_SIZE_T_
typedef	_BSD_SIZE_T_	size_t;
#undef	_BSD_SIZE_T_
#endif

typedef struct entry {
	char *key;
	void *data;
} ENTRY;

typedef enum {
	FIND, ENTER
} ACTION;

typedef enum {
	preorder,
	postorder,
	endorder,
	leaf
} VISIT;

#ifdef _SEARCH_PRIVATE
typedef struct node {
	char         *key;
	struct node  *llink, *rlink;
} node_t;
#endif

__BEGIN_DECLS
int	 hcreate __P((size_t));
void	 hdestroy __P((void));
ENTRY	*hsearch __P((ENTRY, ACTION));
void	*tdelete __P((const void *, void **,
		      int (*)(const void *, const void *)));
void	*tfind __P((const void *, void **,
		      int (*)(const void *, const void *)));
void	*tsearch __P((const void *, void **, 
		      int (*)(const void *, const void *)));
void      twalk __P((const void *, void (*)(const void *, VISIT, int)));
__END_DECLS

#endif /* !_SEARCH_H_ */

---