/* txtdb.dat的内容

       赵春平    28    湖北       无

       zcp  28    荆门       无

       */

       #include <openssl/bio.h>

       #include <openssl/txt_db.h>

       #include <openssl/lhash.h>

      

       /* 名字过滤 */

       static       int    name_filter(char **in)

       {

              if(strlen(in[0])<2)

                     return 0;

              return 1;

       }

 

       static unsigned long index_name_hash(const char **a)

       {

              const char *n;

      

            n=a[0];

            while (*n == '0') n++;

            return(lh_strhash(n));

       }

      

       static int index_name_cmp(const char **a, const char **b)

       {

              const char *aa,*bb;

      

              for (aa=a[0]; *aa == '0'; aa++);

              for (bb=b[0]; *bb == '0'; bb++);

              return(strcmp(aa,bb));

       }

      

       int    main()

       {

              TXT_DB        *db=NULL,*out=NULL;

              BIO               *in;

              int                  num,ret;

              char        **added=NULL,**rrow=0,**row=NULL;

      

              in=BIO_new_file("txtdb.dat","r");

              num=1024;

              db=TXT_DB_read(in,4);

      

              added=(char **)OPENSSL_malloc(sizeof(char *)*(3+1));

                  added[0]=(char *)OPENSSL_malloc(10);

              #if 1

              strcpy(added[0],"skp");

              #else

              strcpy(added[0],"a");     /* 不能插入名字对应的哈希表 */

              #endif

             

              added[1]=(char *)OPENSSL_malloc(10);

              strcpy(added[1],"22");

      

              added[2]=(char *)OPENSSL_malloc(10);

              strcpy(added[2],"chairman");

          

              added[3]=NULL;

      

              ret=TXT_DB_insert(db,added);

              if(ret!=1)

              {

                     printf("err!\n");

                     return -1;

              }

              ret=TXT_DB_create_index(db,0, name_filter,index_name_hash,index_name_cmp);

              if(ret!=1)

              {

                     printf("err\n");

                     return 0;

              }

              row=(char **)malloc(2*sizeof(char *));

                  row[0]=(char *)malloc(10);

              strcpy(row[0],"skp");

              row[1]=NULL;

              rrow=TXT_DB_get_by_index(db,0,row);

              if(rrow!=NULL)

                     printf("%s      %s   %s\n",rrow[0],rrow[1],rrow[2]);

              out=BIO_new_file("txtdb2.dat","w");

              ret=TXT_DB_write(out,db);

              TXT_DB_free(db);

              BIO_free(in);

              BIO_free(out);

              return 0;

       }

       本示例只对第一列做了哈希。需要注意的是，added数组及其元素申请空间时尽量采用OPENSSL_malloc而不是malloc，且其申请的空间由TXT_DB_free(调用OPENSSL_free)释放。