tstats.c

UNIX编程高级环境（第二版）的网络套接字部分的程序源码

#include    <sys/types.h>
#include    <stdio.h>
#include    <unistd.h>
#include    "ourhdr.h"
#include    "db.h"

/* Use the undocmuented _db_hash() function to determine the hash
 * statistics of a database. */

void doit(char *);

main(int argc, char *argv[])
{
    if (argc != 2)
        err_quit("tstats <db>");

    doit(argv[1]);
    exit(0);
}

long    cntr[NHASH_DEF];

void doit(char *pathname)
{
    DB        *db;
    char    key[IDXLEN_MAX], *ptr;
    hash_t    hash;
    int        i, nrec;

    if ( (db = db_open(pathname, O_RDONLY, 0)) == NULL)
        err_sys("db_open error");

    nrec = 0;
    while ( (ptr = db_nextrec(db, key)) != NULL) {
        nrec++;
        hash = _db_hash(db, key);
        cntr[hash]++;
    }

    printf("total #records = %d\n", nrec);
    for (i = 0; i < NHASH_DEF; i++) {
        printf("%3d: %6ld\n", i, cntr[i]);
    }

    if ( (i = _db_checkfree(db)) < 0)
        printf("corrupted free list\n");
    else
        printf("%d records on free list\n", i);

    exit(0);
}