#include <sys/types.h>#include <errno.h>extern int errno;#include "cdb.h"#ifndef SEEK_SET#define SEEK_SET 0#endifint cdb_bread(fd,buf,len)int fd;char *buf;int len;{  int r;  while (len > 0) {    do      r = read(fd,buf,len);    while ((r == -1) && (errno == EINTR));    if (r == -1) return -1;    if (r == 0) { errno = EIO; return -1; }    buf += r;    len -= r;  }  return 0;}static int match(fd,key,len)int fd;char *key;unsigned int len;{  char buf[32];  int n;  int i;  while (len > 0) {    n = sizeof(buf);    if (n > len) n = len;    if (cdb_bread(fd,buf,n) == -1) return -1;    for (i = 0;i < n;++i) if (buf[i] != key[i]) return 0;    key += n;    len -= n;  }  return 1;}int cdb_seek(fd,key,len,dlen)int fd;char *key;unsigned int len;uint32 *dlen;{  char packbuf[8];  uint32 pos;  uint32 h;  uint32 lenhash;  uint32 h2;  uint32 loop;  uint32 poskd;  h = cdb_hash(key,len);  pos = 8 * (h & 255);  if (lseek(fd,(off_t) pos,SEEK_SET) == -1) return -1;  if (cdb_bread(fd,packbuf,8) == -1) return -1;  pos = cdb_unpack(packbuf);  lenhash = cdb_unpack(packbuf + 4);  if (!lenhash) return 0;  h2 = (h >> 8) % lenhash;  for (loop = 0;loop < lenhash;++loop) {    if (lseek(fd,(off_t) (pos + 8 * h2),SEEK_SET) == -1) return -1;    if (cdb_bread(fd,packbuf,8) == -1) return -1;    poskd = cdb_unpack(packbuf + 4);    if (!poskd) return 0;    if (cdb_unpack(packbuf) == h) {      if (lseek(fd,(off_t) poskd,SEEK_SET) == -1) return -1;      if (cdb_bread(fd,packbuf,8) == -1) return -1;      if (cdb_unpack(packbuf) == len)	switch(match(fd,key,len)) {	  case -1:	    return -1;	  case 1:	    *dlen = cdb_unpack(packbuf + 4);	    return 1;	}    }    if (++h2 == lenhash) h2 = 0;  }  return 0;}