/* randread.c   by Michael Thorpe   2005-12-04 */

#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

int main(int argc,char **argv) {
   int b,c,fd,i,loc,size;

   if(argc != 3) {
      fprintf(stderr,"usage: %s <file> <size>\n",argv[0]);
      return(1);
   }
   if(-1==(fd=open(argv[1],O_RDONLY))) {
      fprintf(stderr,"Couldn't open %s (errno %d)\n",argv[1],errno);
      return(-1);
   }
   size=atoi(argv[2]);
   for(i=0;i<10000;i++) {
      loc=rand()%(size-4);
      if(-1==lseek(fd,loc,SEEK_SET)) {
         fprintf(stderr,"Couldn't seek to %d (errno %d)\n",loc,errno);
         return(-1);
      }
      if(4 != read(fd,&b,4)) {
         fprintf(stderr,"Couldn't read at %d (errno %d)\n",loc,errno);
         return(-1);
      }
      c+=b;
   }
   return(0);
}