tests/test-read.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <unistd.h>
   4 #include <sys/types.h>
   5 #include <sys/stat.h>
   6 #include <fcntl.h>
   7 #include <errno.h>
   8 #include <string.h>
   9 #include <stdlib.h>
  10
  11 #define BUFSIZE 1025
  12 char buf[BUFSIZE];
  13
  14 int read_count = 2;
  15
  16 int main(int argc, char *argv[]){
  17         if(argc < 3){
  18                 fprintf(stderr, "usage: %s <file> <count> [buffer|direct]\n", argv[0]);
  19                 exit(1);
  20         }
  21         char *file = argv[1];
  22         read_count = atoi(argv[2]);
  23         int ret = 0,sum = 0, i = 0, fd = -1;
  24         if(argc == 4 && strncmp(argv[3], "direct",6) == 0)
  25                 fd = open(file, O_RDONLY|O_DIRECT);
  26         else
  27                 fd = open(file, O_RDONLY);
  28
  29         while(i++ < read_count){
  30                 memset(buf, 0, BUFSIZE);
  31                 ret = read(fd, buf, BUFSIZE-1);
  32                 if(ret > 0){
  33                         write(STDOUT_FILENO, buf, ret);
  34                         sum += ret;
  35                 }else if(ret == 0){
  36                         printf("======read end======\n");
  37                         break;
  38                 }else{
  39                         printf("error:%d\n", errno);
  40                         break;
  41                 }
  42                 sleep(1);
  43         }
  44         printf("======read sum: %d======\n", sum);
  45         close(fd);
  46         return 0;
  47 }