test/select/test02.c

   1 /*
   2  * Test name: test02.c
   3  *
   4  * Objetive: The purpose of this test is to make sure that select works
   5  * when working with files.
   6  *
   7  * Description: This tests first creates six dummy files with different
   8  * modes and performs select calls on them evaluating the input and resulting
   9  * bitmaps.
  10  *
  11  * Jose M. Gomez
  12  */
  13
  14 #include <sys/types.h>
  15 #include <fcntl.h>
  16 #include <unistd.h>
  17 #include <sys/select.h>
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <limits.h>
  21
  22 void dump_fdset(fd_set *set) {
  23         int i;
  24         for (i = 0; i < OPEN_MAX; i++)
  25         if (FD_ISSET(i, set))
  26                 printf(" %d->1 ", i);
  27         else
  28                 printf(" %d->0  ", i);
  29         printf("\n");
  30 }
  31
  32 void main(void) {
  33         int fd1, fd2, fd3, fd4, fd5, fd6;       /* file descriptors of files */
  34         fd_set fds_read, fds_write;
  35         int retval;
  36
  37         /* Creates the dummy files with different modes */
  38         fd1 = open("dummy1.txt", O_CREAT | O_RDONLY);
  39         if (fd1 < 0) {
  40                 perror("Error opening file");
  41                 exit(-1);
  42         }
  43
  44         fd2 = open("dummy2.txt", O_CREAT | O_RDONLY);
  45         if (fd2 < 0) {
  46                 perror("Error opening file");
  47                 exit(-1);
  48         }
  49
  50         fd3 = open("dummy3.txt", O_CREAT | O_WRONLY);
  51         if (fd3 < 0) {
  52                 perror("Error opening file");
  53                 exit(-1);
  54         }
  55
  56         fd4 = open("dummy4.txt", O_CREAT | O_WRONLY);
  57         if (fd4 < 0) {
  58                 perror("Error opening file");
  59                 exit(-1);
  60         }
  61
  62         fd5 = open("dummy5.txt", O_CREAT | O_RDWR);
  63         if (fd5 < 0) {
  64                 perror("Error opening file");
  65                 exit(-1);
  66         }
  67
  68         fd6 = open("dummy6.txt", O_CREAT | O_RDWR);
  69         if (fd6 < 0) {
  70                 perror("Error opening file");
  71                 exit(-1);
  72         }
  73
  74         /* Create the fd_set structures */
  75         FD_ZERO(&fds_read);
  76         FD_ZERO(&fds_write);
  77         FD_SET(fd1, &fds_read);         /* fd1 => O_RDONLY */
  78         FD_SET(fd2, &fds_read);         /* fd2 => O_RDONLY */
  79         FD_SET(fd3, &fds_write);        /* fd3 => O_WRONLY */
  80         FD_SET(fd4, &fds_write);        /* fd4 => O_WRONLY */
  81         FD_SET(fd5, &fds_read);         /* fd5 => O_RDWR */
  82         FD_SET(fd5, &fds_write);        /* fd5 => O_RDWR */
  83         FD_SET(fd6, &fds_read);         /* fd6 => O_RDWR */
  84         FD_SET(fd6, &fds_write);        /* fd6 => O_RDWR */
  85
  86         printf("* Dump INPUT fds_read:\n");
  87         dump_fdset(&fds_read);
  88         printf("* Dump INPUT fds_write:\n");
  89         dump_fdset(&fds_write);
  90
  91         retval=select(9, &fds_read, &fds_write, NULL, NULL);
  92         printf("\n***********************\n");
  93         printf("After select: \n");
  94         printf("Return value: %d\n", retval);
  95         printf("* Dump RESULTING fds_read:\n");
  96         dump_fdset(&fds_read);
  97         printf("* Dump RESULTING fds_write:\n");
  98         dump_fdset(&fds_write);
  99         /* close and delete dummy files */
 100         close(fd1);
 101         close(fd2);
 102         close(fd3);
 103         close(fd4);
 104         close(fd5);
 105         close(fd6);
 106         unlink("dummy1.txt");
 107         unlink("dummy2.txt");
 108         unlink("dummy3.txt");
 109         unlink("dummy4.txt");
 110         unlink("dummy5.txt");
 111         unlink("dummy6.txt");
 112 }