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 int main(int argc, char *argv[])
  33 {
  34         int fd1, fd2, fd3, fd4, fd5, fd6;       /* file descriptors of files */
  35         fd_set fds_read, fds_write;
  36         int retval;
  37
  38         /* Creates the dummy files with different modes */
  39         fd1 = open("dummy1.txt", O_CREAT | O_RDONLY);
  40         if (fd1 < 0) {
  41                 perror("Error opening file");
  42                 exit(-1);
  43         }
  44
  45         fd2 = open("dummy2.txt", O_CREAT | O_RDONLY);
  46         if (fd2 < 0) {
  47                 perror("Error opening file");
  48                 exit(-1);
  49         }
  50
  51         fd3 = open("dummy3.txt", O_CREAT | O_WRONLY);
  52         if (fd3 < 0) {
  53                 perror("Error opening file");
  54                 exit(-1);
  55         }
  56
  57         fd4 = open("dummy4.txt", O_CREAT | O_WRONLY);
  58         if (fd4 < 0) {
  59                 perror("Error opening file");
  60                 exit(-1);
  61         }
  62
  63         fd5 = open("dummy5.txt", O_CREAT | O_RDWR);
  64         if (fd5 < 0) {
  65                 perror("Error opening file");
  66                 exit(-1);
  67         }
  68
  69         fd6 = open("dummy6.txt", O_CREAT | O_RDWR);
  70         if (fd6 < 0) {
  71                 perror("Error opening file");
  72                 exit(-1);
  73         }
  74
  75         /* Create the fd_set structures */
  76         FD_ZERO(&fds_read);
  77         FD_ZERO(&fds_write);
  78         FD_SET(fd1, &fds_read);         /* fd1 => O_RDONLY */
  79         FD_SET(fd2, &fds_read);         /* fd2 => O_RDONLY */
  80         FD_SET(fd3, &fds_write);        /* fd3 => O_WRONLY */
  81         FD_SET(fd4, &fds_write);        /* fd4 => O_WRONLY */
  82         FD_SET(fd5, &fds_read);         /* fd5 => O_RDWR */
  83         FD_SET(fd5, &fds_write);        /* fd5 => O_RDWR */
  84         FD_SET(fd6, &fds_read);         /* fd6 => O_RDWR */
  85         FD_SET(fd6, &fds_write);        /* fd6 => O_RDWR */
  86
  87         printf("* Dump INPUT fds_read:\n");
  88         dump_fdset(&fds_read);
  89         printf("* Dump INPUT fds_write:\n");
  90         dump_fdset(&fds_write);
  91
  92         retval=select(9, &fds_read, &fds_write, NULL, NULL);
  93         printf("\n***********************\n");
  94         printf("After select: \n");
  95         printf("Return value: %d\n", retval);
  96         printf("* Dump RESULTING fds_read:\n");
  97         dump_fdset(&fds_read);
  98         printf("* Dump RESULTING fds_write:\n");
  99         dump_fdset(&fds_write);
 100         /* close and delete dummy files */
 101         close(fd1);
 102         close(fd2);
 103         close(fd3);
 104         close(fd4);
 105         close(fd5);
 106         close(fd6);
 107         unlink("dummy1.txt");
 108         unlink("dummy2.txt");
 109         unlink("dummy3.txt");
 110         unlink("dummy4.txt");
 111         unlink("dummy5.txt");
 112         unlink("dummy6.txt");
 113         return 0;
 114 }