test/select/test10.c

   1 /*
   2  * Test name: test10.c
   3  *
   4  * Objetive: The purpose of this test is to make sure that select works
   5  * when working with the terminal with timeouts
   6  *
   7  * Description:  This tests wait entry from stdin using select and displays
   8  * it again in stdout when it is ready to write (which is always). It has
   9  * a timeout value as well.
  10  *
  11  * Jose M. Gomez
  12  */
  13
  14 #include <time.h>
  15 #include <sys/types.h>
  16 #include <sys/asynchio.h>
  17 #include <fcntl.h>
  18 #include <unistd.h>
  19 #include <sys/select.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <limits.h>
  23 #include <string.h>
  24
  25 void main(void) {
  26         fd_set fds_read, fds_write;
  27         int retval;
  28         char data[1024];
  29         struct timeval timeout;
  30
  31         while(1) {
  32                 timeout.tv_sec = 3;
  33                 timeout.tv_usec = 0;
  34                 FD_ZERO(&fds_read);
  35                 FD_ZERO(&fds_write);
  36                 FD_SET(0, &fds_read);
  37                 FD_SET(1, &fds_write);
  38                 printf("Input some data: ");
  39                 fflush(stdout);
  40                 retval=select(3, &fds_read, NULL, NULL, &timeout);
  41                 if (retval < 0) {
  42                         fprintf(stderr, "Error while executing select\n");
  43                         exit(-1);
  44                 }
  45                 if (retval == 0) {
  46                         printf("\n Hey! Feed me some data!\n");
  47                         fflush(stdout);
  48                         continue;
  49                 }
  50                 if (!FD_ISSET(0, &fds_read)) {
  51                         fprintf(stderr, "Error: stdin not ready (?)\n");
  52                         exit(-1);
  53                 }
  54                 gets(data);
  55                 if (!strcmp(data, "exit"))
  56                         exit(0);
  57                 printf("Try to write it back\n");
  58                 retval=select(3, NULL, &fds_write, NULL, NULL);
  59                 if (retval < 0) {
  60                         fprintf(stderr, "Error while executing select\n");
  61                         exit(-1);
  62                 }
  63                 if (!FD_ISSET(1, &fds_write)) {
  64                         fprintf(stderr, "Error: stdout not ready (?)\n");
  65                         exit(-1);
  66                 }
  67                 printf("Data: %s\n", data);
  68         }
  69 }