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 int main(int argc, char *argv[])
  26 {
  27         fd_set fds_read, fds_write;
  28         int retval;
  29         char data[1024];
  30         struct timeval timeout;
  31
  32         while(1) {
  33                 timeout.tv_sec = 3;
  34                 timeout.tv_usec = 0;
  35                 FD_ZERO(&fds_read);
  36                 FD_ZERO(&fds_write);
  37                 FD_SET(0, &fds_read);
  38                 FD_SET(1, &fds_write);
  39                 printf("Input some data: ");
  40                 fflush(stdout);
  41                 retval=select(3, &fds_read, NULL, NULL, &timeout);
  42                 if (retval < 0) {
  43                         fprintf(stderr, "Error while executing select\n");
  44                         exit(-1);
  45                 }
  46                 if (retval == 0) {
  47                         printf("\n Hey! Feed me some data!\n");
  48                         fflush(stdout);
  49                         continue;
  50                 }
  51                 if (!FD_ISSET(0, &fds_read)) {
  52                         fprintf(stderr, "Error: stdin not ready (?)\n");
  53                         exit(-1);
  54                 }
  55                 gets(data);
  56                 if (!strcmp(data, "exit"))
  57                         exit(0);
  58                 printf("Try to write it back\n");
  59                 retval=select(3, NULL, &fds_write, NULL, NULL);
  60                 if (retval < 0) {
  61                         fprintf(stderr, "Error while executing select\n");
  62                         exit(-1);
  63                 }
  64                 if (!FD_ISSET(1, &fds_write)) {
  65                         fprintf(stderr, "Error: stdout not ready (?)\n");
  66                         exit(-1);
  67                 }
  68                 printf("Data: %s\n", data);
  69         }
  70         return 1;
  71 }