source: trunk/minix/test/select/test02.c@ 16

/*
 * Test name: test02.c
 *
 * Objetive: The purpose of this test is to make sure that select works
 * when working with files.
 *
 * Description: This tests first creates six dummy files with different
 * modes and performs select calls on them evaluating the input and resulting
 * bitmaps. 
 *
 * Jose M. Gomez
 */

#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/select.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>

void dump_fdset(fd_set *set) {
        int i;
        for (i = 0; i < OPEN_MAX; i++)  
        if (FD_ISSET(i, set))
                printf(" %d->1 ", i);
        else 
                printf(" %d->0  ", i);
        printf("\n");
}

void main(void) {
        int fd1, fd2, fd3, fd4, fd5, fd6;       /* file descriptors of files */
        fd_set fds_read, fds_write;
        int retval;

        /* Creates the dummy files with different modes */
        fd1 = open("dummy1.txt", O_CREAT | O_RDONLY);
        if (fd1 < 0) {
                perror("Error opening file"); 
                exit(-1);
        }
        
        fd2 = open("dummy2.txt", O_CREAT | O_RDONLY);
        if (fd2 < 0) {
                perror("Error opening file");
                exit(-1);
        }

        fd3 = open("dummy3.txt", O_CREAT | O_WRONLY);
        if (fd3 < 0) {
                perror("Error opening file");
                exit(-1);
        }

        fd4 = open("dummy4.txt", O_CREAT | O_WRONLY);
        if (fd4 < 0) {
                perror("Error opening file");
                exit(-1);
        }

        fd5 = open("dummy5.txt", O_CREAT | O_RDWR);
        if (fd5 < 0) {
                perror("Error opening file");
                exit(-1);
        }

        fd6 = open("dummy6.txt", O_CREAT | O_RDWR);
        if (fd6 < 0) {
                perror("Error opening file");
                exit(-1);
        }

        /* Create the fd_set structures */
        FD_ZERO(&fds_read);
        FD_ZERO(&fds_write);
        FD_SET(fd1, &fds_read);         /* fd1 => O_RDONLY */
        FD_SET(fd2, &fds_read);         /* fd2 => O_RDONLY */
        FD_SET(fd3, &fds_write);        /* fd3 => O_WRONLY */
        FD_SET(fd4, &fds_write);        /* fd4 => O_WRONLY */
        FD_SET(fd5, &fds_read);         /* fd5 => O_RDWR */
        FD_SET(fd5, &fds_write);        /* fd5 => O_RDWR */
        FD_SET(fd6, &fds_read);         /* fd6 => O_RDWR */
        FD_SET(fd6, &fds_write);        /* fd6 => O_RDWR */

        printf("* Dump INPUT fds_read:\n"); 
        dump_fdset(&fds_read);
        printf("* Dump INPUT fds_write:\n");
        dump_fdset(&fds_write);

        retval=select(9, &fds_read, &fds_write, NULL, NULL); 
        printf("\n***********************\n");
        printf("After select: \n");
        printf("Return value: %d\n", retval);
        printf("* Dump RESULTING fds_read:\n");
        dump_fdset(&fds_read);
        printf("* Dump RESULTING fds_write:\n");
        dump_fdset(&fds_write); 
        /* close and delete dummy files */
        close(fd1);
        close(fd2);
        close(fd3);
        close(fd4);
        close(fd5);
        close(fd6);
        unlink("dummy1.txt");
        unlink("dummy2.txt");
        unlink("dummy3.txt");
        unlink("dummy4.txt");
        unlink("dummy5.txt");
        unlink("dummy6.txt");
}