delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2007/01/19/04:41:15

X-Spam-Check-By: sourceware.org
Message-ID: <25e2d6fe0701190140u17a989fcva9e3cbf1d935ebd4@mail.gmail.com>
Date: Fri, 19 Jan 2007 10:40:53 +0100
From: "Florent Morin" <morinflorent AT gmail DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: cygwin 1.5.23-2 : I can't use select() with serial device and socket
In-Reply-To: <25e2d6fe0701190139r5e18aa89jc96e2229caaf8649@mail.gmail.com>
MIME-Version: 1.0
References: <25e2d6fe0701180840k6bd5b27di630bca3a0a010ac3 AT mail DOT gmail DOT com> <45AFA5A5 DOT 3406349E AT dessent DOT net> <25e2d6fe0701180902m35903447w69c1ff91ef4eb8d1 AT mail DOT gmail DOT com> <25e2d6fe0701190139r5e18aa89jc96e2229caaf8649 AT mail DOT gmail DOT com>
X-IsSubscribed: yes
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Unsubscribe: <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com

Excuse me, this is my second code :

--------------------------------------------- CODE
----------------------------------------------

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <sys/time.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>

#define BUFFER_SIZE     256
#define DEVICE          "/dev/ttyS0"
#define TO_WRITE        "test communication\n"

int main (void)
{
    char buffer_read[BUFFER_SIZE];
    int data_read;

    char buffer_write[BUFFER_SIZE] = TO_WRITE;
    int data_write;

    int serial_fd;

    fd_set read_set;
    fd_set write_set;

    int written = 0;

    serial_fd = open(DEVICE, O_NONBLOCK | O_NOCTTY | O_RDWR);

    if (serial_fd < 0) {
        perror("open");
        return EXIT_FAILURE;
    } else
        printf("Serial port opened.\n");

    while (1) {
        FD_ZERO(&read_set);
        FD_SET(serial_fd, &read_set);

        FD_ZERO(&write_set);
        FD_SET(serial_fd, &write_set);

        if (select(serial_fd + 1,
                   &read_set,
                   &write_set,
                   NULL,
                   NULL) < 0) {
            perror("select");
            return EXIT_FAILURE;
        }

        if (FD_ISSET(serial_fd, &read_set)) {

            memset(&buffer_read, 0, BUFFER_SIZE);

            printf("Begin reading...\n");

            while ((data_read = read(serial_fd,
                                     buffer_read,
                                     BUFFER_SIZE - 1)) < 0) {
                if (errno == EAGAIN)
                    memset(&buffer_read, 0, BUFFER_SIZE);
                else {
                    perror("read");
                    return EXIT_FAILURE;
                }
            }

            if (data_read < 0)
                perror("read");
            else
                printf("Data readed (%d) : %s\n", data_read, buffer_read);
        } else
            printf("Serial port not ready to read.\n");

        if ((FD_ISSET(serial_fd, &write_set)) && (written == 0)) {
            printf("Begin writing %s...\n", buffer_write);
            written = 1;
            data_write = write(serial_fd, buffer_write, strlen(buffer_write));
            if (data_write < 0)
                perror("write");
            else
                printf("%d caracters written.\n", data_write);
        } else {
            if (FD_ISSET(serial_fd, &write_set))
                printf("Serial port ready to write but no.\n");
            else
                printf("Serial port not ready to write.\n");
        }

        printf("\n---------------------------------------------\n");
        sleep(1);
    }

    close(serial_fd);

    return EXIT_SUCCESS;
}


--------------------------------------- /CODE
---------------------------------------------------------

Thanks,

Florent

--
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
Problem reports:       http://cygwin.com/problems.html
Documentation:         http://cygwin.com/docs.html
FAQ:                   http://cygwin.com/faq/

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019