©2004 by Marc J. Rochkind. All rights reserved. Portions marked "Open Source" may be copied under license.

 

                 

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c7/smsg_client.c

Go to the documentation of this file.

/*
    FIFO-based client
    AUP2, Sec. 7.02.2

    Copyright 2003 by Marc J. Rochkind. All rights reserved.
    May be copied only for purposes and under conditions described
    on the Web page www.basepath.com/aup/copyright.htm.

    The Example Files are provided "as is," without any warranty;
    without even the implied warranty of merchantability or fitness
    for a particular purpose. The author and his publisher are not
    responsible for any damages, direct or incidental, resulting
    from the use or non-use of these Example Files.

    The Example Files may contain defects, and some contain deliberate
    coding mistakes that were included for educational reasons.
    You are responsible for determining if and how the Example Files
    are to be used.

*/
#include "defs.h"
#include "smsg.h"

#define WANT_BUGFIX

/* Client */
/* Assumes no partial reads */

/*[main]*/
int main(int argc, char *argv[])
{
    int fd_server, fd_client = -1, i;
#ifdef WANT_BUGFIX
    int fd_client_w = -1;
#endif
    ssize_t nread;
    struct simple_message msg;
    char fifo_name[100];
    char *work[] = {
        "applesauce",
        "tiger",
        "mountain",
        NULL
    };

    printf("client %ld started\n", (long)getpid());
    msg.sm_clientpid = getpid();
    ec_false( make_fifo_name(msg.sm_clientpid, fifo_name,
      sizeof(fifo_name)) )
    if (mkfifo(fifo_name, PERM_FILE) == -1 && errno != EEXIST)
        EC_FAIL
    ec_neg1( fd_server = open(SERVER_FIFO_NAME, O_WRONLY) )
    for (i = 0; work[i] != NULL; i++) {
        strcpy(msg.sm_data, work[i]);
        ec_neg1( write(fd_server, &msg, sizeof(msg)) )
        if (fd_client == -1)
            ec_neg1( fd_client = open(fifo_name, O_RDONLY) )
#ifdef WANT_BUGFIX
        if (fd_client_w == -1)
            ec_neg1( fd_client_w = open(fifo_name, O_WRONLY) )
#endif
        ec_neg1( nread = read(fd_client, &msg, sizeof(msg)) )
        //printf("client got %d from read\n", nread);
        if (nread == 0) {
            errno = ENETDOWN;
            EC_FAIL
        }
        printf("client %ld: %s --> %s\n", (long)getpid(),
          work[i], msg.sm_data);
sleep(i);
    }
    ec_neg1( close(fd_server) )
    ec_neg1( close(fd_client) )
#ifdef WANT_BUGFIX
    ec_neg1( close(fd_client_w) )
#endif
    ec_neg1( unlink(fifo_name) )
    printf("Client %ld done\n", (long)getpid());
    exit(EXIT_SUCCESS);

EC_CLEANUP_BGN
    exit(EXIT_FAILURE);
EC_CLEANUP_END
}

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