/*************************************************************************\
*                  Copyright (C) Michael Kerrisk, 2026.                   *
*                                                                         *
* This program is free software. You may use, modify, and redistribute it *
* under the terms of the GNU General Public License as published by the   *
* Free Software Foundation, either version 3 or (at your option) any      *
* later version. This program is distributed without any warranty.  See   *
* the file COPYING.gpl-v3 for details.                                    *
\*************************************************************************/

#include "inet_sockets.h"
#include "tlpi_hdr.h"

#define BUF_SIZE 100

int
main(int argc, char *argv[])
{
    int sfd;
    ssize_t numRead;
    char buf[BUF_SIZE];

    if (argc != 2 || strcmp(argv[1], "--help") == 0)
        usageErr("%s host\n", argv[0]);

    sfd = inetConnect(argv[1], "echo", SOCK_STREAM);
    if (sfd == -1)
        errExit("inetConnect");

    switch (fork()) {
    case -1:
        errExit("fork");

    case 0:             /* Child: read server's response, echo on stdout */
        for (;;) {
            numRead = read(sfd, buf, BUF_SIZE);
            if (numRead <= 0)                   /* Exit on EOF or error */
                break;
            printf("%.*s", (int) numRead, buf);
        }
        exit(EXIT_SUCCESS);

    default:            /* Parent: write contents of stdin to socket */
        for (;;) {
            numRead = read(STDIN_FILENO, buf, BUF_SIZE);
            if (numRead <= 0)                   /* Exit loop on EOF or error */
                break;
            if (write(sfd, buf, numRead) != numRead)
                fatal("write() failed");
        }

        /* Close writing channel, so server sees EOF */

        if (shutdown(sfd, SHUT_WR) == -1)
            errExit("shutdown");
        exit(EXIT_SUCCESS);
    }
}