A deamon for sending poem form poem.conf to clients based on KISS <3

poemd.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <syslog.h>
#include <setjmp.h>
#include <time.h>
#include <errno.h>
#include <err.h>

#include <sys/socket.h>
#include <arpa/inet.h>

#ifndef DEBUG
#define perror(msg) syslog(LOG_ERR, "%s: %s", msg, strerror(errno))
#define err(status, msg) perror(msg), _exit(status)
#endif

sigjmp_buf jmp;

void
sighub (__attribute__ ((unused)) int signo)
{
    siglongjmp (jmp, 1);
}

int
main()
{
    int sfd, cfd;
    char poem[BUFSIZ];
    struct sockaddr_in sa;
    FILE *fpoem = NULL;

#ifndef DEBUG
    if (daemon (0, 0))
        err (1, "daemon");
#endif

    if (signal (SIGHUP, sighub))
        err (1, "signal");

    if ((sfd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
        err (1, "socket");

    sa.sin_family = AF_INET;
    sa.sin_addr.s_addr = htonl (INADDR_ANY);
    sa.sin_port = htons (1073);
    if (bind (sfd, (struct sockaddr *)&sa, sizeof (sa)))
        err (1, "bind");

    if (listen (sfd, 10))
        err (1, "listen");

    if (sigsetjmp (jmp, 1))
        fclose (fpoem), close (cfd);

    if (! (fpoem = fopen ("/etc/poem.conf", "r")))
        err (1, "/etc/poem.conf");

    for (;;) {
        if ((cfd = accept (sfd, NULL, NULL)) == -1)
            perror ("accept");

        srand (time (NULL) + rand());
        fseek (fpoem, 0, SEEK_END);
        fseek (fpoem, rand() % ftell (fpoem), SEEK_SET);
        while (ftell (fpoem) > 0
                && fgetc (fpoem) != '\n')
            fseek (fpoem, -2, SEEK_CUR);

        fgets (poem, BUFSIZ, fpoem);
        write (cfd, poem, strlen (poem));
        close (cfd);
    }
}