basic flood program

flut.c

/*
Send a message up to a newline to the server.
Read a reply up to a newline and print it to stdout.
Loop.
Usage:
    ./client [<server-address> [<port>]]
Default ip: localhost.
Default port: 12345
*/

#define _XOPEN_SOURCE 700

#include <assert.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <arpa/inet.h>
#include <netdb.h> /* getprotobyname */
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>

int main(int argc, char **argv) {
	char buffer[BUFSIZ];
	char protoname[] = "tcp";
	struct protoent *protoent;
    char *server_hostname = "127.0.0.1";
    char *user_input = NULL;
    in_addr_t in_addr;
    in_addr_t server_addr;
    int sockfd;
    size_t getline_buffer = 0;
    ssize_t nbytes_read, i, user_input_len;
    struct hostent *hostent;
    /* This is the struct used by INet addresses. */
    struct sockaddr_in sockaddr_in;
    unsigned short server_port = 12345;

    if (argc > 1) {
        server_hostname = argv[1];
        if (argc > 2) {
            server_port = strtol(argv[2], NULL, 10);
        }
    }

    /* Get socket. */
	protoent = getprotobyname(protoname);
	if (protoent == NULL) {
        perror("getprotobyname");
        exit(EXIT_FAILURE);
	}
    sockfd = socket(AF_INET, SOCK_STREAM, protoent->p_proto);
    if (sockfd == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    /* Prepare sockaddr_in. */
    hostent = gethostbyname(server_hostname);
    if (hostent == NULL) {
        fprintf(stderr, "error: gethostbyname(\"%s\")\n", server_hostname);
        exit(EXIT_FAILURE);
    }
    in_addr = inet_addr(inet_ntoa(*(struct in_addr*)*(hostent->h_addr_list)));
    if (in_addr == (in_addr_t)-1) {
        fprintf(stderr, "error: inet_addr(\"%s\")\n", *(hostent->h_addr_list));
        exit(EXIT_FAILURE);
    }
    sockaddr_in.sin_addr.s_addr = in_addr;
    sockaddr_in.sin_family = AF_INET;
    sockaddr_in.sin_port = htons(server_port);

    /* Do the actual connection. */
    if (connect(sockfd, (struct sockaddr*)&sockaddr_in, sizeof(sockaddr_in)) == -1) {
        perror("connect");
        return EXIT_FAILURE;
    }
    fprintf(stderr, "connected\n");
    while (1) {
        #define xoff 0
        #define yoff 0
        #define w 1920
        #define h 1200
        #define BARS 6
        char colours[BARS][7] = {"f40000\0", "ff8601\0", "faf601\0", "018821\0", "4600ff\0", "830189\0"}; //LGBT
        //char colours[BARS][7] = {"fff434\0", "ffffff\0", "9c59cf\0", "2d2d2d\0"}; //NONBINARY
        //char colours[BARS][7] = {"5bcefa\0", "f5a9b8\0", "ffffff\0", "f5a9b8\0", "5bcefa\0"}; //TRANS
        
        
        #define framesize 8500
        char line[framesize] = "\0";
        
        char buf[21];

        int bh = h / BARS;

        for (int y = yoff; y < h + yoff; y++) {
            int col = (y - yoff) / bh;
            for (int x = xoff; x < w + xoff; x++) {
                sprintf(buf, "PX %i %i %s\n", x, y, colours[col]);
                //fprintf(stderr, "%s, %i", buf, col);
                if (strlen(line) + strlen(buf) > framesize) {
                    if (write(sockfd, line, strlen(line)) == -1) {
                        fprintf(stderr, "write error");
                        exit(EXIT_FAILURE);
                    }
                    strcpy(line, buf);
                } else {
                    strcat(line, buf);
                }
            }
        }
    }
    exit(EXIT_SUCCESS);
}