client.c

#define _POSIX_C_SOURCE 200809L
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <stdint.h>
#include <fcntl.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/types.h>
#include "rxb.h"
#include "utils.h"
#ifdef USE_LIBUNISTRING
    #include <unistr.h>
#endif

#define MAX_REQUEST_SIZE (64 * 1024)

int main(int argc, char **argv) {
    int err, sd, i = 1;
    struct addrinfo hints, *res, *ptr;
    char *hostname = argv[1];
    char *port = argv[2];

    if (argc != 3) {
        printf("use: %s <hostname> <port>\n", argv[0]);
        exit(EXIT_FAILURE);
    }

    signal(SIGPIPE, SIG_IGN);

    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    if((err = getaddrinfo(hostname, port, &hints, &res)) != 0) {
        fprintf(stderr, "getaddrinfo error: %s\n", gai_strerror(err));
        exit(EXIT_FAILURE);
    }

    for(ptr = res; ptr != NULL; ptr = ptr->ai_next) {
        if((sd = socket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol)) < 0) {
            printf("connection FAILED at attempt %d\n", i);
            continue;
        }
        if((err = connect(sd, ptr->ai_addr, ptr->ai_addrlen)) == 0) {
            printf("connection ACCEPTED at attempt %d\n", i);
            break;
        }
        i++;
        close(sd);
    }

    if(ptr == NULL) {
        fprintf(stderr, "connection failed.\n");
        exit(EXIT_FAILURE);
    }

    freeaddrinfo(res);

    rxb_t rxb;
    for(;;) {
        
        rxb_init(&rxb, MAX_REQUEST_SIZE * 2);
        
        char mese[1024], tipo[1024], n_res[32];

        puts("mese ('fine' per terminare):");
        if(fgets(mese, sizeof(mese), stdin) < 0) {
            perror("fgets");
            exit(EXIT_FAILURE);
        }
        if(strcmp(mese, "fine\n") == 0) break;
        
        puts("tipo ('fine' per terminare):");
        if(fgets(tipo, sizeof(tipo), stdin) < 0) {
            perror("fgets");
            exit(EXIT_FAILURE);
        }
        if(strcmp(mese, "fine\n") == 0) break;
        
        puts("n_res ('fine' per terminare):");
        if(fgets(n_res, sizeof(n_res), stdin) < 0) {
            perror("fgets");
            exit(EXIT_FAILURE);
        }
        if(strcmp(n_res, "fine\n") == 0) break;

        // send request to the server
        if(write_all(sd, mese, strlen(mese)) < 0) {
            perror("write_all");
            exit(EXIT_FAILURE);
        }
        
        if(write_all(sd, tipo, strlen(tipo)) < 0) {
            perror("write_all");
            exit(EXIT_FAILURE);
        }

        if(write_all(sd, n_res, strlen(n_res)) < 0) {
            perror("write_all");
            exit(EXIT_FAILURE);
        }

        for(;;) {
            char line[MAX_REQUEST_SIZE]; 
            size_t line_len;

            memset(line, 0, sizeof(line));
            line_len = sizeof(line) - 1;

            if(rxb_readline(&rxb, sd, line, &line_len) < 0) {
                perror("rxb_readline");
                rxb_destroy(&rxb);
                close(sd);
                exit(EXIT_FAILURE);
            }
            
#ifdef USE_LIBUNISTRING
            if(u8_check((uint8_t *) line, line_len) != NULL) {
                fprintf(stderr, "not a valid utf-8 string!\n");
                rxb_destroy(&rxb);
                close(sd);
                exit(EXIT_FAILURE);
            }
#endif

            puts(line);
            if(strcmp(line, "----- END REQUEST -----") == 0) break;
        }
    }

    rxb_destroy(&rxb);
    close(sd);
    return 0;
}