wclient.c

#include "io_helper.h"
#include "definitions.h"
#include <pthread.h>
#include <sys/time.h> 
#include <unistd.h>

//
// Send an HTTP request for the specified file 
//
void client_send(int fd, char *filename) {
    char buf[MAXBUF];
    char hostname[MAXFILETYPE];
    char hostheader[MAXBUF];
    
    gethostname_or_die(hostname, MAXBUF);
    
    /* Form and send the HTTP request */
    snprintf(buf, MAXBUF, "GET %s HTTP/1.1\n", filename);
    snprintf(hostheader, MAXBUF, "host: %s\n\r\n", hostname);
    strncat(buf, hostheader, MAXBUF);
    write_or_die(fd, buf, strlen(buf));
}

//
// Read the HTTP response and print it out
//
void client_print(int fd) {
    char buf[MAXBUF];  
    int n;
    
    // Read and display the HTTP Header 
    n = readline_or_die(fd, buf, MAXBUF);
    while (strcmp(buf, "\r\n") && (n > 0)) {
        printf("Header: %s", buf);
	    n = readline_or_die(fd, buf, MAXBUF);
	
    }
    
    // Read and display the HTTP Body 
    n = readline_or_die(fd, buf, MAXBUF);
    while (n > 0) {
        printf("Header: %s", buf);
        n = readline_or_die(fd, buf, MAXBUF);
    }
}

typedef struct _client_data {
    char *host;
    char *filename;
    int port;
} client_data;

void* single_client(void* arg) {
    
    client_data *t = (client_data*)(arg);
    char* host = t->host;
    char* filename = t->filename;
    int port = t->port;
    /* Open a single connection to the specified host and port */
    int clientfd = open_client_fd_or_die(host, port);
    
    client_send(clientfd, filename);
    client_print(clientfd);
    
    close_or_die(clientfd);
    return NULL;

}


int main(int argc, char *argv[]) {
    char *host;
    int port;
    if (argc < 4) {
        fprintf(stderr, "Usage: %s <host> <port> <filename(s)> \n", argv[0]);
        exit(1);
    }

    // Getting the host and the port name
    host = argv[1];
    port = atoi(argv[2]);

    // Total number of files given as input from the command line
    int concur_clients = argc - 3;
    pthread_t threads[concur_clients];

    // Creating threads to server requests for all the files concurrently
    for(int i = 0; i < concur_clients; i++) {
        
        client_data *d = malloc(sizeof(client_data));
        if(d == NULL) {
            printf("Could not create request for: %s\n", argv[3 + i]);
            continue;
        }
        d->host = host;
        d->port = port;
        d->filename = argv[3 + i];
        pthread_create(&threads[i], NULL, single_client, (void *)d);
        
    }
    for(int i = 0; i < concur_clients; i++) {
        pthread_join(threads[i], NULL);
    }

    exit(0);
}