Web page downloader

//./client mech.math.msu.su http://mech.math.msu.su/~vvb/1course/index.html
#include <stdio.h>
#include <iostream>
#include <string.h>
#include <string>
#include <stdlib.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
using namespace std;
int main(int argc, char* argv[]) {
    if(argc<3)
        return 1;
    string peerHost = argv[1]; // = "mech.math.msu.su";
    string url = argv[2]; //= "http://mech.math.msu.su/~vvb/1course/index.html";
    int peerPort = 80;
    //cin>>peerHost;
    //cin>>url;
    //cin>>peerPort;

    int s0 = socket(AF_INET, SOCK_STREAM, 0);
    struct hostent *host = gethostbyname(peerHost.c_str());
    if (host == NULL) {
        perror("Cannot define host address"); exit(1);
    }
    struct sockaddr_in peeraddr;
    memset(&peeraddr, 0, sizeof(peeraddr));
    peeraddr.sin_family = AF_INET;
    peeraddr.sin_port = htons(peerPort);
    memmove(&(peeraddr.sin_addr.s_addr), host->h_addr_list[0], 4);
    printf(
        "peer addr = %d.%d.%d.%d, port %d\n",
        host->h_addr_list[0][0] & 0xff,
        host->h_addr_list[0][1] & 0xff,
        host->h_addr_list[0][2] & 0xff,
        host->h_addr_list[0][3] & 0xff,
        (int) peerPort
    );

    int res = connect(s0,(struct sockaddr*) &peeraddr, sizeof(peeraddr));
    if (res < 0) {
        perror("Cannot connect!"); exit(1);
    }
    printf("Connected. Reading a server message.\n");
    string s = "GET " + url + " HTTP/1.1 \r\nHost: " + peerHost +
    "\r\n\r\n";
    write(s0, s.c_str(), strlen(s.c_str()));

    FILE * pFile = fopen ( "file.html" , "w+" );
    char buffer[1];
    bool flag = false;
    // char prev;
    while (read(s0,buffer,1) > 0) {
        printf("%s", buffer);
        //if(buffer[0]=='\n'&&prev=='\n'||buffer[0]=='\r'&&prev=='\n'||buffer[0]=='\n'&&prev=='\r'||buffer[0]=='\r'&&prev=='\r')
        if(buffer[0]=='<') flag = true;
        if(flag)
        fwrite(buffer , 1, sizeof(buffer) , pFile);
        //prev = buffer[0];
    }

    close(s0);
    fclose (pFile);
    return 0;
}