/*
    Reader/writer to TCP/IP socket
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>

#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netdb.h>

static const char	*name;

static const char *GetLine(void)
{
    static char buff[1024];
    int l;

    if (feof(stdin))
    {
	return(NULL);
    }

    printf("> ");

    if (!fgets(buff, sizeof buff, stdin))
    {
	return(NULL);
    }

    l=strlen(buff);

    if (l > 0 && buff[l-1]=='\n')
    {
	buff[l-1]=0;
    }

    if (strlen(buff))
    {
	return buff;
    }
    else
    {
	return GetLine();
    }
}


static int Connect(const char *n, const char *p)
{
    struct addrinfo *addr, *addr_p;
    struct addrinfo hints = {0};
    int status;
    int sock = -1;

    hints.ai_family = PF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;

    status = getaddrinfo(n, p, &hints, &addr);

    if (status)
    {
	fprintf(stderr, "%s: %s\n", name, gai_strerror(status));
	exit(EXIT_FAILURE);
    }

    for(addr_p = addr; addr_p && sock == -1; addr_p = addr_p->ai_next)
    {
        sock = socket(addr_p->ai_family,
                      addr_p->ai_socktype,
                      addr_p->ai_protocol);

        if (sock != -1)
        {
            if (connect(sock, addr_p->ai_addr, addr_p->ai_addrlen) == -1)
            {
                close(sock);
                sock = -1;
            }
        }
    }

    if (sock == -1)
    {
        fprintf(stderr, "%s: Failed to connect to %s:%s\n", name, n, p);
        exit(EXIT_FAILURE);
    }

    return sock;
}

int main(int argc, char *argv[])
{
    struct sockaddr_in addr;
    socklen_t addrlen;
    const char *p;
    char buff[1024];
    int len;
    int sock;
    int no_read;
    int no_write;

    name=argv[0];

    if (argc<3)
    {
	fprintf(stderr,"%s: usage %s host port [nowrite|noread]\n",name,name);
	exit(EXIT_FAILURE);
    }

    if (argc > 3)
    {
    	no_read = strcmp(argv[3], "noread") == 0;
    	no_write = strcmp(argv[3], "nowrite") == 0;
    }
    else
    {
    	no_read = 0;
    	no_write = 0;
    }

    sock = Connect(argv[1],argv[2]);

    /* Test to see how to get the connected local port number
    */
    addrlen=sizeof(addr);

    if (getsockname(sock,(void*)&addr,&addrlen)!=0)
    {
	perror(name);
    }

    printf("%s: bound through port %d\n",name,ntohs(addr.sin_port));

    while(no_write || (p=GetLine()))
    {
	if (!no_write && (write(sock,p,strlen(p))==-1))
	{
	    perror(name);
	    close(sock);
	    exit(EXIT_FAILURE);
	}

	if (!no_read)
	{
	    if ((len=read(sock,buff,1024))<=0)
	    {
		perror(name);
		close(sock);
		exit(EXIT_FAILURE);
	    }

	    buff[len]=0;
	    printf("%s\n",buff);
	}
    }

    close(sock);
    printf("\n");

    return EXIT_SUCCESS;
}