sep_serv.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#define BUF_SIZE 1024

int main(int argc,char *argv[])
{
    int serv_sock, clnt_sock;
    FILE *readfp;
    FILE *writefp;

    struct sockaddr_in serv_adr, clnt_adr;
    socklen_t clnt_adr_sz;
    char buf[BUF_SIZE]={0,};

    serv_sock=socket(PF_INET, SOCK_STREAM, 0);
    memset(&serv_adr, 0, sizeof(serv_adr));
    serv_adr.sin_family=AF_INET;
    serv_adr.sin_addr.s_addr=htonl(INADDR_ANY);
    serv_adr.sin_port=htons(atoi(argv[1]));

    bind(serv_sock,(struct sockaddr*)&serv_adr,sizeof(serv_adr));
    listen(serv_sock,5);
    clnt_adr_sz=sizeof(clnt_adr);
    clnt_sock=accept(serv_sock, (struct sockaddr*)&clnt_adr,&clnt_adr_sz);

    readfp=fdopen(clnt_sock,"r");
    writefp=fdopen(dup(clnt_sock),"w");

    fputs("FROM SERVER: Hi~ client? \n",writefp);
    fputs("I love all of the world \n",writefp);
    fputs("You are awesome! \n",writefp);
    fflush(writefp);

    shutdown(fileno(writefp),SHUT_WR);
    fclose(writefp);

    fgets(buf, sizeof(buf),readfp); fputs(buf,stdout);
    fclose(readfp);
    return 0;
}