socket学习笔记——并发服务器与I/O程序分割客户端

client.c

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

#define BUF_SIZE 30
void error_handling(char* message);
void read_routine(int sock,char* buf);
void write_routine(int sock,char* buf);

int main(int argc,char* argv[])
{
    int sock;
    pid_t pid;
    char buf[BUF_SIZE];
    struct sockaddr_in serv_addr;
    if(argc != 3)
    {
        printf("usage: %s <ip><port>
",argv[0]);
        exit(1);
    }

    sock = socket(PF_INET,SOCK_STREAM,0);
    memset(&serv_addr,0,sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = inet_addr(argv[1]);
    serv_addr.sin_port = htons(atoi(argv[2]));

    if(connect(sock,(struct sockaddr*)&serv_addr,sizeof(serv_addr)) == -1)
        error_handling("connect error");

    pid = fork();
    if(pid == 0)
        write_routine(sock,buf);
    else
        read_routine(sock,buf);

    close(sock);
    return 0;
}

void read_routine(int sock,char* buf)
{
    while(1)
    {
        int str_len;
        str_len = read(sock,buf,BUF_SIZE);
        if(str_len == 0)
            return;
        buf[str_len] = 0;
        printf("message from server;%s",buf);
    }
}

void write_routine(int sock,char* buf)
{
    while(1)
    {
        fgets(buf,BUF_SIZE,stdin);
        if(!strcmp(buf,"q
") || !strcmp(buf,"Q
"))
        {
            shutdown(sock,SHUT_WR);
            return;
        }
        write(sock,buf,strlen(buf));
    }
}

void error_handling(char* message)
{
    fputs(message,stderr);
    fputc('
',stderr);
    exit(1);
}

server.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <sys/socket.h>

#define BUF_SIZE 30
void error_handling(char* message);
void read_childproc(int sig);

int main(int argc,char* argv[])
{
    int serv_sock,clnt_sock;
    struct sockaddr_in serv_addr,clnt_addr;
    struct sigaction act;
    pid_t pid;
    socklen_t adr_sz;
    int str_len ,state;
    char buf[BUF_SIZE];

    if(argc != 2)
    {
        printf("usage:%s <port>
",argv[0]);
        exit(1);
    }

    act.sa_handler = read_childproc;
    sigemptyset(&act.sa_mask);
    act.sa_flags = 0;
    state = sigaction(SIGCHLD,&act,0);

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

    if(bind(serv_sock,(struct sockaddr*)&serv_addr,sizeof(serv_addr)) == -1)
        error_handling("bind error");
    if(listen(serv_sock,5) == -1)
        error_handling("listen error");
    
    while(1)
    {
        adr_sz = sizeof(clnt_addr);
        clnt_sock = accept(serv_sock,(struct sockaddr*)&clnt_addr,&adr_sz);
        if(clnt_sock == -1)
            continue;
        else
            puts("connecting......");

        pid = fork();
        if(pid == -1)
        {
            close(clnt_sock);
            continue;
        }
        if(pid == 0)
        {
            close(serv_sock);
            while((str_len = read(clnt_sock,buf,BUF_SIZE)) != 0)
                write(clnt_sock,buf,str_len);
            
            close(clnt_sock);
            return 0;
        }
        else
            close(clnt_sock);
    }
    close(serv_sock);
    return 0;
}

void read_childproc(int sig)
{
    pid_t pid;
    int status;
    pid = waitpid(-1,&status,WNOHANG);
    printf("removed proc id:%d
",pid);
}

void error_handling(char* message)
{
    fputs(message,stderr);
    fputc('
',stderr);
    exit(1);
}