[linux] c 实现简单的web服务器

web.c

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

#include "wrap.h"

#define BUFF_SIZE 1024
#define SERV_PORT 8000

void handle_sig(int sig) 
{
    printf("child exit\n");
    wait(NULL);
}

char *http_res_tmpl = "HTTP/1.1 200 OK\r\n"
        "Server: Cleey's Server V1.0\r\n"
        "Accept-Ranges: bytes\r\n"
        "Content-Length: %d\r\n"
        "Connection: close\r\n"
        "Content-Type: %s\r\n\r\n";

void http_send(int sock_client,char *content){
        char HTTP_HEADER[BUFF_SIZE],HTTP_INFO[BUFF_SIZE];
        int len = strlen(content);
        sprintf(HTTP_HEADER,http_res_tmpl,len,"text/html");
        len = sprintf(HTTP_INFO,"%s%s",HTTP_HEADER,content);

        Write(sock_client,HTTP_INFO,len);
}

int main(void)
{
    struct sockaddr_in servaddr, cliaddr;
    socklen_t cliaddr_len;
    int listenfd, connfd;
    char buf[BUFF_SIZE];
    char str[INET_ADDRSTRLEN];
    int i, n;
    
    struct sigaction act;
    act.sa_handler = handle_sig;
    sigemptyset(&act.sa_mask);
    act.sa_flags = 0;
    sigaction(SIGCHLD,&act,NULL);


    listenfd = Socket(AF_INET, SOCK_STREAM, 0);
    
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
    servaddr.sin_port = htons(SERV_PORT);

    int opt = 1;
    setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));

    Bind(listenfd, (struct sockaddr *)&servaddr, sizeof(servaddr));
    Listen(listenfd, 20);

    printf("Accepting connections ...\n");
    while(1) {
        cliaddr_len = sizeof(cliaddr);
        connfd = Accept(listenfd, (struct sockaddr *)&cliaddr, &cliaddr_len);
       
        n = fork();
        if ( n == -1) {
            perror("call to fork");
            exit(1);
        } else if (n == 0) { // child
            Close(listenfd);

            n = Read(connfd, buf, BUFF_SIZE);
            if (n == 0) {
                printf("the other side has been closed.\n");
                break;
            }
            printf("received from %s at PORT %d\n", inet_ntop(AF_INET, &cliaddr.sin_addr, str, sizeof(str)), ntohs(cliaddr.sin_port));
            fputs(buf, stdout); 
            http_send(connfd, "hello world!");
            Close(connfd);
            exit(0);
       } else {  // parent
            Close(connfd);
       }
    }
}

运行服务器：

gcc web.c wrap.c -o web

./web

在浏览器中输入：

http://127.0.0.1:8000

注：wrap.h 在 http://blog.csdn.net/tzshlyt/article/details/53229878 这里提到。