[linux] c 实现简单的web服务器

#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);
}
}
}