signal (SIGALRM,sig_handler) //TRY IT! Struct sockaddr_in server_addr,client_addr If(strstr(fname,'.png'))header=header_jpg ĭebug001(printf('Write %d bytes to %d. ',size,fd)) If(strstr(fname,'.jpg'))header=header_jpg Static ssize_t readln(int sockfd, char *buf,size_t len, int time_out) N=write(fd,header,strlen(header)) //write header Printf('This is the new child(pid=%d) ',getpid()) Ĭhar *header='HTTP/1.1 200 OK Content-Type: text/html charset=UTF-8 ' Sprintf(port,'%d',ntohs(client_addr->sin_port)) Setenv('REMOTE_ADDR', inet_ntoa(client_addr->sin_addr), 1) Clients usingįuture versions of HTTP might optimistically try a new feature,īut if communicating with an older server, retry with old Without the penalty of closing the TCP connection. HTTP can evolve more gracefully, since errors can be reported Spent in TCP's connection opening handshake. Latency on subsequent requests is reduced since there is no time Network congestion is reduced by reducing the number of packetsĬaused by TCP opens, and by allowing TCP sufficient time toĭetermine the congestion state of the network. Waiting for each response, allowing a single TCP connection toīe used much more efficiently, with much lower elapsed time. Pipelining allows a client to make multiple requests without HTTP requests and responses can be pipelined on a connection. Tunnels, or caches), and memory used for TCP protocol control In routers and hosts (clients, servers, proxies, gateways, By opening and closing fewer TCP connections, CPU time is saved Persistent HTTP connections have a number of advantages:

RFC 2616 Hypertext Transfer Protocol - HTTP/1.1 現今 HTTP 除了 HTTP 1.0 與 HTTP 1.1 的差別外還有一重要的改進: HTTP persistent connection (HTTP keep-alive)

Wireshark http 1.0 or 1.1