Erlang实现的一个Web服务器代码实例

作者: 从此我再也不能好好看文字了
来源: 51数据库
2021-07-04

转贴一个简单的web服务器：

httpd.erl

%% httpd.erl - microhttpd 
-module(httpd). 
-author("ninhenry@gmail.com"). 
 
-export([start/0,start/1,start/2,process/2]). 
-import(regexp,[split/2]). 
 
-define(defport,8888). 
-define(docroot,"public"). 
 
start() -> start(?defport,?docroot). 
start(port) -> start(port,?docroot).  
start(port,docroot) -> 
 case gen_tcp:listen(port, [binary,{packet, 0},{active, false}]) of 
  {ok, lsock} -> server_loop(lsock,docroot); 
   {error, reason}  -> exit({port,reason}) 
 end. 
 
%% main server loop - wait for next connection, spawn child to process it 
server_loop(lsock,docroot) -> 
 case gen_tcp:accept(lsock) of 
  {ok, sock} -> 
   spawn(?module,process,[sock,docroot]), 
   server_loop(lsock,docroot); 
  {error, reason} -> 
   exit({accept,reason}) 
 end. 
 
%% process current connection 
process(sock,docroot) -> 
 req = do_recv(sock), 
 {ok,[cmd|[name|[vers|_]]]} = split(req,"[ \r\n]"), 
 filename = docroot ++ name, 
 logreq = cmd ++ " " ++ name ++ " " ++ vers, 
 resp = case file:read_file(filename) of 
  {ok, data} -> 
   io:format("~p ~p ok~n",[logreq,filename]), 
   data; 
  {error, reason} -> 
   io:format("~p ~p failed ~p~n",[logreq,filename,reason]), 
   error_response(logreq,file:format_error(reason)) 
  end,  
 do_send(sock,resp), 
 gen_tcp:close(sock). 
 
%% construct html for failure message 
error_response(logreq,reason) -> 
 "<html><head><title>request failed</title></head><body>\n" ++ 
 "<h1>request failed</h1>\n" ++ "your request to " ++ logreq ++ 
 " failed due to: " ++ reason ++ "\n</body></html>\n". 
 
%% send a line of text to the socket 
do_send(sock,msg) -> 
 case gen_tcp:send(sock, msg) of 
  ok -> ok; 
   {error, reason} -> exit(reason) 
 end. 
 
%% receive data from the socket 
do_recv(sock) -> 
 case gen_tcp:recv(sock, 0) of 
  {ok, bin} -> binary_to_list(bin); 
   {error, closed} -> exit(closed); 
   {error, reason} -> exit(reason) 
 end

运行时在httpd.erl本地建一个public目录，public目录里放一个index.html文件
然后httpd:start()启动服务器，就可以访问了