Description: Here I use a make file to compile my java program and a script file to execute the application which implements “./normal_web_server <port>” interface. Then the client can input linux command to fetch the executed result at the server side. Since there is a specific format for the input URL, which is “/exec/<command>”, and my server will check the format the URL first. If the URL is in invalid format, server will return http 404 response to the client. If the URL is in right format, the server will try to execute the command, if there is no output, the server will return http 200 response with empty content. However, if the output existed, the server will return http 200 response with the corresponding output. 

In addition, for making server keep working without any interrupt, I create one thread for each socket request. So if one socket request let the server hang there (like cat filename), other socket requests can also be executed by the server, which means the server won’t die if you manually terminate the server.