Design and implement Webserver

Design and Implement a Web Server program that can understand (part of)HTTP and can return pages to real client like netscape or explorer. Requirements: 1)It will be in C++ running on a Unix system, 2)It will return pages to real clients, 3)It will be a concurrent server able to process more than one request in parallel using Threads not processes again using Threads not processes. 4)all socket I/O should use system calls(not iostream or stdio library calls), however error messages and log files writing can use library [login to view URL] files can be done with iostream calls or system calls and will depend on which is easier but reading or writing sockets should use system calls. 5)It only needs to deal with GEt,HEAD and POST. 6)it will return enough correct protocol messages (OK or fail acknoledgements, content-length:, content-Type: etc) for clients to work,(NB not content type for CGI), 7)It should return appropriate error responses for "404 Not Found", "501 Not Implemented" and "400 Bad Request", 8)It will use its own port number not 80. 9)it should use a special directory to keep webpages and CGI and PHP programs, 10)It will use a log file to record all transactions,(file locking to cope with concurent access is not necessary), 11)it should support the execution of CGI programs,(providing arguments from the GET request), 12)it should support the execution of PHP programs program should be well commented.I have done the GET request and want coder to include that in the program and do the rest of coding.I will give that coding to coder I will choose to do my work.