nmap . -O: Enable OS detection

commandline session $nmap 127.0.0.1 Starting Nmap 6.00 ( http://nmap.org ) at 2013-11-24 17:56 IST Nmap scan report for localhost (127.0.0.1) Host is up (0.00019s latency). Not shown: 997 closed ports PORT STATE SERVICE 22/tcp open ssh 25/tcp open smtp 111/tcp open rpcbind Nmap done: 1 IP address (1 host up) scanned in 0.10 seconds $nmap …

chmod – change file mode bits

ABOUT chmod In Unix and Unix-like operating systems, chmod is the command and system call which is used to change the access permissions of file system objects (files and directories). It is also used to change special mode flags. The request is filtered by the umask. The name is an abbreviation of change mode.[1] TYPICAL …