Decorators in Python

  Apache HTTPD   is an   HTTP   server   daemon   produced by the   Apache Foundation . It is a piece of software that listens for network requests (which are expressed using the Hypertext Transfer Protocol) and responds to them. It is open source and  many entities use it to host their websites . Other HTTP servers are available (including  Apache Tomcat  which is designed for running server side programs written in Java (which don't use CGI)). CGI  is a protocol that allows an HTTP server to use an external piece of software to determine how to respond to a request instead of simply returning the contents of a static file. Many HTTP servers support the CGI protocol. You can use CGI without an HTTP server, but this typically has few uses beyond allowing a developer to perform command line testing of the CGI program. (You certainly can't interact with it directly from a web browser). HTTP Daemon is a software program that runs in th...

Port forwarding

  There are more elaborate ways, but my method is to use static IP addressed, which I can assign from my router, and enter the addresses into my hosts file. Once you get a static address assigned, either from the router or from the Network Connections dialog (in the IPv4 tab under the Wired or Wireless tab), you edit  /etc/hosts , using sudo or gksu with your preferred text editor, such as gedit or vim, and add a line for each host like so: 192.168.1.100 ComputerName1 192.168.1.101 ComputerName2 The numbers I use are common ones, but your LAN could be different. The names are whatever you want to call the remote computer, and can be anything (though probably best to match the real name). You can also create local websites by name here, if you have a local web server.

Configure ssH based Key Authentication : Linux What is SSH Key-based authentication? As we all know,  Secure Shell , shortly  SSH , is the cryptographic network protocol that allows you to securely communicate/access a remote system over unsecured network, for example Internet. Whenever you send a data over an unsecured network using SSH, the data will be automatically encrypted in the source system, and decrypted in the destination side. SSH provides four authentication methods namely  password-based authentication ,  key-based authentication ,  Host-based authentication , and  Keyboard authentication . The most commonly used authentication methods are password-based and key-based authentication. In password-based authentication, all you need is the password of the remote system's user. If you know the password of remote user, you can access the respective system using  "ssh user@remote-system-name"  command. On the other hand, in key-based...

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 su vs su -

  The Root User Both su and sudo are used to run commands with root permissions. The root user is basically equivalent to the administrator user on Windows – the root user has maximum permissions and can do anything to the system. Normal users on Linux run with reduced permissions – for example, they can’t install software or write to system directories. To do something that requires these permissions, you’ll have to acquire them with su or sudo. Su vs. Sudo The su command switches to the super user – or root user – when you execute it with no additional options. You’ll have to enter the root account’s password. This isn’t all the su command does, though – you can use it to switch to any user account. If you execute the  su bob  command, you’ll be prompted to enter Bob’s password and the shell will switch to Bob’s user account. ADVERTISEMENT Once you’re done running commands in the root shell, you should type  exit  to leave the root shell and go back to limited...

  Configuring  sudo  Access The  sudo  command offers a mechanism for providing trusted users with administrative access to a system without sharing the password of the  root  user. When users given access via this mechanism precede an administrative command with  sudo  they are prompted to enter their own password. Once authenticated, and assuming the command is permitted, the administrative command is executed as if run by the  root  user. Follow this procedure to create a normal user account and give it  sudo  access. You will then be able to use the  sudo  command from this user account to execute administrative commands without logging in to the account of the  root  user. ⁠ Procedure to configure  sudo  Access Log in to the system as the  root  user. Create a normal user account using the  useradd  command. Replace  USERNAME  with the user name that you wish...