What Happens When You Execute PATH=$PATH:`pwd` Command?

Understanding the intricacies of command-line operations is crucial for anyone working with Unix or Linux systems. One such operation that often confuses beginners is the PATH=$PATH:pwd“ command. In this article, we will dive deep into what exactly happens when you execute this command.

Understanding the PATH Variable

Before we delve into the command, it’s important to understand the PATH variable. PATH is an environmental variable in Unix and Linux operating systems. It tells the shell which directories to search for executable files in response to commands issued by a user.

The Command: PATH=$PATH:pwd

The command PATH=$PATH:pwd“ is used to add the current directory to the PATH variable. Here’s how it breaks down:

• PATH: This is the environment variable we’re modifying.
• =: This operator is used to assign a new value to the PATH variable.
• $PATH:: This part of the command retrieves the current value of the PATH variable.
• pwd: This is a Unix command that stands for ‘print working directory’. It outputs the full pathname of the current working directory.
• “ `: These are backticks, used in Unix and Linux systems for command substitution. The command enclosed within the backticks is executed first, and its output is used in the place of the command.

So, PATH=$PATH:pwd“ essentially means “set the PATH to its current value, plus the path of the current directory”.

The Effect of the Command

When you execute the PATH=$PATH:pwd“ command, the shell adds the current directory to the list of directories that it searches for executables. This means that you can run scripts in the current directory without specifying their full path.

For example, if you have a script named myscript.sh in the current directory, you can run it simply by typing myscript.sh instead of its full path.

Important Considerations

While this command can be handy, it’s important to note a few things:

• The change is temporary: The updated PATH variable will only be effective for the current shell session. Once the terminal is closed or a new session is started, the PATH variable will be reset to its default value.
• Security risks: Adding the current directory to the PATH can be a security risk. If the current directory contains a malicious executable with the same name as a system command, the shell might run the malicious executable instead of the system command.

In conclusion, the PATH=$PATH:pwd“ command is a powerful tool that can make your command-line work more efficient. However, it should be used with caution due to potential security risks. Always make sure you understand the implications of a command before you run it.