BASH Programming

Why Do You Need to Put bin/bash at the Beginning of a Script File – bash

When writing a script in the Bash language, it is common practice to start the file with the line #!/bin/bash. This line is called the shebang line and is a crucial component of any Bash script, further to read more about this line go through this guide.

What is bin/bash in Bash Script?

The term “bin/bash” in a Bash script refers to the location of the Bash shell executable on the system. In a Unix-like operating system, the “bin” directory typically contains executable files, including shells. The Bash shell is one of the most used shells in the Unix world, and its executable is typically located in the “/bin” directory. The “#!/bin/bash” line at the beginning of a Bash script is known as the shebang that serves to specify the shell interpreter that is used to run the script.

Why to put bin/bash at the beginning of a script file?

The shebang line is used to provide the address of the interpreter that should be used to run the script so in the case of #!/bin/bash, the script will be interpreted by the Bash shell. This is important because different operating systems have different shells installed, and the same script may not work as expected on all systems unless the correct interpreter is specified.

By including the shebang line, you ensure that the script will be executed by the correct shell, regardless of the environment in which it is run. This helps to ensure compatibility and portability of the script, making it easier to share and reuse across different systems.

Additionally, the shebang line also makes the script executable, allowing it to be run directly from the command line. Without the shebang line, you would need to manually specify the interpreter each time you run the script, which can be tedious and prone to errors.

Can you run the Bash file without /bin/bash?

Yes, you can run a Bash script without specifying /bin/bash as the interpreter. The default system shell, which is usually /bin/sh on most systems, can be used to run a Bash script but if the default shell is not set to bash then you might not be able to run it. However, If your script begins with the line #!/bin/bash, then the system will use the /bin/bash interpreter to run the script, regardless of what the default shell is set to.


The shebang line #!/bin/bash is a crucial component of any Bash script, as it specifies the interpreter to be used and makes the script executable. By including this line at the beginning of your script file, you can ensure that your script will work as expected on any system and will be easy to run and share.

About the author

Aaliyan Javaid

I am an electrical engineer and a technical blogger. My keen interest in embedded systems has led me to write and share my knowledge about them.