How to Run a File in Unix

You can run a file in UNIX by invoking the file name from the command line. Alternatively, you can also choose to invoke a specific shell to run the file.

 Steps:

1

Check that you have permission to run (or) execute the file.

2

Execute permission is denoted by the letter 'x', while ‘r’ denotes read permission and ‘w’ denotes write permission

• If you are the owner of the file, you can grant yourself execute permission by using the ‘chmod’ command. Below example shows the file ‘file.sh’ before and after granting execute permission

3

Execute the file

• To execute the file, go to the directory where the file is and then invoke the file using the relative path.
• Or, you can also execute the file using the full path or absolute path.
• Sometimes, you may want to execute the file in a different shell in order to obtain the special behaviour of that shell. In such cases, the specified shell will start as a subshell of your current shell and execute the file. In the example below, we have executed the file.sh first using the BASH shell, then using the C shell and finally, using the KORN shell.

Tips: 

Standard UNIX file naming convention for executable or runnable files is to suffix the file name with “.sh”

Wiring:

Each shell has its own syntax for variables, functions, arguments etc. So make sure that the shell you are using to run your file is the right one for the job.