How To Write A Bash Script With Falgs . We’ll create four string variables and one numeric variable, this_year: For example we would like to trace script and stop if some command fail (in our case it will be done by command. RM command in Linux explained with examples from candid.technology As the ” file.txt ” is present in the system. Whenever you want to launch the script in the future, just open the bash shell and type the path to the script. The bash interpreter reads each line and executes the update command followed by the upgrade command.