3.7. Scripts

This information is provided in case you want it. You will not need it for this course.

A script is a file that contains commands. When you run the script, the commands are performed. This page describes briefly how to write and run scripts in Linux.

The first line of a script should give the command interpreter to use. If you want your script to be read by the bash command interpreter, the first line should be

To use the sh command interpreter (often used for scripts), use first line
For example, when script
mv * ~/.remove/
is performed, it moves all files in the current working directory into directory .remove in your home directory.


To run a script, put it into a file and mark that file as executable. If the file is called rmall, then

  chmod u+x rmall
changes the permissions (called the mode) of file rmall so that the user (that is, you) can execute it. Now command
runs the script in file rmall.


A script can use command-line parameters. Write $1 to refer to the first parameter, $2 to the second, etc. For example, suppose that the following is stored in a file called show.

  echo $1
  cd $1
Then, after you have marked show to be executable, command
  ./show 2530
will write
where the … part is a listing of what is found in directory 2530. That is very similar to what is done by command
  ls 2530