Batch Files

To save time typing rather long commands, we can save various commands in executable files.

On Windows, just save the commands in a file with a name ending with a '.bat' extension. Eg. r.bat. (To run it, enter 'r'.

On Linux or Mac, we can pick any filename, but after saving the file, we must make the file executable. Eg. chmod 777 r. (To run, enter './r').