Whatever you can do with shell script, you can do with perl and python too or in general any scripting language. However These languages have advantage and disadvantage over each other.
Here are the few reasons why i use the scripts.
- You can write a script to initialize something at boot time of the system. so you don’t need to do manually.
- You can write a script which installs per-requisite and build the code with user input to enable/disable some features.
- To kill or start multiple applications together.
- To observe large database of files and find some patterns out of it.
- System boot scripts (/etc/init.d)
- System administrators, for automating many aspects of computer maintenance, user account creation etc.
- Application package installation tools More detail
- Application startup scripts, especially unattended applications (e.g. started from cron or at)
- Any user needing to automate the process of setting up and running commercial applications, or their own code.