You should add a help menu to this (e.g. ./splitter -h) that shows more useful information on how to use this script.
Another suggestion I have would be to perhaps look into being able to specify the output file type? Especially if you want to do splitting for each individual page.
Other potential ways to improve:
write it in a real programming language
Add a dry-run mode?
Provide a way to use a custom format for the output files
Output files into a directory or provide the location where to output the files
Provide a way to pass extra arguments directly to GhostScript
You should add a help menu to this (e.g. ./splitter -h) that shows more useful information on how to use this script.
Another suggestion I have would be to perhaps look into being able to specify the output file type? Especially if you want to do splitting for each individual page.
Other potential ways to improve: