A simple script to rename a bulk of e-books in Calibre.
Node.js must be installed in your system; script runs from command line:
node calibre_rename.js
All configuration is done from config.json file; adding a GUI is not a priority right now.

query & query_term
The Calibre query needed to get a list of books to be renamed. You can read more on Calibre queries here:
Calibre Search Interface
For now only a single field is supported.

reg_replace
Regex is used to remove unwanted parts in the book name. Test your regex here.
Example:
"reg_replace":"Microsoft|Word|\\.docx"
will remove all occurances of Microsoft, Word and .docx from the book name.
It is case insensitive.

padded_numbers_up_to_thousand
If set true, will pad numbers 1 - 99, with two or three 0's, assuming the book is part of a series.
Calibre will sort the books in this order if name is not padded:
Book 1
Book 10
Book 11
Book 2
Book 20
which is not to my liking. Set it false to disable.

enable_title_set
Must be true for new names to be commited. false for testing or reviewing purposes.

split_str
Regex used to convert stdout into an array. No need to change.

start_calibre_on_script_end
Starts Calibre and exits command line if set to true.
Tested only on Linux Mint 19.1, but should work on other Unix systems as well.

write_to_log & write_to_log_commands
First option creates a new .log file with renaming output for reviewing or book-keeping. Second options logs commands used as well, ala verbose style.

Finally, debug outputs everything to console in case you're a freak :)

Thanks for you time!