Various of my most frequently used scripts and one-liners for my most often required tasks. All run on my Xubuntu 20.04 system.
To get the number of pages of a pdf:
qpdf --show-npages OriginalFile.pdf
To split a pdf into chunks of 300 pages (files will be named NewFile-001-300.pdf, etc.):
qpdf --split-pages=300 OriginalFile.pdf NewFile.pdf
Text File Wrangling
To remove a continuous set of numbered lines (in this example, lines 10 to 15) reiterated over a folder of text files:
sed -i '10,15d' folder/*.txt