When using the pattern of blanking the lines first and then deleting
the blank lines, the program ends up deleting potentially intentional
blank lines. In order to avoid this, use a simple delete rather than the
blanking + blank line deleting pattern.
This program contains the same functionality as previous iterations,
with several changes:
- move to command-based structure using the bash boilerplate template,
- inlcude basic error handling,
- revise variable naming and options for clarity,
- prefer `printf` over `echo`,
- misc other revisions.
