- add 'use warnings' and 'use strict' where missing from Perl scripts.
- fix 'Use of uninitialized value'.
- fix missing declarations.
- test1140.pl: fix 'Possible precedence issue with control flow operator'.
- fix other misc issues.
Most actual errors found during this PR were fixed and merged via
separate PRs.
Likely there are remaining warnings not found and fixed in this PR.
Closes#17877
Since the documentation text blob might be gzipped, it needs to search
for what to output in a streaming manner. It then first searches for
"\nALL OPTIONS".
Then, it looks for the start to display at "\n -[option]" and stops
again at "\n -". Except for the last option in the man page, which
ends at "\nFILES" - the subtitle for the section following all options
in the manpage.
Test 1707 to 1710 verify
Closes#13997