Shellcheck optionals - #25

I've updated the regex used for the shebang & file ending as shellcheck should match the following shells:

• sh
• ash
• dash
• bash
• bats
• ksh
  src

Shebang regex:
Was: '^#!.*sh'
Now: '^#!\(/\|/.*/\|/.* \)\(\(ba\|da\|k\|a\)*sh\|bats\)$'

Test cases:
https://pastebin.com/BKB92wx2

Previous regex matched a lot of invalid shebangs & missed the 6 valid bats shebangs.

Current regex matches just the 6 correct shebangs from each valid shell.
There are probably some cases that I can't think of but it's a lot safer than the existing one.
A compromise would be something like: '^#!/.*\(\(ba\|da\|k\|a\)*sh\|bats\)$'
It matches the zsh fish and extra characters + valid shell ones but they're all at least valid.

File ending regex:
Was: \.sh$|bash$
Now: .+\.(sh|bash|dash|ksh|ash|bats)$

Test cases:
https://pastebin.com/JRJg8N13

Testing script:

#!/usr/bin/env bash
test() {
	if [[ "$1" =~ .+\.(sh|bash|dash|ksh|ash|bats)$ ]]; then
		echo "match     - $1"
	else
		echo "not match - $1"
	fi
}

while IFS= read -r FILE; do
	if [[ "$FILE" != "" ]]; then
		test "$FILE"
	fi
done <<EOF
TEST CASES HERE
EOF

Previous regex would match .sh bash and miss file.ksh file.dash file.ash file.bats

Current regex only matches the 3 normal file names + also matches just .sh .bash etc, which are very unusual but valid file names.
There's no extra checking for slashes etc because file names & escapes could confuse things, just the extension should be enough.

No problem

tabbing should be 2 spaces
Ahh. I think the original changes had 2 spaces. I think I ran shfmt at some point or something

the while loop should use $# -gt 0
The google style guide says it's fine to use (( )) in the testing strings section, and focuses on (( )) in the arithmetic section. But it's up to you :)

The google style guide says it's fine to use (( )) in the testing strings section, and focuses on (( )) in the arithmetic section. But it's up to you :)

shellcheck actually flags this because $# is a number, not a string, so you need to use -gt not >.

SC2071 only complains about the use of > and < within [[ ]]

(( )) can only handle numbers and shellcheck has no issues

Using -gt doesn't work with (( )) and causes the following shellcheck issues

Ahhh I think you are right. Apologies for that! I was so used to switching to [[]] everywhere I think I missed the first pass of shellcheck.

no problem 😃
I'll pop in a PR swapping back to spaces soon ah you've got one already, nice