SC1071 should not get checked if -s is specified

[blueyed]

For bugs

• Rule Id (if any, e.g. SC1000): SC1071
• My shellcheck version (shellcheck --version or "online"): 0.4.6

shellcheck -s sh should use the "sh" dialect, and not look at the shebang line, possibly causing SC1071:

% shellcheck -s sh =(echo '#!/bin/zsh')

In /tmp/zshLclZZ0 line 1:
#!/bin/zsh
^-- SC1071: ShellCheck only supports sh/bash/dash/ksh scripts. Sorry!

[blueyed]

Just came across this again.

Any feedback on this?
Might make it a bit faster even when the shebang parsing would be skipped.

My use case is running it for zsh scripts occasionally.

I could like with a warning, but you could assume that if --shell is specified, this one should be just used.

[blueyed]

Related docs: https://github.com/koalaman/shellcheck/blame/10edba3ab82d58fb262a6ab3cc0245c0e6372259/shellcheck.1.md#L59-L63

The workaround would be for me to remove the shebang before calling shellcheck on it, but I would really like to avoid that.

I think the following needs to be skipped in case the shell option is given, but I do not know how:

shellcheck/src/ShellCheck/Parser.hs

Lines 2964 to 2966 in 10edba3

	sb <- option "" readShebang
	verifyShell pos (getShell sb)
	if isValidShell (getShell sb) /= Just False

[koalaman]

It's probably of very limited use given that basically any syntax that requires #!/bin/zsh also makes shellcheck useless, but I definitely agree that this behavior directly contradicts the purpose of the -s flag.

As of 5005dc0, -s will indeed override this check, and further you can specify the shell override as a directive. This now parses without errors:

#!/bin/zsh
# shellcheck shell=sh
echo "hello world"

[blueyed]

Awesome, thanks!

btw: is there any chance to get back support for Zsh?
What has been the reason to drop it in the first place?
I've only found ed56a83 with no explanations.

[koalaman]

You can follow the progress (or lack thereof) on #809.

[blueyed]

Thanks!