Module shebang: sh or bash?

[VladimirSlavik]

I'm looking at making anaconda's dracut modules report clean when shellcheck-ed.

The modules we have use both #!/bin/sh and #!/bin/bash. However when I examine the actual shell in use, all sh are symlinked to bash. Obviously POSIX compliance makes a difference, but we already have both and it's the same interpreter anyway. It seems I could just unify the shebangs to one interpreter and make my life simple before moving on to the actual shellchecking.

Can I do that, and if so, which is more correct to use?

[haraldh]

In an initramfs with dash installed and bash omitted, /bin/sh points to a posix shell, and all modules which need bash can not be installed.

So that is basically for use cases, where you want a really tiny initramfs.

[VladimirSlavik]

Thanks, basically I read this as having an implicit corollary "However when you did not minimize and know you have bash there, that's another case and you can probably use it at your own risk."