koalaman/shellcheck ? reverse-engineered prompt

Build me a command line tool called ShellCheck that reads bash and sh scripts and points out mistakes, bad quoting, portability problems, and other tricky shell bugs.

I want it to work on a file or on input from stdin, print clear warnings with line numbers, and use a sensible exit code so it can fail in scripts and CI when there are problems. Make the output easy to read in the terminal, and if it’s not too much work, also support a machine friendly format like JSON or compiler style warnings. Include a few good examples and tests for common shell mistakes so I can see it catching the kinds of issues people usually miss.

If you need to look up current docs or behavior details, go ahead and check online first.