I do have one suggestion: you have it ignoring "SC2154: 'var' is referenced but not assigned" by default, which makes sense on the command line because you're often not assigning and then referencing the same variable in a single command. But, I think it would be useful to have a similar warning like "SCREPL01: 'var' is not defined in the local environment," or something, which you might implement in shellcheck-repl itself. That rule could simply check to see if 'var' exists in the current shell's environment or if it's defined in the user's current command.
I think bash is simple enough that you might not have to a full-blown parse on the input to pick out instances of variable use (just look for 'export var', 'unset var', 'var=', and the like). You'd also want to take into account special variables like $RANDOM and $HOSTNAME, but that's pretty trivial.
Thank you, and thanks for the suggestion. Yes, it should be possible to keep the SC2154 check. I probably just disabled it as a quick fix when first started out. I'm tracking this in https://github.com/HenrikBengtsson/shellcheck-repl/issues/15.
> You'd also want to take into account special variables like $RANDOM and $HOSTNAME, but that's pretty trivial.
It seems like ShellCheck is already aware of these special Bash variable, e.g. 'echo $RANDOM' will not trigger SC2154 (or even SC2086 that otherwise asks you to quote variables).
I do have one suggestion: you have it ignoring "SC2154: 'var' is referenced but not assigned" by default, which makes sense on the command line because you're often not assigning and then referencing the same variable in a single command. But, I think it would be useful to have a similar warning like "SCREPL01: 'var' is not defined in the local environment," or something, which you might implement in shellcheck-repl itself. That rule could simply check to see if 'var' exists in the current shell's environment or if it's defined in the user's current command.
I think bash is simple enough that you might not have to a full-blown parse on the input to pick out instances of variable use (just look for 'export var', 'unset var', 'var=', and the like). You'd also want to take into account special variables like $RANDOM and $HOSTNAME, but that's pretty trivial.