how to expand bash function parameters inside function / fix shellcheck SC2294-CodePudding

Assume a function that runs a command in another directory:

sub() {
  cd subdirectory
  eval "$@" || exit
}

I would like to be able to invoke this function with parameters that are expanded inside the subdirectory, e.g. sub ls '$(basename $(pwd))'

However, as the function is defined above, it does not pass shellcheck:

^-- SC2294 (warning): eval negates the benefit of arrays. Drop eval to preserve whitespace/symbols (or eval as string).

Obviously, if I remove the eval, then the parameter is not expanded and if I remove the quotes as well, then the parameter is expanded in the current directory. Which is not what I want.

I understand there are some suggestions in shellcheck's wiki, but I don't know how to make them work.

Is it possible to use eval correctly in this scenario -- without the downsides described in SC2294 -- or do I need to ignore this rule?

CodePudding user response：

Use eval "$*" instead of eval "$@". That will have exactly the same effect (assuming that IFS has its default value) and Shellcheck is happy with it. See Accessing bash command line args $@ vs $* for details of $@ versus $* (quoted and unquoted).

Use of eval is, justifiably, generally discouraged. See Why should eval be avoided in Bash, and what should I use instead?. Sometimes there's no better option though.

CodePudding user response：

... Drop eval ...

So drop it.

sub() {
  cd subdirectory
  "$@" || exit

  # I would do:
  if ! "$@"; then
     exit
  fi
}