Pattern: Passing shell function to external command
Issue: -
Shell functions are only known to the shell. External commands like find
, xargs
, su
and sudo
do not recognize shell functions.
Instead, the function contents can be executed in a shell, either through sh -c
or by creating a separate shell script as an executable file.
Example of incorrect code:
foo() { bar --baz "$@"; frob --baz "$@"; };
find . -exec foo {} +
Example of correct code:
find . -exec sh -c 'bar --baz "$@"; frob --baz "$@";' -- {} +
If you're intentionally passing a word that happens to have the same name as a declared function, you can quote it to make shellcheck ignore it, e.g.
nobody() {
sudo -u "nobody" "$@"
}