busybox/shell/ash_test/ash-misc/func_args1.tests

f() { echo "'f $1 $2 $3' called"; }

set -- a b c
echo "params: $1 $2 $3"
f 1 2 3
echo "params: $1 $2 $3"
true | f 1 2 3
echo "params: $1 $2 $3"