Using $@ vs $*

child.sh

#!/bin/bash
# child.sh
# Prints all args.
while (( "$#" )); do
  echo "arg: $1"
  shift
done

parent.sh

#!/bin/bash
# parent.sh
# Usage:
# >  ./parent.sh 0 'a b c' d e

echo '-- Using $* --'
./child.sh $*

echo '-- Using "$*" --'
./child.sh "$*"

echo '-- Using $@ --'
./child.sh $@

echo '-- Using "$@" --'
./child.sh "$@"