emanuele6 1707062523 learn In bash 4.3 and earlier, <<<$x used to field split and rejoin the value of $x e.g. x=' a    b'; cat <<<$x   was equivalent to  cat <<<'a b', and you had to use double quote <<<"$x" to prevent that from happening and pass $x unmodified. Since bash 4.4, <<<$x and <<<"$x"  are equivalent.