A explicação primitiva simples é:
-
$*
all set arguments é uma string (os argumentos são separados pelo primeiro caractere em$IFS
) -
$@
cada argumento é uma string diferente (os argumentos são separados por nova linha)
De man bash
:
* Expands to the positional parameters, starting from one. When the expansion is not within dou‐
ble quotes, each positional parameter expands to a separate word. In contexts where it is per‐
formed, those words are subject to further word splitting and pathname expansion. When the
expansion occurs within double quotes, it expands to a single word with the value of each param‐
eter separated by the first character of the IFS special variable. That is, "$*" is equivalent
to "$1c$2c...", where c is the first character of the value of the IFS variable. If IFS is
unset, the parameters are separated by spaces. If IFS is null, the parameters are joined with‐
out intervening separators.
@ Expands to the positional parameters, starting from one. When the expansion occurs within dou‐
ble quotes, each parameter expands to a separate word. That is, "$@" is equivalent to "$1" "$2"
... If the double-quoted expansion occurs within a word, the expansion of the first parameter
is joined with the beginning part of the original word, and the expansion of the last parameter
is joined with the last part of the original word. When there are no positional parameters,
"$@" and $@ expand to nothing (i.e., they are removed).