[Happy BASH] BASH中的$*和$@的區別

首先來看一段BASH代碼：

echo "\$@=" $@
echo "\"\$@\"=" "$@"

echo "print each param from \$@"
for var in $@
do
        echo $var
done

echo "print each param from \"\$@\""
for var in "$@"
do
        echo "$var"
done

echo "print each param from \$*"
for var in $*
do
        echo "$var"
done

echo "print each param from \"\$*\""
for var in "$*"
do
        echo "$var"
done

執行./test.sh "a a" b c d，將會得到以下輸出：

$@= a a b c d
"$@"= a a b c d
print each param from $@
a
a
b
c
d
print each param from "$@"
a a
b
c
d
print each param from $*
a
a
b
c
d
print each param from "$*"
a a b c d

總結，總是要用"$@" （雙括號括起來的$@），所有參數的串聯字符串，則用"$*" （仍然是雙括號括起來的$*）。