$* 和 $@ 的区别

$* 和 $@ 都表示传递给函数或脚本的所有参数，不被双引号(" ")包含时，都以"$1" "$2" … "$n" 的形式输出所有参数。
但是当它们被双引号(" ")包含时，"$*" 会将所有的参数作为一个整体，以"$1 $2 … $n"的形式输出所有参数；"$@" 会将各个参数分开，以"$1" "$2" … "$n" 的形式输出所有参数。
下面的例子可以清楚的看到 $* 和 $@ 的区别：

#!/bin/bash
echo "$*=" $*
echo ""$*"=" "$*"

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

执行 sh test "a" "b" "c" "d"，看到下面的结果：