macos – 源代码Bash脚本中的$0不返回脚本名称

我运行了this Stack Overflow question中描述的脚本：

#!/bin/bash

echo
echo '# arguments called with ($@) -->  '"$@"
echo '# $1 -------------------------->  '"$1"
echo '# $2 -------------------------->  '"$2"
echo '# path to me ($0) ------------->  '"$0"
echo '# parent path (${0%/*}) ------->  '"${0%/*}"
echo '# my name (${0##*/}) ---------->  '"${0##*/}"
echo

以下是：

> . show_parms.sh foo

# arguments called with ($@) -->  foo
# $1 -------------------------->  foo
# $2 -------------------------->
# path to me ($0) ------------->  -bash
# parent path (${0%/*}) ------->  -bash
# my name (${0##*/}) ---------->  -bash

有任何想法吗？