示例：
#! /bin/bash
#self-source.sh 一个脚本递归的source自身
maxpasscnt=100
echo -n "$pass_count "
#echo -e "$pass_count "
#echo -e "a\bdddd"
#echo -e "a\ndddd"
let "pass_count += 1"
while [ "$pass_count" -le $maxpasscnt ]
do
#echo $pass_count
. $0
done
echo
exit 0
