linux 特殊变量 亲测

#!/bin/bash

# $$ 该shell本身的PID
printf "The complete list is %s\n" "$$"
# $! shell 最后运行的后台的Process 的PID
printf "The complete list is %s\n" "$!"
# $? 最后运行的命令的结束代码
printf "The complete list is %s\n" "$?"
# $- 用set命令设定的flag一览
printf "The complete list is %s\n" "$-"
# $* 所有参数列表 以"$1 $2 … $n"的形式输出所有参数
printf "The complete list is %s\n" "$*"
# $@ 所有参数列表 以"$1" "$2" … "$n" 的形式输出所有参数。 
printf "The complete list is %s\n" "$@"
# $# 添加到 shell中的参数个数
printf "The complete list is %s\n" "$#"
# $0 shell 本身的文件名
printf "The complete list is %s\n" "$0"
# $1～$n 添加到Shell的各参数值。$1是第1参数、$2是第2参数…。
printf "The complete list is %s\n" "$1"

#!/bin/bash
basedir=$(cd $(dirname $0); pwd)
echo "basedir: " $basedir

#!/bin/bash
if [ "$#" -ne 6];then
echo "Usage this.sh  <remote ip> <user> <password> <local_dir> <filename> <remote_dir>"
exit 1  
fi