$ cat test.sh#!/bin/bashecho '$1' " is $1"echo '$2' " is $2"echo '$3' " is $3"echo "$# arguments"echo "all arguments is $*"$ ./test.sh a b c$1  is a$2  is b$3  is c3 argumentsall arguments is a b c解释：- $0 命令名- $1 $2 ... $n 命令后跟着的位置参数- $# 位置参数的个数- $* 所有位置参数，返回一个字符串- $@ 所有位置参数，返回多个字符串，等价于调用 $1 $2 ... $n