Bash中的$符号

脚本名称：$0
PID：$$
参数个数：$#
脚本返回值：$?
第x个参数：$x
所有参数：[email protected]

 1 #!/bin/bash
 2 echo "The program $0 is now running"
 3 echo "The progress PID is $$"
 4 echo "The last progress PID is $$"
 5 echo "The number of parameter is $# "
 6 echo "The return code of last command is $?"
 7 echo "The first parameter is $1"
 8 echo "The second parameter is $2"
 9 echo "The parameters are: $*"
10 echo "Again, the parameters are: [email protected]"