What is the meaning of variable #,#,@,0,0,1,2,2,*,$$,$ in Linux?

$# 是传给脚本的参数个数$0是脚本本身的名字$1 是传递给该shell脚本的第一个参数$2是传递给该shell脚本的第二个参数[email protected] 是传给脚本的所有参数的列表$* 是以一个单字符串显示所有向脚本传递的参数，与位置变量不同，参数可超过9个$$ 是脚本运行的当前进程ID号$? 是显示最后命令的退出状态，0表示没有错误，其他表示有错误

Difference:@@*

• Same point: All parameters are referenced
• Different points: only in double quotes. Suppose that three parameters were written when the script was run (stored in1123) then " 3) "*" is equivalent to "1123"（Mass transferHandedThe one Ginseng number ) ;" 3 "(pass a parameter), and" @ "is equivalent to"1""1 "" 2 "" $ $ "(three parameters passed)

Example One

# #dels. Sh
echo "number:$#" echo "Scname:$0" echo "First:" echo "Second:$2" echo "Argume:[email protected]" echo "Show Parm list:$*" echo "Show process id:$$" echo "Show Precomm stat: $?"

Execution results

123456789

[@jihite]$ sh del.sh 123number:3scname:del.shfirst: 1second:2argume:123showparm list:1 23showprocess id:21057showprecomm stat: 0

Example Two

#!/bin/shnum=$ #name =$0echo "number: $num" echo "Scname: $name" echo $0echo $1echo $2for ((i=0; i< $num; i++)) do    Echo "$i" Doneecho "Argume:[email protected" "for key in [email Protected]do    echo $keydoneecho"-----------------"for key In "[email protected]" does    echo $keydoneecho "-----------------------------" for Key2 in $*do     echo $key 2doneecho " -----------------"for Key2 in" $* "Do     echo $key 2doneecho" show process id:$$ "Choecho" show Precomm stat: $? "

Execution results

12345678910111213141516171819202122

[@jihite]$ sh del.sh a b                                                      number:2scname:del.shdel.shab01argume:a bab-----------------ab-----------------------------ab-----------------a bshowprocess id:23582del.sh: line 37:cho: command not foundshowprecomm stat: 127

Problem:

echo #0 #1 can you use $i to express it?

Meaning of variable #,#,@,0,0,1,2,2,*,$$,$ in Linux