Shell nesting variable "type $ (($num 1 + $num 2)"-1

[[email protected] shell-test] # chmod a + x para.sh
[[email protected] shell-test] # ll
total 44
-rw-r--r-- 1 root root 0 Jul 14 00:52 012
-rw-r--r-- 1 root root 201 Jul 14 19:04 2
-rw-r--r-- 1 root root 0 Jul 14 00:45 abc
-rwxr-xr-x 1 root root 149 Jul 14 03:24 echoTest1.sh
-rwxr-xr-x 1 root root 149 Jul 14 03:15 echoTest.sh
-rwxr-xr-x 1 root root 164 Jul 13 23:25 hello.sh
-rwxr-xr-x 1 root root 157 Jul 14 00:28 h.tx
-rwxr-xr-x 1 root root 201 Jul 14 19:04 para.sh
drwxr-xr-x 2 root root 4096 Jul 14 00:01 test
-rwxr-xr-x 1 root root 118 Jul 14 02:52 test1.sh
-rwxr-xr-x 1 root root 93 Jul 14 02:37 test $ .sh
-rw-r--r-- 1 root root 7283 Jul 14 02:20 vari.txt
[[email protected] shell-test] # sh para.sh as d f g 56 78
A total of 6 parameters
The parameters is: as d f g 56 78
The parameters is: as d f g 56 78
[[email protected] shell-test] # cat para.sh
#! / bin / bash
echo "A total of $ # parameters"
# 用 $ # represents the number of all parameters
echo "The parameters is: $ *"
#Use $ * for all parameters
echo "The parameters is: [email protected]"
#Using [email protected] also represents all parameters
[[email protected] shell-test] # sh test1.sh as d f g 56 78
0
[[email protected] shell-test] # sh test $ .sh as d f g 56 78
0
[[email protected] shell-test] # cat echoTest.sh
#! / bin / bash

for i in "$ *"
All parameters in # $ * are considered as a whole, so this for loop will only loop once
do
echo "The parameters is: $ i"
done
[[email protected] shell-test] # sh echoTest.sh as d f g 56 78
The parameters is: as d f g 56 78
[[email protected] shell-test] # sh echoTest1.sh as d f g 56 78
The parameters is: as
The parameters is: d
The parameters is: f
The parameters is: g
The parameters is: 56
The parameters is: 78
[[email protected] shell-test] # cat echoTest1.sh
#! / bin / bash

for i in "[email protected]"
All parameters in # $ * are considered as a whole, so this for loop will only loop once
do
echo "The parameters is: $ i"
done
[[email protected] shell-test] # cat echoTest1.sh
#! / bin / bash

for i in "[email protected]"
All parameters in # $ * are considered as a whole, so this for loop will only loop once
do
echo "The parameters is: $ i"
done
[[email protected] shell-test] # vim echoTest1.sh
[[email protected] shell-test] # sh echoTest1.sh as d f g 56 78
iThe parameters is: as
iThe parameters is: d
iThe parameters is: f
iThe parameters is: g
iThe parameters is: 56
iThe parameters is: 78
[[email protected] shell-test] # vim echoTest1.sh
[[email protected] shell-test] # sh echoTest1.sh as d f g 56 78
The parameters is: as
The parameters is: d
The parameters is: f
The parameters is: g
The parameters is: 56
The parameters is: 78
[[email protected] shell-test] # cat echoTest1.sh
#! / bin / bash

for i in "[email protected]"
Each parameter in # [email protected] is considered independent, so if there are several parameters in "[email protected]", it will loop several times
do
echo "The parameters is: $ i"
done
[[email protected] shell-test] # cp echoTest1.sh echoTest2.sh
[[email protected] shell-test] # vim echoTest2.sh
[[email protected] shell-test] # sh echoTest2.sh as d f g 56 78
x = 2The parameters is: as
x = 2The parameters is: d
x = 2The parameters is: f
x = 2The parameters is: g
x = 2The parameters is: 56
x = 2The parameters is: 78
[[email protected] shell-test] # cat echoTest2.sh
#! / bin / bash
x = 1
for i in "[email protected]"
Each parameter in # [email protected] is considered independent, so if there are several parameters in "[email protected]", it will loop several times
do
echo x = $ (($ x +1)) "The parameters is: $ i"
done
[[email protected] shell-test] # vim echoTest2.sh
[[email protected] shell-test] # sh echoTest2.sh as d f g 56 78
1 = 2The parameters is: as
1 = 2The parameters is: d
1 = 2The parameters is: f
1 = 2The parameters is: g
1 = 2The parameters is: 56
1 = 2The parameters is: 78
[[email protected] shell-test] # cat echoTest2.sh
#! / bin / bash
x = 1
for i in "[email protected]"
Each parameter in # [email protected] is considered independent, so if there are several parameters in "[email protected]", it will loop several times
do
echo "$ x = $ (($ x +1)) The parameters is: $ i"
done
[[email protected] shell-test] # vim echoTest2.sh
[[email protected] shell-test] # sh echoTest2.sh as d f g 56 78
1 The parameters is: as
2 The parameters is: d
3 The parameters is: f
4 The parameters is: g
5 The parameters is: 56
6 The parameters is: 78
[[email protected] shell-test] # cat echoTest2.sh
#! / bin / bash
x = 1
for i in "[email protected]"
Each parameter in # [email protected] is considered independent, so if there are several parameters in "[email protected]", it will loop several times
do
echo "$ x The parameters is: $ i"
x = $ (($ x +1))
done
[[email protected] shell-test] # vim echoTest2.sh
[[email protected] shell-test] # sh echoTest2.sh as d f g 56 78
1 The parameters is: as
2 The parameters is: d
3 The parameters is: f
4 The parameters is: g
5 The parameters is: 56
6 The parameters is: 78
[[email protected] shell-test] # cat echoTest2.sh
#! / bin / bash
x = 1
for i in "[email protected]"
Each parameter in # [email protected] is considered independent, so if there are several parameters in "[email protected]", it will loop several times
do
echo $ x The parameters is: $ i
x = $ (($ x +1))
done
[[email protected] shell-test] # vim echoTest2.sh
[[email protected] shell-test] # sh echoTest2.sh as d f g 56 78
The parameters 1 is: as
The parameters 2 is: d
The parameters 3 is: f
The parameters 4 is: g
The parameters 5 is: 56
The parameters 6 is: 78
[[email protected] shell-test] # cat echoTest2.sh
#! / bin / bash
x = 1
for i in "[email protected]"
Each parameter in # [email protected] is considered independent, so if there are several parameters in "[email protected]", it will loop several times
do
echo The parameters $ x is: $ i
x = $ (($ x
+1))
done
[[email protected] shell-test] # ll
total 48
-rw-r--r-- 1 root root 0 Jul 14 00:52 012
-rw-r--r-- 1 root root 201 Jul 14 19:04 2
-rw-r--r-- 1 root root 0 Jul 14 00:45 abc
-rwxr-xr-x 1 root root 163 Jul 14 19:16 echoTest1.sh
-rwxr-xr-x 1 root root 183 Jul 14 19:24 echoTest2.sh
-rwxr-xr-x 1 root root 149 Jul 14 03:15 echoTest.sh
-rwxr-xr-x 1 root root 164 Jul 13 23:25 hello.sh
-rwxr-xr-x 1 root root 157 Jul 14 00:28 h.tx
-rwxr-xr-x 1 root root 201 Jul 14 19:04 para.sh
drwxr-xr-x 2 root root 4096 Jul 14 00:01 test
-rwxr-xr-x 1 root root 118 Jul 14 02:52 test1.sh
-rwxr-xr-x 1 root root 93 Jul 14 02:37 test $ .sh
-rw-r--r-- 1 root root 7283 Jul 14 02:20 vari.txt
[[email protected] shell-test] # cat h.tx
world
#! / bin / Bash
#The first program
# Author: shenchao (E-mail: [email protected])
echo -e "Mr. Shen Chao is the most honest man in LampBrother"
[[email protected] shell-test] # cat test1.sh
#! / bin / bash
num1 = $ 1
num2 = $ 2
#sum = $ (($ num1 + $ num2))
sum = $ (($ num1 + $ num2))
#Variable sum is num1 plus num2
echo $ sum
[[email protected] shell-test] # mv test1.sh sum.sh
[[email protected] shell-test] # ll
total 48
-rw-r--r-- 1 root root 0 Jul 14 00:52 012
-rw-r--r-- 1 root root 201 Jul 14 19:04 2
-rw-r--r-- 1 root root 0 Jul 14 00:45 abc
-rwxr-xr-x 1 root root 163 Jul 14 19:16 echoTest1.sh
-rwxr-xr-x 1 root root 183 Jul 14 19:24 echoTest2.sh
-rwxr-xr-x 1 root root 149 Jul 14 03:15 echoTest.sh
-rwxr-xr-x 1 root root 164 Jul 13 23:25 hello.sh
-rwxr-xr-x 1 root root 157 Jul 14 00:28 h.tx
-rwxr-xr-x 1 root root 201 Jul 14 19:04 para.sh
-rwxr-xr-x 1 root root 118 Jul 14 02:52 sum.sh
drwxr-xr-x 2 root root 4096 Jul 14 00:01 test
-rwxr-xr-x 1 root root 93 Jul 14 02:37 test $ .sh
-rw-r--r-- 1 root root 7283 Jul 14 02:20 vari.txt
[[email protected] shell-test] # sh sum.sh 23 56
79
[[email protected] shell-test] # cat sum.sh
#! / bin / bash
num1 = $ 1
num2 = $ 2
#sum = $ (($ num1 + $ num2))
sum = $ (($ num1 + $ num2))
#Variable sum is num1 plus num2
echo $ sum
[[email protected] shell-test] # 

Shell nesting variable "type $ (($num 1 + $num 2)"-1