linux shell comprehensive programming

1. Write a function to print green OK and red FAILED

Determine whether there is a parameter, if it exists it means Ok, if it does not exist it means FAILED

#!/bin/bash
# **********************************************************
# * Author        : jiangzhier
# * Email         : ???
# * Create time   : 2023-01-03 06:26
# * Filename      : question1.sh
#! /bin/bash

function_1() {
        if [ $# -ne 0 ];then
                echo -e "\033[32m ok \033[0m"
        else
                echo -e "\033[31m failed \033[0m"
        fi
}
function_1 $*

2. Write a function to determine whether there are no positional parameters. If there are no parameters, an error will be prompted.

#!/bin/bash
# **********************************************************
# * Author        : jiangzhier
# * Email         : ???
# * Create time   : 2023-01-03 06:26
# * Filename      : question2.sh
#! /bin/bash

function_1() {
	if [ $# -ne 0 ];then
		echo $*
	else
		echo -e "no arguments.error"
	fi
}
function_1 $*

3. Write a function to implement two numbers as parameters and return the maximum value

#!/bin/bash
# **********************************************************
# * Author        : jiangzhier
# * Email         : ???
# * Create time   : 2023-01-03 06:59
# * Filename      : question3.sh
# * Description   : 
# **********************************************************
fun(){
read -p "Please enter then first digit: " num1
read -p "Please enter then second digit: " num2
if [ -z $num1 ];then
	echo "please enter number1"
	exit 9
fi
if [ -z $num2 ];then
	echo "please enter number2"
	exit 9
fi

echo $num1$num2 | egrep -e ^[0-9]+$ &>/dev/null
state=$?
if [ $state -eq 0 ];then
	max=$num1
	for i in $num1 $num2
		do
		if [ $max -lt $i ];then
			max=$i
		fi	
		done
	echo $max
else
	echo "please enter the number"
fi
}
fun 

4. Write a function to implement two integer bit parameters and calculate addition, subtraction, multiplication and division.

#!/bin/bash
# **********************************************************
# * Author        : jiangzhier
# * Email         : ???
# * Create time   : 2023-01-03 07:27
# * Filename      : question4.sh
# * Description   : 
# **********************************************************
fun(){
	echo "$1+$2=$(($1+$2))"
	echo "$1-$2=`let r=$1-$2;echo $r`"
	echo "$1*$2=$(($1*$2))"
	echo "$1/$2=$(($1/$2))"
	echo "$1%$2=$(($1%$2))"
}
fun $1 $2

5. Assign each line of the /etc/shadow file as an element to the array.

#!/bin/bash
# **********************************************************
# * Author        : jiangzhier
# * Email         : ???
# * Create time   : 2023-01-03 07:35
# * Filename      : question5.sh
# * Description   : 
# **********************************************************
file=/etc/shadow
num=`wc -l < $file`
for i in `seq $num`
do
	arr[$i]=`head -$i $file | tail -1`
done

for i in ${arr[*]}
do 
	echo $i
done

6. Use an associative array to count the number of different types of shells used by users in the file /etc/passwd

#!/bin/bash
# **********************************************************
# * Author        : jiangzhier
# * Email         : ???
# * Create time   : 2023-01-03 07:47
# * Filename      : question6.sh
# * Description   : 
# **********************************************************
declare -A arr
while read line
do
	type=`echo $line | cut -d : -f 7`
	let arr[$type]++
done < /etc/passwd

for i in ${!arr[*]}
do
echo "$i 的数量为 ${arr[$i]}"
done

7. Use an associative array to count the number of files in a specified directory by extension.