Bash Scripting

#!/bin/bash

if [ $# -eq 0 ]
then
    echo -e "You need to specify the target domain.\n"
    echo -e "Usage:"
    echo -e "\t$0 <domain>"
    exit 1
else
    domain=$1
fi

<SNIP>

#!/bin/bash

#!/usr/bin/env python

#!/usr/bin/env perl

#!/bin/bash

value=$1

if [ "$value" -gt "10" ]
then
    echo "Given argument is greater than 10."
elif [ "$value" -lt "10" ]
then
    echo "Given argument is less than 10."
else
    echo "Given argument is not a number."
fi

Dudji@htb[/htb]$ bash if-elif-else.sh HTB
if-elif-else.sh: line 5: [: HTB: integer expression expected
if-elif-else.sh: line 8: [: HTB: integer expression expected
Given argument is not a number.

Dudji@htb[/htb]$ ./script.sh ARG1 ARG2 ARG3 ... ARG9

ASSIGNMENTS:
$0      $1   $2   $3 ...   $9

domain=$1
echo "$domain"

Dudji@htb[/htb]$ variable = "this will result with an error."
command not found: variable

Dudji@htb[/htb]$ variable="Declared without an error."
Dudji@htb[/htb]$ echo $variable
Declared without an error.

#!/bin/bash

domains=(www.inlanefreight.com ftp.inlanefreight.com vpn.inlanefreight.com www2.inlanefreight.com)
echo ${domains[0]}

#!/bin/bash

domains=("www.inlanefreight.com ftp.inlanefreight.com vpn.inlanefreight.com" www2.inlanefreight.com)
echo ${domains[0]}

#!/bin/bash

increase=1
decrease=1

echo "Addition: 10 + 10 = $((10 + 10))"
echo "Subtraction: 10 - 10 = $((10 - 10))"
echo "Multiplication: 10 * 10 = $((10 * 10))"
echo "Division: 10 / 10 = $((10 / 10))"
echo "Modulus: 10 % 4 = $((10 % 4))"

((increase++))
echo "Increase Variable: $increase"

((decrease--))
echo "Decrease Variable: $decrease"

#!/bin/bash

htb="HackTheBox"
echo ${#htb}

echo -e "Additional options available:"
echo -e "\t1) Identify the corresponding network range of target domain."
echo -e "\t2) Ping discovered hosts."
echo -e "\t3) All checks."
echo -e "\t*) Exit.\n"

read -p "Select your option: " opt

netrange=$(whois $ip | grep "NetRange\|CIDR" | tee -a CIDR.txt)
hosts=$(host $domain | grep "has address" | cut -d" " -f4 | tee discovered_hosts.txt)

Dudji@htb[/htb]$ cat discovered_hosts.txt CIDR.txt

165.22.119.202
NetRange:       165.22.0.0 - 165.22.255.255
CIDR:           165.22.0.0/16

case <expression> in
    pattern_1 ) statements ;;
    pattern_2 ) statements ;;
    pattern_3 ) statements ;;
esac

case $opt in
    "1") network_range ;;
    "2") ping_host ;;
    "3") network_range && ping_host ;;
    "*") exit 0 ;;
esac

function name {
    <commands>
}

name() {
    <commands>
}

function network_range {
    for ip in $ipaddr
    do
        netrange=$(whois $ip | grep "NetRange\|CIDR" | tee -a CIDR.txt)
        cidr=$(whois $ip | grep "CIDR" | awk '{print $2}')
        cidr_ips=$(prips $cidr)
        echo -e "\nNetRange for $ip:"
        echo -e "$netrange"
    done
}

#!/bin/bash

function print_pars {
    echo $1 $2 $3
}

one="First parameter"
two="Second parameter"
three="Third parameter"

print_pars "$one" "$two" "$three"

#!/bin/bash

function given_args {
    if [ $# -lt 1 ]
    then
        echo -e "Number of arguments: $#"
        return 1
    else
        echo -e "Number of arguments: $#"
        return 0
    fi
}

given_args
echo -e "Function status code: $?\n"

given_args "argument"
echo -e "Function status code: $?\n"

content=$(given_args "argument")
echo -e "Content of the variable: \n\t$content"

for variable in 1 2 3 4
do
    echo $variable
done

for variable in file1 file2 file3
do
    echo $variable
done

for ip in 10.10.10.170 10.10.10.174
do
    ping -c 1 $ip
done

Dudji@htb[/htb]$ for ip in 10.10.10.170 10.10.10.174;do ping -c 1 $ip;done

stat=1
while [ $stat -eq 1 ]
do
    ping -c 2 $host > /dev/null 2>&1
    if [ $? -eq 0 ]
    then
        echo "$host is up."
        ((stat--))
        ((hosts_up++))
        ((hosts_total++))
    else
        echo "$host is down."
        ((stat--))
        ((hosts_total++))
    fi
done

#!/bin/bash

counter=0

while [ $counter -lt 10 ]
do
    ((counter++))
    echo "Counter: $counter"

    if [ $counter == 2 ]
    then
        continue
    elif [ $counter == 4 ]
    then
        break
    fi
done

#!/bin/bash

counter=0

until [ $counter -eq 10 ]
do
    ((counter++))
    echo "Counter: $counter"
done

if [ "$1" != "HackTheBox" ]
then
    echo -e "You need to give 'HackTheBox' as argument."
    exit 1
elif [ $# -gt 1 ]
then
    echo -e "Too many arguments given."
    exit 1
else
    echo -e "Success!"
fi

Dudji@htb[/htb]$ man ascii

if [ $# -lt 1 ]
then
    echo -e "Number of given arguments is less than 1"
    exit 1
elif [ $# -gt 1 ]
then
    echo -e "Number of given arguments is greater than 1"
    exit 1
else
    echo -e "Number of given arguments equals 1"
fi

if [ -e "$1" ]
then
    echo -e "The file exists."
    exit 0
else
    echo -e "The file does not exist."
    exit 2
fi

if [[ -z $1 ]]
then
    echo -e "Boolean value: True (is null)"
    exit 1
elif [[ $# > 1 ]]
then
    echo -e "Boolean value: True (is greater than)"
    exit 1
else
    echo -e "Boolean value: False (is equal to)"
fi

if [[ -e "$1" && -r "$1" ]]
then
    echo -e "We can read the file that has been specified."
    exit 0
elif [[ ! -e "$1" ]]
then
    echo -e "The specified file does not exist."
    exit 2
elif [[ -e "$1" && ! -r "$1" ]]
then
    echo -e "We don't have read permission for this file."
    exit 1
else
    echo -e "Error occurred."
    exit 5
fi

Dudji@htb[/htb]$ bash -x CIDR.sh

+ '[' 0 -eq 0 ']'
+ echo -e 'You need to specify the target domain.\n'
You need to specify the target domain.

Dudji@htb[/htb]$ bash -x -v CIDR.sh

#!/bin/bash
if [ $# -eq 0 ]
then
    echo -e "You need to specify the target domain.\n"
    exit 1
fi