We will demonstrate how to copy the public SSH key to the server in this tutorial. You must copy your public SSH key to the server’s authorized_keys file in order to use the public-key authentication method. The purpose of adding an SSH key to the server is to provide password-free SSH access to a server. You may be questioning why this is necessary.

How To Add SSH Public Key To Server

The public SSH key can be copied to the server using these two techniques.

1. Copy ssh public key to remote server using ssh-copy-id:

In this  method, we will copy the ssh public key to the server using ssh-copy-id tool. In this process, we will copy the personal computer’s public key to the list of the authorized keys on the remote server. The authorized_keys file is in the ~/.ssh/

ssh-copy-id -i ~/.ssh/id_rsa.pub validusername@IP_ADDRESS_OF_THE_SERVER

When prompted, enter the password for your user account at the remote server. Your public key should be copied to the remote server.
~/.ssh/id_rsa.pub  is the default location for the public ssh key. If you want to use another public key rather than the one in the default location, use the -i option.

2. Manually copy the public ssh key to the server

In this method, we will take the help of manual method where we can manually copy the ssh key to the server.  This method is useful when your server doesn’t allow you ssh login via password. In this process, you need to ask the end-user to provide their pubic key at first.

cat ~/.ssh/id_rsa.pub

Manually append your public key to the remote ssh server’s key to the authorized_keys file. For example, copy the content of your ~/.ssh/id_rsa.pub to the server’s ~/.ssh/authorized_keys file.

Using the following command combination

cat ~/.ssh/id_rsa.pub | ssh user@remote-host 'cat >> ~/.ssh/authorized_keys'

Now, create new directories and files in the end user’s home directory so that you can add the public key of the end user that you have asked for in the previous step.

Now add the public key of the user in /home/user_name/.ssh/authorized_keys file

vim /home/username/.ssh/authorized_keys

Save and close the file.

Now, if your end-users tried to connect to a remote server then they might come across a permission denied error or something like this “r “sign_and_send_pubkey: signing failed: agent refused operation Permission denied (publickey)”.

One of the reasons for this is due to file permission on ssh file.  Make sure to set the correct file permissions:

chmod 700 /home/username/.ssh && chmod 600 /home/username/.ssh/authorized_keys

Change the ownership to the user:

chown -R username:username /home/username/.ssh

Now your end-user can log in to the server without any issue

The post How To Add SSH Public Key To Server first appeared on AtoZ Linux.

Struggling with error then you are at the right place. We have covered the all possible solution for the error “ng is not Recognized as Internal or External Command, Operable Program or Batch File?”.  Before jumping into the solution, let’s have a look into the possible reason for this error.

• If the angular command line tool is not installed on the system
• The ng Path variable is not added in Windows.

How To Fix “ng is not Recognized as Internal or External Command, Operable Program or Batch File?”

Solution for the first reason for the error:

If the angular command line tool is not installed on the system

Run the following command to Install the Angular CLI tool using the following command

> npm install -g @angular /cli

Now verify whether the error is fixed or not with the following command
ng version

The ng Path variable is not added in Windows.

If you are unable to set the ng path in the Windows operating system then you might come across this error. Run the following command using ‘where’ to find out where the ng is installed or where the “ng.exe” file exists. Choose and copy the Path where ng is installed

> where ng

After figuring out the path you can launch the environment variable settings by going to the environment variables set. For your convience we are showing you the step by step guide.

• You can access it by searching it in the “Startup” menu to set ng path to the Windows path.
• Go to the “Environment Variables”.  After that, select the “Path” property under “System variables” and then click the “Edit” button.
• Next, in the “Edit environment variables” window, click “New” put the copied path of ng installation location here, and then click the “Ok“ option.

Now, run the following command to see whether the error has been solved or not in your system. Most probably you will be out of the error issues in your system.

ng version

The post How To Fix “ng is not Recognized as Internal or External Command, Operable Program or Batch File?” first appeared on AtoZ Linux.

Bash: If, Else If, Else Examples For Beginners To Experts

Let’s have a look into the examples of Bash If, Else If, Else examples.

10+ Bash: If, Else If, Else Examples

Here are the bash examples that can be helpful for you:

1. Simple If Statement in bash:

if [ $num -gt 10 ]; then
echo "Number is greater than 10"
fi

2. If-else statement in bash:

if [ $num -gt 10 ]; then
echo "Number is greater than 10"
else
echo "Number is less than or equal to 10"
fi

3. If-else-if statement in bash:

if [ $num -gt 10 ]; then
echo "Number is greater than 10"
elif [ $num -eq 10 ]; then
echo "Number is equal to 10"
else
echo "Number is less than 10"
fi

4. Nested if statement in bash:

if [ $num -gt 10 ]; then
if [ $num -lt 20 ]; then
echo "Number is between 10 and 20"
fi
fi

5. Using logical operators in bash:

if [ $num -gt 10 ] && [ $num -lt 20 ]; then
echo "Number is between 10 and 20"
fi

6. Checking file existence in bash:

if [ -e /path/to/file ]; then
echo "File exists"
else
echo "File does not exist"
fi

7. Checking if a variable is empty in bash:

if [ -z "$var" ]; then
echo "Variable is empty"
else
echo "Variable is not empty"
fi

8. Using a case statement in bash:

case $fruit in
apple)
echo "Fruit is apple"
;;
orange)
echo "Fruit is orange"
;;
*)
echo "Fruit is not apple or orange"
;;
esac

9. Using command substitution in bash:

if [ $(ls /path/to/dir | wc -l) -gt 0 ]; then
echo "Directory is not empty"
else
echo "Directory is empty"
fi

10. Using arithmetic expressions in bash:

if (( $num > 10 )); then
echo "Number is greater than 10"
elif (( $num == 10 )); then
echo "Number is equal to 10"
else
echo "Number is less than 10"
fi

3 examples of If statement in bash on string equality

Using double brackets and == operator:

In this example, we use double brackets and the == operator to test for string equality. The advantage of using double brackets is that it is more flexible and can handle more complex conditions.

if [[ "$str1" == "$str2" ]]; then
echo "Strings are equal"
else
echo "Strings are not equal"
fi

Using the test command and = operator: 

In this example, we are using the test command with the = operator to test for string equality. The test command is equivalent to the [ command, but requires a trailing semicolon or space before the closing bracket.

if test "$str1" = "$str2"; then
echo "Strings are equal"
else
echo "Strings are not equal"
fi

Using the case statement:

In the below example, we are using a case statement to check if $str1 matches $str2. If the two strings match, the “Strings are equal” message is printed. Otherwise, You will see the “Strings are not equal” message in output. The case the statement allows for more complex matching patterns and can be useful in situations where multiple conditions need to be checked.

case "$str1" in
"$str2")
echo "Strings are equal"
;;
*)
echo "Strings are not equal"
;;
esac

3 examples of If statement in bash on number equality

Using double brackets and == operator:

if [[ "$num1" == "$num2" ]]; then
echo "Numbers are equal"
else
echo "Numbers are not equal"
fi

Using the test command and -eq operator:

if test "$num1" -eq "$num2"; then
echo "Numbers are equal"
else
echo "Numbers are not equal"
fi

Using arithmetic expression:

if (( num1 == num2 )); then
echo "Numbers are equal"
else
echo "Numbers are not equal"
fi

3 example of If statement in bash on less than a number

Using double brackets and -lt operator:

if [[ "$num1" -lt "$num2" ]]; then
echo "$num1 is less than $num2"
else
echo "$num1 is not less than $num2"
fi

Using the test command and -lt operator:

if test "$num1" -lt "$num2"; then
echo "$num1 is less than $num2"
else
echo "$num1 is not less than $num2"
fi

Using arithmetic expression:

if (( num1 < num2 )); then
echo "$num1 is less than $num2"
else
echo "$num1 is not less than $num2"
fi

If statement in bash with logical AND operator

In this example, we are using the logical AND operator && to test if $num1 is greater than 0 AND less than 10. The -gt and -lt operators are used for numeric comparison. If both conditions are true, the message “$num1 is between 0 and 10” is printed. Otherwise, the message “$num1 is not between 0 and 10” will be printed. Note that we are using the separate brackets [ ] for each condition that we want to evaluate.

if [ "$num1" -gt 0 ] && [ "$num1" -lt 10 ]; then
echo "$num1 is between 0 and 10"
else
echo "$num1 is not between 0 and 10"
fi

If statement in bash with logical OR operator

In this example, we use the logical OR operator || to test if $day is equal to “Sunday” OR “Saturday”. If either condition is true, the message ” Yay, It’s the weekend!” is printed. Otherwise, the message “Sadly, It’s a weekday” is printed. Note that we use separate brackets [ ] for each condition that we want to evaluate.

if [ "$day" = "Saturday" ] || [ "$day" = "Sunday" ]; then
echo "Yay, It's the weekend!"
else
echo "Sadly, It's a weekday"
fi

3 Examples of elif condition in bash

Using elif to test for multiple conditions: 

if [ "$num" -gt 0 ]; then
echo "$num is positive"
elif [ "$num" -lt 0 ]; then
echo "$num is negative"
else
echo "$num is zero"
fi

Using elif with a different operator: 

In this example, we are using an if statement to test if $user is not equal to “root”. If the condition is true, the message “You do not have root access” is printed.

If the condition is false, then the  elif statement tests if $user is equal to “root”. If this condition is true, the message “You have root access” is printed.

Note that we are using the != and = operators for string comparison.

if [ "$user" != "root" ]; then
echo "You do not have root access"
elif [ "$user" = "root" ]; then
echo "You have root access"
fi

Using elif with a nested if statement: 

• In this example, we are using a if statement to test if $day is equal to “Saturday”. If the condition is true, the message “yay, It’s the weekend!” is printed.
• If the condition is false, the elif statement tests if $day is equal to “Sunday”. If this condition is true, the message ” Yay, It’s the weekend!” is printed.
• If both conditions are false, the else statement executes a nested if statement that tests if $hour is less than 12. If this condition is true, the message “Good morning!” is printed. If the condition is false, the message “Good afternoon!” is printed.

if [ "$day" = "Saturday" ]; then
echo "Yay, It's the weekend!"
elif [ "$day" = "Sunday" ]; then
echo "Yay, It's the weekend!"
else
if [ "$hour" -lt 12 ]; then
echo "Good morning!"
else
echo "Good afternoon!"
fi
fi

The post 10+ Bash: If, Else If, Else Examples In 2025 first appeared on AtoZ Linux.

The way we use the Internet to search for anything is changing because to ChatGPT. Its incredible AI technology allows you to find nearly every answer to your query. If you’re an iPhone user looking for a simple way to use ChatGPT, this article is for you.

Use ChatGPT With Siri On iPhone

In this tutorial, we will show you the step by step method to use ChatGPT on iPhone.  You can easily install the official ChatGPT app from app store for iPhone and use it by logging with your account.

In another method, you can use the third party app called SiriPro.

1. Download the Siri Pro shortcut and wait for a while and  don’t run it yet.

2. Now you need to log in to your OpenAI account and go to the OpenAI API keys page. From here you need to get a Secret Key. After logging to the dashboard in OpenAPI, you will see the option to “Create new secret key.”

Click on it to generate an API key to use with Siri Pro that you have installed in the above step. Once done, copy the OpenAI API key and paste it somewhere as you cannot copy the same API key again.

3. Open the Shortcuts app to access the downloaded Siri Pro shortcut. Tap the three dots to open the shortcut’s settings. There will see a different dialog box.

4. Under the second dialog box titled “Text“, you will see the message – “Insert ChatGPT API Key here.” Paste your previously copied API key here and tap “Done” at the top right of the screen.

5. Now, you can easily use ChatGPT as ChatGPT has now been integrated with Siri on your iPhone. If you want to use it without any limitation then it’s better to buy the ChatGPT pro subscription to avoid the traffic limit.

The post Use ChatGPT With Siri On iPhone In 2024 first appeared on AtoZ Linux.

VirtualBox is one of the most popular  virtualization software available in multiple platforms like Windows, Linux, MacOS and Solaris x86 platforms. In this tutorial, we will guide you through the process of installing VirtualBox on Linux based operating systems.

Meanwhile, if you wants to download .deb files and wants to install by yourself.

1. Ubuntu 22.04
2. ​Ubuntu 20.04
3. ​Ubuntu 18.04 / 18.10 / 19.04

Install VirtualBox On Linux

For Ubuntu or Debian based Linux operating systems:

Install VirtualBox from Ubuntu Repository

Open the terminal and run the following command.

sudo apt install VirtualBox

Run the following command to verify the installation of VirtualBox.

dpkg -l | grep virtualbox

Install VirtualBox On Ubuntu using Oracle’s repository

Run this command in your terminal

 wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo gpg --dearmor -o /usr/share/keyrings/oracle-virtualbox-2016.gpg

Run this command in your terminal

 sudo add-apt-repository "deb [arch=amd64] http://download.virtualbox.org/virtualbox/debian $(lsb_release -cs) contrib"

Run the following command to update the package list.

sudo apt-get update

Run the following command to install Virtual Box on Ubuntu.

sudo apt-get install virtualbox

For other Linux:

• Oracle Linux 9 / Red Hat Enterprise Linux 9
• ​Oracle Linux 8 / Red Hat Enterprise Linux 8
• ​Oracle Linux 7 / Red Hat Enterprise Linux 7 / CentOS 7
• ​openSUSE 15.3 / 15.4 / 15.5
• ​Fedora 36 / 37 / 38
• ​Fedora 35
• ​All distributions

The post Install VirtualBox On Linux | VirtualBox 7.0.10 Released first appeared on AtoZ Linux.