How to Exit if a Bash Variable in Not Set
Sometimes you might want to exit a command if a variable is not set in Bash.
You can do this as follows:
if [ -z "$VARIABLE_NAME" ]; then echo …Linux
45 articles about linux development, tools, and best practices
How to Check OS version and flavor in Linux
If you need to check the version and flavour of the running Linux instance, then you can try the below commands:
cat /etc/os-release
lsb_release -a …How to Save sed Output Directly to a File
You have 3 options here:
Option 1: use tee with sed
sed 's/Hello/Hi/g' file-name | tee file
Option 2: use > with sed
sed …How to Bulk Move All Email from One Account to Another using the CLI
If you find yourself in a position where you need to sync all emails from one account to another, then you can use the imapsync command-line tool to …
How to Install AWS CLI on Linux
You can download and install the AWS CLI on Linux as follows:
Perform the install
curl …How to Reboot Networking on Mac from CLI
If you need to reboot, or restart the networking interface on your Mac, by using the CLI, then you can issue the following commands:
Using the …
Read Article →[Solved] ZipArchive extension: disabled/not installed on Ubuntu
If you have come across the following error:
ZipArchive extension: <strong>disabled/not installed</strong>
This just means that …
Read Article →How to Change the Timestamp of a File on Mac/Linux
If you have a file on your machine, and you want to change the created/modified time/date stamp, then you can use the touch command.
touch -t …How to get Meta-Data information from an AWS EC2 Instance
If you need to query meta-data information from your running EC2 instance, you can curl the following location:
curl …How to List all Running Services on Ubuntu
If you need to view a list of all the services that are either running or stopped (or both) on an Ubuntu server, then you can use the following …
Read Article →How to Upgrade an Ubuntu Server
Upgrading an Ubuntu Server is quite easy, just follow the below commands:
Option 1: Tldr; (just run the below!)
sudo apt-get update && sudo …How to Generate a Random AlphNumeric String in Linux/MacOS
If you need to generate a random AlphaNumeric string from the Linux/MacOS Command-Line, then you can use the following script:
dd if=/dev/random bs=8 …