To set the stage: what exactly do we mean by “packaging”? In simple terms, it’s just a way of bundling up all the files and dependencies for an application into one neat little package that can be easily installed or removed from your Linux machine. This is different than using apt (which stands for Advanced Packaging Tool) because with dpkg (the tool we’re going to talk about today), you have more control over what gets installed and how it gets installed.
So, let’s say you want to install a new program called “awesome-text-editor” on your system. With apt, all you would need to do is open up a terminal window (or use the GUI package manager) and type in:
#!/bin/bash # This line specifies the interpreter to be used for executing the script
sudo apt update # This command updates the list of available packages from the repositories
sudo apt upgrade -y # This command upgrades all installed packages to their latest versions without prompting for confirmation
sudo apt install awesome-text-editor # This command installs the "awesome-text-editor" program on the system
This will automatically download and install any necessary dependencies, as well as the main program itself. But what if you don’t want to use apt? Maybe you prefer a more granular approach where you can choose exactly which packages get installed (and in what order). That’s where dpkg comes in!
To start using dpkg, first make sure it’s already installed on your system:
# This script checks the version of dpkg installed on the system
# First, we need to make sure dpkg is installed on the system
# We can do this by using the "which" command to check if dpkg is in the PATH
# If it is not in the PATH, we will get an error message
# If it is in the PATH, we will get the location of the dpkg executable
which dpkg
# Now, we can use the "dpkg --version" command to check the version of dpkg
# This will print out the version number of dpkg installed on the system
dpkg --version
If this command returns a version number, you’re good to go. If not, you may need to install the package manager itself (which is usually included in most Linux distributions).
Once dpkg is installed and ready to use, let’s say we want to download and install “awesome-text-editor” from a website called “example.com”. First, navigate to that site using your web browser and find the download link for the program (usually in the form of an .deb file).
Next, use wget or curl to download the package:
# This script downloads and installs "awesome-text-editor" from a website called "example.com"
# Navigate to the website using a web browser and find the download link for the program
# Usually in the form of an .deb file
# Use wget to download the package from the specified URL
wget https://www.example.com/awesome-text-editor_1.0_amd64.deb
# Note: wget is a command-line utility for downloading files from the web
# Use the -O flag to specify the output file name
# In this case, we want to name the file "awesome-text-editor_1.0_amd64.deb"
wget -O awesome-text-editor_1.0_amd64.deb https://www.example.com/awesome-text-editor_1.0_amd64.deb
# Use the -P flag to specify the directory where the file will be saved
# In this case, we want to save it in the current directory
wget -P . https://www.example.com/awesome-text-editor_1.0_amd64.deb
# Note: The "." represents the current directory
# Use the -q flag to suppress the output of wget
# This makes the script run silently without displaying any messages
wget -q https://www.example.com/awesome-text-editor_1.0_amd64.deb
# Note: This is useful for automation and scripting purposes
# Use the -c flag to continue a previous download if it was interrupted
# This ensures that the download is not started from the beginning if it was interrupted
wget -c https://www.example.com/awesome-text-editor_1.0_amd64.deb
# Note: This is useful for large files or unstable internet connections
# Use the -nv flag to display only essential information during the download
# This reduces the amount of output and makes the script run faster
wget -nv https://www.example.com/awesome-text-editor_1.0_amd64.deb
# Note: This is useful for scripting and automation purposes
# Use the -i flag to specify a file containing multiple URLs to download
# This allows for batch downloading of multiple files at once
wget -i urls.txt
# Note: The file "urls.txt" should contain a list of URLs, each on a separate line
# Use the -O flag to specify the output file name and the -P flag to specify the directory
# This allows for downloading and saving the file in a specific location with a specific name
wget -O awesome-text-editor_1.0_amd64.deb -P /home/user/Downloads https://www.example.com/awesome-text-editor_1.0_amd64.deb
# Note: This is useful for organizing downloaded files and specifying a specific location for installation
# Use the -h flag to display the help menu for wget
# This provides a list of all available options and their usage
wget -h
# Note: This is useful for troubleshooting and learning more about wget's functionality.
This will save a copy of the .deb file in your current directory (you can change the URL and filename to match whatever you found on the website).
Now that we have the package, let’s use dpkg to install it:
# This line uses sudo to run the dpkg command with root privileges
# This is necessary for installing packages on the system
sudo dpkg -i awesome-text-editor_1.0_amd64.deb
# The -i flag specifies that we want to install the package
# The filename following it is the name of the package we want to install
# The .deb extension indicates that it is a Debian package
# The 1.0 and amd64 in the filename refer to the version and architecture of the package respectively
# These values may vary depending on the package being installed
# It is important to make sure the filename matches the package you want to install
# Otherwise, the installation will fail
This will automatically extract all of the files and dependencies from the .deb file (if necessary) and install them on your system. If there are any conflicts or errors, you may need to use some additional flags with dpkg to resolve them (such as –force-overwrite for overwriting existing files).
And that’s it! With a little bit of practice, using dpkg can be much faster and more efficient than relying on apt or other package managers. Plus, you have the added benefit of being able to choose exactly which packages get installed (and in what order), as well as troubleshoot any issues that may arise during the installation process.
So next time you need to install a new program on your Linux machine, give dpkg a try and see how it works for you!