What is a Shell in Linux?

Learn what is a shell in Linux, your shortcut to a successful career with Linux and open source software

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Commonly mentioned in the Linux (and systems administration) world is the word shell. But what is it?

A shell in the context of Linux is a user interface that allows users to interact with the operating system. It provides a way to execute commands, run programs, and manage files from a command-line interface (CLI) instead of a graphical user interface (GUI). 

Types of Shells

There are several types of shells available in Linux, each with its own features. The most common are listed below.

Bash

The Bourne Again SHell, the default shell for many Linux distributions, known for its rich feature set and scripting capabilities.

Zsh

Z Shell, an extended version of Bash with enhanced features such as improved auto-completion and globbing.

Fish

Friendly Interactive SHell, designed for user-friendliness, with syntax highlighting and automatic suggestions.

Tcsh

An enhanced version of the C shell (csh), offering command-line editing and job control. |

Key Functions of a Shell

Let's review why a shell exists in the first place.

Command Execution

You can run commands to perform tasks such as file manipulation, program execution, and system monitoring.

Scripting

Shells allow users to write scripts to automate repetitive tasks, making system administration more efficient.

Environment Management

Users can set and manage environment variables, affecting how processes behave.

Job Control

You can manage running processes, including background tasks and foreground processes.

How to Access the Shell

So how does one access a shell in Linux?

Open the Terminal

You can typically find the terminal in the applications menu or by using a shortcut like `Ctrl + Alt + T`, using the mouse (click on the terminal icon) or in Gnome, press the Super key -> terminal to start it.

Command Line Interface

Once open, you will see a command prompt where you can type commands.

Basic Commands

Here are some basic commands everyone should know while using the shell.

• ls Lists files and directories.
• cd [directory]: Changes the current directory.
• cp [source] [destination]: Copies files or directories.
• mv [source] [destination]: Moves or renames files or directories.
• rm [file]: Deletes files.

What to learn next

We recommend learning Bash next. Bash is the default shell in most Linux distros, and also default on enterprise Linux distributions such as Ubuntu or RHEL. 

Conclusion

The shell is an essential component of Linux, giving users powerful functionalities for interaction without needing a graphical interface. Understanding how to use the shell can greatly enhance productivity and system control. Whether you're a beginner or advanced user, getting comfortable with the shell will improve your efficiency in managing a Linux environment.

How to Mount Windows Network Drives in WSL

Mounting network drives in Windows Subsystem for Linux (WSL) opens up a whole new dimension for file management and development. Learn how.

The Linux terminal on Ubuntu

Mounting network drives in Windows Subsystem for Linux (WSL) opens up a whole new dimension for file management and development. This process allows you to access files stored on remote servers or shared folders directly from your WSL environment, making it easier to work across platforms.

In this article we'll review a step-by-step guide on how to do it.

Prerequisites

Before diving in, ensure you have the following:

• Windows 10 or Windows 11: Ensure WSL is enabled.
• WSL Installed: You should have WSL set up (either WSL1 or WSL2).
• Network Share Details: Know the network path (e.g., `\\SERVER\ShareName`) of the shared drive you want to mount.

Mounting Network drives in WSL

1. Enable WSL (If Not Already Done)

If you haven’t enabled WSL on your Windows machine, do so with these steps.

First, oen PowerShell as Administrator by searching for PowerShell in the Start menu, right-click, and choose "Run as Administrator".

Next, let's run the WSL Installation Command:

$ wsl --install

If needed, restart your computer by following any prompts to complete the installation.

2. Install Required Packages in WSL

To work with network drives, you might need the `cifs-utils` package for WSL. Open your WSL terminal and run:

sudo apt update
sudo apt install cifs-utils

3. Create a Mount Point

Next, you'll need to create a directory where the network drive will be mounted. Choose a convenient location, like `/mnt/`.

sudo mkdir /mnt/my_network_drive

4. Mount the Network Drive

Now it's time to mount the network drive. Use the following command, replacing the placeholders with your actual server address, share name, username, and password:

sudo mount -t cifs //SERVER/ShareName /mnt/my_network_drive -o username=YOUR_USERNAME,password=YOUR_PASSWORD

- **Example**:

sudo mount -t cifs //192.168.1.10/SharedFolder /mnt/my_network_drive -o username=user,password=pass

5. Access the Mounted Drive

You can now access your network drive at `/mnt/my_network_drive`. Use commands like `ls` to view the contents:

ls /mnt/my_network_drive

6. Unmounting the Drive

When you're finished, you can unmount the drive with:

sudo umount /mnt/my_network_drive

Additional Tips

Persistent Mounting

To automatically mount the drive at WSL startup, add the following line to your `/etc/fstab`:

//SERVER/ShareName /mnt/my_network_drive cifs username=YOUR_USERNAME,password=YOUR_PASSWORD 0 0

Security Considerations

Storing passwords in plain text in `fstab` can be insecure. Instead, consider using a credentials file:

Create a file to store your credentials:

nano ~/.smbcredentials

Add the following lines:

username=YOUR_USERNAME
password=YOUR_PASSWORD

Change permissions to secure the file:

chmod 600 ~/.smbcredentials

Update the `fstab` entry to use the credentials file:

//SERVER/ShareName /mnt/my_network_drive cifs credentials=/home/YOUR_USERNAME/.smbcredentials 0 0

Conclusion

By following these steps, you can seamlessly access Windows network drives from your WSL environment. This integration not only enhances your productivity but also provides a robust way to manage files across different operating systems. Whether you're developing applications or handling files, having access to network resources in WSL is invaluable. 

With this guide, you should be well-set to access your Windows network drive in WSL. Happy coding!

Using WebDAV on Linux

Learn to use WebDAV, a networking tool to mount filesystems, a great option for collaborative environments

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WebDAV (Web Distributed Authoring and Versioning) is an extension of the HTTP protocol that facilitates collaborative editing and management of files on remote web servers. It provides a framework for users to create, change, and move documents on a server, enabling various functionalities crucial for web collaboration.

Key Features

File Management

WebDAV allows users to manage files on a server, including creating, editing, deleting, and moving files.

Collaborative Editing

Multiple users can edit the same document simultaneously, helping in teamwork and collaboration.

Locking Mechanisms

To prevent conflicts, WebDAV supports file locking, which ensures that only one user can edit a document at a time.

Metadata Support

Users can attach metadata to web resources, enhancing information management.

Cross-Platform Compatibility

Compatible with various operating systems and applications, allowing seamless integration.

Deploying WebDAV

So let's see how to deploy and use WebDAV

1. Install davfs2

Install from your package manager (in Ubuntu it's named davfs2) or download the latest version of davfs2 from the davfs2 download page.

2. Configure the davfs2.conf file.

Make sure the following properties in the file are configured as shown below:if_match_bug 1 delay_upload 0 use_locks 0

3. Create the mount point.mkdir

$ sudo mkdir /mnt/dav

4. Mount a share in the dav directory on your server.

For example, to set up a WebDAV connection to dotcms.org at the mount point /mnt/dav on your local host, use the following command:

mount -t davfs http://<IP>/webdav/live/1 /mnt/dav

You will then be prompted for your username and password which will give you access to your WebDAV server.

Unmounting

You must manually unmount the WebDAV folders when you are finished:

$ sudo umount /mnt/dav

Common Use Cases

Content Management Systems (CMS)

WebDAV is often used in CMSs for file management and editing.

Cloud Storage Solutions

Many cloud storage services use WebDAV for file access and editing.

Version Control

WebDAV can be integrated with version control systems to manage document versions effectively. Today, this would be more common to host documents (think Word, Excel, etc) than to replace Git.

Conclusion

WebDAV enhances the capabilities of web servers by providing a structured way to deal with resources, making it an essential tool for collaborative environments.

Using the ip command in Linux

Why you have to stop using ifconfig and start using ip, the modern method for configuring a Linux network interface.

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For a long time, the ifconfig command was the default method for configuring a network interface. It served Linux users well, but networking is complex, and the commands to configure it must be robust. The ip command is the new default networking command for modern systems, and in this article, I'll show you how to use it.

The ip command is functionally organized on two layers of the OSI networking stack: Layer 2 (data link layer) and Layer 3 (network or IP layer). It does all the work in the old net-tools package.

Installing ip

More Linux resources

• Linux commands cheat sheet
• Advanced Linux commands cheat sheet
• Free online course: RHEL Technical Overview
• Linux networking cheat sheet
• SELinux cheat sheet
• Linux common commands cheat sheet
• What are Linux containers?
• Our latest Linux articles

The ip command is included in the iproute2util package. It's probably already included in your Linux distribution. If it's not, you can install it from your distro's software repository.

Comparing ipconfig and ip usage

The ip and ipconfic commands can be used to configure a network interface, but they do things differently. I'll compare how to do common tasks with the old (ipconfig) and new (ip) commands.

View network interface and IP address

If you want to see the IP address of a host or view network interface information, the old ifconfig command, with no arguments, provides a good summary:

$ ifconfig
eth0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
       ether bc:ee:7b:5e:7d:d8  txqueuelen 1000  (Ethernet)                                                       
       RX packets 0  bytes 0 (0.0 B)
       RX errors 0  dropped 0  overruns 0  frame 0
       TX packets 0  bytes 0 (0.0 B)
       TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
       inet 127.0.0.1  netmask 255.0.0.0
       inet6 ::1  prefixlen 128  scopeid 0x10<host>
       loop  txqueuelen 1000  (Local Loopback)
       RX packets 41  bytes 5551 (5.4 KiB)
       RX errors 0  dropped 0  overruns 0  frame 0
       TX packets 41  bytes 5551 (5.4 KiB)
       TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
       inet 10.1.1.6  netmask 255.255.255.224  broadcast 10.1.1.31
       inet6 fdb4:f58e:49f:4900:d46d:146b:b16:7212  prefixlen 64  scopeid 0x0<global>
       inet6 fe80::8eb3:4bc0:7cbb:59e8  prefixlen 64  scopeid 0x20<link>
       ether 08:71:90:81:1e:b5  txqueuelen 1000  (Ethernet)
       RX packets 569459  bytes 779147444 (743.0 MiB)
       RX errors 0  dropped 0  overruns 0  frame 0
       TX packets 302882  bytes 38131213 (36.3 MiB)
       TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

The new ip command provides similar results, but the command is ip address show, or just ip a for short:

$ ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
   link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
   inet 127.0.0.1/8 scope host lo
      valid_lft forever preferred_lft forever
   inet6 ::1/128 scope host  
      valid_lft forever preferred_lft forever
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
   link/ether bc:ee:7b:5e:7d:d8 brd ff:ff:ff:ff:ff:ff
3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
   link/ether 08:71:90:81:1e:b5 brd ff:ff:ff:ff:ff:ff
   inet 10.1.1.6/27 brd 10.1.1.31 scope global dynamic wlan0
      valid_lft 83490sec preferred_lft 83490sec
   inet6 fdb4:f58e:49f:4900:d46d:146b:b16:7212/64 scope global noprefixroute dynamic  
      valid_lft 6909sec preferred_lft 3309sec
   inet6 fe80::8eb3:4bc0:7cbb:59e8/64 scope link  
      valid_lft forever preferred_lft forever

Add IP address

To add an IP address to an interface with ifconfig, the command is:

$ ifconfig eth0 add 192.9.203.21

The command is similar for ip:

$ ip address add 192.9.203.21 dev eth0

Subcommands in ip can be shortened, so this command is equally valid:

$ ip addr add 192.9.203.21 dev eth0

You can make it even shorter:

$ ip a add 192.9.203.21 dev eth0

Remove an IP address

The inverse of adding an IP address is to remove one.

With ifconfig, the syntax is:

$ ifconfig eth0 del 192.9.203.21

The ip command syntax is:

$ ip a del 192.9.203.21 dev eth0

Enable or disable multicast

Enabling (or disabling) multicast on an interface with ifconfig happens with the multicast argument:

# ifconfig eth0 multicast

With ip, use the set subcommand with the device (dev) and a Boolean or toggle multicast option:

# ip link set dev eth0 multicast on

Enable or disable a network

Every sysadmin is familiar with the old "turn it off and then on again" trick to fix a problem. In terms of networking interfaces, that translates to bringing a network up or down.

The ifconfig command does this with the up or down keywords:

# ifconfig eth0 up

Or you could use a dedicated command:

# ifup eth0

The ip command uses the set subcommand to set the interface to an up or down state:

# ip link set eth0 up

Enable or disable the Address Resolution Protocol (ARP)

With ifconfig, you enable ARP by declaring it:

# ifconfig eth0 arp

With ip, you set the arp property as on or off:

# ip link set dev eth0 arp on

Pros and cons of ip and ipconfig

The ip command is more versatile and technically more efficient than ifconfig because it uses Netlink sockets rather than ioctl system calls.

The ip command may appear more verbose and more complex than ifconfig, but that's one reason it's more versatile. Once you start using it, you'll get a feel for its internal logic (for instance, using set instead of a seemingly arbitrary mix of declarations or settings).

Ultimately, ifconfig is outdated (for instance, it lacks full support for network namespaces), and ip is designed for the modern network. Try it out, learn it, use it. You'll be glad you did!