Features, Advantages, and Disadvantages Command line interface (CLI) 

A command line interface is an interface where the user uses text-based commands to communicate with the system. It is also known as a character or console user interface. It was the main way for a user to interact with the computer operating system and application before the use of GUI.

Today it is still embedded in all GUI systems and it is mostly used by advanced users or those who are willing to learn the commands. It is mostly used by software programmers, systems, databases, and network administrators, among other IT specialists.

The main features of CLI are text-based commands, scripting capabilities, and pipes among others that are discussed in this article. The main benefits of using CLI are that it executes its commands faster and requires fewer resources. However, it is not user-friendly and it is hard to learn all the commands.

Features of command line interface (CLI)

Today we have many systems that use a command line interface either as the only interaction method or combined with GUI. For those systems using CLI, these are some of the features that characterize them.

1. Scripting capabilities: Scripts are a combination of commands that can be used to automate some of the common repetitive actions. Scripting allows users to automate commands which may be hard when using a GUI interface.
2. Pipes commands: this is where the output of one command is used as input data for another command. Piping mostly involves more than one command where one depends on the output of another.
3. Command history: CLI systems keep a history of the commands issues which can be used for review in case of problems. The user can also recall a command and use it instead of keying in the whole line again.
4. Text-based: The command line interface is a text or character-based interface that doesn’t have the Windows, Icons, Menus, and Pointers (WIMP) unlike in the GUI interface.
5. Use of keyboard only. Most of the CLI-based systems don’t use pointing devices such as mice since most of the work involves keying commands.
6. Fast command execution: CLI is characterized by fast execution speed compared to GUI. This is because it is more precise and requires fewer resources to execute a command.

Types and examples of CLI uses

The command interface is used in different systems some of which are hidden behind the GUI interface while in others CLI is the main and only interface. Below are some of the systems and areas where the command line interface is used. 

1. Linux operating system. Linux operating system comes either as GUI or CLI. Most Linux servers are CLI while the desktop Linux OSes are GUI.
2. MSDOS. This is the old version of the Windows operating system that used a command-line interface. Still, the Windows operating system used a command prompt which is hidden behind the GUI. To access the command prompt in Windows OS click on the start button and search for CMD.
3. Programming languages. Many programming languages have a command-based interface for programmers. Languages like python and C offers CLI interfaces.
4. UNIX-Based operating system. In most Unix-based systems their default interface is a command line.
5. Network device configuration interface. Networking devices such as routers and switches use a command line interface for configuration. Cisco routers specifically use the command lines for root user configuration.

Advantages of Command Line Interface (CLI)

1. Using programs such as scripting, users can be able to automate the most frequently used commands.
2. The CLI system uses fewer system resources. This is because text-based commands don’t need a lot of memory and a computer processor to execute the command.
3. The system is efficient and fast. It requires fewer steps to execute the same command compared to the GUI system. This makes it a more efficient interface to perform a task.
4. The commands stay the same unlike in GUI where the interface may change. Even when there are system updates the basic command may not change much.
5. The CLI systems are more secure compared to GUI.
6. Since the interface is text-based it doesn’t require a high-resolution computer screen to operate.

Disadvantages of CLI

1. It requires the user to have prior knowledge of the command and its outcome. This means the user knows what to expect from each command.
2. The interface is not user-friendly when compared to GUI systems.
3. The learning curve of CLI is steep since users will have to learn all the commands and how and where to use them.
4. The command has to be typed precisely the way it should and if it has any spelling or syntax error it won’t execute.

Graphic User Interface (GUI) vs Command Line Interface (CLI)

Both the GUI and CLI are the most common types of system interfaces available. Below we compared the 2 types of user interfaces. You can read more on the features, components, advantages, and disadvantages of GUI in this other article.

Criteria	GUI	CLI
Full name	Graphic User Interface	Command Line Interface
Speed	Relatively slow	Commands are executed fast
Learning curve	The interface is simple to learn. Users can even learn how to use it on their own.	The commands are hard to learn and they require mastering many commands.
User-friendliness	It is friendly to use since it uses common icons that users can recognize.	It is not user-friendly since the user will need to learn all the commands.
Components	The main components of GUI are Windows Icons Menus and Pointer (WIMP)	The interface is a text-based system.
Main users	Designed to be used by all levels of users from basic end users to system administrators.	They are commonly used and preferred by advanced users such as programmers and system administrators.