How to use the command 'vncserver' (with examples)

Virtual Network Computing (VNC) allows users to remotely control a computer’s desktop environment from another device. The vncserver command is designed to launch a VNC Server on a machine, enabling multiple clients to connect and interact with its graphical user interface over a network. VNC is cross-platform, making it a versatile tool for remote desktop sharing. This article explores three primary use cases of the vncserver command, demonstrating its functionality with examples.

Use case 1: Launch a VNC Server on the next available display

Code:

vncserver

Motivation:

In environments where remote desktop access is required, such as technical support teams or educational labs, launching a VNC server quickly on the next available display simplifies the process of providing access. Instead of manually specifying display numbers, the system automatically assigns the next free display, streamlining the setup and allowing immediate focus on the task at hand.

Explanation:

• vncserver: This command, without any additional arguments, instructs the system to launch a VNC server instance on the next available display number. VNC display numbers typically start from :1, as :0 is usually reserved for the local display environment of the system.

Example output:

Upon execution, the command output would provide information about the VNC server initiation, similar to the following message:

New 'X' desktop is machine-name:1

Starting applications specified in /home/user/.vnc/xstartup
Log file is /home/user/.vnc/machine-name:1.log

This output confirms the successful launch of a VNC server and specifies the display number and log file location.

Use case 2: Launch a VNC Server with specific screen geometry

Code:

vncserver --geometry 1280x720

Motivation:

Controlling the resolution of the VNC session is critical when working with devices that have specific display requirements or restrictions. For instance, streaming a desktop to a device with limited screen space or ensuring that a remote interface respects certain visual layouts can demand a set geometry. This control over screen resolution ensures that the remote presentation of the desktop is both visually effective and resource-efficient.

Explanation:

• vncserver: Initiates the launch of a VNC server.
• --geometry widthxheight: This argument specifies the desired dimensions of the VNC session screen. In this example, the screen will be 1280 pixels wide and 720 pixels high, a resolution commonly used for HD displays.

Example output:

Executing this configuration generates an output similar to the following, indicating that the session has been successfully initiated with the specified geometry:

New 'X' desktop is machine-name:2

Starting applications specified in /home/user/.vnc/xstartup
Log file is /home/user/.vnc/machine-name:2.log

This alerts the user that the VNC session is running at 1280x720 resolution.

Use case 3: Kill an instance of VNC Server running on a specific display

Code:

vncserver --kill :2

Motivation:

Managing resources and ensuring security are crucial aspects of system administration, particularly in environments where multiple VNC sessions may be running simultaneously. The ability to terminate a specific VNC session helps conserve system resources and ensures that idle or insecure sessions are closed when no longer needed. This is particularly useful for maintaining operational efficiency and preventing unauthorized access.

Explanation:

• vncserver: This is the command responsible for managing VNC server instances.
• --kill: This option specifies that the action is to terminate a running VNC server instance.
• :display_number: Refers to the particular display number of the VNC session to be terminated. In the example vncserver --kill :2, the command will terminate the VNC server running on display :2.

Example output:

Upon executing the command, the system confirms the closure of the specified VNC session:

Killing Xvnc process ID <process_id>

This output indicates that the session on display :2 has been successfully terminated.

Conclusion:

The vncserver command is a powerful tool for setting up and managing remote desktop sessions via VNC. By understanding how to launch a server on the next available display, specify screen geometry, and terminate specific sessions, users and system administrators can harness the full potential of VNC for a variety of applications ranging from support services to secure remote work environments.