mev Command in Linux

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mev is a command used in Linux for monitoring mouse events. It's a part of the gpm package that helps you in capturing movements and button clicks. By using mev, you can observe real-time mouse activity, making it useful for debugging and developing applications that require mouse input.

Table of Contents

Here is a comprehensive guide to the options available with the mev command −

• How to Install mev Command in Linux?
• Syntax of mev Command
• mev Command Options
• Examples of mev Command in Linux

How to Install mev Command in Linux?

To install the mev command on a Linux system, you need to install the gpm package using your package manager. Here are the commands for some common distributions −

For Debian-based systems (like Ubuntu)

sudo apt install gpm

For Red Hat-based systems (like CentOS)

sudo yum install gpm

For Arch Linux

sudo pacman -S gpm

Syntax of mev Command

The general syntax for using the mev command on Linux is −

mev [options]

Where −

• mev is the command used to monitor mouse events.
• [options] are various command-line options to modify how mev

mev Command Options

These are some of the options you can apply when using the command mev in a Linux environment −

Examples of mev Command in Linux

Here are a few scenarios showcasing how to employ the Linux mev command −

• Choose a Virtual Console
• Choose the Default Mask
• Choose the Event Mask
• Enable Emacs Mode
• Accept Commands from Standard Input

Choose a Virtual Console

To monitor mouse events on a specific virtual console, you can use the -C option followed by the console number −

mev -C 1

This command monitors mouse events on virtual console number 1. You will see all mouse activities that occur in that specific console.

Choose the Default Mask

To set a default mask for filtering events, use the -d option followed by the mask number −

mev -d 255

This command sets the default mask to 255, which specifies how mouse events are filtered according to this mask.

Choose the Event Mask

In case you want to specify an event mask for filtering mouse events, use the -e option followed by the event number −

mev -e 3

This command sets the event mask to 3, filtering the events based on this value. It helps in focusing on specific types of mouse events.

Enable Emacs Mode

To enable Emacs mode, which may alter the way events are interpreted, simply use the -E option −

mev -E

This command runs mev in Emacs mode, adjusting how mouse events are handled, which might be useful for certain types of applications.

Accept Commands from Standard Input

To allow mev to accept commands from standard input, use the -i option −

echo "some commands" | mev -i

This setup enables mev to process commands that are piped from standard input, making it more dynamic and interactive.

Filter Drag Events Inside the Screen

If you want to filter drag events that occur within the screen boundaries, you can use the -f option −

mev -f

This command ensures that only drag events happening inside the screen are processed, which is useful for applications tracking such events specifically.

Conclusion

The mev is a versatile command for monitoring mouse events on a Linux system. By leveraging its various options, you can capture and analyze mouse activity in real-time, which is valuable for debugging and developing mouse-dependent applications.

Mastering the mev command enhances your ability to work with input devices, making it easier to diagnose issues and improve system functionality.