How to Use the wall Command on Linux

Linux terminal running on a laptopFatmawati Achmad Zaenuri/

Need to get a quick message out to all logged-in users? Linux’s wall command is punchier than email and auto-targets the logged-in users. It broadcasts a message to everyone using a terminal on a system.

The wall Command

If you need to get a message out—fast—to the logged-in users of your computer, how do you do it? Email doesn’t satisfy the requirements. You don’t know when the email will be read. If you need people to know something right now, that doesn’t cut it. And anyway, you don’t want to clog up the inboxes of logged-out users who don’t need to see the message.

Without exerting a bit of extra effort and wasting some time, you’re not going to know who is logged in and from where. Your system could be located in Aberdeen, Washington but you might have remote users logged in from Aberdeen, Scotland. So how can you target a message specifically at the logged-in users?

Linux and other Unix-like operating systems give you a simple way to do this. The wall command is like a forceful telegram. It will deliver a message to all terminal users, and it dumps the message right under their nose. The users can’t miss it, and you know they’ve got it. You don’t need them to choose to open an application to see if they have a message waiting.

The delivery is as subtle as a custard pie in the face.

Sending A Message

The test machine that this article was researched on was installed with Fedora Linux, but the wall command will behave precisely the same on other distributions.

The one difference you might encounter is some Linux distributions require you to use sudo on the option for sending a message from a text file, while other distributions require you always to use sudo with wall all the time. That’s actually a difference between Linux distributions, not a difference to the operation of the wall command itself.

To send a message to all users, type wall, a space, then the message you wish to send. With Fedora Linux, you must use sudo.

sudo wall Main printer offline until further notice.

wall command in a terminal window

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How to Select an Exact Display Resolution on Your Mac

Mac resolution header

You can change the display resolution of your Mac to make text larger or gain more space. There are some predefined scaled resolutions available, but you can get more granular control over your display’s resolution.

Normally a Mac will run its display at the resolution Apple believes is best. There are also four or five different options—depending on your Mac and display and highlighted below—that provide different outcomes. They’re fine, but they’re options to make text bigger or your desktop larger without using the number-based resolutions we all understand. But if you do some digging, you can get some real control over your display by making actual resolutions available to you.

Default scaled display options


RELATED: How to Run Your Retina Display at its Native Resolution

Why is Display Resolution Important?

A display’s resolution is the number of pixels available both horizontally and vertically. A 4K display has a resolution of 3840 x 2160 pixels, or 3840 pixels horizontally, and 2160 pixels vertically.

How much information you can see on-screen at any given time is governed by its resolution. Higher resolutions mean that more things can be shown on-screen. Those things could be windows, icons, photos, or text in a document. Because of the larger resolution, however, that also means all on-screen elements are smaller, which is something else to consider.

Larger displays usually also have higher resolutions than smaller ones, especially if they are of good quality.

What Makes Retina, Retina?

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What are Notes in Outlook and How Do You Use Them?

outlook logo

Microsoft Outlook lets you create electronic sticky notes that you can display either in Outlook or right on your desktop, letting you get all those real sticky notes off your desk.

Before we start, let’s take a moment to remember that writing passwords down on Post-It notes, electronic or otherwise, is just plain bad. We’ve written about password security extensively over the years, so take a moment to pick a password manager and use it. One day you’ll thank us.

RELATED: Why You Should Use a Password Manager, and How to Get Started

Creating a New Note

The first thing to do is to open up the Notes option in Outlook. Do this by going to the bottom left of Outlook, clicking the three dots in the Navigation option, and then clicking “Notes.”

The Notes option, where you can add, edit, and delete your notes, will open up.

To create a new note, click “New Note.” This will create a new note with the default size and color.

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Uber could give you the option to ‘favorite’ drivers

dims?crop=8000%2C5333%2C0%2C0&quality=85Uber might be developing a feature that lets riders add drivers as a “favorite” so they can ride with them again in the future. App researcher Jane Manchun Wong revealed the potential app addition on Monday, noting that Uber was apparently testing th…

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What Are Internet Worms, and Why Are They So Dangerous?

Jelly worms on a black background.David Orcea/Shutterstock

We don’t hear much about internet worms anymore, but they’re still an important part of the malware ecosystem. But what are worms, how do they spread, and how are they used by hackers?

Internet Worms Spread like Real-World Parasites

Most malware has to brute-force its way onto your computer, either by tricking you into downloading dubious software or by piggy-backing on benign email attachments. But worms are different.

Worms, unlike viruses or trojans, take advantage of a computer’s pre-existing security vulnerabilities at an operating-system level. Worms are also standalone software or files, and they typically travel across a computer network (your home or work network, for example), rather than through software downloads.

The function of an internet worm is similar to that of a real-life parasite. Like a tapeworm, an internet worm duplicates itself across as many hosts (computers) as possible, without trying to create any severe damage.

That’s right; a worm won’t corrupt your files or break your computer. If anything, a worm will slow down a computer or network by sucking up hardware resources or internet bandwidth (again, similar to a real parasite).

But some worms carry malicious payloads—code that makes your computer vulnerable to other malware. Since worms can quietly (and harmlessly) duplicate themselves across networks, they make great vehicles for large-scale virus attacks or ransomware attacks on governments and businesses.

Modern Internet Worms Usually Carry Payloads

On their own, worms are mostly harmless. Sure, they slow down computers and turn high-speed networks into snails, but when compared with file-corrupting viruses and hundred-thousand-dollar ransomware, worms are a walk in the park. That is unless the worm carries a payload.

A concerned PC user researching worms on his phoneGaudiLab/Shutterstock

As of right now, hackers rarely create payload-less worms. Remember, worms target system vulnerabilities. In the age of frustratingly frequent software updates, those vulnerabilities change week by week. Additionally, when a hacker spreads a worm, they’re effectively telling tech companies that an OS vulnerability exists. Once tech companies detect that worm through in-house testing or reports from anti-virus companies, they’ll respond by patching the vulnerability that made the worm possible.

So instead of wasting a perfectly good system vulnerability on a crappy worm, modern hackers like to focus their efforts on large-scale payload attacks. The 2004 Mydoom worm, as an example, contained a RAT payload, which allowed hackers to access infected computers remotely. Since worms travel across networks, these hackers gained access to a ton of different computers, and they used this access to perform a DDOS attack on the SCO Group website.

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The 5 Best PC Sound Cards to Buy in 2019

sound-cards-featured.jpgWhat do gamers and audiophiles have in common? They both enjoy high-quality audio for an immersive experience. Unfortunately, a stock sound card may not deliver that experience. A stock or integrated sound card is sufficient for the average user. It works great when you’re listening to music, watching movies on PC, and doing other light stuff with background music on. However, if you’re a hardcore gamer or an audiophile, you’re serious about sound. You want something that will deliver a punch – something that will make you feel every bit and heighten your immersion level. Fortunately, achieving that rich sound is easy with the best soundcards of… Read more

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How to make iPhone’s Screen Time actually helpful


Your iPhone is keeping track, but is it enough?

It’s been a year since Apple introduced a new feature to its iOS settings: “Screen Time,” the activity and phone use tracker. 

Since updating to iOS 12 and beyond, we’ve been getting daily and weekly reports on our phone with data on mobile usage to help us set limits on how long we can endlessly scroll through Instagram or Twitter. Apple CEO Tim Cook has even used Screen Time to flaunt his company’s questionable anti-phone stance.

I finally did the screen time ios phone thing by limiting the time that I have access to my apps and it’s a game changer! Everyone should do this.

— ★ 🅲🅾🆁🆈 🅺🅴🆁🆁 ★ (@corykerr) May 1, 2019 Read more…

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4 of the Best Android Emulators for Linux

Linux-Android-Emulation-Featured.pngWho said you need a smartphone to enjoy the benefits of Android apps? Perhaps you’d like to have your favorite apps available while you’re working on your Linux PC but don’t want to be tied to your phone. With an Android emulator for Linux, you can enjoy the smartphone experience without the smartphone. After all, Android uses the Linux kernel itself, so running an emulated version of this smartphone OS on your PC isn’t impossible. Here are four of the best Android emulators you can use if you’re running Linux. Related: 6 of the Best Android Emulators to Run Android on Windows 1. Android-x86 The… Read more

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