TweetFollow Us on Twitter

Remote Control

Volume Number: 20 (2004)
Issue Number: 12
Column Tag: Programming

Remote Control

by Brad Belyeu

It's Not Just For Your TV

Welcome

The purpose of having a remote control for you home entertainment center (other than a good thumb workout) is to save you the effort and time of getting out of your recliner to change channels or adjust the volume. It's a great idea, and everyone uses one. Remote control of your Mac is just as easy and convenient. Anyone who has more than one computer has valid reasons to use remote computing. Most people probably don't make use of this great functionality simply because they don't understand how it can make things so much easier for them. The advantages of a TV remote are pretty obvious, but unless we stop to think about it the advantages of remote controlling another computer are not quite as obvious. We'll take a how-to look at some of the powerful things that can be done with different forms of remote computing.

Take Command Line Control

Thanks to the Unix underpinnings of OS X, remote computing is built right into our operating system. You can enable secure command line remote login via SSH in System Preferences Sharing pane.


Secure SHell (SSH) came about due to the increasing security needs when transferring data over the Internet. Back in the early days of the Internet, a lot of data was sent as plain text. Back in the "good old days", you didn't need to worry about who was watching. Unix applications like rsh, rcp, & rlogin were perfectly acceptable for logging into a computer remotely. Now any ten year old that knows how to download and use a packet sniffer can intercept plain text transmissions. SSH provides security by creating a "tunnel" between two computers. Every packet of data sent between the computers is encrypted using an authentication key shared between the computers. If SSH is used correctly, it can make remote computing just as secure as sitting in front of the machine itself.

Secure SHell (SSH) came about due to the increasing security needs when transferring data over the Internet. Back in the early days of the Internet, a lot of data was sent as plain text. Back in the "good old days", you didn't need to worry about who was watching. Unix applications like rsh, rcp, & rlogin were perfectly acceptable for logging into a computer remotely. Now any ten year old that knows how to download and use a packet sniffer can intercept plain text transmissions. SSH provides security by creating a "tunnel" between two computers. Every packet of data sent between the computers is encrypted using an authentication key shared between the computers. If SSH is used correctly, it can make remote computing just as secure as sitting in front of the machine itself.

ssh username@remotehost 

You will then be prompted to enter your password. After entering it correctly your current working directory becomes the home folder of the user you logged in as. To make this meaningful, lets run Software Update on another Mac on your network. To list the available updates, try:

sudo softwareupdate -l

This will list all available updates. It will give you output saying, "Software Update found the following new or updated software" after which it will list each available update. Using the -i argument will install updates. You can specify each one to be installed individually by specifying the updates name.

sudo softwareupdate -i name_of_update 

You can choose to install all "required" updates by using the -r flag in place of the update name. Using the -a command will install all available updates.

You can choose to install all "required" updates by using the -r flag in place of the update name. Using the -a command will install all available updates.

top -u 

This will list all running applications on the remote machine. The -u argument will sort processes by processor usage. The processes at the top of the list are using the most system resources and are more likely to be locking the system up. Take a note of the PID (process ID) to the left of the application name. You can press the Q key to quit the 'top' command, then you can use the 'kill' command to terminate the offending process.

sudo kill process_id 

This will hopefully kill the offending application so you can use your Mac again. If it doesn't kill the application, try using the argument -9 before the process id. The -9 flag is used to send a non-catchable, non-ignorable 'kill' command.

Let's say it's late and you've been using your PowerBook and Airport network to check your email one last time before you retire for the evening. Suddenly you remember that you left the Mac on in the study. Instead of getting out of your warm, cozy bed, just use SSH again to save the day, or night. After logging into the remote system, use the command:

sudo shutdown -h -now 

The -h option halts the system and shuts it down. You can use the -r option in its place to restart the computer instead of shutting it down. The -now option can be replaced with +anynumber to shutdown the computer a certain number of minutes later.

Another great security feature of SSH is port forwarding. You can forward TCP/IP traffic through an SSH shell to secure your data over the Internet. Port forwarding can be used with FTP, HTTP, POP3, SMTP, etc; this can allow you to connect securely to any of these types of servers. The data will be sent through the SSH tunnel. It works like an encrypted subway system connecting two points. Normally the traffic goes over its respected port (80 for HTTP, for example), but when you use port forwarding it is actually sent over SSH's port (22). The syntax is:

ssh -L local_port:hostname:remote_port username@hostname 

To forward your outgoing mail port, you could use the example below.

sudo ssh -L 25:smtp_server_name:25 username host 

If you are running Mac OS X Server, almost any System Preference option can be set through the command line 'systemsetup' command. If you are running a copy of OS X Server view the man page for 'systemsetup' to view all available options.

VNC- Virtual Network Computing

Virtual Network Computing was developed by AT&T laboratories as an open-source cross platform graphical interface for remote desktop computing. It is currently on version 3.3.7. VNC requires a server application and client application to communicate. The server software must be running first on the computer that you want to connect to before the client software can connect to it. Major advantages of VNC include cost (its free!), small & simple file size, platform-independency, and the fact that one desktop can be shared with several computers. No state is stored at the viewer, which means if you're working on something remotely and your computer crashes or locks up nothing will be lost. It is all stored completely on the server. A good & free VNC server application for Mac OS X is OSXvnc by Redstone Software Inc. My VNC client of choice is VNCDimension, a freeware application from AT&T laboratory developers. My favorite part of VNC is that it is cross-platform. If someone has a VNC server running on a pc, it can be accessed from a Macintosh. VNC loads only the viewer application locally. All other work is processed remotely. I will never use a memory hogging virtual pc application on my Mac again. VNC can be used to run applications off your pc while saving tons of processing power on your Mac. You can initiate any program and it will run remotely. Understanding that most of the computers in the world run Microsoft Windows, it is sometimes necessary to run Windows applications. With the cost of Virtual PC starting at $249 (Win XP Home Ver 7), it is worth the extra couple hundred dollars to me to have the extra processing power and storage of actually owning a Windows pc. I run TightVNC freeware on my pc.


Imagine the extra productivity this allows! Of course, I use VNC more often on external networks than I do on my internal network. VNC allows for connections across the Internet as well. I recommend using an SSH session when connecting over an insecure network such as the Internet via port forwarding techniques explained earlier. For details on setting up VNC over SSH, see Aaron Adams article in MacTech Vol 20, No 7 2004. Other VNC clients worth trying are VNCThing and Chicken of the VNC. ShareMyDesktop is another good VNC server.

VNC is a great way to do simple remote computing but there are professional applications which are much more powerful and feature rich than most VNC clients. Let's take a look at these.

Professional Applications

Whether you professionally service computers or you're just the 'computer guy' for your friends and family, you might want to consider purchasing a professional remote desktop application such as Timbuktu. It'll save you a lot of time and money if you make frequent trips to fix small software related problems. Also if you have an Xserve you want to control without hooking up a monitor to it, remote computing applications are a great solution. If you want to share your desktop with up to fifty other Macs in a training type environment, Apple Remote Desktop would be the perfect application. Timbuktu is great for one to one computer connections to fix problems, but ARD seems to be a better application for a lab or classroom type environment.

Apple Remote Desktop can be used to sleep, wake, restart or shutdown a group of Mac OS X systems. Software packages can be installed onto multiple computers at once, and they can even be scheduled to install at times when you network will have its lightest traffic load. ARD can connect to a VNC server running on any platform. It allows you to copy files remotely, and you can also have a real-time text chat with the user sitting at the remote computer. ARD supports Unix commands being sent to remote Macs. Sharing your screen with up to fifty other Macs allows teachers or trainers to demonstrate on-screen to students. If you're using ARD to troubleshoot a problem, it allows you to get a complete hardware report of remote machines. ARD also has a software difference report, which compares installed packages on the admin computer with other computers in a group. Timbuktu has most of the same options as ARD, but it also allows for voice communications. Unfortunately, due to the cost, both of these products are frequently restricted to commercial use.


Brad Belyeu is the President of ABConsulting based out of Oklahoma City, OK. He is an Apple Certified Technician and a certified member of the Apple Consultant Network.

 

Community Search:
MacTech Search:

Software Updates via MacUpdate

Audio Hijack 3.7.3 - Record and enhance...
Audio Hijack (was Audio Hijack Pro) drastically changes the way you use audio on your computer, giving you the freedom to listen to audio when you want and how you want. Record and enhance any audio... Read more
CleanMyMac X 4.6.15 - Delete files that...
CleanMyMac makes space for the things you love. Sporting a range of ingenious new features, CleanMyMac lets you safely and intelligently scan and clean your entire system, delete large, unused files... Read more
Suitcase Fusion 21.2.1 - Font management...
Suitcase Fusion is the creative professional's font manager. Every professional font manager should deliver the basics: spectacular previews, powerful search tools, and efficient font organization.... Read more
Civilization VI 1.3.6 - Next iteration o...
Civilization® VI is the award-winning experience. Expand your empire across the map, advance your culture, and compete against history’s greatest leaders to build a civilization that will stand the... Read more
Dashlane 6.2042.0 - Password manager and...
Dashlane is an award-winning service that revolutionizes the online experience by replacing the drudgery of everyday transactional processes with convenient, automated simplicity - in other words,... Read more
Airfoil 5.9.2 - Send audio from any app...
Airfoil allows you to send any audio to AirPort Express units, Apple TVs, and even other Macs and PCs, all in sync! It's your audio - everywhere. With Airfoil you can take audio from any... Read more
VirtualBox 6.1.16 - x86 virtualization s...
VirtualBox is a family of powerful x86 virtualization products for enterprise as well as home use. Not only is VirtualBox an extremely feature rich, high performance product for enterprise customers... Read more
Xcode 12.1 - Integrated development envi...
Xcode includes everything developers need to create great applications for Mac, iPhone, iPad, and Apple Watch. Xcode provides developers a unified workflow for user interface design, coding, testing... Read more
FileZilla 3.51.0 - Fast and reliable FTP...
FileZilla (ported from Windows) is a fast and reliable FTP client and server with lots of useful features and an intuitive interface. Version 3.51.0: Bugfixes and minor changes: Fixed import of... Read more
KeyCue 9.8 - Displays all menu shortcut...
KeyCue has always been a handy tool for learning and remembering keyboard shortcuts. With a simple keystroke or click, KeyCue displays a table with all available keyboard shortcuts, system-wide... Read more

Latest Forum Discussions

See All

PUBG Mobile has provided yet another upd...
PUBG Mobile has been making a point of publicly mentioning all of their ongoing efforts to vanquish cheating from the popular battle royale. Today two teams within the company have provided updates on their progress. [Read more] | Read more »
Zombieland: AFK Survival is celebrating...
Zombieland: AFK Survival is currently celebrating its one-year anniversary. If you don't quite recognise the name that's because it initially launched as Zombieland: Double Tapper. Anyway, the game is celebrating turning one with two Halloween-... | Read more »
Distract Yourself With These Great Mobil...
There’s a lot going on right now, and I don’t really feel like trying to write some kind of pithy intro for it. All I’ll say is lots of people have been coming together and helping each other in small ways, and I’m choosing to focus on that as I... | Read more »
Genshin Impact Guide - Gacha Strategy: W...
If you're playing Genshin Impact without spending money, you'll always need to be looking for ways to optimize your play to maximize rewards without getting stuck in a position where you're tempted to spend. The most obvious trap here is the game'... | Read more »
Genshin Impact Adventurer's Guide
Hello and well met, fellow adventurers of Teyvat! Check out our all-in-one resource for all things Genshin Impact. We'll be sure to add more as we keep playing the game, so be sure to come back here to check for updates! [Read more] | Read more »
Genshin Impact Currency Guide - What...
Genshin Impact is great fun, but make no mistake: this is a gacha game. It is designed specifically to suck away time and money from you, and one of the ways the game does this is by offering a drip-feed of currencies you will feel compelled to... | Read more »
XCOM 2 Collection on iOS now available f...
The XCOM 2 Collection, which was recently announced to be coming to iOS in November, is now available to pre-order on the App Store. [Read more] | Read more »
Presidents Run has returned for the 2020...
IKIN's popular endless runner Presidents Run has returned to iOS and Android just in time for the 2020 election season. It will see players choosing their favourite candidate and guiding them on a literal run for presidency to gather as many votes... | Read more »
New update for Cookies Must Die adds new...
A new update for Rebel Twins’ platformer shooter Cookies Must Die is coming out this week. The update adds quite a bit to the game, including new levels and characters to play around with. [Read more] | Read more »
Genshin Impact Guide - How to Beat Pyro...
The end game of Genshin Impact largely revolves around spending resin to take on world bosses and clear domain challenges. These fights grant amazing rewards like rare artifacts and ascension materials for weapons and adventurers, but obviously... | Read more »

Price Scanner via MacPrices.net

Use our exclusive iPhone Price Trackers to fi...
Looking for a new Apple iPhone 12 or 12 Pro? Perhaps a deal on last year’s iPhone 11? Check out our iPhone Price Tracker here at MacPrices.net. We track new and clearance iPhone prices from Apple as... Read more
Weekend deal: $100 off 13″ MacBook Airs at Am...
Amazon has new 2020 13″ MacBook Airs on sale for $100 off Apple’s MSRP, starting at only $899. Their prices are the lowest available for new MacBooks from any Apple resellers. These are the same 13″... Read more
New 10.9″ 64GB Apple iPad Air on sale for $55...
Amazon has Apple’s new 2020 10.9″ 64GB WiFi iPad Air on sale today for $549.99 shipped. That’s $40 off MSRP. Pre-orders are available today at this discounted price, and Amazon states that the iPad... Read more
Get a clearance 2019 27″ 5K iMac for up to $5...
Apple has Certified Refurbished 2019 27″ 5K iMacs available starting at $1439 and up to $520 off their original MSRP. Apple’s one-year warranty is standard and shipping is free. The following... Read more
AT&T offers the Apple iPhone 11 for $10/m...
AT&T is offering Apple’s 64GB iPhone 11 for $10 per month, for customers opening a new line of service, no trade-in required. Discount is applied via monthly bill credits over a 30 month period.... Read more
Apple’s 2020 11″ iPad Pros on sale today for...
Apple reseller Expercom has new 2020 11″ Apple iPad Pros on sale for $50-$75 off MSRP, with prices starting at $749. These are the same iPad Pros sold by Apple in their retail and online stores: – 11... Read more
Did Apple Drop The Ball By Not Branding Its C...
EDITORIAL: 10.21.20 – In the branding game, your marketing strategy can either be a hit or a miss and the latter is the case for Apple when it missed out on an opportunity to brand its “SE” series of... Read more
27″ 6-core and 8-core iMacs on sale for up to...
Adorama has Apple’s 2020 27″ 6-core and 8-core iMacs on sale today for $50-$100 off MSRP, with prices starting at $1749. Shipping is free: – 27″ 3.1GHz 6-core iMac: $1749, save $50 – 27″ 3.3GHz 6-... Read more
Apple’s 16″ MacBook Pros are on sale for $300...
B&H Photo has 16″ MacBook Pros on sale today for $300-$350 off Apple’s MSRP, starting at $2099. Expedited shipping is free to many addresses in the US. Their prices are among the lowest available... Read more
Apple has 2020 13″ MacBook Airs available sta...
Apple has a full line of Certified Refurbished 2020 13″ MacBook Airs available starting at only $849 and up to $200 off the cost of new Airs. Each MacBook features a new outer case, comes with a... Read more

Jobs Board

Dental Receptionist - *Apple* Valley Clinic...
Dental Receptionist - Apple Valley Clinic + Job ID: 57314 + Department: Apple Valley Dental + City: Apple Valley, MN + Location: HP - Apple Valley Clinic Read more
*Apple* Mobility Specialist - Best Buy (Unit...
**788165BR** **Job Title:** Apple Mobility Specialist **Job Category:** Store Associates **Store Number or Department:** 001013-Virginia Commons-Store **Job Read more
Cub Foods - *Apple* Valley - Now Hiring Par...
Cub Foods - Apple Valley - Now Hiring Part Time! United States of America, Minnesota, Apple Valley Retail Post Date Oct 08, 2020 Requisition # 124800 Sign Up for Read more
*Apple* Mobility Specialist - Best Buy (Unit...
**784631BR** **Job Title:** Apple Mobility Specialist **Job Category:** Store Associates **Store Number or Department:** 000522-Baxter-Store **Job Description:** The Read more
Senior Data Engineer - *Apple* - Theorem, L...
Job Summary Apple is seeking an experienced, detail-minded data engineeringconsultant to join our worldwide business development and strategy team. If you are Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.