random thoughts
inside Alan's cluttered head
Cell phone voice mail “hack” (customization)
3
15 years
This weekend, I was playing with ring tones, and so I called my iPhone several times to test them out. I started wondering how long it took before my unanswered calls were redirected to voice mail. So I timed it.
By default, it appears that AT&T sets that delay to 25 seconds.
When I worked at Ericsson (1998-2003), I collected a bag of tricks that I used to customize certain features of my phone and my Cingular account. It turns out that some of these tricks still work today. One of those tricks was to set that voice mail delay to a longer value by using the GSM “star” codes.
The wise folks that created the GSM cellular standard understood that some people might have an older phone, but that they might want to use newer network features.
For example, remember the “bag phone” that people used in the early 1990’s? Or the Motorola “brick”? Those had simple calculator-style displays. The did not have a “voice mail” menu… all they could display was numbers! However, the guy at the phone store could program a brick phone to forward unanswered calls to voice mail after a certain delay. Or he could turn on call forwarding. In fact, he is actually telling the BASE STATION to forward unanswered calls, since that’s the piece of equipment that handles that job. After all, the phone itself might be turned off, or have a dead battery, or it might be in Africa somewhere.
It turns out that most features of the GSM network can be accessed using a series of digits dialed into the keypad. The sequence for call forward on no answer is **61*(target number)*11*(seconds)#.
If you typed that sequence into the old Motorola “brick”, a message would be sent to the base station to say “forward my phone calls to the following number if I do not answer within a certain number of seconds”. That same star code works on a modern phone as well.
This is also how “smart” phones work — the user interface runs on a PDA-like device, and star codes are sent over a serial line to the “GSM modem module”, a completely separate phone-on-a-chip that does nothing but handle the phone calls.
Here’s what it looked like when I customized my voice mail delay from my iPhone. First, I dialed the star code to see what my current voice mail setting was. That code is *#61#.
I wrote down the voice mail number — this is the number for AT&T’s voice mail system. Then I dialed **61*+1xxxyyyzzzz*11*10# to see if it would change my “call forward on no answer” delay to 10 seconds.
And I got this confirmation screen.
Then I called my iPhone. Sure enough, after 10 seconds, my call was routed to voice mail.
Of course, 10 seconds is too short — I used that number as a test. So I repeated the process to set the delay to a more reasonable 30 seconds.
A couple of important points:
- This is not hacking. This is a documented feature of GSM cellular networks, and it is exactly what happens behind the scenes when you enter a phone number in the “voice mail” menu of a cellular phone. The only difference is that the menu uses a hard-coded delay value, whereas you can set your own delay if you enter the command manually.
- This process should work on any GSM phone, not just on the iPhone.
Born in the USA
4We can all thank Bruce Springsteen for planting the idea in our heads that a person has to be born in the United States in order to be eligible to become president.
Article II of the US Constitution clearly states the requirements, that a president must be “a natural born Citizen”. Nowhere does it state that the person must be born in the United States. It is true that most people who are born in the US are granted citizenship at birth. It is also true that people who are born outside of the US, from one or more US citizen parents, can also be granted US citizenship at birth.
When my daughter was born in Singapore, many of my friends made the comment that “she can never become president”. However, shortly after her birth, the US Consulate in Singapore presented us with a “Consular Report of Birth of a Citizen of the United States of America”, or Form FS-240. This form clearly declares that my daughter was born a US Citizen, and it is recognized by the US government as proof.
I bring this up because of the current scuttlebutt, claiming that Barack Obama was not born in the United States, and therefore can not legitimately act as president. I am not going to get into that argument.
But I do want to clarify that being born in the US is not a requirement for citizenship, and it is not a requirement for becoming president.
I can only hope that Audrey has this same problem in 30 years.
Do not pass? Go? Do not collect $200?
1On my morning commute to work, I travel along a five-lane highway (two lanes in each direction, plus a shared turn lane). There is a bus stop in front of a large apartment complex, and the bus picks up a huge bunch of kids there.
Every morning, this south-bound bus stops in front of the apartment complex, and several dozen kids get on, taking their sweet time (as kids do). All of the south-bound cars are blocked while the bus is stopped.
At this time, I am usually wondering why that bus does not pull into the apartment complex’s driveway. After all, they are blocking a major roadway during a busy morning commute time.
But it gets worse… not only are all of the SOUTH-bound cars stopped. But the NORTH-bound cars are stopped as well!
North Carolina law does not require the drivers in the opposing lane to stop. But most drivers are not that familiar with the details of the traffic laws. And I suppose that when faced with this choice — either err on the side of stopping when not necessary, or err on the side of passing a stopped school bus — most people would take the more conservative option.
The North Carolina Driver’s Handbook can be downloaded from the DMV’s web site.
On page 43, you’ll see this picture:
And this is the explanation:
Roadway of four lanes or more with a center turning lane: When school bus stops for passengers, only traffic following the bus must stop.
Of course, it also goes on to say:
Children waiting for the bus or leaving the bus might dart out into traffic. Even when the school bus is not in sight, children at a bus stop sometimes will run into the street unexpectedly. Always be careful around school buses and school bus stops.
So, as always, common sense does apply.
I have considered what I might do if I happened to be the first north-bound car to approach as that school bus stopped in the south-bound lane. Would I keep going (with caution, of course)? Or would I stop, just because my fellow citizens might sneer at me for “breaking the law” and for driving with a reckless disregard for out children’s safety?
THINK of the CHILDREN!
How would a police officer react if he were driving right behind me?
I am not saying that stopping for the bus is a bad thing. But I am amused to see how people react when the rules are ambiguous, or when they are incompatible with what seems like a universal blanket rule (Thou shalt stop). Would you want to be the one who follows the letter of the law, but who appears to be a scofflaw?
Compromised?
3
15 years
This morning, when I scanned my email, I ran across a report from rkhunter, a tool that runs on my web server that periodically checks to see if system files have changed, or if users have been added, what processes are listening on ports, and a litany of other tests to detect whether a system might be infected. I get these reports fairly often, usually the day after I do an upgrade, or after I add a new user.
However, today’s email was a little bit alarming. It said that several files had been changed recently. And these files all seemed to do with the same sort of things: running stuff behind the scenes, showing library dependencies, elevating privileges. Basically, these were tools that you would want to modify if you wanted to cover your own tracks.
Warning: The file properties have changed:
File: /bin/sh
Current hash: 23603f77da4ca37705146fd8a4ed951c8b037156
Stored hash : 91654fd25d317bd13a65e10d777ac021f4a1a4f6
Warning: The file properties have changed:
File: /bin/dash
Current hash: 23603f77da4ca37705146fd8a4ed951c8b037156
Stored hash : 91654fd25d317bd13a65e10d777ac021f4a1a4f6
Current inode: 180336 Stored inode: 180255
Current file modification time: 1236603791
Stored file modification time : 1213978027
Warning: The file properties have changed:
File: /usr/bin/dpkg
Current hash: 4e05d20a4f828c31eb5f6dd9cc5f04d1d6202d0a
Stored hash : 09a5bbd0398cc9f02b52440e1241cd942e784a15
Current inode: 248598 Stored inode: 246001
Current size: 375340 Stored size: 371244
Current file modification time: 1236595869
Stored file modification time : 1220443410
Warning: The file properties have changed:
File: /usr/bin/dpkg-query
Current hash: ff8098920430d399933ee24245748983a0661869
Stored hash : 4a1c1226cbe9dd2ddbec7b5652f1fa8aa0b15f09
Current inode: 248600 Stored inode: 246003
Current file modification time: 1236595869
Stored file modification time : 1220443410
Warning: The file properties have changed:
File: /usr/bin/file
Current hash: 4ab93b21aaabb405f4bd2e90f16ee5e952aa746b
Stored hash : 80dc1735091a4309d23e49ce542c58ddd16163dc
Current inode: 245969 Stored inode: 246049
Current file modification time: 1244193699
Stored file modification time : 1215771733
Warning: The file properties have changed:
File: /usr/bin/ldd
Current inode: 248852 Stored inode: 246132
Current file modification time: 1233224578
Stored file modification time : 1222684817
Warning: The file properties have changed:
File: /usr/bin/perl
Current hash: 00d703e925eca6de0c8fc9bd9d4505db4b81ce33
Stored hash : efb4a1a3d02798718b7f2bbfea6787dd0de79968
Current inode: 245962 Stored inode: 246591
Current file modification time: 1246045733
Stored file modification time : 1216891204
Warning: The file properties have changed:
File: /usr/bin/sudo
Current hash: e649919d4bbc6ac78e38497ca94dc387cc2811a7
Stored hash : 49e97774326fc9eb5f7cb680477c1d56f4e28921
Current inode: 246543 Stored inode: 246747
Current file modification time: 1234840625
Stored file modification time : 1220275024
Warning: The file properties have changed:
File: /usr/sbin/cron
Current hash: 5efdffc9796731168fb7acc8688c5a02e0da42dd
Stored hash : 04924b72b749e8179bb5839bac1a296c7acf93c4
Current inode: 245910 Stored inode: 248315
Current file modification time: 1242164811
Stored file modification time : 1220989568
One or more warnings have been found while checking the system.
Please check the log file (/var/log/rkhunter.log)
I scanned /var/log/dpkg.log, to see if I had recently done an update, and I did not see anything. That little paranoid part of my brain started to wake up (those that know me might clarify that when I say “little”, I really mean “big”).
So briefly, someone had changed the following files on my server. How could I tell if they were the “real” ones or not?
- /usr/sbin/cron
- /usr/bin/sudo
- /usr/bin/perl
- /usr/bin/ldd
- /usr/bin/file
- /usr/bin/dpkg-query
- /usr/bin/dpkg
- /bin/dash
- /bin/sh
What bothered me about this combination was that dpkg was in that list, so I could not use any of the apt/dpkg tools to verify the integrity of my packages against what is published on the Ubuntu mirrors.
So I had to take matters into my own hands. I went to the Ubuntu packages site and searched for the first package, ‘cron’. From there, I could click on the ‘i386’ link to download a local copy of the cron_3.0pl1-100ubuntu2.1_i386.deb file onto my laptop (not onto the suspect server). I extracted the contents using dpkg -x cron_3.0pl1-100ubuntu2.1_i386.deb .. From there, it was pretty easy to compare MD5 checksums of the files.
$ ls cron_3.0pl1-100ubuntu2.1_i386.deb $ dpkg -x cron_3.0pl1-100ubuntu2.1_i386.deb . $ ls cron_3.0pl1-100ubuntu2.1_i386.deb etc usr var $ md5sum usr/sbin/cron c1d78d8a9a99b52df8ecba41517ab013 usr/sbin/cron $
This checksum matched the one on my server. So that means my binary files were legitimate (this does not explain how they got updated without leaving a trail in the logs, but that is another issue).
Lather, rinse, and repeat for all of the suspected files.
I hope this little story helps someone else defuse that panicky feeling that sets in when your intrusion detection system sends you an unpleasant email.
The toys that feed my obsession
1I have always been a bit of a gadget freak, with a real interest in personal computing devices. I discovered early on just how useful it could be to have a lot of information at your fingertips.
Way back in 1992, when most people were running Windows 3.1 and Novell networks were cool, I bought a Zeos Pocket PC, a small DOS-based PC about the size of a VHS videotape that ran off of 2 AA batteries. It had Microsoft Works built into ROM, and 384k of battery-backed RAM to store my files. That was a sweet little PC, and I used it to store lots of convenient stuff, from my stock portfolio to my personal address book and calendar. You really can store a lot of data in 384k — if it’s all text.
In 1996, my wife (trend setter that she is) bought a Palm Pilot. The built-in apps were very clean and polished, and there were thousands of third-party apps that could be downloaded. I followed right behind her with one of my own. Moving from DOS to PalmOS was a bit of a shock — it was like suddenly moving into a nice neighborhood where someone else cleaned your house (but sometimes you could not find where they stored your stuff). I quickly grew to love that platform, even writing a few simple apps of my own. Over the years, we upgraded Palm devices several times.
The next year, I started working for Ericsson. This was in the early days of digital cellular (in the US), and I was excited about trying hand-held devices that were also wireless. But Ericsson never managed to fill this void with one single device. Instead, I carried a “Bat Man utility belt” of gadgets: a Palm PDA, an Ericsson GSM phone, and an Ericsson IrDA adaptor. Bluetooth was still under development at the time… still called MC Link, but eventually I upgraded my utility belt.
At one point, I got fed up with PDA’s. In the battle for pocket space, the phone always won over the PDA. And most of the time, I was either at home or at work, so I almost always had a PC nearby. I also started to worry about security — what if I lost my PDA, what would a thief know about me? So I gradually weaned myself from all of my “must have” Palm applications and I moved my portable data to the hot new thing… a thumb drive. I encrypted the whole darned thing, plugged it in at work or at home, backed it up often, and never worried about losing it. The only time that I found myself missing the PDA was when I needed my calendar. So once in a while, I would print it out and keep it in my pocket… on paper… old school.
It made sense to start moving some of my data to the web. There are nice web apps for doing calendars and address books and lots of stuff like that. Some use Google. I chose to host it on my own server, where I knew it was safe from prying (and marketing) eyes.
When it was time to get a new cell phone, my wife secretly bought me an LG vx9900 “enV” phone. It was one of the first phones that flipped open to reveal a QWERTY keypad. It had a pretty good WAP web browser that allowed quick retrieval of some type of info: weather forecast and radar, geocache hints, and my personal stuff (address book, etc) that I had moved to the web already.
In the summer of 2007, known around my house as “the summer of toys”, I found myself with a new mandate: I wanted portable internet access while we went to China in the fall. Looking back at my great experiences with Palm devices, I bought a used Palm Tungsten C on eBay. This is one of the few Palm PDA’s that sported an 802.11 wifi link. However, after a few weeks of pre-China tinkering, I decided that the screen was too small (in pixels), the email access stunk, and the browser was only suitable for the absolute simplest of web pages. I relegated it to my geocaching bag, where its only job was to occasionally look up geocache hints. Within a month, I had cracked the screen. C’est la vie.
About a week before we were to leave for China, I spotted a clearance sale on Woot where they were dumping the Nokia 770 as Nokia geared up for their new model. I snatched one up, and it performed flawlessly on our trip, accessing the internet wherever we were (using either free or “borrowed” wifi). I accessed email through a web mail app on my server at home, and we looked up dozens of things online, from local attractions to pharmaceutical advice. I did not have to worry about virus-laden PC’s in internet cafe’s and hotels (or at my in-laws’ house) and I did not have to navigate through a Chinese version of Windows XP. Best of all, since the N770 runs Linux under the hood, there are a lot of nice tricks that you can do, like running a VPN, or syncing via SSH over wifi.
The next year, I attended a hacker conference. Like a flashback to the Zeos Pocket PC 1992, I encountered a guy using the Asus Eee PC. Within a week, I had one of my own, and it became my primary computer for the next year. I immediately wiped the solid state disk and installed Ubuntu. The flash disk is pretty modest, so I did not store any of my stuff on it, preferring instead to keep that on my encrypted flash drive. Being small enough to keep in a bookbag meant that it went everywhere I went. And on the rare occasions when I needed more screen real estate, I simply plugged into a VGA monitor.
—
This month, I enter a new chapter in my long series of relationships with small machines. I bought an Apple iPhone 3G S. I am extremely excited about this device. Like the Palm, it has a ton of third-party applications. Like the Nokia 770, its browser is good enough to make it an effective “vacation PC”. Like the Nokia 770, It uses either the open wifi of your generous neighbors, or the cellular network. But unlike the “Ericsson Bat Man utility belt”, this device does it all in one, very small and sexy unit.
To summarize:
- 1992 Zeos Pocket PC – PC? yes… pocket? that’s a stretch
- 1996 Palm Pilot – a very nice PDA with a lot of third party apps
- 1999 the Ericsson “Bat Man utility belt” – no one ever called Bat Man a geek
- 2004 thumb drive – where most of my stuff lives
- 2005 the web – where a lot of my stuff lives
- 2007 LG vx9900 “enV†phone – a nice phone with a simple browser
- 2007 Palm Tungsten C – not really worth it
- 2007 Nokia 770 – the web in your pocket
- 2008 Asus Eee PC – big enough to be a full PC, small enough to carry everywhere
- 2009 Apple iPhone 3G S – we shall see
Summer vacation in the moutains
0We took a week off while the girls were “tracked out” of school, and we went to the mountains.
Saturday 2009-07-18
We eased into our vacation by driving half-way to the mountains, stopping in Winston-Salem to visit my parents. We spent some time with my two grandmothers. And then we came went for a walk around the neighborhood, pointing at all of the houses where my childhood friends used to live, and we caught up on what we had heard from everyone.
Sunday 2009-07-19
We packed up the Family Truckster and headed to the mountains by way of Hiddenite, NC. This town is famous for the minerals found there, and was named after an associate of Thomas Edison, who was sent there to find a particular type of mineral. Instead, he found a completely unknown type of stone, which ended up bearing his name. The town later changed its name as well.
The gem mine in Hiddenite is a lot of fun for smaller kids. But older and more cynical kids might wonder why such large stones can be found in such soft and freshly ground up dirt. One older and more cynical friend took his kids to see a geologist at NC State University, who told them that the rocks they had brought back from the Hiddenite mine were not native to North America. Hmm.
From the mine, we headed up through Lenoir and into Blowing Rock, which would be our home for the next week.
Monday 2009-07-20
Our plan for the day was to head over to Grandfather Mountain, but we were in no hurry to get started. So instead, we explored the local park in Blowing Rock, and we found a couple of geocaches. It had been a long time since we had done that as a family, and the two we found did not disappoint (one “virtual” and one multi-stage cache).
We finally headed out to Grandfather Mountain, where low cloud occasionally obscured the peaks. The swinging bridge seemed even higher than it is because of the visible cloud moisture blowing up one side of the mountain and through the gap between the peaks. Sydney showed no restraint as she ran on the rocks, while the rest of us imagined the impending disaster. We took plenty of pictures, and finally made our way down to the museum, where we saw such attractions as: lunch, bears, a bald eagle, and fudge.
While we were there, we ran into a guy from my office… hey, isn’t that against the rules?
Tuesday 2009-07-21
On Tuesday, we went into Boone to see Mystery Hill, which can best be described as a tacky little tourist trap that aspires to be something bigger than it is. The main attraction is the room that is built at a 45-degree angle, which is a much more compelling optical illusion that you might expect. The rest of it was like a very small science museum, with some funny mirror tricks and a large hula-hoop bubble station. Next door is a museum that houses items from the first half of the 20th century… a good chance to explain things like a record player to my two digital-age children.
The main attraction of the day was Tweetsie Railroad. They had a lot of little shows and shops and carnival-style rides and even a petting zoo. But at center stage was the steam locomotive, which takes a short trip around the park, with a cowboys-and-indians adventure thrown in.
We wrapped up the day with a couple of geocaches, a good way to discover some of the local parks.
Wednesday 2009-07-22
On Wednesday, we decided to get out of town and into the woods, with a day hike at Linville Falls. Our trip the Blue Ridge Parkway was slow because of very thick fog. And when we reached the Linn Cove Viaduct, it seemed like the road just ended at a cliff.
There is a very nice National Park at the Falls, with very wide and comfortable trails that take you to several vantage points to see the falls. This was the perfect setting for a family hike… a fairly high climb, but an easy grade and lots of rewards along the way. We took a lot of pictures at the peak, and then returned back for a picnic lunch.
On the trail back out, I noticed that there was a geocache hidden near one of the overlooks (I did not expect this, since geocaches are usually not allowed on National Park land). So I had to find it. I was rewarded with a geocoin whose last stop had been in the United Arab Emirates.
We had our picnic lunch, and then headed down into the valley to Linville Caverns (Foong asked me when we stopped what that smell was, and then we realized that it was our burning brake pads). The cavern was cool, in more ways than one.
And as we left, it started raining. Good timing. We took an extremely scenic route back to Blowing Rock. Part of that was due to our GPS being stuck in “shortest distance” mode — it did not seem to matter that part of that route was really some hillbilly’s driveway.
Thursday 2009-07-23
On our last full day in the mountains, we decided not to do any one big thing, but instead to see a bunch of smaller things. So we drove to the small town of Valle Crucis. The big attraction there is an old general store with an entire room devoted to candy (our girls each got one handful of whatever they wanted).
We drove to Fosco, NC, where we found an “Earth cache” — a geocache that is educational, and somehow related to some natural earth formation. This one required us to take a picture of a mountain that looked like it had a face on it.
We went back to Blowing Rock, where we explored the old manor house at Moses H. Cone Memorial Park. Finally, we saw The Blowing Rock, which is a rock outcropping on the windy side of the mountain. This was the last of many, many gift shops that we visited during the week.
Friday 2009-07-24
We woke up on Friday and packed up to leave. We headed back a different way than we came, a route that seemed to be one long ramp that goes straight down the mountain. On the way back, we stopped in Wilkesboro at Moravian Falls, a slide-type waterfall with a small campground next door (and, of course, a geocache).
When we got back to Winston-Salem, we were reunited with our dog, Maggie, and we got to spend another night with Mimi and Pops.
Saturday 2009-07-25
Saturday was “tech support” day, helping Mimi and Pops with digital photos, backups, and how to post to Craigslist. Eventually, we tore ourselves away from the fun and returned home.
When we got home, we gave the girls a rock tumbler, which we used to polish the stones that we had found in the Hiddenite mine.
Plant my key
4
15 years
Here’s a neat little script that I developed at “the oven place”. It “plants” my SSH key on a remote machine, so I can get in later without entering a password.
#!/bin/sh
user_at_machine=$1
# plant my SSH key on the target machine
cat $HOME/.ssh/id_rsa.pub | \
ssh $user_at_machine \
"if [ ! -d .ssh ] ; then mkdir -m 700 .ssh ; fi ; \
cat >> .ssh/authorized_keys"
All of the action takes place in one single line (which I broke up here so it would wrap OK). It takes your public key from the machine you’re on, and it pipes it into an SSH session, which you’ll have to type your password into. On the remote machine, it creates a .ssh directory if it needs to, and then it appends your public key to an authorized_keys file.
The next time you log in to that remote machine, you will not need to enter your password.
Counting down with ‘pv’
0
15 years
Here’s a neat tool.
Ever start some long task, and wonder how much longer it has to go? There’s a small utility called pv (short for “pipe viewer”) that counts time and bytes through a pipe, and it shows a nice progress bar.
Here’s how I used it to watch a very large file being compressed (note the use of the most excellent lzma compression utility.
$ pv < winxp.vdi | lzma > winxp.vdi.lzma 1.79GB 0:21:50 [1.49MB/s] [===> ] 10% ETA 3:11:02
Note that if I had used a different pipe notation, pv would not have been able to read the input file size, and therefore it could not make estimates of remaining time. So instead, it shows you the “Knight Rider” scanning eye for progress.
$ cat winxp.vdi | pv | lzma > winxp.vdi.lzma 5.48MB 0:00:04 [1.27MB/s] [ <=> ]
Nice tool. Thanks, Andrew!
Save that thought…
1
15 years
At work, our build process can produce thousands of lines of code, and sometimes the important bits can slide off of the terminal’s scrollback buffer.
So I created an alias that logs all output of the shell. It’s nothing fancy… it’s just a call to script with an argument to put the time and date in the filename. But it goes a step further, actually exec-ing the script command, so you do not have to exit twice when you’re done (once to exit the script, and once to exit the original shell).
alias log='exec script "/home/alan/logs/terminal-$(date +%Y%m%d-%H%M%S)-$$.log"'
Still, this requires you to think about logging before you start your work.
Since I normally launch my shell windows from a Gnome application launcher icon, I decided to modify that launcher so that EVERYTHING is logged.
On Gnome, right-click on the panel at the top and select “+ Add to panel…”. Then select “application launcher” and pick out the gnome-terminal from the menus. You’ll have a little terminal icon on the top Gnome panel.
Right-click on that terminal icon and select “properties”. It should say “gnome-terminal”. Change it to the following:
sh -c "exec gnome-terminal -x script $HOME/logs/terminal-$(date +%%Y%%m%%d-%%H%%M%%S)-$$.log"
The double-percents are so the launcher will not interpret them.
Now, when you click on that application launcher icon, a new terminal window will open, and all output to that terminal will be logged.
Firefox: invalid or unsupported form of compression
0
15 years
Occasionally, I have been seeing the following error in Firefox (v3.0.11).
The page you are trying to view cannot be shown because it uses an invalid or unsupported form of compression.
It occurs frequently when I am using a SOCKS proxy. One web site which happens to exhibit the problem more than others is Bruce Schneier’s blog.
The work-around that seems to work for me is to do a “Tools / Clear Private Data…” and select Cache, Cookies and Offline Website Data.
There’s a lively discussion on the Mozilla support forum, but no one seems to know what the source of the problem is.
Peek-a-boo!
0Please welcome the newest addition to our family, a hermit crab named “Peekaboo”.
He comes from Wings at Atlantic Beach. He lives in a plastic shoe box with a sandy floor, a water dish to bathe in, and LEGO’s to crawl on. He likes to be sprayed with water, and he likes to crawl up Audrey’s arm.
Two heads are better than one
0
15 years
At work, I got a new PC with two monitors, and I have really enjoyed having the extra screen real estate.
When I worked from home this week, I decided that I needed to try hooking an external monitor to my HP laptop. I was happy that, unlike the last time I tried this a few years ago, it “Just Worked” ™ without any special calesthenics on my part.
I wondered why Gnome decided to put the panels (the bars at the top and the bottom) on the external monitor instead of on the laptop display. To me, it seemed more natural to have the “start” menu (actually, the “Applications, Places, System” tri-menu) on the external display instead of right in front of me.
It turns out that this is really easy to fix. Gnome has this configuration tool that is roughly equivalent to the Windows registry… yuck. You can access it using either gconf-editor or gconftool-2. Inside that deep mine of settings, there is one jewel that tells where the panels should go. So I wrote a quick script to move the panels from one monitor to the other and back.
#!/bin/bash
m=$1
if [[ ( ! -z "$m" ) && ( ( $m -eq 1 ) || ( $m -eq 0 ) ) ]]
then
menu="/apps/panel/toplevels"
panels=$(gconftool-2 --dump $menu | \
grep '<key>.*/monitor</key>' | \
sed -e 's/^.*<key>//g' -e 's/</key>.*$//g')
for p in $panels
do
gconftool-2 --set "$menu/$p" --type integer "$m"
done
else
echo "usage --> $0 [ 0 | 1 ]"
echo "moves gnome panels to monitor 0 (VGA) or 1 (LCD)"
fi
exit 0