I’ve used this successfully and can attest to how handy it is. Kudos to Iceni for putting that Howto together.

BT dongles are getting cheap enough today that this is very doable. Most phones have BT already, so why not try it out?

Linksys also makes a USB Bluetooth adapter with a movable antenna. I’ve not heard anything about that particular adapter, but I would wager that its range is greater than that of normal Bluetooth dongles.

That’s it for today!

-LightningCrash

To start with, awk has three major elements that you need to be aware of when you’re working with it. These are the field separator, the pattern, and the action for the pattern.

Your fied separator is obviously what is inbetween the text elements you want to work with. If you open up a terminal and type ‘ps -elf’, you’ll see that this would just be spaces. Some files, like CSV files, have commas as the separator. Awk can be told what to look for via the -F option on the command-line, or in the program itself. For one-off piping, I prefer to do it via the -F option.

The pattern is much like an ‘if … then’ statement in other programming languages. If there isn’t a pattern, the action specified will be applied to all rows of input.

What makes awk handy is that it gives you capabilities that the `cut` command simply can’t provide. For instance, if I have a twenty-column CSV and I would like to spit out the third and eleventh column, I can execute the following:

awk -F',' '{print $3 FS $11}' file.input

The -F’,’ tells awk that the input fields will be separated by commas. The area enclosed in the braces is the action I talked about earlier. I didn’t specify a pattern before the action, so the action was applied to every line of input. “print $3 FS $11” tells awk to print to the screen the third field of input, the field separator (which we defined as a comma with the -F’,'), and the eleventh field of input.

If I wanted to do the same, but only print lines where the third field was over a number, say, 110, I could execute the following:

awk -F',' '$3 > 110 {print $3 FS $11}'" file.input

The pattern before the braces functions much like an “if … then”. If the third field is over 110, awk prints out the third field, the field separator, and the eleventh field.

There is much, much more that you can do with awk, but this should be enough to hint you in the right direction. I know I use awk daily for various tasks related to command-line mischief. A common thing I use awk for is to manipulate /etc/passwd, where some user account information is stored.

Fortunately, GNU awk is often smart enough to pick up the field separators without specifying the -F option. For instance, /etc/passwd is separated by a colon “:”, but GNU awk automatically recognizes this. It’s worth noting that on some other systems without GNU utilities, awk may behave in ways that you don’t anticipate.

That’s it for the moment, just some small tips to get you moving. I’d recommend picking up a book on AWK. I recommend you pick up a copy of “The AWK Programming Language” by Aho, Kernighan and Weinberger. It only makes sense, since they are the creators of AWK. I have also been told that the O’Reilly AWK book is very good. In addition, the GNU awk is well-documented all over the Internet, so you shouldn’t be lacking in study material if you put some effort into it.

Until next time!

-LightningCrash

Case in point: I was comparing two lists of accounts. I wanted the accounts that were present in the newer file. Diff gave me output, but the diff output wasn’t what I wanted.

comm is handy for this. You would do the following to get the list I want:
comm -1 -3 oldfile newfile

Lovely! comm is actually part of the GNU Core Utilities and was written by Richard Stallman and David MacKenzie. That confirmed my suspicions that comm subscribed to an old UNIX adage for some utilities: Do one thing very, very well.

I have nothing more to say about comm, you’ll have to wear it out yourself.

Until next time,

-LightningCrash

A prompt buzz of the site showed some promise, much like a pre-psychotic Britney Spears. At a paltry $3/mo, who could argue with that pricing, either? My fond memories of the Quicken application under Windows led me to believe that finally, I could have my Quicken functionality back, but under Linux. Or, for that matter, independent of any operating system.

I was wrong.

You see, the real Quicken application does a mighty number of wonderful deeds, carefully crafted to the exacting specifications that you’ve come to accept from Intuit since the widespread adoption of Quicken in the early nineties. I don’t need to explain to you what the real Quicken does, though. I merely have to show you what the online version does.

In extended detail, what Quicken Online does for you:

1. Downloads your data from your financial institutions
2. Lets you categorize it
3. Puts it in a pie chart

Let’s pretend for a moment that the above is actually useful. What can you do with the above? I’ve come up with some clever ideas.

1. Spend more money in an attempt to make one part of the pie bigger than the other
2. Point out the pie to random people in your office building
3. Pretend that the pie chart is an actual, multi-colored pie
4. Go buy a real pie
5. Tell your friends you’re so utterly independent of Micro$h4ft Winblows that you don’t even need Quicken for Windows, even under WINE support
6. Go to the liquor store and buy some real WINE support
7. Run those damn kids off your lawn

I have to wonder what the development plan was for Quicken Online. Perhaps the business case went a bit like this:

1. Create a quick webapp and call it Quicken Online
2. Market the webapp
3. ???
4. PROFIT!!

I give this application a C for effort, and an F for execution.

Of course, F is for Fail.

-LightningCrash

Watch to the rescue!

Watch executes a command at a specified period. For instance, if I’m extracting a file and want to monitor the progress, I can simply type:

watch 'ls -la filename.ext'

and I will get the output from `ls -la filename.ext` every 2 seconds.

If my internet connection is down and I am impatiently waiting for it to come back up, I can run:

watch -n15 'ping -c1 www.google.com'

If I’m forking processes in a Bash script and want to make sure none of them are hung:

watch -n2 'ps ax|grep [p]rocessname'

It’s very handy!

I periodically come across an issue whereby `tail -f /var/log/syslog` will hang after operating for a couple of hours. I solve this by using the following instead:

watch -n5 'tail -n20 /var/log/syslog'

`man watch` to find more uses for this program. I tried `woman watch` but apparently Linux doesn’t carry those.

and holy sweet crap, it’s been a long time since I wrote an article on this site!

Until next time,

-LightningCrash

So I decided to make a signature that would include a random Latin phrase in every e-mail I send. Thankfully, Evolution makes this easy.

First, I make a text file which I call sigquotes.txt , and stash it in my home directory, under a folder for personal items. I put one quote per line.

Next, I have to write a little ditty to grab a random line from that file and output the results. I used PHP for this, but almost anything could have worked. I dump the following into sigrand.php :
<?
$quoteFile = "/home/icanhaslinux/personal/sigquotes.txt";

$fp = fopen($quoteFile, "r");
$content = fread($fp, filesize($quoteFile));
$quotes = explode("\n",$content);
fclose($fp);

srand((double)microtime()*1000000);
$index = (rand(1, sizeof($quotes)) - 1);

echo "________<br>LightningCrash<br>Resident Unix Witchdoctor<br><br>";
echo $quotes[$index] . "<br>";
?>

Easy enough. I had problems getting the php itself to run as a script, so I had to make another short script to launch the PHP file. I put the following into sigrand.sh :

/usr/bin/php5-cgi -q /home/icanhaslinux/personal/sigrand.php


I chmod +x sigrand.sh and go on my way to the next step.

I fire up Evolution, go to Edit->Preferences. I go to Composer Preferences and click on Signatures. Then I click on the “Add Script” button, name it Random Latin, navigate to /home/icanhaslinux/personal, and select sigrand.sh as my signature script.

That part is done. Now to make it default for my outgoing e-mail. From the Preferences page, I click edit on my e-mail account. On this page, I have a drop-down box where I can select my signature for this account. I select Random Latin, of course. I then click OK and Close.

Now, to test it out, just fire up a new e-mail.

Until next time!
-LightningCrash

EDIT:   It’s been requested that I make clear what license this code is issued under. I consider the code snippets on this article to be public domain and not subject to licensing. Use the code in this article as you see fit.

You gotta love Fair Use.

RIAA Radar has a website that will let you search for artists, albums, keywords, etc and it will give you information as to whether or not an album was released under the RIAA.

So I did a view-source on their search page and determined that there are only three variables that you need to POST in order to search: searchtype, keyword, and submit.

I can use wget to grab the file, like so:
wget http://www.riaaradar.com/search.asp --post-data "searchtype=ArtistSearch&keyword=Audioslave&submit=Go\!" -O Audioslave

This saves the file as Audioslave. Audioslave IS represented by the RIAA, by the way.

Now, how do I take my ripped albums and compare them to the RIAA Radar site?

(more…)

1. Send yourself a one-time reminder e-mail about something.

You can do this via the handy ‘at’ command. For instance, if I wanted to shoot myself an e-mail after work reminding me to pick up my laundry from the dry cleaners, I could do the following:
echo "mail -s 'Get dry cleaning' me@myemailaddress.com < /dev/null" | at 17:45

I can also send this e-mail to my cell phone, giving me another reminder away from my computer. US AT&T users can send messages to their telephone number @txt.att.net and it will be received as an SMS message on the phone.

2. Pop up a one-time reminder on your computer about something.

The ‘at’ command comes in handy again. If I want to remind myself to let my dogs in from the back yard, I can simply type:
echo "DISPLAY=$DISPLAY xmessage Let dogs in!" | at 18:15

At 6:15, a little message box will pop up telling me to let the dogs in.
You can also specify times for ‘at’ by using NOW + interval.
For instance, using
at "NOW + 30 minutes"

will give me an execution time of 30 minutes from now. I could use hours, days, or weeks to get whatever effect I wanted. In addition, an e-mail log of everything will be sent to my local e-mail account, detailing what went on.

3. Alarm Clock with ‘at’

If you need to wake up early one morning, or you want to wake up from a nap, you can use your computer as an alarm clock and play an MP3 for you to wake up to. This one is straightforward enough. You’ll need mpg321 installed to use this, and know the path to the mp3 file you want to play.
echo "mpg321 ~/Trivium/Rain.mp3" | at 5:30AM

You’ll have to execute pkill mpg321 in a terminal to make it shut up, though.

4. Alarm Clock with ‘cron’

Now we’re going to do the same thing, but on every weekday of every month.
Execute crontab -e and then type in the following:
30 5 * * 1-5 mpg321 ~/Trivium/Rain.mp3 >/dev/null

Now, every weekday at 5:30, you’ll get that mp3 blasting out over your speakers. Obviously you’ll need to specify your own MP3 file. You’ll also need to execute pkill mpg321 to make this one shut up. Your spouse may not like this idea, but assure your spouse that it will make you wake up more easily.

5. Alarm Clock with KAlarm

You’ll need to install KAlarm for this one. KAlarm will let you run XWindows applications (or even command line apps) via a cron-like process. It can also send e-mails and pop up messages. Check out their documentation here.
You can schedule MP3s with XMMS and Totem much in the same way as you can mpg321.
xmms ~/Trivium/Rain.mp3
totem ~/Trivium/Rain.mp3

You can set up Kalarm to run these programs and blast out your music for a specified time. If you haven’t killed the application within that set time period, Kalarm can kill it for you. Which is handy when you’re not home and you have heavy metal blasting through your 7.1 Surround Sound speakers at 5:30 in the morning for your neighbors to hear. Eviction isn’t high on anybody’s priorities list.

Did I miss anything? Leave it in the comments section.
Until next time!
-LightningCrash

I back up my personal e-mail server, my home desktop, and my MythTV box to Amazon’s S3 service. I run weekly full backups of select directories on my desktop, and then incrementals throughout the week. My MythTV box backs up its database on its own, so I just tarball the output and dump it to a folder on my desktop machine, which gets put on S3 when the backup job runs. My mail server runs full backups of select directories every night.

I used some bits and pieces from Paul Stamatiou’s article on S3 backups. You can read that article here.

I added in some bits and pieces for using an include/exclude file, and modified it to run incrementals on my desktop. I also got to use mktemp to do some of my bidding, which was very handy.

All told, my Amazon S3 bill for last month was $1.48 for ~8GB of transfer in, and ~3.7 storage GB/mo. I pair down my stored files weekly to meet some retention guidelines, so that contributed some to my low bill.

But all in all, I’m VERY impressed with S3. I definitely got my $1.48 worth!