Shallow Thoughts : : 2006
Akkana's Musings on Open Source Computing and Technology, Science, and Nature.
Fri, 29 Dec 2006
A friend called me for help with a sysadmin problem they were having
at work. The problem: find all files bigger than one gigabyte, print
all the filenames, add up all the sizes and print the total.
And for some reason (not explained to me) they needed to do this
all in one command line.
This is Unix, so of course it's possible somehow!
The obvious place to start is with the find command,
and man find showed how to find all the 1G+ files:
find / -size +1G
(Turns out that's a GNU find syntax, and BSD find, on OS X, doesn't
support it. I left it to my friend to check man find for the
OS X equivalent of -size _1G.)
But for a problem like this, it's pretty clear we'd need to get find
to execute a program that prints both the filename and the size.
Initially I used ls -ls, but Saz (who was helping on IRC)
pointed out that du on a file also does that, and looks a
bit cleaner. With find's unfortunate syntax, that becomes:
find / -size +1G -exec du "{}" \;
But now we needed awk, to collect and add up all the sizes
while printing just the filenames. A little googling (since I don't
use awk very often) and experimenting led to the final solution:
find / -size +1G -exec du "{}" \; | awk '{print $2; total += $1} END { print "Total is", total}'
Ah, the joys of Unix shell pipelines!
Update: Ed Davies suggested an easier way to do the same thing.
turns out du will handle it all by itself: du -hc `find . -size +1G`
Thanks, Ed!
Tags: linux, CLI, shell, backups, pipelines
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17:53 Dec 29, 2006
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Thu, 21 Dec 2006
At dinner last night, amid the ubiquitous miasma of egregious
Christmas music which is inescapable in public places starting
in mid November, during "The Twelve Days of Christmas" Dave got a
faraway expression in his eyes. My mother asked why, and he explained
that he was thinking about the mathematics of the song: how many items
of each type have been given by the end, and which items are more
numerous?
There are two ways to interpret the song.
On the second day of Christmas, my true love gave to me
Two turtle doves
And a partridge in a pear tree.
So by the second day, you have two turtle doves, and you have the
original partridge -- but do you also have a second partridge, as a
literal interpretation of the song implies? Or is the song simply
repeating all the previous gifts, not implying that they're given again?
Most people seem to assume the latter, but let's take the song
literally and assume that on the third day, you get three french hens,
plus two more turtle doves (that makes four) and one new partridge (for
a total of three).
My first thought was that at time step T, you double what you had in
step T-1 (you're getting all the same stuff yet again) and add T for the
new gifts. But that's not right: you get a new load of each item (one
partridge, two doves, three hens, and so forth) but you don't double
all the accumulated extras who are now crowding your back yard.
Time to start writing down the sums.
At each time T, the quantity you have of the Jth item is:
That's easy: it's just NJ,T = J*T- J*(J-1)
(pretend you've given J of the Jth object at each time step; but
since you didn't give it before timestep J, subtract all the ones
up to timestep J-1).
NJ,T = J * (T - J + 1)
If all you want to know is how many of each item you have at the end
(on the 12th day), plug in T-12:
NJ,12 = J * (13 - J)
A quick sanity check: that means you'll have 12 of item 1
(partridges in pear trees), because you've gotten one new one each time,
and 12 of item 12 (drummers drumming), which you got in one big noisy
box on the last day. Likewise, you'll have 22 each of items 2 (turtle
doves, of which you got two every day except the first day) and 11
(pipers piping), which you got on day 11 and again on day 12.
So the curve which interested Dave is an inverted parabola; you get
the least number of the first and last gifts, and the largest quantity
of the two middle gifts: six geese a'laying and seven swans
a'swimming. How many geese and swans do you get in the end?
Here's the surprising answer:
N6,12 = N7,12 = 6 * 7 = 42
Douglas Adams fans will immediate recognize this as the solution to
the ultimate question of Life, the Universe, and Everything. Now
you know what the question was!
One last question: how many items, total, of all types will you have
by the end of the twelfth day?
Since you already know how many of each item you have, just add them
all up:
| | 12 | | 12 | | 12 | | 12
|
| Ntot = | Σ j * (13-j)
| =
| Σ (j * 13 - j2)
| = 13 *
| Σ j | - | Σ j2
| | j=1 | | j=1 | | j=1 | | j=1
| |
Fortunately, we know that
| A
|
| Σ i | = A (A + 1) / 2
|
| i=1
|
and
| A
|
Σ i2 | = A (A + 1) (2A + 1) / 6
| | i=1
| |
so we can use those identities to figure out how many total items we'll have:
| Ntot | = { 13 * (12 * 13) / 2 } - { 12 * 13 * 25 / 6 }
|
| | = 364
|
So it turns out that true love packs a present for just about every day
of the year into those twelve days!
(And I found an excuse to play with using HTML tables to display
equations.)
Tags: science
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Sat, 09 Dec 2006
Another person popped into #gimp today trying to get a Wacom tablet
working (this happens every few weeks). But this time it was someone
using Ubuntu's new release, "Edgy Eft", and I just happened to have
a shiny new Edgy install on my laptop (as well as a Wacom Graphire 2
gathering dust in the closet because I can never get it working
under Linux), so I dug out the Graphire and did some experimenting.
And got it working! It sees pressure changes and everything.
It actually wasn't that hard, but it did require
some changes. Here's what I had to do:
- Install wacom-tools and xinput
- Edit /etc/X11/xorg.conf and comment out those ForceDevice lines
that say "Tablet PC ONLY".
- Reconcile the difference between udev creating /dev/input/wacom
and xorg.conf using /dev/wacom: you can either change xorg.conf,
change /etc/udev/rules.d/65-wacom.rules, or symlink /dev/input/wacom
to /dev/wacom (that's what I did for testing, but it won't survive a
reboot, so I'll have to pick a device name and make udev and X
consistent).
A useful tool for testing is /usr/X11R6/bin/xinput list
(part of the xinput package).
That's a lot faster than going through GIMP's input device
preference panel every time.
I added some comments to Ubuntu's bug
73160, where people had already described some of the errors but
nobody had posted the steps to work around the problems.
While I was fiddling with GIMP on the laptop, I decided to install
the packages I needed to build the latest CVS GIMP there.
It needed a few small tweaks from the list I used on Dapper.
I've updated the package list on my GIMP Building
page accordingly.
Tags: linux, X11, imaging, gimp, ubuntu
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Thu, 23 Nov 2006
People keep showing up on GIMP's IRC channels and asking about
JPEG 2000 support. There was a
Summer
of Code "Wavelet" project last summer which implemented JPEG 2000 support
(among other things) but no one ever seems to know where to find it.
So I asked Simon, who was the mentor for that project. Turns out
he had tarballs, but didn't think it was appropriate to link them
from his own site, especially as they were somewhat tricky to
compile.
The consensus among the developers was that it would be nice to
have jp2 and the other wavelet plug-ins available on the
GIMP Plug-in Registry.
So I fiddled with them, fixed a couple of Makefile issues,
added READMEs with author credit and building instructions,
and uploaded them to the registry. The plug-ins are:
- jp2
- JPEG 2000 support
- denoise
- A noise removal plug-in
- ihalf
- Inverse halftoning -- remove halftones from printed images.
I haven't actually used these plug-ins (couldn't find a JPEG2k file
to test) -- I just wanted to help
make them available for people who need them.
While I was at it I updated my vastly out-of-date registry
entries for Pandora and added an entry for my label/business card
script.
Tags: gimp
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Mon, 20 Nov 2006
I just tried Ubuntu's newest release, "Edgy
Eft", on the laptop (my trusty if aging Vaio SR17).
I used the "xubuntu" variant, in order to try out their lighter
weight xfce-based desktop.
So far it looks quite good.
But the installation process involved
quite a few snags: here follows an account of the various workarounds
I needed to get it up and running.
Live CD Problems
First, I tried to use the live CD, since I've heard it has a nice
installer. But it failed during the process of bringing up X, and
dumped me into me a console screen with an (initramfs) prompt.
I thought I had pretty good Linux creds, but I have to confess
I don't know what to do with an (initramfs) prompt; so I gave up
and switched to the install CD. Too bad! I was so impressed with
Ubuntu's previous live CDs, which worked well on this machine.
Guessing Keyboard Layout
Early on, the installer gives you the option to let it guess your
keyboard layout. Don't let it! What this does is subject you
to a seemingly infinite list of questions like:
Does your keyboard have a squiggle key?
where each
squiggle is a different garbled, completely illegible
character further mangled by the fact that the installer is running at
a resolution not native to the current LCD display. After about 15 of
these you just give up and start hitting return hoping it will end
soon -- but it doesn't, so eventually you give up and try ctl-alt-del.
But that doesn't work either. Pulling the power cord and starting over
seems to be the only answer. Everyone I've talked to who's installed
Edgy has gone through this exact experience and we all had a good
laugh about it. Come to think of it, go ahead and say yes to the
keyboard guesser, just so you can chuckle about it with the rest of us.
Once I rebooted and said no to the keyboard guesser, it asked three or
four very straightforward questions about language, and the rest
of the installation went smoothly. Of course it whined about not
seeing a network, and it whined about my not wanting it to overwrite
my existing /boot, and it whined about something to do with free
space on my ext3 partitions (set up by a previous breezy install),
but it made it through.
X Hangs on the Savage
On the first reboot after installation, it
hung while trying to start X -- blank screen, no keyboard
response, and I needed to pull the plug. I was prepared for that
(longstanding bug 41340)
so I immediately suspected dri. I booted from another partition and
removed the dri lines from /etc/X11/xorg.conf,
which fixed the problem.
Configuring the Network
Now I was up and running on Xubuntu Edgy.
Next I needed to configure the network (since the installer won't do
it: this machine only has one pcmcia slot, so it can't have
a CDROM drive and a network card installed at the same time).
I popped in the network card (a 3com 3c59x cardbus card) and waited
expectantly for something to happen.
Nada. So I poked around and found the network configuration tool in
the menus, set up my IP and DNS and all that, and looked in vain for
a "start network" or "enable card" or some similar button that would
perform an ifup eth0.
Nada again. Eventually I gave up, called up a terminal, and ran
ifup eth0, which worked fine.
Which leads me to ask:
Given that Ubuntu is so committed to automatic hardware detection that
it forces you to run hal, which spawns large numbers of daemons that
poll all your disks a couple of times a second -- why can't it notice
the insertion of a cardbus networking card?
And configure it in some easy way without requiring the user to know
about terminals and networking commands?
Ubuntu Still Wins for Suspend and Hibernate
Around this point I tested suspend and hibernate. They both worked
beautifully out of the box, with no additional twiddling
needed. Ubuntu is still the leader in suspending.
sudo: Timestamp Woes
Somewhere during these package management games, I lost the ability
to sudo: it complained "Timestamp too far in the future", without
telling me which file's timestamp was wrong so that I could fix it.
Googling showed that lots of other people were having the
same problem with Edgy, and found an answer: use the GUI Time and
Date tool to set the time to something farther in the future than
the timestamp sudo was complaining about, then run sudo -k to do
some magic that resets the timestamp. Then you can set the time back
to where it belongs. Why does this happen? No one seems to know, but
that's the fix.
(I found some discussion in
bug 43233.)
vim isn't vim?
I restored my normal user account, logged in as myself with my normal
fvwm environment, and went to edit (with vim) a few files. Every time,
vim complained:
"E319: Sorry, the command is not available in this version: syntax on"
after which I could edit the file normally. Eventually I googled to
the answer, which is
très bizarre: by default,
vim-common is installed but
vim is not. There's a binary
named vim, and a package which seems to be vim, but it isn't vim.
Installing the package named
vim gives you a vim that
understands "syntax on" without complaining.
Conclusion
That's the list. Edgy is up and running now, and looks pretty good.
The installer definitely has some rough edges, and I hope my
workarounds are helpful to someone ... but the installer is only
a tiny part of the OS, something you run only once or twice.
So don't let the rough installer stop you from installing Edgy and
trying it out. I know I look forward to using it.
Tags: linux, ubuntu
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Wed, 08 Nov 2006
Mercury transited the sun today. The weather forecast predicted
rain, and indeed, I awoke this morning to a thick overcast which
soon turned to drizzle. But miraculously, ten minutes before the
start of the transit the sky cleared, and we were able to see
the whole thing, all five hours of it (well, we weren't watching
for the whole five hours -- the most interesting parts are the
beginning and end).
I had plenty of practice with solar observing yesterday,
showing the sun to a group of middle school girls as part of
an astronomy workshop.
This is organized by the AAUW, the same group that runs the annual
Tech Trek
summer science girls' camps. (The Stanford Tech Trek has a star
party, which is how I got involved with this group.)
It's the second year I've done the astronomy workshop for
them; this year went pretty smoothly and everybody seemed to
have a good time observing the sun, simulating moon phases,
learning about the Doppler effect and plotting relative distances
of the planets on a road map.
But what I really wanted to write about was the amazing video
shown by last weekend's SJAA speaker, Dr. Ivan Linscott of Stanford.
As one of the team members on the New Horizons mission to Pluto,
he was telling us about Pluto's tenuous atmosphere. There isn't a
lot of information on Pluto's atmosphere yet, but one of the goals of
New Horizons is to take readings as Pluto occults the sun to
see how sunlight is refracted through Pluto's atmosphere.
But that's no problem: it turns out we've already
done more challenging occultation studies than that.
Back in December 2001, Titan occulted a binary star, and
researchers using Palomar's Adaptive Optics setup got a
spectacular video of the stars being refracted through Titan's
atmosphere as the occultation progresses.
This is old news, of course, but most of us hadn't seen it before
and everyone was blown away. Remember, this is a video from Earth,
of the atmosphere of a moon of Saturn, something most Earth-based
telescopes would have trouble even resolving as a disk.
Watch
the Titan occultation video here.
Tags: science, astronomy
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Tue, 24 Oct 2006
I get tons of phishing scam emails spoofing Amazon. You know, the
ones that say "Your Amazon account may have been compromised: please
click here to log in and verify your identity", and if you look at the
link, it goes to
http://123.45.67.8/morestuff instead of
http://www.amazon.com/morestuff. I get lots of similar phishing
emails spoofing ebay and various banks.
But yesterday's was different. The URL was this:
http://www.amazon.com/gp/amabot/?pf_rd_url=http://211.75.237.149/%20%20/amazon/xec.php?cmd=sign-in
Check it out: they're actually using amazon.com, and Amazon has a 'bot
called amabot that redirects you to somewhere else. Try this, for
example:
http://www.amazon.com/gp/amabot/?pf_rd_url=http://bn.com
-- you start on Amazon's site and end up at Barnes & Noble.
When a family member got tricked by a phish email a few months ago
(fortunately she became suspicious and stopped before revealing
anything important)
I gave her a quick lesson in how URLs work and how to recognize the
host part. "If the host part isn't what you think it should be,
it's probably a scam," I told her. That's pretty much the same as what
Amazon says (#6 on their "Identifying Phishing or Spoofed E-mails"
page). I guess now I need to teach her how to notice
that there's another URL embedded in the original one, even when the
original one goes to the right place. That's a bit more advanced.
I suspect a lot of anti-phishing software uses the same technique and
wouldn't have flagged this URL.
I reported the phish to Amazon (so far, just an automated reply, but
it hasn't been very long). I hope they look into this use of their
amabot and consider whether such a major phishing target really needs
a 'bot that can redirect anywhere on the net.
Tags: tech, web, security
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Sun, 01 Oct 2006
The cool, overcast fall weather is here (first rain of the season,
too), and it's amazing how much difference it makes in the squirrels'
behavior and appetites. They're hungry again!
Just as Notch dropped from thirteen or fifteen nuts in
a day last winter to one or two during summer (of course, she probably
has plenty of other food sources aside from us), now that fall is here
we had to make an emergency run to the nut store to satisfy the hordes.
The kids, Chiquita and Scrape (as Dave took to calling Ringlet
after she got a scrape on her shoulder), are friskier in addition to
being hungrier. Today Scrape spent most of the morning running up and
down the guava tree, bounding in the air or doing front-flips for no
reason, and starting tussles with Chiquita. When not tussling with her
sibling, Chiquita spent most of the morning eating -- she's noticably
bigger than Scrape and it's not hard to see why.
Ringtail drops by periodically to check on how the kids are doing
in day care. Then she'll dig up a nut and move on. She never lingers.
We try to feed her, but she has an amazing inability to see food even
when she's standing right on top of it. She looks sleek and robust, so
I guess she's getting plenty to eat somewhere else, but watching her
nose around and still miss a nut right in front of her face, I
sometimes wonder how she survives.
Notch usually doesn't drop by until afternoon, and seems to avoid the kids.
Squirrels must have inhibitions about fighting youngsters (even those
not their own), since she's never been hesitant to chase away any
interloping adult squirrel. It'll be interesting to see how long the
truce lasts between Notch and Ringtail's kids -- and how long the
kids will stick together before going their separate ways.
Tags: nature, squirrels, urban wildlife
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Thu, 21 Sep 2006
A few days ago, I saw our neighbor squirrel, "Ringtail", struggling
along the fence with a baby in her mouth, and hoped that she was
moving closer to us so we'd get to see the babies when they got older.
My wishes were answered: the very next morning a new young squirrel
appeared to play on the fence. Dave called "her" (we're not sure about
gender yet) Chiquita.
It's easy to tell squirrel youngsters:
not only are they much smaller than adults, but they're quite klutzy
and cautious about the aerial feats that the adults do without
hesitation. Chiquita was fairly klutzy, once falling out of the red
oak onto the motorcycle shed (a drop of maybe five feet, which didn't
seem to hurt her).
Then the following day, both Ringtail and Chiquita showed up ...
with another baby. This one has a ringed tail like "his" odd-looking
mom, but otherwise looks like an ordinary young grey squirrel.
Ringtail took a few nuts then disappeared, leaving the kids at
nursery school (a role which we're only too happy to fill).
We think they hang out in the atlas cedar in the front yard
when they leave here.
We've been greatly entertained for the last few days, watching
how fast the kids learn the business of being a squirrel. On the
first day, they had a lot of trouble moving head-first downward
on the fence: while Notch will scamper right down then leap to the
deck, Chiquita stretches as far down as she can get with her rear
claws hooked over the top of the fencepost, then stays there for
many minutes, evidently trying to work up the nerve to move downward.
When she does move, it's carefully, step by step, and making the leap
over to the deck (only about six inches) also takes time and nerve.
When squirrels are fearful of something, they lash their tails wildly,
like an angry cat.
A red oak tree gives much better purchase for your claws.
Neither squirrelet shows any hesitation about leaping the couple of
feet from the fence to the tree trunk, though sometimes Chiquita
misses and has to run around the tree trunk before she gets a secure
hold. And when they're both in high spirits they'll chase each other
at high speed through the tree's branches.
Their antics can be pretty funny -- like when Chiquita was nerving
herself to drop from the deck to the ground, but her wildly-swinging
tail dislogdged a rock on the deck, which fell next to her and sent
her into a panic causing her to drop off the deck.
Both of them, but especially Ringlet, love the potted fuscia I have
sitting on the kayak stand. They stand on their hind legs, reach down
into the pot and dig: they'll bury a nut, then immediately dig it out
again. Sometimes they eat the fuscia, too. The fuscia is not looking
at all healthy now, and I've written it off as a squirrel toy.
Even from one day to the next, it's easy to see their skills
improve. Yesterday afternoon Ringlet even made the jump from the roof
to the fence -- only a few feet, but the landing is tricky since the
top of the fence is less than an inch wide. They do still stumble and
fall pretty often -- Ringlet fell from the tree to the ground
yesterday, making an audible thump, then lay there for a few
minutes before getting up. But they're looking more graceful every
day. Ringtail still brings them by in the morning and drops them off,
then heads off to work (or wherever it is she goes once the kids
are safely in day care).
Notch hasn't been around much, though I can't imagine she's been
scared off by Ringtail and the kids. I did catch sight of her
yesterday. I was sitting in the yard watching Chiquita. (The kids
are fairly tolerant of our presence as long as we move slowly, but
we're still trying to get them accustomed to moving about the yard
and finding nuts in the right places.) She'd finally moved from the
tree across the fence to the post nearest the office, and I was hoping
she'd come down and take a drink of water and notice the nut I'd put
there for her. After about five minutes on the fencepost, looking
longingly down at the water but evidently not feeling confident enough
for a head-down descent, she finally started to make a move -- then
froze. I caught movement out of the corner of my eye: Notch was
ambling along the deck right past my chair. While Chiquita watched,
rapt and motionless, Notch went decisively to the nut hole, pulled
out the whole walnut (she dislikes all pre-shelled walnuts -- we've
tried bulk ones from the local fruit stand and bagged ones from Trader
Joe's, but Notch and I both agree that neither taste as good as the
walnuts in the shell) and marched back the way she'd come.
That was enough for Chiquita: as soon as Notch was safely out of sight,
Chiquita came straight down the fencepost and onto the deck,
sniffed at the shelled nut (not hungry) and had a long drink of water.
I still don't know if Notch knew Chiquita was there -- squirrels don't
seem to have territorial battles with youngsters, so maybe Notch was
just being nice to the kid. (And she obviously wasn't hungry anyway,
or she would have eaten the walnut and asked for more.)
Pictures of Ringtail and Chiquita (no Ringlet yet)
here.
Tags: nature, squirrels, urban wildlife
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Sat, 16 Sep 2006
One of our occasional visitors is a very odd squirrel.
She's very large, with powerful hindquarters (enough so that
she walks differently from most squirrels, in a sort of waddle)
and a long, long tail that's ringed like a raccoon.
We call her
"Ringtail".
She doesn't visit often: Notch usually chases her off.
And she's not very good at finding the nuts we set out for the
squirrels, let alone being bold enough to come to the door.
We hadn't seen her for several weeks when today I heard a nut-crack
noise out in the yard, peered out and saw Ringtail on the fence --
with a baby squirrel in her mouth. Go Ringtail!
Carrying baby squirrels usually means it's time to change dens,
I believe. Grey squirrels apparently keep several dens, and change
from one to another when one den gets too dirty and full of parasites.
With any luck she and her babies are moving to a more nearby den,
and we'll be seeing them more often now.
Tags: nature, squirrels, urban wildlife
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Mon, 04 Sep 2006
I've been updating some web pages with tricky JavaScript and CSS,
and testing to see if they work in IE (which they never do) is
a hassle involving a lot of pestering of long suffering friends.
I've always heard people talk about how difficult it is to get
IE working on Linux under WINE. It works in
Crossover Office
(which is a good excuse to get Crossover: the company, Codeweavers,
is a good open source citizen and has contributed lots of work
to WINE, and I've bought from them in the past) but most people
who try installing IE under regular WINE seem to have problems.
Today someone pointed me to
IEs 4
Linux. It's a script that downloads IE and installs it under WINE.
You need wine and cabextract installed.
I was sure it couldn't be that simple, but it seemed easy enough to try.
It works great! Asked me a couple of questions, downloaded IE,
installed it, gave me an easy-to-run link in ~/bin, and it runs fine.
Now I can test my pages myself without pestering my friends.
Good stuff!
Tags: tech, web, linux
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Fri, 25 Aug 2006
The BBC had a
good
article today about the International Astronomical Union
vote that demoted Pluto from planet status.
It was fairly obvious that the previous proposal, last week,
that defined "planet" as anything big enough that its gravity made
it round, was obviously a red herring that nobody was going to take
very serious. Fercryinoutloud, it made the asteroid Ceres a planet,
as well as Earth's moon (in a few billion years when it gets a bit
farther away from us and ceases to be considered a moon).
But apparently there were several other dirty tricks played by the
anti-Pluto faction, and IAU members who weren't able to be in the
room at the time of the vote are not happy and are spoiling for
a rematch. The new definition doesn't make much more sense than
the previous one, anyway: it's based on gravitationally sweeping
out objects from an orbit, but that also rules out Earth, Mars,
Jupiter and Neptune, all of which have non-satellite objects along
their orbits.
And of course the public is pretty upset about it for sentimental,
non-scientific reasons. Try searching for Pluto or "Save Pluto" on Cafe Press to see the amazing
selection of pro-Pluto merchandise you can buy barely a day after
the IAU decision. (Personally, I want a Honk
if Pluto is still a planet bumper sticker.)
It'll be interesting to see if the decision sticks.
So do I have a viable definition of "planet" which includes Pluto
but not Ceres or the various other Kuiper belt objects which are
continually being discovered?
Why, no, I don't. But the discussion is purely semantic anyway.
Whether we call Pluto a planet doesn't make any difference to
planetary science. But it does make a difference to an enormous
collection of textbooks, museum exhibits, and other
science-for-the-public displays.
Pluto is big enough to have
been discovered in 1930, back in the days before computerized
robotic telescopes and satellite imaging; it's been considered
a planet for 76 years. There's no scientific benefit to changing
that, and a lot of social and political reason not to -- especially
now with New Horizons
headed there to give us our first up-close look at what Pluto
actually looks like.
There are two possible bright notes to the Pluto decision.
First, Mark Taylor pointed
out that it has become much easier to observe all the planets
in one night, even with a very small telescope or binoculars.
And second, maybe Christine Lavin will make a new
updated version of her song Planet X
and go on tour with it.
Tags: science, astronomy
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22:56 Aug 25, 2006
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Belated release announcement: 0.5b2 of my little map viewer
PyTopo
has been working well, so I released 0.5 last week with only a
few minor changes from the beta.
I'm sure I'll immediately find six major bugs -- but hey, that's
what point releases are for. I only did betas this time because
of the changed configuration file format.
I also made a start on a documentation page for the .pytopo file
(though it doesn't really have much that wasn't already written
in comments inside the script).
Tags: programming, python, gtk, pygtk, mapping, GIS
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22:10 Aug 25, 2006
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Sun, 20 Aug 2006
I finally got my Microsoft Rebate voucher!
Remember the California
Microsoft antitrust case, oh so many years ago?
A bit over three years ago (seems longer) it was determined in a
class-action suit that Microsoft had been abusing their monopoly in
order to overcharge for their software. Any Californian who had
purchased Microsoft products between February 1995 and December 2001
could apply for a rebate based on the number of MS products purchased.
(Curiously, no one ever seemed to point out that Microsoft did not
reduce its prices after this decision, nor did I ever see anyone
question why it's okay for them to overcharge now when it wasn't okay
then. That has puzzled me for some time. Perhaps questions like that
show why I'm a programmer instead of a lawyer or corporate exec.)
Over the years since the decision I've periodically wondered what ever
happened to the rebate vouchers we were supposed to get. But a few
weeks ago they started appearing. I got mine late last week.
The voucher is only redeemable for purchased software (from anyone,
not just Microsoft) or a fairly restrictive list of hardware:
computers (but not components to build a
computer), printers, monitors, scanners, keyboards, mice or trackballs.
For a Linux user who builds computers from parts (to avoid paying the
"Microsoft Tax" or to get a better price), it's a little tough to
use up that voucher. Now where did I put the receipt for that printer
I bought a few years ago? Or maybe it's time to buy a copy of
Crossover Office for
testing web sites against IE.
In any case, if you sent in your rebate claim way back when and
haven't heard anything, watch your mailbox. They say most people should
receive their vouchers this month (August). If you don't, you can
find more information at microsoftcalsettlement.com.
Tags: tech
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Sat, 19 Aug 2006
It's been a week jam-packed with Linuxy stuff.
Wednesday I made my annual one-day trip to Linuxworld in San
Francisco. There wasn't much of great interest at the conference
this year: the usual collection of corporate booths (minus Redhat,
notably absent this year), virtualization as a hot keyword (but perhaps
less than the last two years) and a fair selection of sysadmin tools,
not much desktop Linux (two laptop vendors), and a somewhat light
"Dot Org" area compared to the last few years.
I was happy to notice that most of the big corporate
booths were running Linux on a majority of show machines, a nice
contrast from earlier years. (Dell was the exception, with more
Windows than Linux, but even they weren't all Windows.)
Linuxworld supposedly offers a wireless network but I never managed to
get it to work, either in the exhibit hall or in the building where
the BOFs were held.
Wednesday afternoon's BOF list didn't offer much that immediately
grabbed me, but in the end I chose one on introducing desktop
Linux to corporate environments. Run by a couple of IBM Linux
advocates, the BOF turned out to be interesting and well presented,
offering lots of sensible advice (base your arguments to management
on business advantages, like money saved or increased ability to get
the job done, not on promises of cool features; don't aim for a
wholesale switch to Linux, merely for a policy which allows employees
to choose; argue for standards-based corporate infrastructure since
that allows for more choice and avoids lock-in). There was plenty
of discussion between the audience and the folks leading the BOF,
and I think most attendees got something out of it.
More interesting than Linuxworld was Friday's Ubucon,
a free Ubuntu conference held at Google (and spilling over into
Saturday morning).
Despite a lack of advertising, the Ubucon was very well attended.
There were two tracks, ostensibly "beginner" and "expert", but
even aside from my own GIMP talk being a "beginner" topic, I
ended up hanging out in the "beginner" room for the whole day,
for topics like "Power Management", "How to Get Involved", and
"What Do Non Geeks Need?" (the last topic dovetailing into the
concluding session Linux corporate desktops).
All of the sessions were quite interactive
with lots of discussion and questions from the audience.
Everyone looked like they were having a good time, and I'm sure
several of us are motivated to get more deeply involved with Ubuntu.
Ubucon was a great example of a low-key, fun,
somewhat technical conference on a shoestring budget and I'd love to
see more conferences like this in the bay area.
Finally, the week wrapped up with the annual Linux Picnic in
Sunnyvale, a Silicon Valley tradition for many years and always a good
time. There were some organizational glitches this year ... but it's
hard to complain much about a free geek picnic in perfect weather
complete with t-shirts, an installfest, a raffle and even (by
mid-afternoon) a wireless network. Fun stuff!
Tags: linux, conferences, linuxworld, ubucon, ubuntu
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Tue, 15 Aug 2006
"Favicons" are those little icons you see to the left of the URLbar
in a browser, and for each site in the bookmarks menu or toolbar.
They're just a file named
favicon.ico in the top level of
a web site, and they're a nice addition to a site.
(More details in the
Wikipedia entry.)
I'd made a few favicons in the distant past by creating a
32x32 image, saving it as ppm, then using ppmtowinicon.
But when I tried it in GIMP recently, I ran into trouble.
GIMP can save ICO files: Save As, click Select
File Type and choose "Microsoft Windows icon (ico)".
That gets you a dialog where you have to choose a color depth and
palette. I tried different settings, but the resulting images
never showed up properly in Firefox.
But then I tried saving as ppm and using ppmtowinicon and
that no longer worked either. Argh! What's up?
The silly answer, it turns out, is that it had nothing to do
with how GIMP was saving the images. The problem was that Firefox
caches favicons, and shift-reload or Clear Cache doesn't help.
When you're testing a new favicon, you have to load the url
for the favicon.ico itself (and reload it if necessary).
Success at last! It even handles transparency, so you can
make shaped favicons that show up nicely against a tab, menu
or toolbar background.
Of course, editing a 32x32 pixel image is a fun exercise in itself.
I recommend using a second view (View->New View).
Expand one view a lot (800x works well) so you can edit individual
pixels, while the other view remains at normal size so you can see
your final icon as others will see it in the browser.
Tags: gimp
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11:57 Aug 15, 2006
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Fri, 04 Aug 2006
Every time I click on a mailto link, Firefox wants to bring up
Evolution. That's a fairly reasonable behavior (I'm sure Evolution
is configured as the default mailer somewhere on my system even
though I've never used it) but it's not what I want, since I
have mutt running through a remote connection to another machine
and that's where I'd want to send mail. Dismissing the dialog is
an annoyance that I keep meaning to find a way around.
But I just learned about two excellent solutions:
First: network.protocol-handler.warn-external.mailto
Set this preference to TRUE (either by going to about:config
and searching for mailto, then doubleclicking on the line for
this preference, or by editing the config.js or user.js file
in your firefox profile) and the next time you click on a
mailto link, you'll get a confirmation dialog asking whether
you really want to launch an external mailer.
"Ew! Cancelling a dialog every time is nearly as bad as cancelling
the Evolution launch!" Never fear: this dialog has a
"Don't show me this again" checkbox, so check it and click Cancel
and Firefox will remember. From then on, clicks on mailto links
will be treated as no-ops.
"But wait! It's going to be confusing having links that do
nothing when clicked on. I'm not going to know why that
happened!"
Happily, there's a solution to that, too:
you can set up a custom user style
(in your chrome/userContent.css directory) to show a custom
icon when you mouse over any mailto link. Shiny!
Tags: tech, web, firefox, mozilla
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21:19 Aug 04, 2006
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Tue, 01 Aug 2006
I'm working on some little Javascript demos (for a workshop at
this summer's
Get SET girls'
technology camp) so I've had the Javascript Console up for most of
my browsing over the last few days. I also have Mozilla's
strict Javascript checking on
(
user_pref("javascript.options.strict", true); in prefs.js
or user.js) since I don't want to show the girls code that generates
warnings. (Strict mode also reports errors in CSS.)
It's been eye opening how many sites give warnings.
You know that nice clean ultra-simple Google search page?
One CSS error and one JS warning. But that's peanuts to the pages
of errors I see on most sites,
and they're not all missing "var" declarations.
I have to hit the "Clear" button frequently if I want to be able to
see the errors on the pages I'm working on.
And my own sites? Yes, I admit it, I've seen some errors in my own
pages too. Though it makes me feel better that there aren't very many
of them (mostly CSS problems, not JS). I'm going to keep the JS
Console visible more often so I'll see these errors and correct them.
Tags: programming
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00:06 Aug 01, 2006
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Sat, 29 Jul 2006
A few weeks ago, hiking in the woods, I noticed it was happening
again: the smell of chlorine in a forest far away from pools or
other likely sources of chlorine smell. This happened about this time
last summer, too. It only lasts for a few weeks: apparently there's
something that blooms briefly in deep redwood forests which smells
like pool chlorine.
Whatever it is, it's pervasive and not very localized.
I never notice it getting stronger near any of the
trails where we hike -- it's more a general odor one notices while
driving along forest roads.
That makes it hard to narrow it down to a specific plant.
Googling wasn't entirely enlightening, but it did suggest that the
most likely culprit is a mushroom.
Various species of Mycena mushrooms apparently emit a
chlorine-like odor, especially when they're growing on wood.
Chlorine smells are also reported from
Marasmius oreades, the "fairy ring" or "scotch bonnet" mushroom,
and from Amanita chlorinosma and A. polypyramis.
But I didn't find anything about widespread seasonal blooms of
any of these mushrooms.
So the mystery remains, and I guess all that's left is to remember,
when hiking in the redwood forest at this time of year,
to stop and smell the mushrooms.
Tags: nature, chlorine
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11:36 Jul 29, 2006
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Wed, 26 Jul 2006
Administrivia:
I've switched over to using static files with pyblosxom, instead of
generating everything from a CGI, to save some load on the server.
That means that URLs on this blog are changing to be a bit cleaner.
For instance, this entry, instead of being
http://shallowsky.com/blog/index.cgi?blogging/tostatic.html,
becomes http://shallowsky.com/blog/blogging/tostatic.html
instead.
The RSS URL changes from http://shallowsky.com/blog/?flav=rss to
http://shallowsky.com/blog/index.rss
The best top level URL to use is http://shallowsky.com/blog/
I've hacked up a python CGI script that will try to remap the URLs
appropriately, so old feeds will continue to work for a while.
But it probably isn't very robust, and I'd like to get rid of the
script eventually, so please update any bookmarks you might have to
this blog.
Tags: blogging
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23:38 Jul 26, 2006
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I just got back from the local Safeway,
where a one-pound box of sugar cubes costs $1.49.
A two-pound box, same brand, is $3.99.
What a deal!
Even better, the two-pound price is up: it used to be $3.49 a few
months ago (no change in the one-pound price).
I guess too many people were jumping on that incredible $3.49 deal,
so they had to raise it.
Tags: science, humor
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17:25 Jul 26, 2006
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Tue, 18 Jul 2006
I got slashdotted yesterday -- a positive
Slashdot
book review of Beginning GIMP. Hooray!
The comments were mostly the usual mix of flames from
Photoshop users saying "GIMP sucks because it isn't like Photoshop",
with hardly anything about the book; no surprise there.
I don't know why Photoshop users seem so compelled to attack
the GIMP, but obviously they do since this happens so often.
They don't seem to be willing to accept "Some people like one
style of user interface, other people like another style, and
a highly complex application like GIMP or Photoshop is going
to take some time to learn no matter how it's designed."
Slashdot linked to Barnes
& Noble rather than Amazon, which is understandable
since BN has a killer 40% off sale in progress on Apress books
(they have
at $26.99 for BN members,
$29.99 otherwise).
Apress also pointed me toward a couple other reviews that I hadn't
seen yet, so I created a review
page to link to them.
Tags: gimp
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18:37 Jul 18, 2006
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Mon, 10 Jul 2006
An unexplained change in the screen blanking timeout sent me
down the primrose path of learning about dpms, vbetool and screen
blanking. I guess it had to happen eventually.
It started when my laptop, which normally can sit for about ten
minutes before the screen goes black, suddenly started blanking
the screen after only two minutes.
After a few days of sporadic research, I now know what pieces are
involved and how to fix the timeout. But it turns out not everything
works the way it's supposed to.
I've written up my findings:
A Primer on
Screen Blanking Under Xorg.
Tags: linux, X11
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12:55 Jul 10, 2006
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Sun, 09 Jul 2006
On my wall I have a calendar with pretty pictures of wolves,
and assorted wolf facts for each month.
July features a wolf howling. In the lists of facts is:
If conditions are right a wolf's howl can carry 10 miles / 16.09
kilometers.
I wonder why wolves are so much more precise when they're howling
in metric?
Tags: humor
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18:09 Jul 09, 2006
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Fri, 07 Jul 2006
I put a "baby carrot" out on the door ledge to see
if the squirrels might like it. (In summer, we're not getting many
squirrel visits. There must be something pretty yummy growing in
the neighborhood. Notch comes by every second or third day,
eats a few pieces of walnut then waits expectantly for take-up
(a whole walnut she can take away and bury). A male youngster we
suspect is Notch's also comes by every day or two, to eat a few nuts
and drink water. We haven't seen Nonotchka for months, and I fear the worst.)
Turns out squirrels have zero interest in carrots. We put the
carrotlet into the nut dish and forgot about it for a few days,
and discovered something interesting: carrot raisins!
![[carrot nanotube]](/blog/images/nanocarrot.jpg)
Turns out carrots are mostly water, and they shrink even more than
grapes when you let them dry out.
I'm going to let it dry out some more and see what happens. I'm hoping
for fame and fortune as the first person to create carrot nanotubes.
Tags: humor
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10:32 Jul 07, 2006
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Thu, 06 Jul 2006
Anyone following the voting machine controversy in the last
presidential election -- or, even more, anyone who wasn't
following it and might not be aware of the issues -- should
check out Robert F. Kennedy, Jr's article in Rolling Stone,
Was the 2004 Election Stolen?
The article is long, detailed and well researched article, and it will
make you question whether we really live in a democracy.
Apparently Kennedy is considering
filing
whistleblower lawsuits against two of the voting machine
companies. This won't do anything to change our national elections,
but at least it might help get the word -- and the evidence -- out
into the public eye.
Tags: politics, elections, voting, government
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12:36 Jul 06, 2006
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Sat, 03 Jun 2006
A few months ago, someone contacted me who was trying to use my
PyTopo map display script for a different set of map data, the
Topo! National Parks series. We exchanged some email about the
format the maps used.
I'd been wanting to make PyTopo more general
anyway, and already had some hacky code in my local version to
let it use a local geologic map that I'd chopped into segments.
So, faced with an Actual User (always a good incentive!), I
took the opportunity to clean up the code, use some of Python's
support for classes, and introduce several classes of map data.
I called it 0.5 beta 1 since it wasn't well tested. But in the last
few days, I had occasion to do some map exploring,
cleaned up a few remaining bugs, and implemented a feature which
I hadn't gotten around to implementing in the new framework
(saving maps to a file).
I think it's ready to use now. I'm going to do some more testing:
after visiting the USGS
Open House today and watching Jim Lienkaemper's narrated
Virtual
Tour of the Hayward Fault,
I'm all fired up about trying again to find more online geologic
map data.
But meanwhile, PyTopo is feature complete and has the known
bugs fixed. The latest version is on
the PyTopo page.
Tags: programming, python, gtk, pygtk, mapping, GIS
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18:25 Jun 03, 2006
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Thu, 01 Jun 2006
On Dapper, whenever I tried to add a new printer or make any
modifications to the existing printer's settings, I would eventually
come to a dialog prompting me to enter username and password for
'CUPS'. There seemed to be no right answer: there is no user called
"cups" (there's a "cupsys", but that's not what it was asking for),
and trying either my own username and password, or root's, just
popped up the dialog again. A second attempt always led to a blank
white page.
But Carla
knew the answer. You're supposed to read:
zless /usr/share/doc/cupsys/README.Debian.gz
then skip to the end of the file where there's a brief hint
about this problem, stating that "Administration over the web
interface is disabled by default since it
requires the CUPS daemon to be able to read /etc/shadow."
Note that they don't actually disable it in a way that
tells users it's disabled. CUPS apparently doesn't check for
read permission on the shadow file before opening it,
or check whether there was an error in reading it;
it just silently bombs out with no indication what went wrong.
To fix it:
adduser cupsys shadow
adduser yourname lpadmin
You may not need the second line if you're already in group
lpadmin (type
groups to find out).
Then reboot. (Restarting cups and logging out and back in might
be enough: you need to get cups and your login session seeing their
new group permissions.)
Now, magically, the CUPS web interface works!
Tags: linux, printing
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23:15 Jun 01, 2006
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Mon, 29 May 2006
Over dinner, I glanced at the cover of the latest Dr. Dobb's
(a new article on Ruby on Rails),
then switched to BBC World News. The first Beeb headline
was
Aid
flow begins for Java victims.
I guess I was a little distracted from dinner preparations ...
my first thought was "Are they going to give them all copies of
Ruby and Rails?"
Then, of course, I remembered the earthquake.
Oh, right, those Java victims!
(Not to make light of the situation there, which sounds grim.
And just as I was writing this, I got email from the USGS Earthquake
Notification Service reporting another aftershock in Indonesia,
this one magnitude 5.6. I hope it doesn't make matters worse.)
Tags: programming
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22:05 May 29, 2006
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Sat, 27 May 2006
Dave thought I wasted too much presentation time
reversing the layers in my panorama example prior to running
Pandora.
I'm sure he's right.
The problem is that GIMP's "Open as Layers", if you select multiple
layers, opens them in the opposite direction from the way you'd
generally expect to use them in a panorama, with the lexigraphically
first layer on the top of the stack rather than the bottom.
The very next day, someone showed up on IRC asking how to reverse layers,
because "Open as Layers" opened them in the wrong order to use for an
animation.
At Mitch's suggestion, I wrote a reverse-layers script-fu (which Mitch
improved by pointing out that it didn't handle the possible error case
of a floating layer. As it happens, re-ordering floating layers works
fine in current CVS, but apparently it's not supposed to. I suspect
being able to move layers without alpha off the bottom position in
the stack may also be a bug, so I added a guard against that).
(Update: No, it turns out it's intentional that non-alpha layers
can be moved anywhere in the stack in 2.3.)
Layer->Stack->Reverse Layer Order is now included in CVS GIMP,
but for users of earlier versions I've made it available:
reverse-layers.scm.
Meanwhile, I made a new version of Pandora which can build a
panorama in either direction. I still find it slightly jarring to
assemble a panorama from right to left after building them from
left to right for so long, but maybe I'll get used to it.
I caught another bug at the same time: I was testing one of the
parameters set in the GIMP dialog (which sets a toggle to either TRUE
or FALSE) like this:
(if use-mask (do-stuff))
That doesn't work in script-fu.
Turns out TRUE is just an integer, while if
apparently only tests for Lisp nil or non-nil. So you have to say
(if (= use-mask TRUE) (do-stuff))
if you want tests to work against booleans coming from GIMP dialogs.
Tags: gimp
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23:22 May 27, 2006
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Fri, 26 May 2006
It's been a busy couple of weeks. My book (
Beginning GIMP: From Novice to Professional)
finally started arriving on people's doorsteps.
I first found out it was shipping from an email from a reader
in Ohio: "I just received your book, and I have a question ..."
He was the first of the Amazon shipments.
Over the next few days, more Amazon shipments started trickling in --
my mom got hers, a couple of friends got their copies. But it was
nearly a week before either I or the home office of Apress received
our copies, so in the meantime I was pumping everyone I knew for
information -- "How does it look?"
Finally my copies arrived. It's beautiful! I'm so happy with the
printing job Apress arranged. Bright colors on thick glossy paper. The
colors are surprisingly different from what I saw on the PDF that went
to the printer -- the active window borders on all the screenshots
(royal blue on my screen) are almost purple!
Now I can better appreciate why people who print professionally
care so much about details like ICC color profiles. Fortunately, I
knew there might be some color shift, so none of the figures in the
book depend on exact colors (the RGB color circles aren't precisely
Red, Green and Blue, but I'm sure readers will understand them).
So now I'm on the lecture/booksigning circuit. What fun!
I've only given a couple of talks so far; last night was a PenLUG talk that went well, with
lots of audience questions. The audience ranged from beginners to
experienced graphics programmers to someone who's interested in using
GIMP in a scientific context (comparing images; I told him about
the geologist I talked to a few months ago who was doing just that,
using Difference or Subtract layer modes to compare two aerial photos
of the same area) to a professional photographer who uses GIMP in his
work. One of the great side benefits of speaking about GIMP is getting
a chance to hear all the ways people use it for different purposes.
I made some business cards to hand out, but no one takes them.
That's okay: it was a good excuse to fiddle with my
gimplabels
script-fu and learn how to print really nice business cards from GIMP.
Making business cards is easy with gLabels, but since it uses
gnome-print it can only print using the system's default settings,
which makes for really chintzy looking, pixellated cards.
Gimp-print, on the other hand, can print in high resolution to nice
glossy photo-quality card stock.
I'm gradually learning how to give a better GIMP talk,
collecting interesting examples to show and minimizing the
time spent fumbling over menus or waiting for progress bars.
And dealing with the occasional glitch:
last night, SIOX for some reason refused to select my flower image,
after working perfectly the hundred or so previous times
I've used it on that image.
(What timing! Just last week I also received my ATM-B award from
Toastmasters.
Too bad outside GIMP talks don't count toward the next level.)
Fortunately GIMP is very visual, so it's easy and fun to find whizzy
examples and techniques that most people haven't seen before.
People have lots of interest in GIMP and image editing in general, and
they want to hear more about it and have lots of questions. It's a
topic everyone can appreciate. After all, who doesn't like looking at
cool images?
Tags: gimp
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11:32 May 26, 2006
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Sun, 14 May 2006
I had a page of plaintext which included some URLs in it, like this:
Tour of the Hayward Fault
http://www.mcs.csuhayward.edu/~shirschf/tour-1.html
Technical Reports on Hayward Fault
http://quake.usgs.gov/research/geology/docs/lienkaemper_docs06.htm
I wanted to add links around each of the urls, so that I could make
it part of a web page, more like this:
Tour of the Hayward Fault
http://www.mcs.csu
hayward.edu/~shirschf/tour-1.html
Technical Reports on Hayward Fault
htt
p://quake.usgs.gov/research/geology/docs/lienkaemper_docs06.htm
Surely there must be a program to do this, I thought. But I couldn't
find one that was part of a standard Linux distribution.
But you can do a fair job of linkifying just using a regular
expression in an editor like vim or emacs, or by using sed or perl from
the commandline. You just need to specify the input pattern you want
to change, then how you want to change it.
Here's a recipe for linkifying with regular expressions.
Within vim:
:%s_\(https\=\|ftp\)://\S\+_<a href="&">&</a>_
If you're new to regular expressions, it might be helpful to see a
detailed breakdown of why this works:
- :
- Tell vim you're about to type a command.
- %
- The following command should be applied everywhere in the file.
- s_
- Do a global substitute, and everything up to the next underscore
will represent the pattern to match.
- \(
- This will be a list of several alternate patterns.
- http
- If you see an "http", that counts as a match.
- s\=
- Zero or one esses after the http will match: so http and https are
okay, but httpsssss isn't.
- \|
- Here comes another alternate pattern that you might see instead
of http or https.
- ftp
- URLs starting with ftp are okay too.
- \)
- We're done with the list of alternate patterns.
- ://
- After the http, https or ftp there should always be a colon-slash-slash.
- \S
- After the ://, there must be a character which is not whitespace.
- \+
- There can be any number of these non-whitespace characters as long
as there's at least one. Keep matching until you see a space.
- _
- Finally, the underscore that says this is the end of the pattern
to match. Next (until the final underscore) will be the expression
which will replace the pattern.
- <a href="&">
- An ampersand, &, in a substitute expression means "insert
everything that was in the original pattern". So the whole url will
be inserted between the quotation marks.
- &</a>
- Now, outside the <a href="..."> tag, insert the matched url
again, and follow it with a </a> to close the tag.
- _
- The final underscore which says "this is the end of the
replacement pattern". We're done!
Linkifying from the commandline using sed
Sed is a bit trickier: it doesn't understand \S for
non-whitespace, nor = for "zero or one occurrence".
But this expression does the trick:
sed -e 's_\(http\|https\|ftp\)://[^ \t]\+_<a href="&">&</a>_' <infile.txt >outfile.html
Addendum: George
Riley tells me about
VST for Vim 7,
which looks like a nice package to linkify, htmlify, and various
other useful things such as creating HTML presentations.
I don't have Vim 7 yet, but once I do I'll definitely check out VST.
Tags: linux, editors, pipelines, regexp, shell, CLI
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13:40 May 14, 2006
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Sat, 29 Apr 2006
Today was opening day for the Hayward fault!
Well, okay, the fault itself has been there a while, but it was
opening day for the
Hayward
Fault: Exposed! exhibit in Fremont.
They've dug a trench into the Hayward fault as part of the 1906 San
Francisco Earthquake Centennial activities, so people can walk a
stairway and stand right in a fault and see what it looks like.
I'm a volunteer docent for the exhibit: one of the people
who help answer questions about the fault, the trench, and earthquakes
in general, and who also help with details such as setup, safety, and
getting people to sign the liability waiver as they enter the exhibit.
(My photos and
fault facts here.)
Opening day was a bit hectic even aside from the usual opening-day
flutters because it was a big day in Fremont Central Park: there was a
huge manga festival at the Teen Center right next to the fault trench,
complete with live band all day, and over at Lake Elizabeth at the
other end of the park was the annual "Splashdown" rubber ducky race.
We expected chaos. But we didn't get it: everything went surprisingly
smoothly. We got lots of visitors who were there specifically to see
the fault, not just spillover from the other events: apparently it had
gotten press on the TV news and several newspapers. There may also
have been word of mouth advertising: a surprising number of the
visitors I talked to were CERT volunteers or otherwise actively
involved in bay area disaster preparedness programs. They were already
very well informed about seismic hazards and earthquakes, and eager to
see the fault for themselves.
We ended up with about 600 visitors (perhaps a fourth to a third of them
teens from the manga festival). Everyone was very well behaved, asked
good questions and seemed to appreciate the exhibit. It's lovely to
volunteer at exhibits where you spend all your time answering
questions, chatting with people and explaining the exhibit, not
worrying about policing people and enforcing rules.
(Well, maybe there was a little bit of chaos. The band at the manga
festival included karaoke. It's not every day that one gets the
opportunity to try to explain paleoseismology and radiocarbon dating
while someone a few feet away is belting out "Bohemian Rhapsody"
over a loudspeaker but forgetting the words.)
We were pleased to see that everyone spent a lot of time around the
(excellent) poster displays from the USGS,
which cover everything from earthquake preparedness to
stratigraphy of this particular trench to geologic maps of the
Hayward fault and the bay area. Most people missed the parking lot
displays on the way in (a sign pointing to cracks in the pavement
and an offset curb, highlighted with orange spray paint), but we told
them what to look for so they could catch them on the way out.
The exhibit will get more press tonight: two or three different TV
channels showed up today and interviewed Heidi Stenner, the USGS
geologist organizing the exhibit, as well as some of the visitors.
So with any luck we'll continue to get good turnouts.
The trench will be open through the end of June.
Most of the other docents are either seismologists or seismology
graduate students. It wasn't a problem: the
questions most people were asking were straightforward questions
I could answer easily. But it was fun listening to the other docents
and learning from them, and when someone asks a tricky question,
you sure can't beat being able to turn to the researcher who did
the original study on this trench in 1987 (Jim Lienkaemper) and
get the straight scoop! (He also developed the USGS Virtual Tour
of the Hayward Fault web site).
The Hayward fault last let go in 1868, a magnitude-6.9 event called
"The Great San Francisco Quake" until the 1906 earthquake on the San
Andreas took over that title.
Trench studies like Lienkaemper's have shown that historically this
fault has a large earthquake every 130 to 150 years. Our visitors
didn't need a calculator to do the math.
Tags: science, geology
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23:46 Apr 29, 2006
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Tue, 25 Apr 2006
I've long been an advocate of making
presentations
in HTML rather than using more complex presentation software such as
PowerPoint, Open Office Presenter, etc. For one thing, those
presentation apps are rather heavyweight for my poor slow laptop.
For another, you can put an HTML presentation on the web and everyone
can see it right away, without needing to download the whole
presentation and fire up extra software to see it.
The problem is that Mozilla's fullscreen mode doesn't give you an easy
way to get rid of the URL/navigation bar, so your presentations look
like you're showing web pages in a browser. That's fine for some
audiences, but in some cases it looks a bit unpolished.
In the old Mozilla suite, I solved the problem by having a separate
profile which I used only for presentations, in which I customized
my browser to show no urlbar. But having separate profiles means you
always have to specify one when you start up, and you can't quickly
switch into presentation mode from a running browser. Surely there was
a better way.
After some fruitless poking in the source, I decided to ask around
on IRC, and Derek Pomery (nemo) came up with a wonderful CSS hack to
do it. Just add one line to your chrome/userChrome.css file.
In Firefox:
#toolbar-menubar[moz-collapsed=true] + #nav-bar { display: none !important; }
In Seamonkey:
#main-menubar[moz-collapsed=true] + #nav-bar { display: none !important; }
This uses a nice CSS trick I hadn't seen before, adjacent
sibling selectors, to set the visibility of one item based on the state
of a sibling which appears earlier in the DOM tree.
(A tip for using the DOM Inspector to find out the names of
items in fullscreen mode: since the menus are no longer visible, use
Ctrl-Shift-I to bring up the DOM Inspector window.
Then File->Inspect a Window and select the main content window,
which gets you the chrome of the window, not just the content.
Then you can explore the XUL hierarchy.)
This one-line CSS hack turns either Firefox or Seamonkey
into an excellent presentation tool. If you haven't tried using
HTML for presentations, I encourage you to try it. You may find
that it has a lot of advantages over dedicated presentation
software.
Addendum: I probably should have mentioned that
View->Toolbars->Navigation Controls
turns off the toolbar if you just need it for a one-time
presentation or can't modify userChrome.css.
You have to do it before you flip to fullscreen, of course,
since the menus won't be there afterward,
and then again when you flip back.
I wasn't happy with this solution myself because of the two
extra steps required every time, particularly because the steps
are awkward since they require using the laptop's trackpad.
Tags: tech, web, firefox, speaking
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17:59 Apr 25, 2006
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Sun, 23 Apr 2006
Firefox' print system doesn't know how to print just even or just
odd pages of a document, so when I need to print out a web page
and want it double sided, I've been doing the Duplex Dance:
hover over the printer ready to grab each page as it comes out
the front so that I can quickly flip it and feed it back into the
top of the printer fast enough that the printer doesn't time out
with "Out of Paper".
Of course, more often I just sigh and let it print single sided
because that's just way too much hassle.
But today is Earth Day, so I decided it was time to find a better
solution. The solution, obviously, begins with telling the browser
to print to a Postscript file. Then the challenge is to find a way to
print only the odd pages of the Postscript file, put the pages back
in the printer, then print only the even pages.
First I tried to use mpage, which claims to be able to do this.
It looked like this command should do it:
mpage -j 1%2 file.ps | lpr
But it didn't work -- it said it was spooling something to the
printer, but nothing ever came out. Upon saving the mpage output
to a file, I found that gv couldn't show it, citing postscript
errors.
But it turns out there's a much easier way: the CUPS lp program
has an option called page-set precisely for this purpose,
and it's smart about detecting postscript input.
This command did the trick:
lp -o page-set=odd file.ps
Then flip the sheets, insert back into the printer, and repeat
with
even instead of
odd. Lovely!
This is documented in http://localhost:631/help/options.html?QUERY=odd#PAGESET
-- and the CUPS in-browser help has a search function that took me
right to it, I'm happy to note.
Other programs which may to be able to split postscript files into
odd and even pages include psselect and perhaps dviduplex.
With a smarter print dialog (one that allowed specifying a custom
print command, like Mozilla's used to) you could even define several
custom printers, one that printed even pages and one that printed
odd. Alas, Firefox' print dialog doesn't allow such things, or even
allow defining extra printers.
(The Mozilla bug asking for odd/even printing is bug
35228).
From a quick search of about:config, it
looks like you might be able to set up something by hand using
the print.printer_CUPS/printername.print_command preference
(by default mine was set to
lpr ${MOZ_PRINTER_NAME:+'-P'}${MOZ_PRINTER_NAME}) but I
notice something even more interesting: two variables called
print.printer_CUPS/printername.print_evenpages and
print.printer_CUPS/printername.print_oddpages (both set to
true by default). Also interesting are plex.0.name and
plex.count.
Might be an easy way to get duplex printing
straight from the browser, after doing a little hand-editing to
try and persuade Firefox that there's more than one printer.
I'll try it next time I need to print something.
(It seems wrong to spend Earth Day printing more pages than I
actually need.)
Tags: linux, printing
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20:21 Apr 23, 2006
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Tue, 18 Apr 2006
Every now and then I search for a map (usually a geologic map) and
end up at a
USGS
page like this one.
The web viewer is impossible, so that link over on the left --
Download Image Now (16M) -- looks awfully tempting, and I
always go for it.
What they don't tell you is what sort of image you're getting; after
you download that 16M, you end up with a file called something like
q250_1388a_us_c.sid, which no image viewer I've ever found
considers to be an image file. Even ImageMagick, which can handle
almost anything, is baffled by .sid files.
It turns out that .sid stands for "Mr. Sid", a file format for very
large raster images. The format is controlled by a company called
LizardTech, and it's apparently so scary that no one has ever managed
to reverse engineer it. The only way to read a Mr. Sid file is to use
one of the programs (available in binary form only) from LizardTech.
Fortunately LizardTech does provide at least one of their programs,
mrsisddecode, as a Linux binary. Get it from their
download
page. Then you can type a command like mrsiddecode -i
q250_1388a_us_c.sid -o q250_1388a_us_c.jpg to convert the
file into some other image format (which will be quite large -- this
particular map is 17170 x 9525).
(Apparently there's an SDK which is also available for Linux,
available here.
The gdal toolkit used by MapServer and certain other GIS
applications make use of this SDK. I hear it's somewhat picky
about GCC version, but otherwise works.)
I'm happy that I've found something that will convert MrSid files
to a format I can use, but
it's a little discouraging that the USGS is restricting its
public maps to a format that can be read only with software from a
single company. I wonder if the USGS has a contingency plan concerning
all these Mr. Sid maps in case anything ever happens to LizardTech?
Aren't open formats safer in the long run?
Tags: science, geology
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22:50 Apr 18, 2006
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Sat, 15 Apr 2006
Today's SF Chronicle had a
story
about the nesting peregrine falcons on a building in San Francisco.
In past years, they've had a "Peregrine Cam" allowing people to
watch the falcons as they raised their chicks.
Well, this year the Peregrine Cam
is back -- only now it's streaming video that requires a fast broadband
connection and Microsoft's Windows Media Player.
If you just want to see
the falcons, you're out of luck if your connection isn't
up to streaming a full video feed, or if you're on a platform like
Linux where Windows Media Player isn't offered.
Linux does have several video player applications which can play
WMV format, but that's not enough. When I visited the page, what
I got was a streamed video advertisement for the company that provides
the streaming technology (in stuttering jerks that left no doubt that
their bandwidth requirement is higher than the wimpy DSL available in
this part of San Jose can provide). But that was all; the video ended
after the ad, with no glimpse of falcons.
(I suppose I should be grateful that their Viewing FAQ even mentions
Linux, if only to say "Linux users can't view the Peregrine Cam
because it needs WMP." Other folks who can't use the camera are
people with earlier versions of WMP, Mac users using Safari or Opera
or who don't have Stuffit, and people behind corporate firewalls.)
The site doesn't have a Contact or Feedback link, where one
might be able to ask "Could you possibly consider posting an
photos, for those of us who would love to see the falcons
but can't use your whizzy Microsoft-dependant streaming video
technology?" Not everyone even wants high-bandwidth streaming
video. Alas, the closest they offer is the 2006 Diary,
updated irregularly and only with 200x200 thumbnail images.
Update: mplayer users with the appropriate codec can view the
camera with the following command:
mplayer "http://powerhost.live.powerstream.net/00000113_live1?MSWMExt=.asf"
Thanks to Guillermo Romero for poking through the source to find
a URL that works.
Tags: nature, birds
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12:25 Apr 15, 2006
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Fri, 14 Apr 2006
I'm not very consistent about looking at the statistics on my web site.
Every now and then I think of it, and take a look at who's been
visiting, why, and with what, and it's always entertaining.
The first thing I do is take the apache log and run webalizer
on it, to give me a breakdown of some of the "top" lists.
Of course, I'm extremely interested in the user agent list:
which browsers are being used most often? As of last month, the Shallowsky
list still has MSIE 6.0 in the lead ... but it's not as big a lead
as it used to be, at 56.04%. Mozilla 5.0 (which includes all Gecko-
based browsers, as far as I know, including Mozilla, Firefox, Netscape
6 and 7, Camino, etc.) is second with 20.31%. Next are four search
engine 'bots, and then we're into the single digit percentages with
a couple of old IE versions and Opera.
AvantGo (they're still around?) is number 11 with 0.37% -- interesting.
It looks like they're grabbing the Hitchhiker's Guide to the Moon;
then there are a bunch of lines like:
sync37.avantgo.com - - [05/Apr/2006:14:29:25 -0700] "GET / HTTP/1.0" 200 4549 "http://www.nineplanets.org/" "Mozilla/4.0 (compatible; AvantGo 6.0; FreeBSD)"
and I'm not sure how to read that (nineplanets.org is
The Nine Planets, Bill Arnett's
excellent and justifiably popular planetary site, and he and I have
cross-links, but I'm not sure what that has to do with avantgo and my
site). Not that it's a problem: of course, anyone is welcome to read
my site on a PDA, via AvantGo or otherwise. I'm just curious.
Amusingly, the last user agent in the top fifteen is GIMP Layers, syndicating this blog.
Another interesting list is the search queries: what search terms did
people use which led them to my site? Sometimes that's more
interesting than other times: around Christmas, people were searching
for "griffith park light show" and ending up at my lame collection of
photos from a previous year's light show. I felt so sorry for them:
Griffith Park never puts any information on the web so it's impossible
to find out what hours and dates the light show will be open, so I
know perfectly well why they were googling, and they certainly weren't
getting any help from me. I would have put the information there if
I'd known -- but I tried to find out and couldn't find it either.
But this month, no one is searching on anything unusual. The top
searches leading to my site for the past two months are terms like
birds, gimp plugins, linux powerpoint, mini laptops, debian chkconfig,
san andreas fault, pandora, hummingbird pictures, fiat x1/9,
jupiter's features, linux photo,
and a rather large assortment of dirt bike queries. (I have very
little dirt bike content on my site, but people must be desperate to
find web pages on dirt bikes because those always show up very
prominently in the search string list.)
Most popular pages are this blog (maybe just because of RSS readers),
the Hitchhiker's Guide to the Moon, and bird photos, with an
assortment of other pages covering software, linux tips, assorted
photo collections, and, of course, dirt bikes.
That's most of what I can get from webalizer. Now it's time to look at
the apache error logs. I have quite a few 404s (missing files).
I can clean up some of the obvious ones, and others are coming from
external sites I can't do anything about that for some reason link
to filenames I deleted seven years ago; but how can I get a list of
all the broken internal links on my site, so at least I can fix
the errors that are my own fault?
Kathryn on Linuxchix pointed me to dead-links.com, a rather cool
site. But it turns out it only looks for broken external
links, not internal ones. That's useful, too, just not what I
was after this time.
Warning: if you try to save the page from firefox, it will
start running all over again. You have to copy the content and paste
it into a file if you want to save it.
But Kathryn and Val opined that wget was probably the way to go
for finding internal links. Turns out wget has an option to delete
each file after downloading it, so you can wget a whole site but not
actually need to use the local space to duplicate the site.
Use this command:
wget --recursive -nd -nv --delete-after --domains=domain.com http://domain.com/ | tee wget.out 2>&1
Now open the resulting file in an editor and search repeatedly for
ERROR to find all the broken links. Unfortunately the errors are on
a separate line from the filenames they reference,
so you can't just use a grep. wget also
gets some things wrong: for instance, it tries to download the .class
file of a Java applet inside a .jar, then reports an error when the
class doesn't exist. (--reject .class might help that.)
Still, it's not hard to skip past these errors,
and wget does seem to be a fairly good way of finding broken internal links.
There's one more check left to do in the access log.
But that's a longer story, and a posting for another day.
Tags: tech, web
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Wed, 12 Apr 2006
Driving home from dinner, watching the alpenglow fade from the
gleaming domes of Lick Observatory, I found myself thinking about the
talk last night:
a wonderful geology seminar by Michael Carr of the USGS on
the subject of "Water on Mars".
I had a chance to chat briefly with the speaker before the meeting.
We got to talking about the moon. It turns out that he spent some of
his early career at Lick, working with a few colleagues to make a
geologic map of the moon. How? By sketching the terminator every night
from the eyepiece of the 36" refractor, and trying to deduce the
geology from the topography they sketched. Talk about dream jobs!
It was interesting to compare Carr's talk to the SJAA talk on the same subject earlier
this year by Jeff Moore of NASA/Ames (always one of my favorite
SJAA speakers). Carr's talk was quite a bit more detailed
and heavier on the geologic details, not surprising since he was
speaking to a room full of geologists and geology students.
He even showed a stratigraphic column of the Burns Cliff area
that the Opportunity rover investigated near Meridiani.
I learned quite a bit that I can apply toward my "Mars Rock" collection.
I have a set of rocks that are similar to the various interesting
rocks on the moon (I finally found some anorthosite a few months ago).
I use them when I give presentations on the moon.
It goes over very well: I think people get a better idea of what the
moon is made of and how its surface looks when they get a chance to
handle the rocks and look at them up close.
I have a start on a similar collection for Mars, but of course
the most interesting Mars-like rocks to show people aren't the
boring black and red basalts; they're the ones the Rovers have been
discovering that point to a history of water. So those are the rocks
I'm most interested in adding: the sulfates and other evaporites,
sandstones made of evaporite sediments, hematite "blueberries"
(Moqui Marbles, on Earth), and jarosite.
I'd never heard of jarosite before, but from a bit of web research
the day after the talk, it turns out to be one of the minerals
implicated in the controversy that was in the news last year about
modern-day generation of methane on Mars.
Some people attributed the extra methane to the
presence of biological organisms, though others were quick to point
out that there are plenty of non-biological ways to release methane.
Interestingly, one of the audience members at the talk commented that
in the Sierras jarosite is a weak biological indicator (because the
biological organisms prevent formation of carbonates, if I understood
him correctly). So it's a pretty interesting mineral even for someone
who doesn't hold out much hope for finding life on Mars.
Here's a
good summary of the rocks found in the Burns Cliffs.
Tags: science, geology
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22:27 Apr 12, 2006
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Thu, 06 Apr 2006
We were travelling for a week, so we left the squirrels with plenty of
nuts to bury. (I'm sure our backyard will be a maze of walnut and
hazelnut sprouts once the spring weather arrives.)
On our return, we found Nonotchka nursing an injury, limping on
her left rear leg and sporting two wounds on that haunch. We're
guessing she had a close encounter with a cat or similar predator.
(Dave saw Notch face off with a cat just a few days ago. Notch was
crossing the street back to the place where we think she has her nest,
when a cat came out of someone's yard. Notch stopped and sat up in the
middle of the street, facing the cat. The cat stopped, too, and they
sized each other up. Finally Notch turned and casually sauntered off
the way she'd been going, obviously having decided she had enough
escape options and wouldn't have trouble outrunning the cat. The
cat turned and stalked off the other way: "Oh, I wasn't hungry ayway.")
Since our return Nonotchka has gotten steadily gotten better.
She seemed very hot for a few days,
constantly running off to flop onto the cold concrete in the
shade, and the soles of her paws were hot when she came over to take
nuts. We suspect she was fighting an infection. But her temperature is
better now, and the fur is growing back over the wounded area.
She's walking better every day, and it's hard to see that anything is
wrong, until she jumps. She can't jump as high as before,
and climbing the fence is harder. With any luck it's just stiffness,
and she'll get over that in a few days.
We've made a special effort to make sure she gets plenty of nuts,
despite Notch's frequent presence. But today they had an encounter
that makes me wonder if we need to worry about that any more.
I was feeding Notch some breakfast nuts when Nonotchka appeared on the
fence. Normally Nonotchka would stay there, or retreat across the
street, when Notch is around;
but today she causually walked down the fencepost and sniffed around
under the deck where we often leave nuts.
Notch stopped eating and turned to look. They eyed each other for
a bit. Eventually Notch rushed Nonotchka, who retreated back
under the deck -- but not very far. Notch hopped a few feet over to the
grass under the orange tree and began to roll, dig, and pull herself
through the grass (to leave her smell there?) After about a minute,
Nonotchka appeared from under the deck and began rolling/digging/pulling
herself through a patch of grass under the guava tree, not more than
four feet away from Notch. Notch tolerated it for maybe half a minute,
then it got to be too much and she rushed Nonotchka again with a
little bark.
Nonotchka retreated again, but still not very far, and they spent the
next few minutes eying each other, circling slowly around the yard,
in a slow chase that ended with them exiting into the cedar in the
front yard, where I lost sight of them.
Five minutes later Nonotchka showed up at the office door to take a
nut I'd left there, but she took it up to the fence and wouldn't come
back to eat anything more.
I guess squirrel territory isn't immutable. It's nice to see Nonotchka
asserting herself a little.
Tags: nature, squirrels, urban wildlife
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]
Sat, 01 Apr 2006
When I plug in my camera (or flash card reader) to upload photos,
they always upload as executable. I knew there must be an easy
way to fix it, and finally got around to it.
I'm sure you are fully capable of reading man pages and figuring this
out, just like I was. (Hint: the solution is in man mount.)
But wouldn't you rather have it just spoon-fed to you?
(I know I would have.) So here it is:
you need the fmask option to mount.
It's a mask, so you set it to the bits you
don't want set when you mount the filesystem
(on top of your normal umask).
My /etc/fstab entry for my camera or other flash card device
now looks like this:
/dev/sda1 /pix vfat rw,user,fmask=111,noauto 0 0
(On the laptop it's sdb1 because the built-in memory stick reader
always grabs sda.)
Tags: linux, filesystems
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22:39 Apr 01, 2006
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Wed, 29 Mar 2006
What to do with a few extra hours in a boring motel with no net access?
How about digging into fixing one of Emacs' more annoying misfeatures?
Whenever I edit an html file using emacs, I find I have to stay away
from double dashes -- I can't add a phrase such as this one.
If I forget and type a phrase with a double dash, then as soon
as I get to the end of that line and emacs decides it's time to wrap
to the next line, it "helpfully" treats the double dashes as a
comment, and indents the next line to the level where the dashes were,
adding another set of dashes. I've googled, I've asked on emacs IRC
help channels, but there doesn't seem to be any way out. (I guess no
one else ever uses double dashes in html files?)
It's frustrating: I like using double dashes now and then. And aside
from the occasional boneheaded misfeature like this one, I like using
emacs. But the dash problem been driving me nuts for a long time
now. So I finally dug into the code to cure it.
First, the file is sgml-mode.el, so don't bother searching anything
with html in the name. On my system it's
/usr/share/emacs/21.4/lisp/textmodes/sgml-model.el.
Edit that file and search for "--" and the first
thing you'll find (well, after the file's preamble comments) is a
comment in the definition of "sgml-specials" saying that if you
include ?- in the list of specials, it will hork the typing of double
dashes, so that's normally left out.
A clue! Perhaps some Debian or Ubuntu site file has changed
sgml-specials for me, and all I need to do is change it back!
So I typed
M-x describe-variable sgml-specials
to see the current setting.
Um ... it's set to "34". That's not very helpful. I haven't a clue how
that translates to the list of characters I see in sgml-mode.el.
Forget about that approach for now.
Searching through the file for the string "comment" got me a few more
hits, and I tried commenting out various comment handling lines until
the evil behavior went away. (I had to remove sgml-mode.elc first,
otherwise emacs wouldn't see any changes I made to sgml-mode.el.
If you haven't done much elisp hacking, the .el is the lisp source,
while the .elc is a byte-compiled version which loads quicker but
isn't intended to be edited by humans. For Java programmers, the .elc
is sort of like a .class file.)
Commenting out these four lines did the trick:
(set (make-local-variable 'font-lock-syntactic-keywords)
'(("\\(<\\)! *--.*-- *\\(>\\)" (1 "!") (2 "!"))))
;; This will allow existing comments within declarations to be
;; recognized.
(set (make-local-variable 'comment-start-skip) "\\(?:\\)?")
To regenerate the .elc file so sgml-mode will load faster, I ran emacs
as root from the directory sgml-mode.el was in, and typed:
M-x byte-compile-file sgml-mode.el
All better! And now I know where to find documentation for all those
useful-looking, but seemingly undocumented, keyboard shortcuts that
go along with emacs' html mode. Just search in the file for
html-mode-map, and you'll find all sorts of useful stuff.
For instance, that typing Ctrl-C Ctrl-C followed by various letters: u
gets you an unordered list, h gets you an href tag, i an image tag,
and so on, with the cursor positioned where you want to type next.
It doesn't seem to offer any basic inline formatting (like
<i> or <em>), alas; but of course that's easy to add
by editing the file (or maybe even in .emacs). To add an <em>
tag, add this line to html-mode-map:
(define-key map "\C-c\C-ce" 'html-em)
then add this function somewhere near where html-headline-1 and
friends are defined:
(define-skeleton html-em
"HTML emphasis tags."
nil
"" _ "")
Of course, you can define any set of tags you use often, not just
<em>.
HTML mode in emacs should be much more fun and less painful now!
Update: If you don't want to modify the files as root, it also
works fine to copy sgml-mode.el to wherever you keep personal
elisp files. For instance, put them in a directory called
~/.emacs-lisp then add this to your .emacs:
(setq load-path (cons "~/.emacs-lisp/" load-path))
Tags: emacs, editors
[
22:48 Mar 29, 2006
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]
Mon, 20 Mar 2006
Dave has been complaining for a long time about the proliferation of
files named
.serverauth.???? (where
???? is various
four-digit numbers) in his home directory under Ubuntu. I never saw
them under Hoary, but now under Breezy and Dapper I'm seeing the same
problem.
I spent some time investigating, with the help of some IRC friends.
In fact, Carla
Schroder, author of O'Reilly's Linux Cookbook, was
the one who pinned down the creation of the files to the script
/usr/bin/startx.
Here's the deal: if you use gdm, kdm, or xdm, you'll never see
this. But for some reason, Ubuntu's startx uses a program
called xauth which creates a file containing an "MIT-MAGIC-COOKIE".
(Don't ask.) Under most Linux distributions, the magic cookie goes
into a file called .Xauthority. The startx script checks an
environment variable called XENVIRONMENT for the filename; if it's not
set to something else, it defaults to $HOME/.Xenvironment.
Ubuntu's version is a little different. It still has the block of
code where it checks XENVIRONMENT and sets it to
$HOME/.Xenvironment if it isn't already set. But a few
lines later, it proceeds to create the file under another, hardwired,
name: you guessed it, $HOME/.serverauth.$$. The XENVIRONMENT
variable which was checked and set is never actually used.
Programmers take note! When adding a feature to a script, please take
a moment and think about what the script does, and check to see
whether it already does something like what you're adding. If so,
it's okay -- really -- to remove the old code, rather than leaving
redundant and obsolete code blocks in place.
Okay, so why is the current code a problem? Because startx
creates the file, calls xinit, then removes the file. In other words,
it relies on xinit (and the X server) exiting gracefully. If anything
else happens -- for example, if you shut your machine down from within X --
the startx script (which does not catch signals) can die
without ever getting to the code that removes the file. So if you
habitually shut down your machine from within X, you will have a
.serverauth.???? file from each X session you ever shut down that way.
Note that the old setup didn't remove the file either, but at least it
was always the same file. So you always have a single .Xauthority file
in your home directory whether or not it's currently in use. Not much
of a problem.
I wasn't seeing this under Hoary because under Hoary I ran gdm, while
with Dapper, gdm would no longer log me in automatically so I had to
find
another approach to auto-login.
For Ubuntu users who wish to go back to the old one-file XAUTHORITY
setup, there's a very simple fix: edit /usr/bin/startx (as
root, of course) and change the line:
xserverauthfile=$HOME/.serverauth.$$
to read instead
xserverauthfile=$XAUTHORITY
If you want to track this issue, it's bug bug
35758.
Tags: linux, X11, ubuntu
[
21:24 Mar 20, 2006
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]
Sun, 19 Mar 2006
Periodically I get requests from people without C compilers (which
usually means Windows users) who are interested in using my
GIMP plug-in
Pandora,
which helps with making panoramic images
by loading all the images, positioning them approximately, and
adding layer masks. I always regret that I don't have a Windows
binary to offer people.
I've been thinking for a while that it would be easy to do a Pandora
plug-in in script-fu, so that any GIMP user could run it.
The only reason Pandora was written in C is
that it provides a modified file selection dialog allowing you to
choose the files you want in sequence. But it's not like the UI
for that dialog is any great shakes (it's always been confusing,
even to me, and I wrote it), and of course it uses the old gtk
file selector, which has been orphaned for quite some time.
The way to work around this in script-fu is to let the user open
all the images as layers in a single image using the normal Open
and Open as Layers functions, then transform that image into
a panorama by resizing it bigger and moving the layers to the right
place. Easy! It's been on my list to do for a long time, but I
didn't get motivated to write it until this morning when I
wasn't doing anything else and another Windows user showed up
on #gimp asking about panoramas.
I should have done it earlier. It only took an hour or two,
and works as well as the old C version. It's available on the
Pandora page.
Feedback or bug
reports appreciated!
Tags: gimp
[
19:02 Mar 19, 2006
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]
Sat, 18 Mar 2006
I needed to send a formal letter, so I thought, as a nice touch,
I'd print the address on the envelope rather than handwriting it.
I felt sure I remembered glabels, that nice, lightweight,
straightforward label printing program, having envelope options.
But nope, it doesn't have any paper sizes corresponding to envelopes.
(It has a size called A10 but it's 1.0236 x 1.4567 inches, not the 4.13 x
9.50 I'd expect for a number-ten envelope.)
Darn, that would have been perfect.
OpenOffice doesn't have anything in its templates list that
corresponds to an envelope, nor does it have anything in the Wizards
list. But googling showed me -- aha! -- that it's hidden in the
Insert menu, Insert->envelope -- so if you want to
create a new envelope document, create some other type of document
first, go to Insert and bring up the envelope dialog, click New to get
the envelope, then close the blank dummy document.
But then it doesn't offer a choice of envelope sizes, and puts the text in
odd places so you have to fiddle with the margins to get the recipient
and return address in normal places. Then, when you go to Preview or
Printer Settings, it has forgotten all about the fact that it's doing
an envelope and now tries to print in the middle of a sheet of paper.
In theory you could fix this by setting the paper size to the size of
the envelope -- except that OOo doesn't actually have any envelope
sizes in its paper list.
Okay, let's try abiword instead.
Abiword has a nice selection of paper sizes, including some common
envelope sizes. Choosing A10 envelope and Landscape mode lets me
compose a nice looking envelope. But then when I go to Print Preview,
it turns out it wants to print it in portrait mode, with the addresses
going across the short dimension of the envelope. The Print dialog
offers a Paper tab which includes an Orientation dropdown, but
changing that from Landscape to Portrait makes no difference: the
preview still shows the addresses disappearing off the short dimension
of the envelope.
I suppose I should try kword. But it depends on nine other packages,
and I was tired of fighting. I gave up and wrote the address
out by hand.
The next day, though, I went back to gLabels, poked around for a bit
and found out about "Template Designer" (in the File menu).
It's almost there ... it's easy to set up custom sizes, but it
prints them in the middle of a US-letter page, rather than lined
up against the edge of the printer's feeder. I'm dubious that you
could feed real envelopes this way with any reliability. Still,
it's a lot closer than the word processing programs could get.
Tags: linux, printing
[
18:36 Mar 18, 2006
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]
Fri, 17 Mar 2006
Our little squirrel family has grown to four. Notch has returned,
after being gone for over a month, and now displays nipples like
Nonotchka's. Turns out they were both females!
Notch is still as graceful, strong, and dominant as ever, and
hangs around keeping Nonotchka from feeding. But we've found a
solution: give Notch a nut in the shell, and she will take it
off to bury it, which gives us a little time to sneak some nuts
to Nonotchka before Notch flies back like a furry bolt of lightning.
Sometimes the ruse doesn't work. Once Dave went outside and chased
Notch across the yard, over the fence and into the cedar while I
communed with Nonotchka. Dave though he had her; but Notch vanished
into the cedar branches, ran down the trunk and snuck under the gate
while Dave was still watching the upper branches. Nonotchka only
got a few nuts that time.
But that's not all. We have two other squirrels now, both apparently
youngsters (they're scruffy, skinny, slightly smaller than our
established squirrels, and markedly less graceful). One has white
tufts between his ears, so I'm calling him Tuft; the other doesn't
have a name yet and doesn't come by very often. They're both males,
and yes, it is possible to tell when they're sitting up, contrary to
some web pages I've seen.
Both of the kids are very nervous about us, and won't feed when we're
anywhere in sight. But they're not nervous about Notch; the three of
them sometimes eat at the same time, sitting on different parts of
the fence, something Notch would never allow Nonotchka to do.
Dave is convinced that they're Notch's kids from last year, and
that he sees a family resemblance. The two kids sometimes quarrel
mildly between themselves, and chatter at each other, but only
when Notch isn't around; when she is, they're respectful and
submissive.
Since the Notch Gang of three all tolerate each other, this makes it
difficult to get any food to Nonotchka. She's taken to coming by later
in the afternoons; the kids get up early in the morning, and Notch
likes coming by around lunchtime.
Dave taped a little wooden shelf at the bottom of the office door
where we can put nuts. Notch and Nonotchka learned it pretty quickly:
not because they're any good at finding new nut sources (it takes
them forever to notice a nut that's in a place where they don't
normally find any; sometimes I wonder how the species survives)
but because they're both bold enough to come to the door and look
in when they're hungry, and eventually they bump their noses into
the nuts on the shelf. Tuft is starting to notice the door-nuts, too,
and will take one, then run off when he notices he's being watched.
I was able to get some
photos
of Nonotchka at the door (plus a few new shots of her outside
in interesting poses).
I tried to photograph Tuft today but he's too nervous.
Tags: nature, squirrels, urban wildlife
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19:27 Mar 17, 2006
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]
This morning I was all ready to continue working on an ongoing web
project when I discovered that mysql wasn't running.
That's funny, it was running fine yesterday! I tried
/etc/init.d/mysql start, but it failed. The only error message
was, "Please take a look at the syslog."
So I hied myself over to /var/log, to discover that
mysql.log and mysql.err were both there, but empty.
Some poking around /etc/mysql/my.cnf revealed that logging is
commented out by default, because: "# Be aware that this log
type is a performance killer."
I uncommented logging and tried again, but /var/log/mysql.err
remained blank, and all that was in mysql.log was three lines
related basically giving its runtime arguments and the name of the
socket file.
Back to the drawing board. I was well aware that I had changed the
mysql settings yesterday. See, mysqld on Ubuntu likes to create its
socket as /var/run/mysqld/mysqld.sock, but other apps, like
Ruby, all expect to find it in /tmp/mysql.sock. It's easy enough to
change Ruby's expectations. But then I found out that although the
cmdline client mysql also expects the socket in
/var/run/mysqld, it depends on something called
mysqladmin that wants the socket in /tmp. (I may have
those two reversed. No matter: the point is that you can't use the
client to talk to the database because it and the program it depends
on disagree about the name of the socket. This is probably a Dapper bug.)
Okay, so I had to pick one. I decided that /tmp/mysql.sock was
easier to remember and more standard with non-Debian setups. I knew
where to change it in the server (/etc/mysql/my.cnf is there and well
commented) but the mysql client doesn't use that, and it took some
googling and help from clueful friends to find out that what it wanted
was a new file called /etc/my.cnf (how's that for a nice clear
configuration file name?) containing one line:
socket = /tmp/mysql.sock
That done, mysql started and ran and everything worked. Woo!
Except that it didn't the following morning after a reboot, and didn't
give any error messages as to why.
Off I went on a merry chase across init files: /etc/init.d/mysql calls
/etc/mysql/debian-start (which made me realize that debian has added
yet another config file, debian.cnf, which has yet another copy
of the line specifying the socket filename) which calls
/usr/share/mysql/debian-start.inc.sh as well as calling various
other programs. But those were all red herrings:
the trick to debugging the problem was to run mysqld
directly (not via /etc/init.d/mysql start: it actually does
print error messages, but they were being hidden by using the init.d
script.
The real problem turned out to be that I had changed the location of the
socket file, but not the pid file, in /etc/mysql/my.cnf, which was
also located by default in /var/run/mysqld. Apparently that
directory is created dynamically at each boot, and it isn't created
unless it's needed for the socket file (whether the pid file needs it
doesn't matter). So since I'd moved the socket file to /tmp,
/var/run/mysqld wasn't created, mysqld couldn't create its pid file
and it bailed. Solution: edit my.cnf to use /tmp for the pid file.
Tags: programming
[
13:29 Mar 17, 2006
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]
Wed, 15 Mar 2006
I updated my Ubuntu "dapper" yesterday. When I booted this morning,
I couldn't get to any outside sites: no DNS. A quick look at
/etc/resolv.conf revealed that it was empty -- my normal
static nameservers were missing -- except for a comment
indicating that the file is prone to be overwritten at any moment
by a program called resolvconf.
man resolvconf provided no enlightenment. Clearly it's intended
to work with packages such as PPP which get dynamic network
information, but that offered no clue as to why it should be operating
on a system with a static IP address and static nameservers.
The closest Ubuntu bug I found was bug
31057. The Ubuntu developer commenting in the bug asserts that
resolvconf is indeed the program at fault. The bug reporter
disputes this, saying that resolvconf isn't even installed on the
machine. So the cause is still a mystery.
After editing /etc/resolv.conf to restore my nameservers,
I uninstalled resolvconf along with some other packages that I clearly
don't need on this machine, hoping to prevent the problem from
happening again:
aptitude purge resolvconf ppp pppconfig pppoeconf ubuntu-standard wvdial
Meanwhile, I did some reading.
It turns out that resolvconf depends on
an undocumented bit of information added to the
/etc/network/interfaces file: lines like
dns-nameservers 192.168.1.1 192.168.1.2
This is not documented under
man interfaces, nor under
man
resolvconf; it turns out that you're supposed to find out about it
from
/usr/share/doc/resolvconf/README.gz. But of course, since
it isn't a standard part of
/etc/network/interfaces, no
automatic configuration programs will add the DNS lines there for you.
Hope you read the README!
resolvconf isn't inherently a bad idea, actually; it's supposed to
replace any old "up" commands in interfaces that copy
resolv.conf files into place.
Having all the information in the interfaces file would be a better
solution, if it were documented and supported.
Meanwhile, be careful about resolvconf, which you may have even
if you never intentionally installed it.
This
thread on a Debian list discusses the problem briefly, and this
reply quotes the relevant parts of the resolvconf README (in case
you're curious but have already removed resolvconf in a fit of pique).
Tags: linux, ubuntu, networking
[
15:22 Mar 15, 2006
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]
Tue, 14 Mar 2006
People are forever turning up on #gimp to ask (quite reasonably)
how to center a layer, since GIMP offers no built-in way to do that.
There are Python and Perl scripts around somewhere (and
it's easy to write, a great project if you're thinking about
learning how to write GIMP scripts in any language).
And the new Align tool can probably center, for those
using GIMP 2.3, but the tool is a bit difficult for most
people to figure out (fear not, the UI is still being developed).
But for those who want a quick solution:
Center a Layer:
Cut, then paste. The pasted layer comes out centered.
(Unfortunately this loses text information, so if it's a text
layer this isn't an ideal solution.)
Paste a layer on top of a copy of itself:
Do a
Layer to Imagesize before copying.
Then copies of the layer will overlap the original.
Tags: gimp
[
19:51 Mar 14, 2006
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]
Mon, 13 Mar 2006
Back when I laboriously installed Ruby and Rails on Ubuntu "Hoary
Hedgehog" (which involved basically ignoring all the Ubuntu packages
and building everything, including Ruby itself, from source), I was
cheered by the notes in Ubuntu's forums and bugzilla indicating that
as of the next release ("Breezy Badger") all the right versions
would be there, and all this source compilation would no longer
be necessary.
I didn't get around to trying it until today. Breezy and its successor
"Dapper Drake" do indeed have a rails package as well as a Ruby
package, and I happily installed them. All looked great -- until
I actually tried to use them on a real-world application. It turns
out that the Ruby and Rails packages don't include gems, Ruby's
package manager (similar to the CPAN system familiar to Perl
programmers). And gems is required for doing anything
useful in Rails.
Drat! After several false starts, I eventually found the
instructions on this
page. Except that installs way more than seems necessary
for what I need to do, and if you copy/paste lines from that page
you may end up with a bunch of packages you don't want, like an
out of date version of mysql.
So here are simplified instructions for using Ruby on Rails
on Ubuntu Breezy or Dapper.
As yourself:
wget http://rubyforge.org/frs/download.php/5207/rubygems-0.8.11.tgz
tar zxvf rubygems-0.8.11.tgz
As root:
cd rubygems-0.8.11
ruby setup.rb
gem install rubygems-update
gem install rails
Say yes to all dependency questions during the gem install of rails.
Add your web server and database of choice (you probably already
have them installed, anyway) and you should be good to go.
You may note that the page I referenced tells you to install two
versions of rails: the Ubuntu package plus the one from gems.
At least on Dapper, you don't need both. Installing rails pulls
in the packages:
irb irb1.8 libpgsql-ruby1.8 libreadline-ruby1.8
libredcloth-ruby1.8 libruby1.8 rake rdoc rdoc1.8 ruby ruby1.8
I haven't experimented with which of these packages are and are not needed.
If you run into problems, some set of packages from this list
may solve them.
Update: it seems that none of these are required. Many of them
are dummy packages anyway, which contain no files related to the
actual package name. For instance, the rake package contains,
not rake, but a single bash completion file related to rake.
So you should be fine ignoring all of them,
installing just Ruby and nothing else.
(I filed bug
34840 requesting that Ubuntu ship a usable version of Rails,
since it didn't seem to be filed already.)
Tags: programming
[
22:56 Mar 13, 2006
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]
Tue, 07 Mar 2006
Nonotchka has had her litter. Or at least she lost the tummy and
regained her old svelte and graceful form as of yesterday afternoon.
Of course, we haven't seen any squirrelets; she'll have them
stashed away in a nest somewhere safe.
We're slightly worried about her. She came to eat today as usual
(ravenously: she ate ten hazelnuts all at once then took several
more away to bury), and although she seemed friendly and energetic,
she left blood spots on Dave's jeans. I hope this is just some sort of
normal postpartum condition and not an injury. She didn't seem to
be in pain. (I get this from Dave; I was away when she
made her visit. She's definitely spending less time here
now that she has a family to take care of.)
So we'll keep an eye on her, make sure she's well fed and hope that
she's okay and that in a few months she might start bringing the
kids by. Apparently grey squirrels nurse for an amazing three months
before they're ready to go out on their own. There are usually four
to a litter.
(Update the following day: She seems fine. She's still energetic
and hungry, and there's been no more blood.)
Meanwhile, Notch is gone. We haven't seen him at all since getting
back from our trip. We're getting occasional visits from a new
squirrel: scruffy, young-looking and not terribly well coordinated.
Dave thinks the newcomer is a male. He's confused about nuts, or
well fed from someone else's yard: he'll sniff at a hazelnut in
the shell then leave it where it lies.
Perhaps he just doesn't like hazelnuts and is holding out for a walnut.
It seems odd that this scrawny newcomer could have chased the
burly, graceful and confident Notch away from his territory.
My guess is that Notch decided there was some other yard he
liked better, since even before the trip we'd been seeing him
only infrequently.
Tags: nature, squirrels, urban wildlife
[
23:30 Mar 07, 2006
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]
Thu, 02 Mar 2006
We went away for a week, to visit family for my grandmother's
100
th birthday (yay, Grandma!) Of course, before we left
we made sure our squirrels had lots of nuts buried, so they weren't
dependent on the shelled nuts we've been feeding them.
When we got back, Nonotchka wasted little time in visiting us,
and she's just as friendly as ever (to someone with a walnut in
hand). But there are some other changes. At first, we weren't
sure if she seemed fatter; but eventually we saw her from angles
that left
no doubt.
And her belly fur has changed; instead of the
brownish grey, now it's white like Notch's, except for six
dark spots arranged in pairs down her abdomen.
Looks like we guessed right about Nonotchka's gender (well, we
had a 50% chance) and she's going to be a mom!
I hope we get to see the baby squirrels when they're old enough to
leave the nest. Maybe she'll even bring them by when they're old
enough to be weaned.
We haven't seen Notch at all since we got back. I hope he's all
right. He'd been spending a lot of time across the street anyway,
so perhaps he's found a territory he likes better than our yard.
Tags: nature, squirrels, urban wildlife
[
12:29 Mar 02, 2006
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]
Sun, 05 Feb 2006
I've been unable to persuade Ubuntu's "Dapper Drake" to log me in
automatically via gdm. My desktop background flashes briefly during
the login process, then vanishes; it appears that it actually is
logging me in briefly, then immediately logging me out and presenting
me with the normal gdm login screen.
I never liked gdm much anyway. It's heavyweight and it interferes with
seeing shutdown messages. The only reason I was using it on Hoary
was for autologin, and with that reason gone, I uninstalled it.
But that presented an interesting problem: it turns out that
Dapper doesn't actually allow users to run X. The error message is:
Unable to open wrapper config file /etc/X11/Xwrapper.config
X: user not authorized to run the X server, aborting.
The fix turned out to be trivial: make the X server setuid
and setgid (
chmod 6755 /usr/bin/X). Mode 4755 (setuid only,
no setgid) also works, but other Debian systems seem to set both bits.
The next question was how to implement auto-login without gdm or kdm.
I had already found a useful
Linux Gazette
article on the subject. The gist is that you compile a short C
program that calls login with your username, then you call getty with
your new program as the "alternate login program".
Now, I have nothing against C, but wouldn't a script be easier?
It turns out a script works too. Replace the tty1 line in
/etc/inittab with a line like:
1:2345:respawn:/sbin/getty -n -l /usr/bin/myloginscript 38400 tty1
where the script in question looks like:
#! /bin/sh
/bin/login -f username
At first, I tried an even simpler approach:
1:2345:respawn:/bin/login -f username
That logged me in, but I ended up on /dev/console instead of
/dev/tty1, with a message that I had no access to the tty and
therefore wouldn't be able to use job control. X didn't work
either. The getty is needed in order to switch control
from /dev/console to a real virtual terminal like /dev/tty1.
Of course, running X automatically once you're logged in is trivial,
just a line or three added to .login or .profile (see the Linux
Gazette article referenced above for an example).
It works great, it's very fast, plus I can watch shutdown messages
again. Nice!
Update 9/9/2006: the Linux Gazette article isn't accessible any more
(apparently Linux Journal bought them and made the old articles
inaccessible). But here's an example of what I do in my .login
on Dapper -- this is for tcsh, so bash users subtitute "fi" for "endif":
if ($tty == tty1) then
startx
endif
Tags: linux, ubuntu, boot
[
11:53 Feb 05, 2006
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]
Sat, 04 Feb 2006
I've been meaning to upgrade my desktop machine from Ubuntu's "Hoary
Hedgehog" release for some time -- most notably so that I can get the
various packages needed to run GTK 2.8, which is now required to build
the most current GIMP.
Although I'm having good success with "Breezy Badger", the stable
Ubuntu successor to "Hoary", on my laptop, Breezy is already
borderline as far as GIMP requirements, and that can only get worse.
Since I do more development on the desktop, I figured
it was worth trying one of the pre-released versions of Ubuntu's
next release, "Dapper Drake".
Wins over hoary and breezy: it handles my multiple flash card reader
automatically (on hoary and breezy I had to hack the udev
configuration file to make it work).
I've had a few glitches, starting with the first auto-update wanting
to install a bunch of packages that didn't actually exist on the
server. This persisted for about a week, during which I got a list
of 404s and "packages held back" warnings every time I updated or
installed anything. It didn't seem to hurt anything -- just a minor
irritant -- and it did eventually get fixed. That's life with an
unstable distribution.
Dapper has the same problem that hoary and
breezy have with hald polling the hard disk every few seconds
(bug 27323).
In addition, hald seems to spawn a rather large number of
hald-addon-storage processes
(probably to handle the built-in multi flash card reader).
(Uncommenting the storage.automount_enabled_hint in
/etc/hal/fdi/policy/preferences.fdi didn't help.)
Killing hald (and nuking /usr/sbin/hald
so it won't restart) solves both these problems, but it also
stops hotplugged USB devices from working: apparently Dapper
has switched to using hal instead of hotplug for USB. Ouch!
In any case, hald came back on a dist-upgrade so it looks like
I'll have to find a more creative solution.
The printing packages have problems.
I tried to add my printer via the CUPS web interface,
but apparently it didn't install any printer drivers by default, and
it's not at all obvious where to get them. The drivers are there, in
/usr/share/cups/model/gutenprint/5.0/en, but dapper's cups apparently
isn't looking there. I eventually got around the problem by
uncompressing the ppd file and pointing CUPS directly at
/usr/share/cups/model/gutenprint/5.0/en/stp-escp2-c86.5.0.ppd.
(Filed bug
30178.)
Dapper's ImageMagick has a bug in the composite command:
basically, you can't combine two images at all. So I have to generate
web page thumbnails on another machine until that's fixed.
gdm refuses to set up my user for auto-login, and I hit an interesting
localization issue involving GIMP (I'll report on those issues separately).
Most other things work pretty well. Dapper has a decent set of
multimedia apps and codecs, and its kernel and udev setup seem to work
fine (it can't suspend my desktop machine, but neither can any other
distro, and I don't really need that anyway).
Except for the hald problem, Dapper looks like a very usable system.
Tags: linux, ubuntu
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19:27 Feb 04, 2006
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Thu, 02 Feb 2006
In early December, a squirrel staked out our yard as part of his
territory. We encouraged him with nuts. He has a notch in one ear,
so I called him "Notch".
Later that month, another squirrel showed up. Sometimes Notch chased
the new squirrel (especially when food was involved), but at other
times they seemed to be playing in a friendly way. Apparently
December is breeding time for squirrels.
There's no easy way to identify the gender of grey squirrels (at
least from a distance), so we arbitrarily decided that the larger,
tougher and more territorial Notch was a male, and the newcomer
must be female. Dave dubbed her "Nonotchka".
(Of course we're hoping that in a few months it will become obvious
which one is actually the female, and soon afterward we will have
little squirrels to watch.)
Both Notch and Nonotchka have become rather tame (though not quite
to the point of taking food from our hands), and we've been able to
get some decent (though not spectacular) photos while feeding them.
Unfortunately, the final review process for the GIMP book got in the
way of organizing the photos or writing squirrel essays, and I'm
only now starting to catch up.
So here they are: our
Suburban Squirrels.
Tags: nature, squirrels, urban wildlife
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15:57 Feb 02, 2006
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Mon, 30 Jan 2006
Although I haven't been writing about it here, for most of
the past year I've been working on a new GIMP book for Apress, called
Beginning
GIMP: From Novice to Professional.
Today the work was over: the last bits shipped to the printer!
The rest is just waiting (... and waiting ... and waiting ...)
Amazon has a page
on it already (complete with typo in the description; sigh)
for folks who like to pre-order their books months early.
Scheduled release date is currently late April.
(I think they have to grow the trees first.)
In case you haven't already heard other authors say it, writing a
book is a lot more work than you think it will be. Even if other
authors have already told you that it's more work than you think it
will be, it's more work than that. If you thought you already knew
the subject you were writing about, think again. You'll find out how
little you really knew. You'll discover all sorts of options you never
noticed in your favorite tools, and new (and often better) ways to
do things than the methods you'd been using for years.
You'll discover bugs in plug-ins no one's used in a while,
and why things you always thought were bugs really aren't.
That's the good sort of "too much work": the kind that keeps
you learning, so that you come away from it with more than you
started with. It's been fun. But I confess that I'll be glad to take
a rest for a while and work on some long neglected coding projects.
I celebrated ship-to-printer with a little GIMP hacking
(adding that feature list to configure that I
wished
for last week, so now GIMP will warn you of any missing features
before you start your 45-minute build);
and with lamb kebab with zereshk polo at Chatanoga.
Tags: gimp
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22:38 Jan 30, 2006
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Tue, 24 Jan 2006
I've been frustrated for some time at GIMP 2.3's inability to save
EXIF data whenever I save a JPEG image. There were several bugs
report on the problem, and I just assumed that this was something
which had broken somewhere along the line and hadn't been fixed yet.
It turns out it was a stupid build problem on my machine: I didn't have
libexif-dev installed on either of my Ubuntu systems, and GIMP's
configure script wasn't warning me about it in any obvious way.
(Of course, had I taken the time to read through the 3679 lines of
config.log, the information was buried in there around
line 2199.)
So now I have EXIF again, at least on the laptop (hooray!) but I
also learned something more important: after running configure for
the first time on any new system, before running make, do this:
grep -i "will not" config.log
That may not flag everything, but at least it's a start at getting
a list of features that have been disabled because of dependencies
you forgot to install (anything which configure is smart enough to
tell you "will not be built").
Schumaml had the great idea of putting a list of enabled features
in the About box. Maybe I'll look into doing that in a week or two
(when the current crunch is over and I have more time to upgrade my
development machine so that it can use gtk 2.8 and I can actually
build GIMP again).
Update: I added
a printout similar to the one I thought I remembered, so there
should be no further need to grep for "will not".
Tags: gimp
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15:11 Jan 24, 2006
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Thu, 12 Jan 2006
Anyone who's been following the Sony CD rootkit story -- the one where
Sony audio CDs come infected with a program which, when the CD is
played on Windows PCs, installs a rootkit which is virtually
impossible to uninstall and which makes the PC susceptible to all
sorts of third-party attacks -- won't want to miss
Trend
Micro's information page regarding Sony's rootkits.
Highlight:
This tool works by applying a relatively new technology called
rootkit technology. Rootkits are used to hide system
information, such as running processes, files, or registry entries.
As a standalone application, it is non-malicious. However, certain malware
applications use it [ ... ]
Good thing Trend Micro is there to give us the lowdown on this new
(and non-malicious) rootkit technology!
In a vaguely related note: a speaker at my Toastmasters club today
planned a Powerpoint presentation. (This is unusual in Toastmasters,
but does happen occasionally.) He diligently showed up early to
set up his computer and the projector so he'd be ready before the
meeting started. As we were about to begin the meeting, with the
projector showing his first slide, suddenly a dialog popped up
on top of the slide, informing him that his system auto-update
was finished, and he needed to reboot. It offered two buttons:
[Reboot now] [Reboot later].
The later button was greyed out.
Isn't it nice when your system helpfully gives you automatic updates?
He fiddled for a while but finally gave up and rebooted. I couldn't
help noticing that the first screen that appeared upon reboot was a
Trend Micro screen.
Tags: tech
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21:17 Jan 12, 2006
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Sat, 07 Jan 2006
Slate's "Today's Papers" column brings us word of a Wall Street
Journal article (alas, subscribers-only) describing a new service:
Friends
Beyond the Wall Photos. For a small fee, an image from a prison
photo can be combined with photos of families, vacations, or posh cars
to make it look like you've been on holiday with the kids rather than
behind bars! No more need to explain why those visiting room photos
have such a drab background!
And here I thought learning GIMP skills was just an amusing hobby.
Tags: humor
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21:41 Jan 07, 2006
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Wed, 04 Jan 2006
I installed the latest Ubuntu Linux, called "Breezy Badger", just
before leaving to visit family over the holidays. My previous Ubuntu
attempt on this machine had been rather unstable (probably not
Ubuntu's fault -- 2.6 kernels and this laptop don't get along very
well) but Ubuntu seems to have some very sharp kernel developers, so
I was curious to see whether there'd been progress.
Installation:
Didn't go well. I had most of the same problems I'd had installing
Hoary to this laptop (mostly due to the installer assuming that a
CDROM and network must remain connected throughout the install,
something that's impossible on a laptop where both of those functions
require sharing the single PCMCIA port). The Breezy installer has the
additional "feature" that it tends to hang if you change things like
the CDROM while the install is in progress, trashing everything and
forcing you to restart from the beginning. (Filed bug 20443.)
Networking:
But eventually I found a sequence that let me get a network-less
Breezy onto the laptop, and I'm happy to report that Breezy's built-in
networking tools were able to add networking after the first boot
(something that hadn't worked in Hoary). Well, admittedly I did have
to add a script, /etc/hotplug/pci/3c59x, to call ifup when my cardbus
network card is plugged in; but every other distro needs that too, and
Breezy is the first 2.6-based distro which correctly calls the script
every time.
Suspend:
Once up and running, Breezy shows impressive laptop savvy.
Like Hoary, it can suspend either to disk or to RAM; unlike Hoary, it
can do this without my needing to hack any config files except to
uncomment the line enabling suspend to RAM in /etc/default/acpi-support.
It does print various error messages on stdout when it resumes from
sleep or hibernate, but that's a minor issue.
Not only that, but it restores both network and usb when resuming from
suspend (on hoary I had to hack some of the suspend scripts to make
that work).
(Kernel flakiness:
Well, mostly it suspends fine. Unplugging a usb mouse at the wrong
time still causes a kernel hang.
That's a 2.6 bug, not an Ubuntu-specific problem.
And the system also tends to hang and need to be power cycled about
one time out of five when exiting X; perhaps it's an Xorg bug.)
Ironically, my "safe" partition on this laptop (a much-
modified Debian sarge) mysteriously stopped seeing PCMCIA on the first
day away from home, so I ended up using Breezy for the whole trip
and giving it a good workout.
Hal:
One problem Breezy shares with Hoary is that every few seconds, the
hald daemon makes the hard drive beep and whir. Unlike Hoary, which
had an easy
solution, Breezy ignores the storage_media_check_enabled and
storage_automount_enabled hints. The only way I found to disable
the beeping was to kill hald entirely by renaming /usr/sbin/hald
(it's not called from /etc/init.d, and I never did find out who was
starting it so I could disable it). Removing hald seems to have caused
no ill effects; at least, hotplug of pcmcia and usb still works, as do
udev rules. (Filed bug 21238.
Udev:
Oh, about those udev rules! Regular readers may recall that I had some
trouble with Hoary regarding
udev
choking on multiple flash card readers which I solved
on my desktop machine with a udev rule that renames the four fixed,
always present devices. But with a laptop, I don't have fixed devices;
I wanted a setup that would work regardless of what I plugged in.
That required a new udev rule. Here's the rule that worked for me:
in /etc/udev/permissions.rules, change
BUS=="scsi", KERNEL=="sd[a-z]*", PROGRAM="/etc/udev/scripts/removable.sh %k 'usb ieee1394'", RESULT="1", MODE="0640", GROUP="plugdev"
to
BUS=="scsi", KERNEL=="sd[a-z]*", NAME{all_partitions}="%k", MODE="0640", GROUP="plugdev"
Note that this means that whatever scripts/removable.sh does, it's not
happening any more. That doesn't seem to have caused any problem,
though. (Filed
bug 21662
on that problem.)
Conclusion:
Overall, Breezy is quite impressive and required very little tweaking
before it was usable. It was my primary distro for two weeks while
travelling; I may switch to it on the desktop once I find a workaround
for bug
352358 in GTK 2.8 (which has been fixed in gnome cvs, but
that doesn't make it any less maddening when using the buggy version).
Tags: linux, ubuntu, laptop
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