There was light fog this morning when I rode my bike to BART.  It made me think of this picture I took  from our roof on the morning of March 19, 2009.

I spotted these tow trucks on The Embercardaro around 2:30 in the afternoon on Monday, September 1.  They were waiting to scoop up any cars left in the curb lane once 3pm rolled around.

This picture is the first I have postprocessed using The Gimp.  I used the dodging and burning tool to bring out some of the shadows and make the overexposed sky a little less dominating in the frame.

Evening of January 1, 2009.  I like how the pyramid looks like an antenna spraying radiation out into the sky.

Temperance bearing an hourglass; detail of Lorenzetti's Allegory of Good Government, 1338

Frequently I need to execute a fairly long running task, such as unpacking a large tar file or running a long build.  I want to get feedback on the progress of the task, but I don’t necessarily want to fill my terminal window with lots of superfluous text by using the verbose output option.  Not only is the scrolling text distracting and difficult to follow, outputting the text can be  a significant bottleneck on slow connections.

To solve this problem I use a script called “dots,” which I list below.  This script prints a single period character for every 1000 lines of input.  You can specify a different number of lines necessary to create a dot as the first argument to the command.  Any command with verbose output can be piped into dots to generate a simple progress bar.

#!/usr/bin/perl

$| = 1;  # flush output immediately
$i = 0;

if ($#ARGV < 0) {
  $number = 1000;
} else {
  $number = shift(@ARGV);
}

while (<STDIN>) {
  print '.' unless ($i % $number);
  $i++;
}

print "\n";

jdblair@zaphod:~/src$ tar xvfj linux-2.6.30.5.tar.bz2 | dots
..............................

jdblair@zaphod:~/src$ rm -rfv linux-2.6.30.5 | dots
..............................

If you still want to be able to check the output, such as the text generated by a long running make command, use the tee command to generate a log file.  This example generates a dot for every 10 lines of output, since the compiler output is generated comparatively slowly.

jdblair@zaphod:~/src/linux-2.6.30.5$ make bzImage 2>&1 | tee build.log | dots 10
................................................................................
................................................................................
....................

A photo from the archives.  June 15, 2008, cleaning up art supplies at my son’s old school, Crestmont School.

$ rm *;*

The response from the shell was this:

sh: *: command not found

Then, to my horror, when I listed the directory I could see all my files were gone.

The unix nerds in the audience will have already noticed what happened.  You see, the semicolon is the magic character that ends a command line.  I had told the shell to remove all my files then run a command called *.

Game over, at least for all the files in my home directory.

This story came up in a particularly geeky thread yesterday on Facebook, and Nick Shapiro told me a trick he learned from our mutual friend Greg Sutter.

Put a file called “-i” in directories containing vital files.  If you run “rm *” the file called “-i” tricks rm into running in “interactive” mode, which gives you a chance to bail out.

Here’s an example:

$ mkdir tmp; cd tmp
$ touch ./-i
$ touch foo bar baz
$ rm *
rm: remove regular empty file `bar'?

Now you have a chance to notice what happened and hit control-c to exit.

To remove the file, use

$ rm ./-i

Another handy related trick: a perl one-liner is also a great way to remove files with tricky names:

$ perl -e "unlink('-i');"

This trick also works great for files with other inconvenient names, like -, –, ;, >, and <, for which the “./” technique above doesn’t work.

UPDATE:

My friend Joe Ardent points out something I had forgotten: The GNU convention is to ignore any arguments after “–” in the argument list.  Thus, you can also do this:

$ touch -- -i
$ rm -- -i

Joe also reminds me that you can escape special shell characters using the backslash character. Thus, “rm \<” works, which is simpler than the perl one liner.  Just when you think you’re an expert in something…

I took this picture in December, 2008 at dusk.  New Economy Dry Cleaners and Laundry is located at Sacramento and Fairview, in South Berkeley.  I’ve never taken any laundry there, but I think their name is fabulous.

The combination of two human foibles, the endowment effect and the status-quo bias are combining to make fixing our health care system particularly difficult. The endowment effect describes the tendency of people to overvalue something they already have. The status-quo bias is the fancy cognitive psychology term for humankind’s deep-seated resistance to change. This resistance is driven by our fear of loss. As explained in the article,

Behavioral economists have established that we feel the pain of losses more than we enjoy the pleasure of gains. So when we think about change we focus more on what we might lose rather than on what we might get. Even people who aren’t all that happy with the current system, then, are still likely to feel anxious about whatever will replace it.

You can predict the result of combining the endowment effect and the status quo bias with regards to our health care system: people who currently have coverage overvalue the coverage they have, and fear any change to the system will leave them worse off.

Unfortunately, if they’re lucky enough to have good health insurance, people tend to fail to see how tenuous their coverage actually is. Since most people’s insurance coverage is linked to their employment, losing one’s job (something increasingly probable in today’s economy) leaves one without any health insurance coverage at all. Further, the insurance industry practice of rescission, or the retroactive cancellation of an insurance policy, means everybody has a small but very real chance that the coverage one thinks one has will be yanked away just when it is needed most.

In other words, as the New Yorker helpfully explains, to keep the status quo of existing coverage, we’re going to have to have to change the way the system works. This paradox goes a long way towards explaining why the case for healthcare reform is so difficult to make with the American public.

I have nothing written ready to post, so I offer another photo blog entry.

This is Central Concrete, located at 24th and Peralta Streets in West Oakland, on the morning of March 27, 2009.

different angle, same morning

Close up of the giant metal woman sculpture, found on its side behind American Steel, on 20th Street between Poplar and Mandella Parkway.  This sculpture appeared earlier in the Art Shadow post.  Picture taken August 18, 2009.

I saw the sculpture being loaded on a flatbed truck just this last Tuesday (August 25), presumably on its way to Black Rock City.

Some other pictures taken the same day at the same location appeared on Myrtle Street Review.