Displaying articles with tag scripting

Finding bad JPEGs with Xorg hacks in Ubuntu

Posted by hank, Sun Nov 25 00:46:00 UTC 2007

So, I have all these JPEGs, and I want to know which ones are corrupt (specifically, ones that end prematurely). qiv will spit out the following to STDERR when it finds one:


Premature end of JPEG file

So, this is nice, except it’s entirely unscriptable. The solution I found was using the following script to the display the images in sequence:


perl -e 'for(glob("*.png *.jpg")){$output = `qiv "$_" 2>&1;`; if($output =~ /Premature/){print $_, "\n";}}'

All this does is mix STDERR with STDOUT for a qiv of the file, and check the output for the word “Premature”. If it finds the word, it prints the filename. Simple.

The only problem is that qiv doesnt have a way to just check whether a JPEG file is corrupt (and if there is a command line utility that does, please let me know). To make it go thru the list, I wrote this little gem:


while(true); do xte "key q"; done

All this does is send the q key to the Xserver infinitely. All I have to do is put focus on the first qiv window to make it and all subsequent qiv windows receive q’s. So, just run it, and click on the window. Then there are lots of flashes, and eventually that perl script will print out the names of the bad files. It’s totally ghetto, but it’s the best I’ve got right now. The point of this post is to hopefully find new ways to do this more programmatically.

Tags: scripting

Setting EXIF dates with a loop

Posted by hank, Tue Sep 18 00:11:00 UTC 2007

Magic EXIF recursive tagging!

Have you ever had your files all nicely nested in directories, but needed to change their EXIF dates? Here’s what I used today to do it:


# Structure like this: 1997/08/Picture.Whatever Maybe Some Spaces.jpg

# Delete the EXIF tags (DONT DO THIS UNLESS YOU KNOW WHAT YOU'RE DOING!)
find . -mindepth 3 -exec jhead -de "{}" \;

# Make Fresh EXIF tags
find . -mindepth 3 -exec jhead -mkexif "{}" \;

# Set the dates according to the Year and Month information in the filenames
find . -mindepth 3 | perl -ne '@a = split(/\//, $_); chomp($_); print `jhead -da$a[1]:$a[2]:01-2007:09:17 "$_"`, "\n"'

This worked wonderfully.

Tags: scripting

Using seq to zero-pad strings in a series

Posted by hank, Sat May 19 08:06:00 UTC 2007

I thought this was pretty cool:

for i in `seq -f "%03g" 1 100`; do wget http://www.gozerog.com/images/Hawking_$i.jpg; done

We were trying to do this the other night using bash, but to no avail since the square brackets only work for local file path expansion. I should have remembered seq. Also, this example shows how to 0-pad a series using seq and bash, noted by the *-f* option. Three cheers for seq!

Tags: scripting