Mothers day hacks

Firstly Happy Mother’s day to my mother.

Google is, as usual, busily releasing doodles. Today, the doodle takes you through a Rube Goldberg -esque sequence, giving you four decisions to make along the way. Each decision gives you one of three different choices, and at the end, a unique drawing is displayed. I expect:

3 * 3 * 3 * 3 = 81

different permutations. At the end of the process, you can print your image. I got directed to:

https://www.google.ca/logos/2013/mom/print/3311.html

which suspiciously has a four digit filename composed of three’s and ones. Inspecting the file in firefox shows that the main image url is:

https://www.google.ca/logos/2013/mom/hdcards/3311.jpg

with a similarly suspicious “3311“. I decided that I wanted to see all the permutations without having to refresh google’s page. Jumping to a terminal, and using some bash expansion magic:

$ cd /tmp
$ mkdir hack1
$ cd hack1/
$ wget https://www.google.ca/logos/2013/mom/hdcards/{1..3}{1..3}{1..3}{1..3}.jpg
[snip]
FINISHED --2013-05-12 07:07:22--
Total wall clock time: 1m 23s
Downloaded: 81 files, 138M in 1m 19s (1.75 MB/s)

I am pleased to see that 81 files have downloaded, and that they’re all unique:

$ md5sum * | sort | uniq | wc -l
81

and all png’s:

$ file * | awk '{print $2}' | sort | uniq | wc -l
1
$ file * | head -1
1111.jpg: JPEG image data, EXIF standard

Now I can very easily browse through the images with eog, and select my favourite.

Hope this has been instructive,

Happy hacking,

James

 

Fixing jerky scrolling in Firefox

Fedora did a lovely job of updating me to the latest version (v. 20) of Firefox. One problem I found, was that scrolling on certain pages was quite jerky. Performance was worse (or more likely) on pages with a frameset, and pages which were long. Pages with many images made this problem worse.

It turns out that the workaround is to disable hardware acceleration:

After you’ve unchecked this box, restart Firefox, and scrolling is now considerably smoother.

Hopefully this helped you out. Most likely there is some driver issue or deficiency with the X drivers. I’m using an excellent Thinkpad X201. I’ve also had at least two cases of X freezing while I was manipulating a Firefox window, so perhaps this is related, and hopefully this won’t happen to me anymore.

Happy hacking,

James

 

Knowing when to release and deploy your code (…and a mini script)

Knowing when to release and deploy your code can turn into a complicated discussion. In general, In general, I tend to support releasing early and often, for some value of $early and $often. I’ve decided to keep this simple and introduce you to one metric that I use…

I think that I am fairly diligent in adding plenty of comments to my source code. I might even sometimes add too many. I create plenty of XXX, FIXME, or TODO tagged comments as reminders of things to work on.

To me, XXX represents an important problem that should get looked at or fixed; FIXME, reminds me that I should definitely look into something, and finally, TODO gives me homework or things to pursue when I’m in need of a new project.

I try to resolve most if not all XXX tagged comments before making a 0.1 release, FIXME’s to consider something very stable, and a lack of TODO’s mean something is completely done for now.

To count all these, I wrote a little tool that greps through the top-level directories in my ~/code/ folder, and displays the results in a table. Feel free to give it a try, and use it for your own projects.

While I don’t see this as a particularly game changing utility, it scratches my itch, and helps me keep up my bash skills. The code is available here. Let me know if you have any improvements, or if the source isn’t enough documentation for you.

Happy hacking,

James

running your file manager from a terminal

I do a lot of my work in a terminal. For the unfamiliar, this might seem strange, however once you’re comfortable with your shell, this is the best place to be. I don’t restrict myself to it though. I often want to spawn a file manager, or a graphical text editor. When I run nautilus, I usually see something like this:

james@computer:~/some/awesome/directory$ nautilus .
Initializing nautilus-open-terminal extension
Shutting down nautilus-open-terminal extension
james@computer:~/some/awesome/directory$

This is useful, because I can open a file browser right where I want it, it’s annoying, because nautilus runs in that terminal until I close it. (This doesn’t happen if the nautilus process is always running, but since GNOME 3, it isn’t.)

My solution is a short bash script that runs nautilus, and leaves your terminal alone. I named my script nautilus, and placed it inside my ~/bin/. Here is the script:

#!/bin/bash
# run nautilus from a terminal, without being attached to it; similar to nohup
# use the full path of nautilus to avoid it calling itself (recursion!)
{ `/usr/bin/nautilus "$@" &> /dev/null`; } &

I hope this is useful for you too. Feel free to do the same for gedit, nemo, and any other app which you often find convenient to run from the terminal. You can generalize this by leaving out the nautilus program:

#!/bin/bash
if [ "$1" == "" ]; then
        echo "usage: ./"`basename $0`"  (to run a command nohup style)"
        exit 1
fi
# do a nohup bash style according to:
{ `"$@" &> /dev/null`; } &

I name the above script run.sh, and it helps me out from time to time, when I don’t want to touch my mouse.

In case you haven’t heard about it, there’s also an open-terminal extension for nautilus and nemo which lets you get to a terminal, from your file manager. A quick internet search should help you install it.

If you found this information useful, please let me know, and as always,

Happy hacking,

James

PS: If you plan to do this for gedit, you probably want to preserve stdin, so that you can still pipe things in. To do this, you’ll probably want:

{ `/usr/bin/gedit "$@" &> /dev/null`; } < /dev/stdin &    # accept stdin too!

learn how to do one minute hacks, in three minutes

I write this technical blog for you to enjoy, and to help me remember. So where do I get all this knowledge? I figure it out! Here’s how I learned to fix a small gedit annoyance in one minute, and within the next three, you’ll be able to do the same for other types of problems too. Ready? Set? Go!

I use gedit enough, that when I hack, I often end up using up more than the five allotted spaces in the “recent files” sections. I wanted to see eight. Since I knew it would have been silly for the developers to hard code the number five, I decided there was a chance that they stored it in the dconf settings. (BTW, there’s also an amazing “Dashboard” plugin which I use for more complex recent-files searching…)

Enter dconf-editor. Run this, and start browsing through the hierarchy. You’ll notice that the org.gnome.* hierarchy has a lot going on. Look around, and you’ll find a “gedit” section. Once there, you’ll probably recognize some of the key names, as preferences you’ve seen. I searched for the number 5 and I found it next to a ‘max-recents’ key.

You can edit this with the editor, or for your convenience, just run:

gsettings set org.gnome.gedit.preferences.ui max-recents 8

the corresponding ‘read’ command is:

gsettings get org.gnome.gedit.preferences.ui max-recents

of course. The interesting thing about these settings, is that if coded properly, their actions are “live”. Which means, you can toggle them on and off, and in most cases, you’ll see the results immediately. Similarly, if you toggle a particular setting in gedit, you should see the changes instantly in dconf-editor.

Have fun playing with this and,

Happy hacking,

James

 

Picking up the pieces after a Fedora 18 install

I love GNOME and Fedora, but “upgrading” from Fedora 17 to 18 did not go well for me. I recommend you wait until either these are all fixed, or Fedora 19+ suits your needs. Here are a list of problems I had, and some workarounds. Hopefully proper patches to these bugs will get merged quickly, so that you don’t need to use these fixes.

Problem: Boot fails after upgrade from Fedora 17 to Fedora 18. I used the new “fedup” method.

Workaround: I did a fresh install. Make sure you have backups first, of course. I didn’t feel like spending a lot of time debugging why it broke.

Problem: The <Backspace> key no longer goes “up” in nautilus. I hope this wasn’t a “feature removal”.

Workaround: Add:

(gtk_accel_path "<Actions>/ShellActions/Up" "BackSpace")

to your: ~/.config/nautilus/accels and restart nautilus of course.

Problem: Split view (extra pane) functionality is missing in nautilus 3.6

Workaround: The GNOME developers plan to eventually replace this in a similar form. Until then, you can install the nemo file manager, which is a fork of nautilus 3.4 and is packaged in Fedora 18. (yum install nemo nemo-open-terminal)

Problem: GNOME Shell background is entirely black in overview mode.

Workaround: Using gnome-tweak-tool, under the “Desktop” section, set “Have file manager handle the desktop“, to “OFF“. Unfortunately, this disables viewing of files on your desktop. This wasn’t a problem in Fedora 17.

Problem: Restarting the X server with the familiar Control-Alt-Backspace, can’t be enabled in the keyboard shortcuts menu as it used to.

Workaround: This option is now hidden in the gnome-tweak-tool under typing: terminate.

I hope this scratches your itches!

Happy hacking,

James

How to send and receive files like a professional

Everyone needs to send and receive files sometimes. Traditionally people send files as email attachments. This still works great, and supports encryption, but many mail servers are slow and cap the upper file size limit.

ICQ was a great solution back in the 1990’s, but those days are now over. (I still remember my number.)

A lot of folks use dropbox, which requires a dropbox account, and for you to trust them with your files.

If you want a simple solution that doesn’t need internet access (if you’re on a LAN, for example) you can use droopy and woof. These are two shell scripts that I keep in my ~/bin/. Droopy lets you receive a file from a sender, and woof lets you send one their way. Unfortunately, they don’t support ssl. This could be a project for someone. (Hint)

I recently patched droopy to add inline image support. I’ve emailed my patch to the author, but until it gets merged, you can get my patched version here. (AGPLv.3+)

Hopefully these are helpful to you.

Happy hacking,

James