When I write articles, sometimes I feel the need to show how the commands behave interactively, not only the sequence of commands you have to type.
It’s easier to understand by looking at an animation, than reading “when you hit TAB <this happens>”.
For example, can you explain how the emmet plugin for VIM works, better than this, using only words?
Fortunately, the solution is pretty easy.
You need a few open source tools, if you’re on a Mac, like me, you should already have installed Homebrew, and Imagemagick (
brew install imagemagick).
To record your sessions, you need
brew install ttyrec on Mac).
usage: ttyrec [-u] [-e command] [-a] [file] OPTIONS -a Append the output to file or ttyrecord, rather than overwriting it. -u With this option, ttyrec automatically calls uudecode(1) and saves its output when uuencoded data appear on the session. It allow you to transfer files from remote host. You can call ttyrec with this option, login to the remote host and invoke uuencode(1) on it for the file you want to transfer. -e command Invoke command when ttyrec starts.
file is the name of the file that will be used to record the session. If no file name is given,
ttyrecord will be used.
A new session is started as soon as you launch
ttyrec and is automatically saved when you close the session with
To replay an already saved session, use
ttyplay [-s SPEED] [-n] [-p] file OPTIONS -s SPEED multiple the playing speed by SPEED (default is 1). -n no wait mode. Ignore the timing information in file. -p peek another person's tty session.
Let’s see how it looks
Now that we have a recorded sessions, we need to convert it to an animated GIF.
ttygif for the task.
There’s no installer for it, you must compile it from the sources
$ git clone https://github.com/icholy/ttygif.git $ cd ttygif $ make
Once make is done, you will find some executable files in the folder
-rwxr-xr-x 1 maks staff 881 Nov 5 16:08 concat.sh -rwxr-xr-x 1 maks staff 829 Nov 5 16:08 concat_osx.sh -rwxr-xr-x 1 maks staff 14836 Nov 5 16:08 ttygif
In my setup I’ve linked
concat_osx.sh in case you’re on a Mac) to
/usr/local/bin/ttyconcat to avoid name clashes.
Creating the gif is a two steps process: first you launch
ttygif <recfile> to generate a sequence of PNGs, then you launch the
ttyconcat script we linked before and it automatically creates the animated GIF for you.
Optionally you can pass and output filename to
ttyconcat, if omitted the image will be saved as
If you are a prefectionist, there’s an optional final step, install
brew install gifsicle) and give your animation the final touches.
I usually add a fixed delay between frames, make it loop forever and optimize the size with this command line
gifsicle --delay=10 --loop=0 -O3 < in.gif > out.gif
More otpions can be found on the
gifsicle man page.