cat a json file - with pretty print
jq . /path/to/json_fileSelect a single key
jq '.path.to.key'The command above will return "42" for a json that looks like "{path: {to: {key: 42}}}"
Delete all entries in an object, except for one
jq '.foo|=bar'The command above will return "{foo: {bar:''}}" for a json that looks like "{foo: {bar:'', baz: ''}}"
This is probably not even enough to get started. Luckily there's plenty of docs to read @ https://stedolan.github.io/jq/manual/
That's a long title just to say "how to turn off your TV". Only I want to show how to do it even if you lost your remote control.
Chromecast can turn your TV on and off, as long as it supports something called HDMI CEC. Of course the Chromecast itself needs to be powered, i.e. you can't plug it to a USB port in your TV.
The "on" part is easy: you just start casting something (your pictures, for example) and Chromecast automagically turns your TV on. The off part is a bit harder.
Turning off is, obviously, an implemented feature, as the Google assistant can do it. After some Wireshark sniffing, I couldn't find any URL you can call in a Chromecast to turn off the TV. Some people invested more time on this than me, so I assume there's just no simple way to directly use a Chromecast for this. Luckily you can use the Google assistant.
I wrote "simple way". The following maybe doesn't quite qualify as "simple", but it's not too time consuming. It's certainly not elegant, but hey (as of the date I'm writing this article) it works.
There's no easy way to make a Chromecast turn off a TV, so instead we'll interface with a Google assistant, then ask the assistant to do it for us. There's also no easy way to do this with an API, but the assistant's voice recognition is actually quite good. Let's start by installing the SDK:
pcm.!default {
type asym
capture.pcm "mic"
}
pcm.mic {
type plug
slave {
pcm "null"
}
}You should now have the samples from the SDK running. At least those that don't crash. If you have a microphone, you can ask anything you normally ask the Google assistant like... the weather?
The assistant can turn off your TV if you say "Turn off $Chromecast_Name". But what if you don't like talking to your phone?
I'm sure you expect I'll reveal a nice, clean way to invoke the assistant and make it turn off your Chromecast. Sorry, that would take too long. There is a text interface for the assistant but I wasn't able to have it running in less than 15 minutes, so these are your options:
command.wav: RIFF (little-endian) data, WAVE audio, Microsoft PCM, 16 bit, mono 16000 HzWhatever method you choose, create a wav file with the command you want to execute (i.e. "turn off $Chromecast_name) and put it in the directory where you installed the Google Assistant SDK.
You're ready now. Goto the directory where you installed the SDK and recorded your voice command, then try this:
$ source env/bin/activate
$ googlesamples-assistant-pushtotalk --device-model-id $AN_ID_YOU_GOT_FROM_GOOGLE --project-id $YOUR_GOOGLE_PROJECT_ID --once --verbose -i ./command.wavWith a bit of luck that should shut down your TV.
Linkdump:
A few years back I developed a VlcRemote control app for Android. According to this chart, I didn't actually save any time doing so. The time I spent spent developing the app is more than the cumulative time I would have spent by getting up from the couch and manually controlling VLC. That said, not having to leave the coziness of a warm blanket in winter probably made it worth the investment.
Not long ago I decided to submit this app to F-Droid. I'm too cheap to pay the 20ish dollars for Google App Store, and since I don't have any commercial interest I don't see the point. I didn't think I'd actually get any users there, but today I got my first bug report. So much happiness! You'd think I shouldn't be happy about my crappy software not-working, but hey, someone actually took the time to try it out. Even more, someone cared enough to submit a bug report!
Open source rules!
If you don't want to read many pages on file transfer standards (Samba? What's that?) you can try this little snippet:
python -m SimpleHTTPServer $PORTThis will create an http server sharing the current directory. HTTP, luckily, is one of those things that tend to work everywhere, always.
Bonus: some other ways of doing the same thing at https://gist.github.com/willurd/5720255
I have been using Ubuntu for a while now. From the time when Canonical actually mailed real, physical CDs of the distro. So get of my lawn.
In all of my Linux years I have never, ever, had such a horrible installation experience as I did this weekend with Ubuntu 15.10. I may go as far as saying not even Windows ME was this horrible to install. I hit dozens of critical show-stopper bugs, from poor UEFI support to an installer that crashed when clicking "Go back". And that's only the installation, don't get me started on the new KDE Plasma 5 desktop... (hint: my big desktop screen is NOT a phone. Swiping to login? Bad idea for a mouse).
A few hints for any other poor souls that made the fatal mistake of installing Ubuntu ME:
2016? Still not the year of the Linux desktop.
Update: XFCE is great... except it doesn't really support moving the mouse. Seems Ubuntu is having a nostalgic release and decided to introduce old bugs from 2012!
There's a quick tip in Linux that can help you track down a lib gone haywire:
cat /proc/<pid>/smapssmaps will report every mapped section of memory for a certain process, how big the memory allocation is and which binary created the allocation.
qdbus org.freedesktop.ScreenSaver /ScreenSaver LockHow many times have you been comfortably watching a movie from the couch only to find out you forgot the subtitles? How about being snugly tucked under a blanket, only to find out you need to brave the cold of winter just to add a new episode of your latest binge-watching series? Yeah, that can easily ruin your day.
Worry no more: with VlcFreemote you can now install a tiny Android app to control your VLC server.
FAQ:
I hacked together IMGeotagger, a Geotagger for Linux (though it should work in Windows too) that uses Google maps.
Recently, after coming back from a trip, I tried to geotag (*) my pictures. I don't have a fancy GPS device for my camera but I do have a fairly good memory. There are applications that will let you drop your pics to a map, then get the GPS coordinates out of that. Unfortunately, the current state of geotagging applications in Linux is just sad.
Gotten Geography mostly works. I don't find it very nice to use, though. Pictag doesn't even work anymore, although I have hacked a version which at least manages to start in modern Ubuntu setups. That puts it more or less at the same level as Gotten Geography. Both suffer from a fatal problem: there is no latin charset maps for places that don't use a latin alfabet. Now, this is clearly not a fault in either program.
Both Gotten and Pictag use the (incredibly awesome) Open Street Map project. OSM provides some default map rendered tiles, and those are in the "local" language. Transliterating the local written name of a street is not an easy task. The rules in each place are completely different, some places have a completely different name in latin chars than they do in the local alphabet and a million other problems that can't be solved as a general case.
What to do when there are no readily available OSM tiles with latin chars? There is a fairly good product that does provide latin names for most (all?) places in the world: Google maps. Now, there is a reason neither Gotten nor Pictag use Google maps for geotagging: Google maps has no (free?) API to get tiles which you can embed in an application. It does let users view their maps in a browser, though. And the map URI is a nice and easy way to translate from map-tiles to map-coordinates.
I'm not 100% sure if IMGeotagger falls under Google maps terms of use, so I may have to take it down in the future. What it does is pretty simple: you use a browser to select a place, then IMGeotagger retrieves the location from the URI of the browser. This will break when Google maps changes their URI structure; until then, IMGeotagger works pretty well and it uses a really nice map (sorry OSM, G. Maps are pretty good).
You can grab the IMGeotagger (and its source code, as it's open source) from https://github.com/nicolasbrailo/IMGeotagger.
(*) What's geotagging? That's adding GPS coordinates on the exif metadata of your pictures. This is only useful to nerds and very pedantic people who enjoy analyzing photo albums to get GPS plots and other nerdy things like that.
foo.o: foo.cpp
g++ -c foo.cooyou should instead write this:
foo.o: foo.cpp
$(COMPILE.cpp) foo.cooCOMPILE.cpp will have the default compiler you are supposed to use, and probably some helpful parameters as well. Likewise, LINK.cpp will have the linker you are supposed to use.
There are many useful predefined variables in make. Be sure to check them all by running "make -p" in a console.
1. Don't use the recycling bin. This sort of breaks my workflow, so I prefer to: 2. Use nautilus.
You'll have to install gtk packages, but that's a small price to pay to have KDE not crash every couple of minutes.
Luckily, when you are using the 's'earch command you can pick a different separator. Instead of typing "%s/\/foo\/bar\/baz\//foo\/bar\//g", you can simply type "%s#/foo/bar/baz/#foo/bar/#g". Vim will automagically detect you want to use '#' as a delimiter, and you'll end up with a much more readable pattern.
Extra tip: this also works in sed
#!/bin/bash
foobar() {
echo "See ya!"
}
trap "foobar" EXITIt doesn't mater how you end this script, "foobar" will always be executed. Want to read more about bash traps? Check http://linuxcommand.org/wss0160.php
TL;DR: Link to a mostly working hacked version of Pictag, on my Github repo.
Since Google decided not to support Picasa for Linux anymore (yes, a long time ago) I've been looking for a decent photo management alternative. Lately I've settled with Digikam, it does everything Picasa used to do (and much better, I may add) except for providing a way to geotag your pictures on a map.
Most geotagging solutions involve having an already created waypoints map from a GPS device, which then gets processed and magically added to the images' exif data. That didn't cut it for me, I don't have, nor want, a GPS I can take on holidays, plus I really only want to drag and drop pictures on a map. That's where pictag comes in.
At the moment pictag seems to be a bit abandoned, as there are no more packages for Ubuntu 13.04. Luckily with some hacking it's possible to get it running.
First, since there's no package for Pictag you'll need to take care of the dependencies yourself. On a more or less vanilla 13.04 install, this should do the trick:
sudo apt-get install python-setuptools \
python-distutils-extra \
geoclue-ubuntu-geoip \
liblaunchpad-integration-common \
libchamplain-0.12-0 \
libchamplain-0.12-dev \
libchamplain-gtk-0.12-0 \
libchamplain-gtk-0.12-dev \
python-pyexiv2 \
libclutter-gtk-1.0-0 \
libclutter-gtk-1.0-devAfter you've taken care of that you can download the latest version from Launchpad (while writing this article that should be 12.07.17) and run ./bin/pictag, only to watch it fail miserably.
Pictag seems to be using GSettings, a very annoying Gnome settings manager which won't work unless you actually install whatever program you're trying to run. Luckily we can just hack it out of Pictag simply by commenting out all references to self.settings in PictagWindow.py and Window.py. Either that or get my hacked version of Pictag, on my Github repo.
With some luck, my hacked version of Pictag should run pretty much OK on Ubuntu 13.04 or newer. There seems to be a few issues with libchamplain (the mapping library) on earlier versions of Ubuntu that may cause the map to display only broken images. If you can't load any maps you'll have to get a newer Ubuntu. Or fork my repo and get hacking :)
The other day I wanted to use my tv for a slideshow of my travel pictures. Something simple, just select a folder and have a program like Shotwell create a slideshow with a random order on my tv. Of course, Ubuntu and double screen equals fail. For some reaason all the programs I tried either were incapable of using the tv as the slideshow screen (even after cloning screens... now that's a wtf) or where not able to recursively use all the pictures in a folder.
feh to the rescue. It's not pretty, but feh seems to be exactly what I was looking for. It's a CLI application for Linux and after some RTFM I came up with this script:
feh ~/Pictures \
--scale-down \
--geometry 1920x760 \
--slideshow-delay 9 \
--recursive \
--randomize \
--auto-zoom \
--draw-filename \
--image-bg blackYou can probably figure out by yourself what each option means. If not, just man feh.