Lua scripts in Darktable. How to?

Marci · August 26, 2016, 1:34pm

Hello everyone!

I see people talking about lua scripts that perform certain tasks, but I
don’t know how to install them, how to use them, if I can use them with the custom version of
DT from the Debian repos or if anything else is needed… Maybe it is
explained somewhere but, up to now, I haven’t found any info on the
subject (That is , how to install them and run them). Could someone give any advise or any link to a “how to”?

Thanks.

chris · August 26, 2016, 2:18pm

In general, you don’t need something special as long as you are relying solely on the internal lua functionality. Some of the available scripts are utilizing external programs, which of course should be available on your system and installed in a way that dt/lua will find them.

(Edit: It could be that the custom version you are referring to is built without lua support, but this is unlikely.)

The more recent versions of dt have lua support (IIRC starting with 1.4), but I recommend a recent version from the 2.0 series (2.0.5 is the most recent version), since lua support improved over time and versions.

There is a repository of scripts for darktable at https://github.com/darktable-org/lua-scripts. The installation process is described on this page as well. More details are given in the use manual, especially https://www.darktable.org/usermanual/ch09.html.php and there section 9.1.7. “Sharing scripts”.

Claes · August 26, 2016, 2:29pm

Hi @Marci,

Have you seen this?

Have fun!
Claes in Lund, Sweden

houz · August 26, 2016, 7:59pm

On recent versions of darktable you can find out by running darktable --version.

Marci · August 28, 2016, 4:33pm

Thanks. I’ve already installed it, though it doesn’t seem to work very well for me. I’ll keep on trying…

Claes · August 28, 2016, 6:17pm

Hi @Marci!

Check the following:
In your /home/YourUserName/.config/darktable folder, you are supposed to have a lua folder and a luarc text file.

The luarc text file ought to contain the line
require "examples/hello_world"

The lua folder has to contain another folder, named examples
And the examples folder, i.e. /home/YourUserName/.config/darktable/lua/examples/ is to contain the text file hello_world.lua
That file contains these three lines:

local dt = require "darktable"
dt.configuration.check_version(...,{2,0,0},{3,0,0})
dt.print("hello, world")

So, whenever you start Darktable, the words hello, world ought to be shown on the monitor.

OK so far?

Have fun!
Claes in Lund, Sweden

Marci · August 30, 2016, 6:41am

Thank you, Claes.

This one works well, but if I install the whole bunch of scripts, for
example, appears a new tab in “preferences”, but there is no more than
the list of scripts, with no option to choose or change anything. I
haven’t tried all of them, but the gimp and hugin ones dont seem to do
anything…

But now I know how to install them and ¡that’s a start!

pk5dark · August 30, 2016, 7:42am

You can start darktable from a terminal with

darktable -d lua

to check what goes wrong.

BTW it would be good to know which darktable version you are using. As the lua part is relatively new, most scripts require a recent darktable version.

Tobias · August 31, 2016, 9:31am

The gimp and hugin scripts are written for the latest git version and not the stable version.
If you use the stable dt version you need to to require “yield.lua” before “gimp.lua” in your $HOME/.config/darktable/luarc.

The “yield.lua” makes the scripts compatible with the stable dt version.

Soren_Garup · December 5, 2017, 8:52pm

Hi all,

I’m new here and I know this is an old string, but when running:
darktable -d lua

in terminal, I get this:

LUA ERROR : /home/z/.config/darktable/lua/examples/hello_world.lua:2: Module examples/hello_world is not compatible with API 4.0.0

Does anyone have any experience with this ?

soren

ps
darktable 2.2.5
lua5.3

Tobias · December 5, 2017, 9:02pm

Could you show me the Script?

Important is this line with the version check:
dt.configuration.check_version(...,{2,0,0},{3,0,0},{4,0,0},{5,0,0})

This Version should work:

github.com

darktable-org/lua-scripts/blob/master/examples/hello_world.lua

--[[
    This file is part of darktable,
    copyright (c) 2014 Tobias Ellinghaus

    darktable is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    darktable is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with darktable.  If not, see <http://www.gnu.org/licenses/>.
]]

--[[
HELLO WORLD

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Soren_Garup · December 5, 2017, 9:15pm

solved

change hello_world.lua to:

local dt = require “darktable”
dt.configuration.check_version(…,{2,0,0},{3,0,0},{4,0,0})
dt.print(“hello, world”)

Soren_Garup · December 14, 2017, 1:40am

Thanks Tobias,

I didn’t see your answer before now, but I figured it out a week ago (see post below)
slight_smile:

But now that I’ve got the attention from someone who knows Darktable, maybe you know the answer to this ?

I’m trying to get rid of Darktables dead thumbnails, and it seems like the solution is this:
"you may occasionally run the script purge_non_existing_images.sh from darktable’s toolset to clean-up your database. "

But what isn’t explained where to use the script ?
In terminal ?
and where is mentioned tool-set ?

Soren

Tobias · December 14, 2017, 8:24am

I don’t know this script, but if you look into the github log @houz, @LebedevRI and @hanatos all contributed to this script:

github.com

darktable-org/darktable/blob/master/tools/purge_non_existing_images.sh

#!/bin/bash

#
# Usage: purge_non_existing_images [-p]
#        -p  do the purge, otherwise only display non existing images
#

if ! command -v sqlite3 >/dev/null
then
    echo "error: please install sqlite3 binary".
    exit 1
fi

if pgrep -x "darktable" >/dev/null
then
    echo "error: darktable is running, please exit first"
    exit 1
fi

configdir="${HOME}/.config/darktable"

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They should know more about it.

houz · December 14, 2017, 11:01am

Yes, that’s the one. It requires an installed sqlite3 executable. And make sure to have a backup of your library.db.

Soren_Garup · December 14, 2017, 12:13pm

Thanks a lot for the script Tobias

I got the other script from https://www.darktable.org/usermanual/ch02s02s03.html.php but it doesn’t explain (very well) where to insert the script ?

Are scripts inserted in terminal or in some hidden feature within the Darktable GUI ?

Soren

houz · December 14, 2017, 12:29pm

That is a regular shell script, run from a terminal.

Soren_Garup · December 14, 2017, 12:35pm

Thanks a lot houz

I will try it out later today

Soren_Garup · December 14, 2017, 10:20pm

Thanks a lot
it worked, ridded me of almost 2000 sculls

Now I only wish it would generate thumbnails in the background and save a copy on the same drive as the raw files

paperdigits · December 14, 2017, 10:29pm

You can specify darktable’s datadir to be wherever you want it with the --datadir <data directory> switch at the command line. Or you can add that to a .desktop file.