Metadata-Version: 2.4
Name: term-background
Version: 1.0.1
Summary: Determine if shell has a light or dark background
Home-page: http://github.com/rocky/shell-term-background
Author: Rocky Bernstein
Author-email: rb@dustyfeet.com
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python :: 2.6
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3.2
Classifier: Programming Language :: Python :: 3.3
Classifier: Programming Language :: Python :: 3.4
Classifier: Programming Language :: Python :: 3.5
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: 3.7
Classifier: Programming Language :: Python :: 3.8
Classifier: Programming Language :: Python :: 3.9
Description-Content-Type: text/x-rst
License-File: COPYING
Dynamic: author
Dynamic: author-email
Dynamic: classifier
Dynamic: description
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The Python module contained  is part of a broader set of scripts

For the shell scripts, if you source this from a shell session it will set and export ``COLORFGBG`` to ``0;15`` for dark backgrounds and ``15;0`` for light backgrounds which is
a convention used by some programs. Since I find this a little arcane, the program also sets and exports ``LC_DARK_BG`` to 1 for dark backgrounds and 0 for light. The ``LC_`` (locale) assists in some ssh configurations which often will let environment variables with that prefix get passed along and set to a remote ssh session.

The heuristics it uses is to try to query the background color using an `xterm control sequence <https://www.talisman.org/~erlkonig/documents/xterm-color-queries/>`_.

Many, but not all, terminals support this query. So as a fallback we query environment variable ``COLORFGBG`` and failing this we use some
defaults for some known terminals set from the ``TERM`` environment variable. OSX has its own way of querying characteristics so we use that too if you are running on that OS.

When we can get pixel intensities of red, blue, and green values of the background, we can use that determine light and dark based the combined sum: zero values indicate an absense of a particular color and compare that with the values of the foreground.

You can set any of these environment variables to influence the output decision.

Many thanks to Thomas Dickey, Egmont Koblinger, and Gilles, for explanations (and code!) via `unix.stackexchange <http://unix.stackexchange.com/questions/245378/common-environment-variable-to-set-dark-or-light-terminal-background/245381#245381>`_. John Green had the idea to compare the foreground and background colors instead comparing the background against the midway gray color and implemented that change here.

Of course bugs and lacuna in this code are mine.

