Small daemon to set screen temperature. ctempd can either set the screen's temperature once with the -s option or run in the background and set the screen's temperature automatically based on the time of day.

• Set screen temperature continuously in the background
• Set screen temperature once

ctempd is written in C and known to work on the operating systems listed in the table below. To compile it you need the following things:

• A recent C compiler (tested with both clang >= 11 and GCC >= 8)
• make (tested with both BSD and GNU make)
• libXrandr
• libX11 core development libraries

Install the dependencies as follows:

By default, the Makefile looks for external includes and libraries in /usr/local/{include,lib}, /usr/X11R6/{include,lib}. If your distribution uses special path, you have to modify the Makefile accordingly.

Compile and install with the following commands:

$ make
# make install

Let ctempd automatically adapt the screen temperature based on the time of day. The highest temperature at noon is 5400K:

$ ctempd 5400

ctempd logs via syslog, you can check the current temperature in your system's log messages.

Set the screen temperature to 3200K once.

$ ctempd -s 3200

isscrolls was written by Matthias Schmidt and is public domain. The algorithm to set the screen temperature was written by Ted Unangst and is also public domain.