NAME radharc - Adjust display colour temperature after the Sun SYNOPSIS radharc [-M method] [-S site] [-c crtc] ... [-R rule] [-p priority] [-f fade-in] [-F fade-out] [-h [high-temp][@high-elev]] [-l [low-temp][@low-elev]] (-L latitude:longitude | -t temperature [-d] | -x) DESCRIPTION radharc adjusts the colour temperature of your monitor according the the elevation of the Sun. This is intended to reduce eye strain and reduce deplayed sleep phase syndrome. radharc is inspired by redshift(1) but uses libcoopgamma(7) to allow it to be used alongside other programs that also modify the monitors colour output, as long as the also use libcoopgamma(7). OPTIONS The following options are supported: -c crtc Apply the filter to the CRTC with the monitor whose EDID is crtc. By default, the filter is applied to all monitors. If crtc is '?', all available CRTC's are listed. -d Keep the process alive and remove the filter on death. -f fade-in Set effect fade-in time (gradual application when the program starts). The value is interpreted a real number of seconds. -F fade-out Set effect fade-out time (gradual restoration when the program stops). The value is interpreted a real number of seconds. -h [high-temp][@high-evel] Selects that the colour temperature shall be high-temp Kelvins when the Sun's elevation is high-evel degrees or higher above the horizon. This option only has effect when combined with the -L option. -l [low-temp][@low-evel] Selects that the colour temperature shall be low-temp Kelvins when the Sun's elevation is low-evel degrees or lower above the horizon. This option only has effect when combined with the -L option. -L latitude:longitude Selects the location the Sun's elevation shall be calculated for. The program will run until it is manually terminated and continually readjust the colour temperature according the the Sun's elevation. The latitude and longitude shall be specified in decimal format. Positive numbers shall be used GPS coordinates north of the equator and GPS coordinates east of the prime meridian. Negative number shall be used for GPS coordinates south of the equator and GPS coordinates west of the prime meridian. -M method Adjustment method name or number. Recognised names include: dummy Dummy method randr X RAndR vidmode X VidMode drm Linux DRM gdi Windows GDI quartz Quartz Core Graphics The adjustment methods are supported via libgamma(7). Only methods that were enabled when libgamma was compiled will be supported. If method is '?', all available adjustment methods are printed. -p priority Set the priority of the filter. Filters with higher priority are applied before filters with lower priority. The value must be a signed 64-bit integer (between -9223372036854775807 and 9223372036854775807). radharc's default priority is -2305843009213693952. If priority is '?', the utility's default priority is printed. -R rule Set the rule of the filter to rule. This is the last part of the filter's identifier (class). The default rule is standard. -S site Select the site to which to connect. For example ':0', for local display 0 when using X. -t temperature Colour temperature, in Kelvins, to apply. -x Remove the currently applied filter. OPERANDS No operands are supported. SEE ALSO coopgammad(1), cg-tools(7), redshift(1), blueshift(1)