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Diffstat (limited to 'redshift.1')
| -rw-r--r-- | redshift.1 | 1318 |
1 files changed, 1127 insertions, 191 deletions
@@ -1,238 +1,1174 @@ .TH REDSHIFT 1 REDSHIFT-NG .SH NAME -redshift \- set color temperature of display according to time of day +redshift \- Automatically adjust display colour temperature according the Sun + .SH SYNOPSIS .B redshift -\fR[\fB\-l\fR \fILAT\fB:\fILON\fR | \fB\-l\fR \fIPROVIDER\fB:\fIOPTIONS\fR] [\fB\-t\fR \fIDAY\fB:\fINIGHT\fR] [\fIOPTIONS\fR...] +[-b +.IR brightness ] +[-c +.IR config-file ] +[-D | +D] +[-g +.IR gamma ] +[-l +.IB latitude : longitude +| -l +.IR provider [\fB:\fP options ]] +[-m +.IR method [\fB:\fP options ] +[-P | +P] [-r | +r] [-dv] +[-O +.I temperature +| -o | -p | -t +.I temperature +| -x] | -h | -V + .SH DESCRIPTION .B redshift -adjusts the color temperature of your screen according to your +adjusts the colour temperature of your screen according to your surroundings. This may help your eyes hurt less or reduce the risk for delayed sleep phase syndrome if you are working in front of the screen at night. .PP -The color temperature is set according to the position of the sun. A -different color temperature is set during night and daytime. During -twilight and early morning, the color temperature transitions smoothly -from night to daytime temperature to allow your eyes to slowly -adapt over a period of about an hour. At night the color temperature -should be set to match the lamps in your room. This is typically a low -temperature at around 3000K\-4000K (default is 4500K). During the day, -the color temperature should match the light from outside, typically -around 5500K\-6500K (default is 6500K). The light has a higher -temperature on an overcast day. -.PP -In addition to the command-line tool \fBredshift\fR, the GUI -\fBredshift-gtk\fR provides an alternative interface that shows up as a -notification icon in the desktop environment. +The colour temperature is set according the the position of the Sun. +A different colour temperature is set during the night and during the +day. During dawn and early morning, the colour temperature transitions +smoothly from night- to day-time temperature to allow your eyes to +slowly adapt over a period of about an hour. At night, the colour +temperature should be set to match the maps in your room. This is +typically a low temperature at around 3000K-4000K (default is 4500K). +During the day, the colour temperature should match the light from +outside. Typically around 5500K-6500K (default is 6500K). The light has +a lower temperature on an overcast day. +.PP +In addition to the command-line tool +.BR redshift , +the GUI +.BR redshift-gtk (1) +provides an alternative interface that shows up as a notification icon +in the desktop environment. + .SH OPTIONS +The following options are supported: +.TP +.BI -b\fR\ brightness +Synonym for +.B -b +.IB brightness : brightness\fR. +.TP +.BI -b\fR\ day : night +Monitor whitepoint brightness to apply at daytime and at +nighttime. (Default: 1:1) + +The values most be between 0.1 and 1.0. + +.I day +or +.I night +may be omitted, to keep unmodified, however +at least one must be specified. +.TP +.BI -c\fR\ config-file +Load settings from specified configuration file. + +.B /dev/null +can be used to tell +.B redshift +not to load the configuration file. + +If +.RB \(dq - \(dq, +the standard input will be used. +.TP +.B -D +Start in enabled state. (Default) +.TP +.B +D +Start in disabled state. + +Ignored in one-shot mode. +.TP +.B -d +Keep the process alive and remove the colour effects +when killed. + +Ignored for +.B -p +and +.BR -x ; +always active for +.B -t +and the +.B quartz +adjustment method. +.TP +.BI -g\fR\ gamma +Synonym for +.B -g +.IB gamma : gamma\fR. .TP -\fB\-h\fR +.BI -g\fR\ day : night +Synonym for +.B -g +.IB day : day : day : night : night : night\fR. + +However, if +.I day +is omitted, it is a synonym for +.B -g +.BI : night : night : night\fR, +or if +.I night +is omitted, it is a synonym for +.B -g +.IB day : day : day :\fR. +.TP +.BI -g\fR\ red : green : blue +Synonym for +.B -g +.IB red : green : blue : red : green : blue\fR. +.TP +.BI -g\fR\ day-r : day-g : day-b : night-r : night-g : night-b +Additional gamma correction to apply at daytime and +at nighttime. (Default: 1:1:1:1:1:1) + +The values most be between 0.1 and 10.0. + +.IB day-r : day-g : day-b +or +.IB night-r : night-g : night-b +may be omitted, +to keep unmodified, however at least one set must be specified. +Individual components of one set cannot be omitted, either +nothing is omitted or an entire set, including its two colons +.RB ( : ) +are omitted. +.TP +.B -h Display help message. .TP -\fB\-v\fR -Enable verbose output. +.BI -l\fR\ latitude : longitude +Your current location, in degrees. Shall be formatted a single +real number, rather than split into integer degrees, minutes +and seconds. The location should be specified using the GPS +coordinate system. .TP -\fB\-V\fR -Show program version. +.BI -l\fR\ provider\fR[ : options\fR] +Select provider for automatic location updates. + +Use +.B -l list +to see available providers. + +Use +.BI -l\ provider :help +to see available options. .TP -\fB\-b\fR \fIDAY\fB:\fINIGHT\fR -Screen brightness to apply (between 0.1 and 1.0). +.BI -m\fR\ method\fR[ : options\fR] +Method to use to set colour temperature. +Use +.B -m list +to see available methods. + +Use +.BI -m\ method :help +to see available options. .TP -\fB\-c\fR \fIFILE\fR -Load settings from specified configuration file. +.BI -O\ temperature +This is a synonym for +.B -O +.IB temperature : temperature\fR. .TP -\fB\-g\fR \fIR\fB:\fIG\fB:\fIB\fR -Additional gamma correction to apply. -.TP -\fB\-l\fR \fILAT\fB:\fILON\fR -Your current location, in degrees, given as floating point numbers, -towards north and east, with negative numbers representing south and -west, respectively. -.TP -\fB\-l\fR \fIPROVIDER\fR[\fB:\fIOPTIONS\fR] -Select provider for automatic location updates -(Use \fB"\-l list"\fR to see available providers). -.TP -\fB\-m\fR \fIMETHOD\fR[\fB:\fIOPTIONS\fR] -Method to use to set color temperature -(Use \fB"\-m list"\fR to see available methods). -.TP -\fB\-o\fR -One-shot mode (do not continuously adjust color temperature). Use this with the -\fB\-P\fR option to clear the existing gamma ramps before applying the new color -temperature. -.TP -\fB\-O\fR \fITEMP\fR -One-shot manual mode (set color temperature). Use this with the \fB\-P\fR option -to clear the existing gamma ramps before applying the new color temperature. -.TP -\fB\-p\fR -Print mode (only print parameters and exit). -.TP -\fB\-P\fR -Reset existing gamma ramps before applying new color effect. -.TP -\fB\-x\fR -Reset mode (remove adjustment from screen). -.TP -\fB\-r\fR -Disable fading between color temperatures. -.TP -\fB\-t\fR \fIDAY\fB:\fINIGHT\fR -Color temperature to set at daytime/night. -.PP -The neutral temperature is 6500K. Using this value will not -change the color temperature of the display. Setting the -color temperature to a value higher than this results in -more blue light, and setting a lower value will result in -more red light. -.PP -Default temperature values: -.IP -Daytime: 6500K, night: 4500K -.SH CONFIGURATION FILE -A configuration file with the name \fIredshift.conf\fR can optionally be -placed in \fI~/.config/redshift/\fR (if the environment variable -XDG_CONFIG_HOME is undefined) or \fI${XDG_CONFIG_HOME}/redshift/\fR -(if XDG_CONFIG_HOME is defined). The file has standard INI format. General -program options are placed under the \fBredshift\fR header, while options -for location providers and adjustment methods are placed under a -header with the name of that provider or method. General options are: -.TP -\fBtemp\fR = \fIday\fB:\fInight\fR +.BI -O\ day : night +One-shot manual mode (set colour temperature). The colour set +is interpolated between day and night depending on the Sun's +elevation or the clock time (depending on which +.B redshift +is configured to use). + +Values must be at least 1000 and integral. + +Use this with the +.B -P +option to clear the existing gamma ramps +before applying the new color temperature. + +This is a synonym for +.B -t +.IB day : night +.BR -o . +.TP +.B -o +One-shot mode (do not continuously adjust colour temperature). + +Use this with the +.B -P +option to clear the existing gamma ramps +before applying the new color temperature. +.TP +.B -P +Reset exiting gamma ramps before applying new colour effects. +.TP +.B +P +Preserve preexisting gamma adjustments. (Default) +.TP +.B -p +Print parameter and exit. +.TP +.B -r +Disable fading between colour temperatures. +.TP +.B +r +Enable fading between colour temperatures. (Default) +.TP +.BI -t\fR\ temperature +This is a synonym for +.B -t +.IB temperature : temperature\fR. +.TP +.BI -t\fR\ day : night +Colour temperature to set at daytime and at nighttime. + +Values must be at least 1000 and integral. + +The value 6500 is equivalent to no colour temperature +adjustment. + +Default mode, but default values may change between +versions. +.TP +.B -V +Show program implementation and verison. +.TP +.B -v +Enable verbose output. +.TP +.B -x +Remove adjustments from screen. +.PP +For mutually exclusive options or options specified multiple times, +the last specified takes effect, except the first specified option +that outputs text (except +.BR -p ) +is used. However, if the daytime +alue or nighttime value is omitted for an option, the last previously +pecified value will be used; that is, for example, +.B -t 5000: +and +.B -t :3000 +do not override each other, but +.B -t 5000: +overrides, if specified later, +.B 6000 +but not +.B 3000 +in +.BR "-t 6000:3000" . +.PP +Options in the command line override settings from the configuration +file. + +.SH OPERANDS +None. + +.SH STDIN +Not used. + +.SH INPUT FILES +None. + +.SH ASYNCHRONOUS EVENTS +.B redshift +takes the standard action for all signals except: +.TP +.B SIGINT .TQ -\fBtemp\fR = \fIinteger\fR +.B SIGTERM .TQ -\fBtemperature\-day\fR = \fIday\fB:\fInight\fR +.B SIGQUIT +Smoothly disable the effects of +.B redshift +and terminate the +process. If already sent, immediately disable the effects +and terminate the process. +.TP +.B SIGUSR1 +Disable the effects of +.BR redshift , +or if already disabled, reenable them. +.TP +.BR SIGUSR2 \ with\ value\ \fI0\fR +Normally signals may be processed out of order, however +when this signal is received, +.B SIGUSR2 +will be blocked until all pending +.B SIGUSR2 +signals has been processed, creating signal processing +order barrier. This is useful when mixing +.B SIGUSR2 +value +.I 3 +(reloading configuration file) with other configuration changing +.I SIGUSR2 +values. +.TP +.BR SIGUSR2 \ with\ value\ \fI1\fR +Disable the effects of +.BR redshift . +.TP +.BR SIGUSR2 \ with\ value\ \fI2\fR +Enable the effects of +.BR redshift . +.TP +.BR SIGUSR2 \ with\ value\ \fI3\fR +Reload the configuration file. + +Settings from the command line will be overriden. +.TP +.BR SIGUSR2 \ with\ value\ \fI4\fR +Execute into the currently installed version of +.BR redshift . + +Only available on Linux. +.TP +.BR SIGUSR2 \ with\ value\ \fI5\fR +Set the +.B fade +setting to off. +.TP +.BR SIGUSR2 \ with\ value\ \fI6\fR +Set the +.B fade +setting to on. +.TP +.BR SIGUSR2 \ with\ value\ \fI7\fR +Set the +.B preserve-gamma +setting to off. +.TP +.BR SIGUSR2 \ with\ value\ \fI8\fR +Set the +.B preserve-gamma +setting to on. +.TP +.BR SIGUSR2 \ with\ value\ \fI9\fR +Exit the process without removing the its effects. +If the used adjustment method does not support leaving +the effects, they will be removed. +.TP +.BR SIGUSR2 \ with\ value\ \fI10\fR +Do not terminate +.B redshift +the standard output and standard error are closed. +.TP +.BR SIGUSR2 \ with\ value\ \fI11\fR +Enable verbose mode. (The +.B -v +option will be treated as specified.) +.TP +.BR SIGUSR2 \ with\ value\ \fI12\fR +Disable verbose mode. + +Ignore if started in verbose mode +.RB ( -v +option). +.TP +.BR SIGUSR2 " with other values or no value" +Ignored. + +.SH STDOUT +The standard output is used to print state information and requested +help information. The output is subject to localisation, and the +following formats apply for the +.RB \(dq C \(dq +locale. Applications taking use of this information must make sure +to set the message locale to +.RB \(dq C \(dq. +For floating-point values +.RB (\(dq %f \(dq) +the precision is not documented as it may change between versions and +applications should not expect any particular precision to be used. +.PP +When +.B -m list +is specified, the available gamma ramp adjustment methods +are printed with the header +.B \(dqAvailable adjustment methods:\en\(dq +followed by the list in the format +.RS +.nf + +\fB\(dq%s%s\en\(dq, \fI<arbitrary whitespace>\fP, \fP<method name>\fR. + +.fi +.RE +.PP +The list is terminated by an empty line. Additional information for +human users is printed after the empty line. +.PP +When +.B -l list +is specified, the available location providers are +printed with the header +.B \(dqAvailable location providers:\en\(dq +followed by the list in the format +.RS +.nf + +\fB\(dq%s%s\en\(dq, \fI<arbitrary whitespace>\fP, \fP<provider name>\fR. + +.fi +.RE +.PP +The list is terminated by an empty line. Additional information for +human users is printed after the empty line. +.PP +When +.BR "-m method:help" , +.BR "-l provider:help" , +or +.B -h +is specified help information is printed on in unspecified format, +intended only for human users. +.PP +When +.B -V +is specified, the used version of the program is printed to +the standard output in the format +.RS +.nf + +\fB\(dq%s %s\en\(dq, \fI<implementation name>\fP, \fP<version number>\fR. + +.fi +.RE +.PP +If +.B -v +is specified and the colour settings depend on the Sun's +elevation, the elevation thresholds are printed to the standard +output in the format +.RS +.nf + +\fB\(dqSolar elevations: day above %f, night below %f\en\(dq,\fR +\fI<minimum solar elevation at daytime>\fB,\fR +\fI<maximum solar elevation at nighttime>\fR. + +.fi +.RE +This line may be printed, if +.B -v +is specified, if +.B redshift +is configured. +.PP +If +.B -v +is specified and the colour settings depend on the clock time, +the time schedule is printed to the standard output, with the header +.B \(dqSchedule:\en\(dq +and the footer +.BR "\(dq(End of schedule)\e\n\(dq" , +in the format +.RS +.nf + +\fB\(dq%s%f%% day at %02u:%02u:%02u\en\(dq, \fI<arbitrary whitespace>\fP,\fR +\fI<dayness level (0-100)>\fB, \fP<start hour (0-23)>\fP,\fR +\fI<start minute (0-59)>\fB, \fP<start second (0-59)>\fR. + +.fi +.RE +These lines may be printed, if +.B -v +is specified, if +.B redshift +is configured. +.PP +If +.B -v +is specified, the colour settings is printed to the standard +output in the format +.RS +.nf + +\fB\(dqTemperatures: %luK at day, %luK at night\en\(dq\fR +\fB\(dqBrightness: %f:%f\en\(dq\fR +\fB\(dqGamma (Daytime): %f, %f, %f\en\(dq\fR +\fB\(dqGamma (Night): %f, %f, %f\en\(dq,\fR +\fI<daytime colour temperature>\fB, \fP<nighttime temperature>\fP,\fR +\fI<daytime whitepoint brightness>\fB, \fP<nighttime brightness>\fP,\fR +\fI<daytime red gamma>\fB, \fP<daytime green gamma>\fP,\fR +\fI<daytime blue gamma>\fB, \fP<nighttime red gamma>\fP,\fR +\fI<nighttime green gamma>\fB, \fP<nighttime blue gamma>\fR. + +.fi +.RE +Each line may be printed, if +.B -v +is specified, if +.B redshift +is configured. +.PP +If the colour effects depend on the Sun's elevation, the user's +geographical location will printed to the standard output in the +format +.RS +.nf + +\fB\(dqLocation: %f %c, %f %c\en\(dq,\fR +\fIfabs(<GPS latitude>)\fB, \fPsignbit(<GPS latitude>) ? 'S' : 'N'\fP,\fR +\fIfabs(<GPS longitude>)\fB, \fPsignbit(<GPS longitude>) ? 'W' : 'E'\fR. + +.fi +.RE +This message is printed when the program starts and any time the +location is updated. +.PP +If the colour effects are non-static, the current period of the day +(which determine the colour effects) is printed to standard output, if +.B -v +or +.B -p +is specified, in the format +.RS +.nf + +\fB\(dqPeriod: %s\en\(dq, \fI<period>\fR + +.fi +.RE +where +.I <period> +is +.BR None , +.BR Daytime , +or +.BR Night , +or in the format +.RS +.nf + +\fB\(dqPeriod: Transition (%f%% day)\en\(dq, \fI<dayness level> * 100\fR. + +.fi +.RE +.I <dayness level> +is exclusively between 0 (night) and 1 (daytime). +.PP +This message is printed when the program starts and any time it +changes (if +.B -v +is specified). +.PP +If +.B -v +or +.B -p +is specified, the colour settings are printed to the +standard output when the program standard and any time it changes +(fade effect is ignored). These are printed in three different +messages and, on chagne, only the settings that changed are printed: +.RS +.nf + +\fB\(dqColor temperature: %luK\en\(dq, \fI<colour temperature>\fR; + +\fB\(dqBrightness: %f\en\(dq, \fI<whitepoint brightness level (0-1)>\fR; + +\fB\(dqGamma: %f, %f, %f\en\(dq, \fI<red gamma>\fP, \fP<green gamma>\fP, \fP<blue gamma>\fR. + +.fi +.RE +.PP +If +.B -v +is specified, and if running in continual mode, the program will print +.B \(dqStatus: Enabled\en\(dq +if starting in or when entering enabled mode, and +.B \(dqStatus: Disabled\en\(dq +if starting in or when entering disabled mode. +.PP +If +.B -v +is specified, and if running in continual mode, the program will print +.B \(dqFade: Enabled\en\(dq +or +.B \(dqFade: Disabled\en\(dq +to indicate whether the +.B fade +setting is enabled, when the program starts and when the +setting is modified. +.PP +If +.B -v +is specified, and if running in continual mode, the program will print +.B \(dqPreserve gamma: Enabled\en\(dq +or +.B \(dqPreserve gamma: Disabled\en\(dq +to indicate whether the +.B preserve-gamma +setting is enabled, when the +program starts and when the setting is modified. +.PP +If the +.B dummy +gamma ramp adjustment method is used, any time a colour +change is applied (including each fade step), the colour temperature +is output, for debugging purposes (brightness and gamma are not printed), +to the standard output in the format +.RS +.nf + +\fB\(dqTemperature: %lu\en\(dq, \fI<colour temperature>\fR. +.fi +.RE + +.SH STDERR +Default. + +.SH OUTPUT FILES +None. + +.SH FILES +Unless the +.B -c +option is used, +.B redshift +will look for its configuration +file, and if found, load it. When searching for the configuration file, +.B redshift +will load the first found file. It will primary look for +.IR redshift-ng/redshift.conf , +secondarily for +.IR redshift/redshift.conf , +and tertiarily for +.IR redshift.conf , +in each directory it searches. It +will search the following directories in order: the directory set in +the environment variable +.IR XDG_CONFIG_HOME , +the directory set in the +environment variable +.I localappdata +(Windows only), the +.I .config +directory inside directory set in the environment variable +.IR HOME , +and the +.I .config +directory inside the user's home directory. For the two +latter, it will quaternarily look for the file +.IR .redshift.conf . +If not found, it will also look for the file in each directory listed in the +environment variable +.I XDG_CONFIG_DIRS +(delimited by colon +.RB ( : ) +on Unix-like systems and by semicolon +.RB ( ; ) +on Windows), however it try each +directory before moving on to then next filename option. Lastly, on +Unix-like systems, it will look for the file in +.IR /etc . +This means that the preferred location for the configuration file is +.IB ${XDG_CONFIG_HOME} /redshift-ng/redshift.conf\fR. +.PP +.B redshift +will use the same pattern to find the hook directory, and the +tested subdirectories for each search directory are +.I /redshift-ng/hooks +and secondarily +.IR /redshift/hooks . +All executable files, in the found +directory, that are neither prefixed with a period +.BR ( . ) +or suffixed with a tilde +.RB ( ~ ) +will be used as hooks scripts, and will be executed in +arbitrary order. Subdirectories are not search for executable files. +This means that the preferred location for the hook scripts is (directly +inside) +.IB ${XDG_CONFIG_HOME} /redshift-ng/hooks/\fR. + +.SH EXTENDED DESCRIPTION +.SS Configuration file +The configuration file uses the standard INI format. General program +options are placed under the +.B redshift +header +.RB ( [redshift] ), +while options for location providers are adjustment methods are +placed under a hader with the name of that proivder or method. +.PP +General options are: +.TP +.BI temp\fR\ =\ temperature .TQ -\fBtemperature\-day\fR = \fIinteger\fR -Temperature (day and night) +.BI temperature\fR\ =\ temperature +Set temperature for daytime and nighttime. The value shall be +format in the same way as with the +.B -O +and +.B -t +options. .TP -\fBtemp\-day\fR = \fIinteger\fR +.BI temp-day\fR\ =\ integer .TQ -\fBtemperature\-day\fR = \fIinteger\fR -Daytime temperature +.BI temperature-day\fR\ =\ integer +Set temperature for daytime. That value shall be an integer no +less than 1000 (Kelvin). .TP -\fBtemp\-night\fR = \fIinteger\fR +.BI temp-night\fR\ =\ integer .TQ -\fBtemperature\-night\fR = \fIinteger\fR -Night temperature +.BI temperature-night\fR\ =\ integer +Set temperature for nighttime. That value shall be an integer +no less than 1000 (Kelvin). +.TP +.BI brightness\fR\ =\ brightness +Set whitepoint brightness for daytime and nighttime. The value +shall be format in the same way as with the +.B -b +option. +.TP +.BI brightness-day\fR\ =\ 0.1-1.0 +Set whitepoint brightness for daytime. That value shall be an +within [0.1, 1.0]. .TP -\fBfade\fR = \fI0 or 1\fR -Disable or enable fading between color temperatures when Redshift starts or -stops +.BI brightness-night\fR\ =\ 0.1-1.0 +Set whitepoint brightness for nighttime. That value shall be an +within [0.1, 1.0]. .TP -\fBbrightness\fR = \fIday\fB:\fInight\fR +.BI gamma\fR\ =\ gamma +Set gamma correction for daytime and nighttime. The value shall +be format in the same way as with the +.B -g +option. +.TP +.BI gamma-day\fR\ =\ 0.1-10.0 .TQ -\fBbrightness\fR = \fI0.1\-1.0\fR -Screen brightness (day and night) +.BI gamma-day\fR\ =\ red : green : blue +Set gamma correction for daytime. Values must be within [0.1, +10.0], and are applied to each colour channel individually, +however if only one value is specified it is applied to all +each channels. .TP -\fBbrightness\-day\fR = \fI0.1\-1.0\fR -Screen brightness at daytime +.BI gamma-night\fR\ =\ 0.1-10.0 +.TQ +.BI gamma-night\fR\ =\ red : green : blue +Set gamma correction for nighttime. Values must be within [0.1, +10.0], and are applied to each colour channel individually, +however if only one value is specified it is applied to all +each channels. .TP -\fBbrightness\-night\fR = \fI0.1\-1.0\fR -Screen brightness at night +.BI fade\fR\ =\ \fP0 " or " 1 +Disable (if +.BR 0 ) +or enable (if +.BR 1 ) +fading between colour settings with large differences. + +The +.B -r +and +.B +r +options can be used to override this setting. .TP -\fBelevation-high\fR = \fIdecimal\fR -The solar elevation in degrees for the transition to daytime +.BI preserve-gamma\fR\ =\ \fP0 " or " 1 +If +.BR 1 , +preapplied colour calibrations (all applied effects are +assumed to be colour calibrations) will be preserved, if +.BR 0 , +colour calibrations will be reset while +.B redshift +is running. + +The +.B -P +and +.B +P +options can be used to override this setting. + +Note that if +.BR 0 , +colour calibrations will be reset even when +.B redshift +is running but is disabled. This is necessary to +support the +.B -o +and +.B -O +options. + +This setting is ignored when +.B coopgamma +is used as +.B coopgamma +allows multiple programs to modify the gamma ramps +at the same time. .TP -\fBelevation-low\fR = \fIdecimal\fR -The solar elevation in degrees for the transition to night +.BI start-disabled\fR\ =\ \fP0 " or " 1 +Start +.B redshift +in disabled (if +.BR 1 ) +or enabled (if +.BR 0 ) +state. + +The +.B -D +and +.B +D +options can be used to override this setting. .TP -\fBdawn-time\fR = \fIHH\fB:\fIMM\fR[\fB\-\fIHH\fB:\fIMM\fR] -The custom time interval for the transition from night to day in the morning. -When specified, the solar elevation will not be used to determine the current -daytime/night period. If this option is set, dusk-time must also be specified. +.BI elevation-high\fR\ =\ decimal +The lowest solar elevation, in degrees, during daytime. .TP -\fBdusk-time\fR = \fIHH\fB:\fIMM\fR[\fB\-\fIHH\fB:\fIMM\fR] -The custom time interval for the transition from day to night in the evening. -When specified, the solar elevation will not be used to determine the current -daytime/night period. If this option is set, dawn-time must also be specified. +.BI elevation-low\fR\ =\ decimal +The highest solar elevation, in degrees, during nighttime. .TP -\fBgamma\fR = \fIday\fB:\fInight\fR -.TQ -\fBgamma\fR = \fI0.1\-10.0\fR +.BI dawn-time\fR\ =\ HH : MM\fR[ : SS\fR][ - HH : MM\fR[ : SS\fR]] .TQ -\fBgamma\fR = \fIR\fB:\fIG\fB:\fIB\fR -Gamma adjustment to apply (day and night) +.BI dusk-time\fR\ =\ HH : MM\fR[ : SS\fR][ - HH : MM\fR[ : SS\fR]] +Custom time interval for the transition from night to day +.RB ( dawn-time ) +and for the transition from day to night +.BR ( dusk-time ). + +When specified, both settings must be specified and the +solar elevation will not be used to determine the current +daytime/nighttime period, nor will a location provider +used. + +The left-hand hour must be within [0, 23], but the right-hand +hour may be within [0, 47], the timespan must not be greater +than 24 hours. The minutes and seconds must be within [0, 59], +and the default value for the seconds is 0. .TP -\fBgamma-day\fR = \fI0.1\-10.0\fR -.TQ -\fBgamma-day\fR = \fIR\fB:\fIG\fB:\fIB\fR -Gamma adjustment to apply at daytime +.BI adjustment-method\fR\ =\ name +Select adjustment method. Options for the adjustment method can +be given under the configuration file heading of the same name. + +Not used if the +.B -p +option is specified. .TP -\fBgamma-night\fR = \fI0.1\-10.0\fR -.TQ -\fBgamma-night\fR = \fIR\fB:\fIG\fB:\fIB\fR -Gamma adjustment to apply at night -.TP -\fBpreserve-gamma\fR = \fI0 or 1\fR -Reset existing gamma ramps before applying new color effect. (On by default) -.TP -\fBstart-disabled\fR = \fI0 or 1\fR -Start redshift in disabled state. (Off by default) -This option is only used when started in continual mode. -.TP -\fBadjustment\-method\fR = \fIname\fR -Select adjustment method. Options for the adjustment method can be -given under the configuration file heading of the same name. -.TP -\fBlocation\-provider\fR = \fIname\fR -Select location provider. Options for the location provider can be -given under the configuration file heading of the same name. -.PP -Options for location providers and adjustment methods can be found in -the help output of the providers and methods. -.SH EXAMPLE -Example for Copenhagen, Denmark: -.IP -\fB$\fR redshift \-l 55.7:12.6 \-t 5700:3600 \-g 0.8 \-m randr \-v -.PP -An example configuration file with the same effect as the above -command line: -.IP +.BI location-provider\fR\ =\ name +Select location provider. Options for the location provider can +be given under the configuration file heading of the same name. + +Not used if +.B dawn-time +and +.B dusk-time +are used or if the colours +settings are specified to be the same during the day and the +night. +.PP +Options for the location provider +.B manual +are: +.TP +.BI lat\fR\ =\ decimal +The GPS latitude of the user's geographical location. +Shall be specified in degrees and formatted a single +real number, rather than split into integer degrees, +minutes and seconds. Positive values used for the +northern hemisphere and negative values are ued for +the southern hemisphere. +.TP +.BI lon\fR\ =\ decimal +The GPS longitude of the user's geographical location. +Shall be specified in degrees and formatted a single +real number, rather than split into integer degrees, +minutes and seconds. Positive values used for the +eastern hemisphere and negative values are ued for +the western hemisphere. +.PP +There are no options for the location providers +.B geoclue2 +(may be available on Unix-like systems) and +.B corelocation +(available on Mac OS X). +.PP +Options for the location provider +.B randr +(preferred method for X) are: +.TP +.BI screen\fR\ =\ integer +X screen to apply adjustments to. Default is determined +by the environment variable +.IR DISPLAY . +.TP +.BI crtc\fR\ =\ "integer list or " all +Comma-separated (,) list of CRTC indices for monitors to +apply adjustments to. All available CRTCs are used if the +list is empty or if the setting is omitted. + +.B all +may be specified as a synonym for an empty list. + +The index of the first CRTC is 0. +.PP +Options for the location provider +.B vidmode +(fallback method for X) are: +.TP +.BI screen\fR\ =\ integer +X screen to apply adjustments to. Default is determined +by the environment variable +.IR DISPLAY . +.PP +Options for the location provider +.B drm +(method for Linux without display server) are: +.TP +.BI card\fR\ =\ integer +Index of graphics card to apply adjustments to. +.TP +.BI crtc\fR\ =\ "integer or " all +Index of CRTC for monitor to apply adjustments to. + +.B all +may be specified to apply adjustments to each available +CRTC on the graphics card. + +The index of the first CRTC is 0. +.PP +There are no options for the adjustment methods +.B wingdi +(available on Windows), +.B quartz +(available on Mac OS X), and +.B dummy +(used for debugging, does not apply any colour effects). + +.SS Hooks +Executable files (that are not dotfiles or tilde files) in the hook +directory (see the +.B FILES +section), are executed on certain events. +The file inherit the +.B redshift +process standard input and standard +error, however the standard output is redirected to the standard error. +.PP +Each file is executed with at least one argument. This first argument +indicate what event has taked place. Additional arguments may be +provided for additional event data. +.PP +.B redshift +will be the parent process of the executed script. +.PP +Currently available events are: +.TP +.B period-changed +This indicate that the period of the day has changed (and at +start of continual mode). The script will be provided two +additional arguments (the second argument and the third +argument). The second argument will the previous period, and +the third argument will be the new period. The argument values +will be either of +.BR night , +.BR daytime , +.BR transition +(transition in either direction between night and daytime), or +.B none +(not previously or no longer calculated). +.B none +appears as the +previous period at start up and can also appear when the when +.B redshift +is reconfigured if the colour settings no longer +depending on the period of the day or has started depending +on the period of the day. + +.SS Gamma ramps +.B redshift +applies a redness effect to the graphical display. The +intensity of the redness can be customised and scheduled to only be +applied at night or to be applied with more intensity at night. +.PP +.B redshift +uses colour correction lookup tables (CLUTs), usually called +gamma ramps or gamma correction ramps, to apply this effect. + +.SS Colour temperature +The redness effect applied by +.B redshift is modelled after black-body +radiation, specifically with a 10 degree observer. Although black-body +radiation starts at 0, +.BR redshift 's +model start at the conventional 1000K +(1000 Kelvin). For this reason, no colour temperature below 1000K can be +specified. However, as there is a limit can be determined for the colour +when the colour temperature appreciates infinity, the upper limit for +allow colour temperature is instead determined by the data type it is +stored in. However, it also means that it is meaningless to use colour +temperatures above 40000K. +.PP +The sRGB colour space, and modern monitors, use the standard illuminant +D65 as the reference for pure white, modelling ideal day light. The +correlated colour temperature of D65 is called 6500K, however it's +actually 6504K, but +.BR redshift 's +defines this illuminant has having the colour temperature 6500K. +This means that 6500K is the neutral (no effect) colour temperature. +.PP +The current version +.B redshift +assumes the monitor uses sRGB. However +this is usually only true for CRT monitors. HDR-capable monitors +particular diverges significant for sRGB. This means that the display +colour does not perfectly correlated to the specified colour temperate. +Lower (more red) colour temperatures, about 1900K and below, are out of +gamut, and thus incorrect even on sRGB monitors. + +.SH EXIT STATUS +Default. + +.SH EXAMPLES +Example for the superelliptical roundabout in Stockholm, Sweden: +.RS +.nf + +redshift -l 59.333:18.065 -t 5700:3600 -b 1:0.8 +.fi +.RE +.PP +Example configuration file equivalent to above command: +.RS .nf -[\fBredshift\fR] -temp\-day=5700 -temp\-night=3600 -gamma=0.8 -adjustment\-method=randr -location\-provider=manual - -[\fBmanual\fR] -lat=55.7 -lon=12.6 + +[redshift] +temperature-day=5700 +temperature-night=3600 +brightness-day=1 +brightness-night=0.8 +location-provider=manual + +[manual] +lat=59.333 +lon=18.065 .fi -.SH HOOKS -Executables (e.g. scripts) placed in folder \fI~/.config/redshift/hooks\fR -will be run when a certain event happens. The first parameter to the -script indicates the event and further parameters may indicate -more details about the event. The event \fBperiod-changed\fR is indicated -when the period changes (\fBnight\fR, \fBdaytime\fR, \fBtransition\fR). The second -parameter is the old period and the third is the new period. The event -is also signaled when Redshift starts up with the old period set to -\fBnone\fR. Any dotfiles in the folder are skipped. -.PP -A simple script to handle these events can be written like this: -.IP +.RE +.PP +Sample hook script: +.RS .nf + #!/bin/sh -case \fB$1\fR in - \fBperiod-changed\fR) - exec notify-send "Redshift" "Period changed to \fB$3\fR" +case "$1" in + period-changed) + notify-send "redshift-ng" "Period changed from $2 to $3";; esac .fi -.SH AUTHOR +.RE + +.SH KNOWN ISSUES +.SS No or incorrect effect on cursor +Some graphics drivers apply the effect (colour corrects) twice or not at +all on hardware cursors. It is often possible to reconfigure the display +server to use software cursors, to avoid this problem, however at mouse +pointer performance cost that may be noticeable on very low-end computer. + +.SS D65-flashes +For some versions of some graphics drivers, there will be an occasional +flash where gamma ramps are not applied to the output. + +.SS Limited hardware support +Low-end hardware, especially embedded devices, often lack colour +correction features .B redshift -was written by Jon Lund Steffensen <jonlst@gmail.com>. -.PP -Both +abuse to apply its effect. .B redshift -and this manual page are released under the GNU General Public -License, version 3. -.SH KNOWN ISSUES +is not always able to tell if support is missing. + +.SS Limited software support +.B redshift +does not yet support Wayland. If your environment contains the +variable +.IR WAYLAND_DISPLAY , +you are using a Wayland compositor and cannot +currently expect +.B redshift +to work. Even with Wayland support, it would be up to each individual +Wayland compositor to opt in to support applications like +.BR redshift . + +.SS Backlight control +.B redshift +uses gamma ramps rather than backlight control to adjust +brightness. This actually intentional and for your best. Most +contemporary monitors require Pulse-Width Modulation, which causes +flicker than can cause eye-strain and headaches, to adjust backlight. +Using gamma ramps is a safe option, it's also considerably less work +basically no extra code and posses no additional limitations. It's often +not possible to adjust backlight on desktop monitors from software, for +devices for which it is possible (mostly telephones and laptops, however +not all have fine-grained enough configurability to be usable) it's not +possible from software to determine well enough how changing the +backlight settings changes the backlight physically. If you still want +backlight to be controlled, you can hook in a tool such as +.BR adjbacklight (1). + +.SS Flickering and temporary suspension +.B redshift +uses the gamma ramps for the monitor to apply it's effect. The +gamma ramps where originally intended for colour correction. Therefore +there is no standardised why have multiple applications applying +different effects without overriding each other. This can cause +continuous flicker if multiple instance are running or effects +temporarily disappearing. By default, .B redshift -will not affect the color of your cursor when your graphics driver -is configured to use hardware cursors. Some graphics drivers have an -option to disable hardware cursors. +uses +.BR coopgammad (1), +which is a daemon applications can opt to use instead of directly +setting the gamma ramps themselves, +.BR coopgammad (1) +can then calculate the result of all +of the effects and apply them as one, allowing the user to use multiple +applications that apply different effects. However +.BR coopgammad (1) +still has to compete with applications that does not use it. + +.SS DRM and display servers +Using the DRM gamma ramp adjustment method can block starting or +switching to and already started display server (like X). Users may +also find that trying to switch to and an already started display cases +the computer hang, or more precisely appear to hang, as the display +server is not beign presented, the screen freezes, and the keyboard +doesn't do anything. (Once upon a time, this wasn't as catastrophic, +and it probably depend on display server implementation details.) The +only solution, abort from restarting the computer, is to remote into +it and kill the display server. + +.SH RATIONALE +To prevent the user from accidental making the screen black, brightness +level below 0.1 are forbidden. +.PP +To prevent colour distortion and making the screen too white, brightness +level above 1.0 are forbidden. +.PP +Gamma correction is preserved for backwards compatibility and is +deprecated (gamma parameters in particular). + +.SH NOTES +\(dqColour temperature\(dq, or just \(dqtemperature\(dq, is actually short for +\(dqcorrelated colour temperature\(dq. (Your monitor is not a black-body +radiator.) And specifically the correlated colour temperature of the +monitor's whitepoint. +.PP +It's common for users to miss to specify a coordinate as negative, +which, if missed on the longitude can swap day and night. The latitude +is negative on the southern hemisphere and the longitude is negative on +the western hemisphere. + +.SH SEE ALSO +.BR cg-tools (7), +.BR coopgammad (1), +.BR radharc (1) |