1REDSHIFT(1)                 General Commands Manual                REDSHIFT(1)
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NAME

6       redshift - set color temperature of display according to time of day
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SYNOPSIS

9       redshift [-l LAT:LON | -l PROVIDER:OPTIONS] [-t DAY:NIGHT] [OPTIONS...]
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DESCRIPTION

12       redshift adjusts the color temperature of your screen according to your
13       surroundings. This may help your eyes hurt less or reduce the risk  for
14       delayed  sleep phase syndrome if you are working in front of the screen
15       at night.
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17       The color temperature is set according to the position of  the  sun.  A
18       different  color  temperature  is  set during night and daytime. During
19       twilight and early morning, the color temperature transitions  smoothly
20       from  night  to  daytime temperature to allow your eyes to slowly adapt
21       over a period of about an hour. At night the color  temperature  should
22       be set to match the lamps in your room. This is typically a low temper‐
23       ature at around 3000K-4000K (default is 4500K).  During  the  day,  the
24       color temperature should match the light from outside, typically around
25       5500K-6500K (default is 6500K). The light has a higher  temperature  on
26       an overcast day.
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28       In  addition  to  the  command-line tool redshift, the GUI redshift-gtk
29       provides an alternative interface that shows up as a notification  icon
30       in the desktop environment.
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OPTIONS

33       -h     Display help message.
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35       -v     Enable verbose output.
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37       -V     Show program version.
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39       -b DAY:NIGHT
40              Screen brightness to apply (between 0.1 and 1.0).
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42       -c FILE
43              Load settings from specified configuration file.
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45       -g R:G:B
46              Additional gamma correction to apply.
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48       -l LAT:LON
49              Your  current location, in degrees, given as floating point num‐
50              bers, towards north and east, with negative numbers representing
51              south and west, respectively.
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53       -l PROVIDER[:OPTIONS]
54              Select provider for automatic location updates (Use "-l list" to
55              see available providers).
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57       -m METHOD[:OPTIONS]
58              Method to use to set color temperature (Use  "-m  list"  to  see
59              available methods).
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61       -o     One-shot  mode  (do  not continuously adjust color temperature).
62              Use this with the -P option to clear the  existing  gamma  ramps
63              before applying the new color temperature.
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65       -O TEMP
66              One-shot manual mode (set color temperature).  Use this with the
67              -P option to clear the existing gamma ramps before applying  the
68              new color temperature.
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70       -p     Print mode (only print parameters and exit).
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72       -P     Reset existing gamma ramps before applying new color effect.
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74       -x     Reset mode (remove adjustment from screen).
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76       -r     Disable fading between color temperatures.
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78       -t DAY:NIGHT
79              Color temperature to set at daytime/night.
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81       The  neutral temperature is 6500K. Using this value will not change the
82       color temperature of the display. Setting the color  temperature  to  a
83       value  higher than this results in more blue light, and setting a lower
84       value will result in more red light.
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86       Default temperature values:
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88              Daytime: 6500K, night: 4500K
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CONFIGURATION FILE

91       A configuration file with the  name  redshift.conf  can  optionally  be
92       placed in ~/.config/. The file has standard INI format. General program
93       options are placed under the redshift header, while options  for  loca‐
94       tion  providers  and  adjustment methods are placed under a header with
95       the name of that provider or method. General options are:
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97       temp-day = integer
98              Daytime temperature
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100       temp-night = integer
101              Night temperature
102
103       fade = 0 or 1
104              Disable or enable fading between color  temperatures  when  Red‐
105              shift starts or stops
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107       brightness-day = 0.1-1.0
108              Screen brightness at daytime
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110       brightness-night = 0.1-1.0
111              Screen brightness at night
112
113       elevation-high = decimal
114              The solar elevation in degrees for the transition to daytime
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116       elevation-low = decimal
117              The solar elevation in degrees for the transition to night
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119       dawn-time = HH:MM[-HH:MM]
120              The custom time interval for the transition from night to day in
121              the morning.  When specified, the solar elevation  will  not  be
122              used  to  determine  the  current  daytime/night period. If this
123              option is set, dusk-time must also be specified.
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125       dusk-time = HH:MM[-HH:MM]
126              The custom time interval for the transition from day to night in
127              the  evening.   When  specified, the solar elevation will not be
128              used to determine the  current  daytime/night  period.  If  this
129              option is set, dawn-time must also be specified.
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131       gamma = R:G:B
132              Gamma adjustment to apply (day and night)
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134       gamma-day = R:G:B
135              Gamma adjustment to apply at daytime
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137       gamma-night = R:G:B
138              Gamma adjustment to apply at night
139
140       adjustment-method = name
141              Select  adjustment method. Options for the adjustment method can
142              be given under the configuration file heading of the same name.
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144       location-provider = name
145              Select location provider. Options for the location provider  can
146              be given under the configuration file heading of the same name.
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148       Options  for  location providers and adjustment methods can be found in
149       the help output of the providers and methods.
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EXAMPLE

152       Example for Copenhagen, Denmark:
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154              $ redshift -l 55.7:12.6 -t 5700:3600 -g 0.8 -m randr -v
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156       An example configuration file with the same effect as the above command
157       line:
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159              [redshift]
160              temp-day=5700
161              temp-night=3600
162              gamma=0.8
163              adjustment-method=randr
164              location-provider=manual
165
166              [manual]
167              lat=55.7
168              lon=12.6
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HOOKS

171       Executables  (e.g.  scripts)  placed in folder ~/.config/redshift/hooks
172       will be run when a certain event happens. The first  parameter  to  the
173       script  indicates  the  event  and further parameters may indicate more
174       details about the event. The event period-changed is indicated when the
175       period  changes  (night,  daytime, transition). The second parameter is
176       the old period and the third is the new period. The event is also  sig‐
177       naled when Redshift starts up with the old period set to none. Any dot‐
178       files in the folder are skipped.
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180       A simple script to handle these events can be written like this:
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182              #!/bin/sh
183              case $1 in
184                  period-changed)
185                      exec notify-send "Redshift" "Period changed to $3"
186              esac
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AUTHOR

189       redshift was written by Jon Lund Steffensen <jonlst@gmail.com>.
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191       Both redshift and this manual page are released under the  GNU  General
192       Public License, version 3.
193

BUGS

195       Please report bugs to <https://github.com/jonls/redshift/issues>
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KNOWN ISSUES

198       redshift  will  not  affect the color of your cursor when your graphics
199       driver is configured to use hardware  cursors.  Some  graphics  drivers
200       have an option to disable hardware cursors.
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204                                                                   REDSHIFT(1)
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