1REDSHIFT(1) General Commands Manual REDSHIFT(1)
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6 redshift - set color temperature of display according to time of day
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9 redshift [-l LAT:LON | -l PROVIDER:OPTIONS] [-t DAY:NIGHT] [OPTIONS...]
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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.
16 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.
27 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.
31
33 -h Display help message.
34 -v Enable verbose output.
36 -V Show program version.
38 -b DAY:NIGHT
40 Screen brightness to apply (between 0.1 and 1.0).
41 -c FILE
43 Load settings from specified configuration file.
44 -g R:G:B
46 Additional gamma correction to apply.
47 -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.
52 -l PROVIDER[:OPTIONS]
54 Select provider for automatic location updates (Use "-l list" to
55 see available providers).
56 -m METHOD[:OPTIONS]
58 Method to use to set color temperature (Use "-m list" to see
59 available methods).
60 -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.
64 -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.
69 -p Print mode (only print parameters and exit).
71 -P Reset existing gamma ramps before applying new color effect.
73 -x Reset mode (remove adjustment from screen).
75 -r Disable fading between color temperatures.
77 -t DAY:NIGHT
79 Color temperature to set at daytime/night.
80 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.
85 Default temperature values:
87 Daytime: 6500K, night: 4500K
89
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:
96 temp-day = integer
98 Daytime temperature
99 temp-night = integer
101 Night temperature
102 fade = 0 or 1
104 Disable or enable fading between color temperatures when Red‐
105 shift starts or stops
106 brightness-day = 0.1-1.0
108 Screen brightness at daytime
109 brightness-night = 0.1-1.0
111 Screen brightness at night
112 elevation-high = decimal
114 The solar elevation in degrees for the transition to daytime
115 elevation-low = decimal
117 The solar elevation in degrees for the transition to night
118 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.
124 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.
130 gamma = R:G:B
132 Gamma adjustment to apply (day and night)
133 gamma-day = R:G:B
135 Gamma adjustment to apply at daytime
136 gamma-night = R:G:B
138 Gamma adjustment to apply at night
139 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.
143 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.
147 Options for location providers and adjustment methods can be found in
149 the help output of the providers and methods.
150
152 Example for Copenhagen, Denmark:
153 $ redshift -l 55.7:12.6 -t 5700:3600 -g 0.8 -m randr -v
155 An example configuration file with the same effect as the above command
157 line:
158 [redshift]
160 temp-day=5700
161 temp-night=3600
162 gamma=0.8
163 adjustment-method=randr
164 location-provider=manual
165 [manual]
167 lat=55.7
168 lon=12.6
169
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.
179 A simple script to handle these events can be written like this:
181 #!/bin/sh
183 case $1 in
184 period-changed)
185 exec notify-send "Redshift" "Period changed to $3"
186 esac
187
189 redshift was written by Jon Lund Steffensen <jonlst@gmail.com>.
190 Both redshift and this manual page are released under the GNU General
192 Public License, version 3.
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195 Please report bugs to <https://github.com/jonls/redshift/issues>
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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.
201 REDSHIFT(1)