redshift-rebooted/rewrite/CONFIG.md

Configuration File Support

Redshift supports configuration files in INI format, compatible with the original C version.

Configuration File Locations

Redshift searches for configuration files in the following locations (in order of priority):

1. $XDG_CONFIG_HOME/redshift/redshift.conf
2. $XDG_CONFIG_HOME/redshift.conf (fallback)
3. $HOME/.config/redshift/redshift.conf
4. $HOME/.config/redshift.conf (fallback)
5. /etc/redshift/redshift.conf (system-wide)
6. /etc/redshift.conf (system-wide fallback)

Configuration Sections

[redshift] - Main Settings

Temperature settings:

• temp-day - Day color temperature in Kelvin (default: 6500)
• temp-night - Night color temperature in Kelvin (default: 3500)

Transition settings:

• fade or transition - Smooth transition (0=off, 1=on, default: 1)
• elevation-high - Solar elevation for day in degrees (default: 3.0)
• elevation-low - Solar elevation for night in degrees (default: -6.0)

Time-based transitions (alternative to elevation):

• dawn-time - Dawn time range, e.g., 6:00-7:45
• dusk-time - Dusk time range, e.g., 18:35-20:15

Brightness settings:

• brightness - Single value for both day and night (0.1-1.0)
• brightness-day - Day brightness (0.1-1.0)
• brightness-night - Night brightness (0.1-1.0)

Gamma settings:

• gamma - Single value for all RGB channels, or R:G:B format
  • Example: gamma=0.8 (applies 0.8 to all channels)
  • Example: gamma=0.8:0.7:0.9 (R=0.8, G=0.7, B=0.9)
• gamma-day - Day gamma value(s)
• gamma-night - Night gamma value(s)

Provider/Method settings:

• location-provider - Location provider (manual, geoclue2)
• adjustment-method - Gamma adjustment method (randr, dummy)

[manual] - Manual Location

• lat - Latitude (-90 to 90)
• lon - Longitude (-180 to 180)

Note: Longitudes west of Greenwich (e.g., Americas) are negative.

[randr] - RandR Method Settings

• screen - X11 screen number to adjust (default: all screens)
• crtc - Specific CRTC to adjust (optional)

Priority Order

Settings are applied in the following priority order (highest to lowest):

1. Command-line arguments (highest priority)
2. INI configuration file
3. Default values (lowest priority)

Examples

If you specify -t 6000 on the command line and temp-day=5700 in the config file, the command-line value (6000K) will be used.

Sample Configuration

[redshift]
; Color temperature
temp-day=5700
temp-night=3500

; Enable smooth transitions
fade=1

; Brightness (optional)
brightness-day=0.9
brightness-night=0.7

; Gamma correction (optional)
gamma=0.8
; Or per-channel: gamma=0.8:0.7:0.9

; Solar elevation thresholds (optional)
;elevation-high=3
;elevation-low=-6

; Or use time-based transitions (optional)
;dawn-time=6:00-7:45
;dusk-time=18:35-20:15

; Location and adjustment method
location-provider=manual
adjustment-method=randr

[manual]
lat=40.7
lon=-74.0

[randr]
screen=0

Location Priority

Locations are determined in the following order:

1. Command-line location (-l LAT:LON)
2. INI config manual location ([manual] section)
3. Saved TOML location (from previous runs)
4. GeoClue2 automatic detection (if available)
5. Interactive selection (fallback)

Command-Line Options

You can override any config file setting with command-line arguments:

# Override temperature from config
redshift -t 6000 --temp-night 4000

# Override brightness
redshift -b 0.8

# Override gamma
redshift -g 0.9

# Override location
redshift -l 40.7:-74.0

# Print current settings
redshift -p

# Verbose output (shows where settings come from)
redshift -v

Compatibility

This implementation is compatible with the original Redshift configuration file format. Existing redshift.conf files should work without modification.