Provided by: disper_0.3.1-1_all 
NAME
disper - on-the-fly display switcher
SYNOPSIS
disper [options] (-l|-s|-c|-e|-p|-i)
DESCRIPTION
Disper re-routes your screen output to one or more connected displays. For example when giving a
presentation, all one wants is that the beamer, which has just been connected, is able to show whatever
you prepared.
There is the option to either clone all detected displays, or extend the desktop to them. Resolutions are
automatically detected by default. For cloning, the highest resolution supported by all displays devices
is chosen; for extending every display device gets its preferred or highest supported resolution. For
special setups requiring more detailed control, one can still use the vendor-supplied display
configuration utilities.
OPTIONS
--version
show program's version number and exit
-h, --help
show this help message and exit
-v, --verbose
show what's happening
-q, --quiet
be quiet and only show errors
-r RESOLUTION, --resolution=RESOLUTION
set resolution, e.g. "800x600", or "auto" to detect the display's preferred resolution, "max" to
use the maximum resolution advertised, or "off" to disable the display entirely. For extend it is
possible to enter a single resolution for all displays or a commaseparated list of resolutions
(one for each display). Beware that many displays advertise resolutions they can not fully show,
so "max" is not advised.
-d DISPLAYS, --displays=DISPLAYS
comma-separated list of displays to operate on, or "auto" to detect; the first is the primary
display.
-t DIRECTION, --direction=DIRECTION
where to extend displays: "left", "right", "top", or "bottom"
--scaling=SCALING
flat-panel scaling mode: "default", "native", "scaled", "centered", or "aspect-scaled"
--plugins=PLUGINS
comma-separated list of plugins to enable. Special names: "user" for all user plugins in
~/.config/disper/hooks; "all" for all plugins found; "none" for no plugins.
--cycle-stages=CYCLE_STAGES
colon-separated list command-line arguments to cycle through; "-S:-c:-s" by default
ACTIONS
Select exactly one of the following actions
-l, --list
list the attached displays
-s, --single
only enable the primary display
-S, --secondary
only enable the secondary display
-c, --clone
clone displays
-e, --extend
extend displays
-p, --export
export current settings to standard output
-i, --import
import current settings from standard input
-C, --cycle
cycle through the list of cycle stages
FILES
$XDG_CONFIG_HOME/disper/config or ~/.config/disper/config or ~/.disper/config
Default command-line options to include at each disper invocation. Multiple lines are
concatenated, and lines starting with # are ignored. A typical example might include:
# enable all plugins in ~/.config/disper/hooks
--plugins=user
# cycle over clone and extend
--cycle-stages='-c : -e'
$XDG_CONFIG_HOME/disper/hooks/ or ~/.config/disper/hooks/ or ~/.disper/hooks/
Directory containing user hooks. These can be enabled with the --plugins option.
/usr/share/disper/hooks/
Directory containing system hooks. User hooks take preference of system hooks or plugins.
CYCLE
There is a possibility to cycle between different setups with a single disper invocation using the option
--cycle. The options to cycle through are specified by the option --cycle-stages, which consists of a
colon-separated list of disper options. To alternate, for example, between clone and extend, one could
use
disper --cycle-stages='-e : -c' --cycle
Currently the last selected stage is stored in the file $XDG_CONFIG_HOME/disper/last_cycle_stage
(actually the file last_cycle_stage in the directory of the last configuration file read). This means
that when display configuration is modified by something else than disper (for example by restarting the
computer), cycling will continue from where it was last time, not necessarily from the current display
configuration. This is something that may change in the future.
PLUGINS
It is possible to execute user-supplied hooks on display switch, for example to display a notification or
change the wallpaper. Which ones are enabled is specified by the --plugins option. System hooks are
located in /usr/share/disper/hooks/ while user hooks should be placed in $XDG_CONFIG_HOME/disper/hooks
(or ~/.config/disper/hooks/ or ~/.disper/hooks/).
Each hook is an executable file (which includes scripts). The following environment variables are
available when invoked:
DISPER_VERSION
Version of disper (0.3.1).
DISPER_LOG_LEVEL
Log level: 0 (quiet), 1 (normal) or 2 (verbose).
DISPER_STAGE
Execution stage: prepare or switch. Most plugins will only need to act on the switch stage, which
is just after the display switch has happened. Please make sure to execute an action only on
switch for future compatibility. (There are ideas for import and export as well.)
DISPER_DISPLAYS
Space-separated list of displays that have output. These names may be slightly different from what
disper uses internally because they have to be valid environment variable names. (e.g. DFP_0
CRT_0)
DISPER_LAYOUT
One of: clone, top, right, bottom or left.
DISPER_BB_RESOLUTION
Size of full bounding box (e.g. 1024x768).
For each of DISPER_DISPLAYS the resolution of the corresponding display is supplied as well. If only
DFP-0 would be attached, DISPER_DISPLAYS would contain just DFP_0 and the following variables would be
set as well:
DISPER_RESOLUTION_DFP_0
Resolution of display DFP-0 (e.g. 1024x768).
If you want to write your own hook you can also look at the ones supplied with disper in
/usr/share/disper/hooks/.
AUTHOR
Written by Willem van Engen.
SEE ALSO
xrandr(1), nvidia-settings(1)