Provided by: disper_0.3.0-1_all
disper - on-the-fly display switcher
disper [options] (-l|-s|-c|-e|-p|-i)
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.
--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, or "max" to use the maximum resolution advertised. For extend it is possible to enter a single resolution for all displays or a comma-separated 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 ~/.disper/hooks; "all" for all plugins found; "none" for no plugins. --cycle-stages=CYCLE_STAGES colon-separated list command-line arguments to cycle through
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
~/.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 ~/.disper/hooks --plugins=user # cycle over clone and extend --cycle-stages='-c : -e' ~/.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.
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 ~/.disper/last_cycle_stage. 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.
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 ~/.disper/hooks/. Each hook is an executable file (which includes scripts). The following environment variables are available when invoked: DISPER_VERSION Version of disper (). 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/.
Written by Willem van Engen.