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dasher - Man Page

graphical predictive text entry system


dasher [Options] [filename]


Dasher is an information-efficient text-entry interface, driven by natural continuous pointing gestures. Dasher is a competitive  text-entry system wherever a full-size keyboard cannot be used.


dasher takes the following options:

-a,  --appstyle=STYLE

Application style.  STYLE can be any of traditional, direct, compose, or fullscreen. The default is whatever was specified on the previous invocation of Dasher, or traditional when Dasher is started for the first time.

-?,  --help

Describe command line options.


Describe the options available with --options.

-o,  --options [option=value[,option=value...]]

Override stored options. Options values are remembered for subsequent invocations of Dasher.


The main Dasher interface is a window with a blank background containing a column of letters on the right hand side. Click the mouse button to start.   When the pointer is to the right of the crosshair the screen will zoom towards the point underneath the mouse pointer.  To select a letter, move the mouse pointer into it and watch how it zooms underneath the crosshair.    A new column of letters will appear. Staying within the box for the selected letter, move the pointer over one of these letters to select it as the next letter. Moving the mouse pointer to the left of the crosshair, or outside of the box for previously selected letters, allows you to change previously selected letters.

Application Styles


Dasher displays an edit box above the main window. Text entered via Dasher will appear in the edit box allowing the text to be edited directly.


The edit box is not displayed. Dasher runs without focus and the text goes into whatever window does have focus. This way you can use it more practically to run your desktop.


dasher expands to the entire screen.

The Preferences Dialog

The preferences dialog is split into several panes.


Choose a different alphabet. Dasher will automatically retrain itself if the alphabet specified training file is present.


Choose a different colour scheme.


Alter various control options

One dimensional mode

Map the Y position of the mouse to a 2 dimensional position on the Dasher canvas (useful for limited mobility users)

Eyetracker mode

Similar to one dimensional mode, but behaves normally except at the right-hand side of the canvas. Designed for eyetracker users.

Converting Training Files to Utf-8

Dasher requires that training files be in the UTF-8 format, whereas most text files are likely to be in ISO-8859 format. This doesn't matter for plain text, but accented characters are encoded differently. In order to convert them, use the iconv(1) program. For instance, if your training file is in ISO-8859-1 format (Western European), run iconv -f ISO-8859-1 -t UTF-8 trainingfile >newtrainingfile



Directory containing system-wide configuration files.


Directory containing user specific configuration files.

Dasher will utilise files of the following form from both of these directories:


The files defining the alphabets available to Dasher.


The files defining the colour schemes available to Dasher.


Files containing the training data used by Dasher.  These are UTF-8 encoded text and should contain a representative sample of the relevant language. User specific training files can be used to augment system wide data.

Refer to the Dasher manual for more information regarding the format and editing of these files.


The Dasher Project <dasher@mrao.phy.cam.ac.uk>.

See Also

The Dasher project web page is http://www.inference.phy.cam.ac.uk/dasher/


2008-02-28 5.0.0