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Version: 303270 (debian - 07/07/09)

Section: 7 (Divers)


display-file - Render display into image file


 display-file: [-flushcmd=<command>] [-flushframe=<n>]
               [-flushtime=<t>] <filename>


Renders an image into a file. The file can be a framebuffer device (e.g. /dev/fb0), in which case a reasonable representation of the image will be drawn on the console so long as the program's mode matches the framebuffer's mode.
Note: This target generates no input. The display-multi(7) target can be used in order to see (and control) what the program does (using a normal target) and then generate a snapshot when the program exits.


filename is the file to render the images to. If the filename is a PPM file (has the extension .ppm), then the image will be generated at ggiClose(3) time. Otherwise the file is a custom GGIFILE format and is generated continuously.

The display-file target can be used to generate movies from running LibGGI applications. To do this, set -flushcmd to a shell command to execute at the times given by one of the two other parameters. This looks typically like:

 ppmtogif foo.ppm > foo.%04d.gif

The command is passed through a printf(3) which has the current count of saved frames as an argument (or rather as 10 arguments to allow a few more complex commands).

This shell command is either executed at every n-th invocation of ggiFlush or every t seconds, where t can have fractional components (specified as decimal).

Note, that the invocation of the shell command will slow down the program, so make sure you use a reasonable value, if you use the -flushtime argument.

The primary file is updated before every invocation of the shell command.


DirectBuffer always available.