Overview

fbcat takes a screenshot using the Linux framebuffer device. Two executables are provided:

• Low-level fbcat that operates on the current virtual terminal and writes the screenshot to stdout in the PPM format:

  $ fbcat > screenshot.ppm
  $ file screenshot.ppm
  screenshot.ppm: Netpbm image data, size = 1280 x 1024, rawbits, pixmap

• High-level fbgrab that supports the PNG format and virtual terminal switching:

  $ fbgrab '-?'
  Usage: fbgrab [option...] <filename.png|->
  
  Options:
  -c <N>      grab from /dev/ttyN
  -C <N>      grab from /dev/ttyN, for slower devices
  -d <dev>    use framebuffer device <dev>
  -i          turn on PNG interlacing
  -s <N>      sleep <N> seconds before making screenshot
  -?          show this help message and exit
  
  If the specified destination is "-", the PNG output is piped to stdout.

See the manual pages for details.

The following visuals are supported:

• TRUECOLOR
• DIRECTCOLOR
• PSEUDOCOLOR
• STATIC_PSEUDOCOLOR
• MONO01
• MONO10

Prerequisites

The following software is needed to build fbcat:

• C compiler
• Linux kernel userspace headers
• GNU make

Additionally, the following software is needed to rebuild the manual pages from source:

• xsltproc (part of libxslt)
• DocBook XSL stylesheets

fbgrab requires the following software:

• chvt (part of KBD)
• pnmtopng (part of Netpbm) or GraphicsMagick or ImageMagick

Installation

To install system-wide:

$ make
$ sudo make install

The default installation prefix is /usr/local. You can specify different one using the PREFIX variable, e.g.:

$ make install PREFIX="$HOME/.local"