fbgrab(1)

📦
version 1.5 · 2 versions
, in alpine 3.24, arch rolling

💅 fbgrab — like, the framebuffer screenshot girly

okay so real talk, this is the manual page for fbgrab, a general commands manual situation. yes bestie, we're reading the docs together and it's gonna be cute. 🎀

✨ NAME ✨

fbgrab — takes screenshots using the framebuffer device. that's it, that's the whole vibe. 📸

✨ SYNOPSIS ✨

fbgrab [options] filename

✨ DESCRIPTION ✨

so fbgrab reads the framebuffer device (/dev/fb*) or a dump of it and saves a PNG image file. and like — you can use it for making screenshots of virtually any application, from traditional test applications to your X-windows desktop, as well as framebuffer applications. it's giving versatility, it's giving range, it ate. 🔥

✨ OPTIONS ✨

  • -? — print usage information. a little help menu moment, we love her. 🫶
  • -a — ignore the alpha channel, specifically for drivers that are out here incorrectly setting but not actually supporting an alpha channel. messy of them, honestly. 💀
  • -b bitdepth — the number of bits per pixel used. this one's optional when you're reading from a device.
  • -c console — specifies which console (or virtual terminal — like other people call this feature) to grab. sometimes this changing is faster than the framebuffer gets refreshed (especially when grabbing framebuffer apps). if that's your situation, you should use -C console ... instead — that one waits some time before grabbing. heads up though: you can't use -s in this case. no cap. ⚠️
  • -d device — specifies which framebuffer device you want to read. if you don't use this option, it takes the value from the FRAMEBUFFER environment variable. and if no FRAMEBUFFER environment variable is given, or if its value is NULL, then DEFAULT_FB is taken (see source code), which usually is /dev/fb0. the chain of custody is real. 🔗
  • -f filename — read from from file instead of device. yep, "from from", she said it twice, iconic. this requires that -w (width), -h (height) and -b (bitdepth) are specified. no skipping, bestie. 📄
  • -h height — the height of the framebuffer in pixels. optional when reading from device.
  • -i interlacing — turns off interlacing. so if you do not want ADAM7 interlacing, you should use the -i option. got it? good. 🦋
  • -l line length, a.k.a. stride — the length in pixels between the start of each row in the framebuffer, which might be larger or equal to width. optional when reading from device.
  • -s seconds — specifies how many seconds to wait before grabbing. fbshot does not lock console switching, so you can switch it while waiting — and if you cannot use -c, this requires normally that fbgrab is run as root. 👑 (yes, root. main character energy, but make it permissions.)
  • -v verbose — be verbose. that's it. that's the whole description. she's blunt, we respect it. 🗣️
  • -w width — the width of the frambeuffer in pixels. optional when reading from device. (typo is hers, not mine, and honestly? she's still slaying.)
  • -z compression level — set png compression level 0 (fast) to 9 (best). pick your fighter. ⚡

✨ TODO ✨

like, things she will get to eventually, bestie: 🌸

  • Low-end bit depths, eg 1, 2, 4 & 8 bits.
  • Companion program fbput that would display a picture in the frambuffer.
  • Better utilization of the PNG-lib — all formats are first converted to 32 bitdepth and then stored as PNG — hardly the right approach. 😭 (her words! she's being honest about her own code!)

✨ EXAMPLES ✨

okay so first up:

fbgrab fb.png

will take a framebuffer snapshot. easy, clean, no notes. ✨

or, if you don't have fbgrab at your machine, you can do:

cp /dev/fb0 framebuffer.dump

and then:

fbgrab -w 1024 -h 768 -l 2048 -b 16 -f framebuffer.dump fb.png

to convert it to a picture. look at you go, converting dumps to pics, absolutely ate that. 💅

✨ AUTHOR ✨

Written by Gunnar Monell <gunnar.monell@gmail.com>. Basically a rewrite of fbshot by Stephan Beyer <fbshot@s-beyer.de>. two icons collaborating, we love to see it. 🫶

(C) 2002-2020 Gunnar Monell <gunnar.monell@gmail.com>

(C) 2000 Stephan Beyer <fbshot@s-beyer.de>

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. ⚠️ (like, genuinely, no warranty. she's serious about this one.)

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

aaaand that's the whole page bestie! 🎀 mwah 💋 — copyright vibes are (C) 2002 - 2020 Gunnar Monell, GPL, and this cute little manual page is dated the same era, fbgrab(1) and out. 🌈⭐

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