xwincat

X11 window position logger with a simple output format: One window position change per line on stdout.

Image credit: Pixabay user 123090

Nice for drawing some sort of composited overlay, or for fun statistics.

Format

On startup, xwincat prints a line

screen <width> <height>

where the integers <width> and <height> represent the dimensions of the first screen it found.

Whenever a window changes position or size, it prints a line

window <window_id> <x> <y> <width> <height>

where the fields are again pretty self-explanitory. The (x,y) position is from top-left of the screen.

Popup windows (with the override_redirect-flag set) are ignored by default, but can be enabled if you want them with the -popups flag.

If you passed -time, an epoch timestamp is additionally printed at the end of window lines.

Compilation

Just make.

Don't have clang? Edit the makefile to use gcc.

Usage

Flags you can pass (all optional):

• -display <display>: set target X display (default :0)
• -time: also append epoch timestamps (default: don't)
• -popup: also print popup window changes (default: don't)
• -help: print usage hints and exit

Interrupt signal (C-c) to end.

Related programs

If you want to similarly log what keys are pressed, you might like xkbcat.

License

ISC.