1# Headless mode
2
3Runs NeferWL without a screen, for tests and quick checks:
4
5```sh
6neferwl --backend=headless --screenshot /tmp/neferwl-shots
7WAYLAND_DISPLAY=<name from the log> foot
8```
9
10- `latest.png` shows the current frame. Every frame is also saved as `frame-NNNNNN.png`, so the directory grows.
11- `--size 640x360,640x360` creates two outputs, arranged left to right,
12  for testing `focus-monitor-left/right` and moving columns between outputs.
13- With several outputs, each writes to `<dir>/HEADLESS-<n>/`.
14- `--timeout 5s` stops NeferWL after 5 seconds.
15- `grim` and recorders work too; see [Screen capture](capture.md).
16
17## Input scripts
18
19`--input <file>`, or `--input -` for stdin, plays one command per line:
20
21| Command | Effect |
22|---|---|
23| `type <text>` | Type text |
24| `key Super+Return` | Press a key, with optional Shift, Ctrl, Alt or Super |
25| `hold Super+h 1s` | Press a key like `key`, hold it, then release it |
26| `sleep 1s` | Wait |
27| `move <x> <y>` | Move the pointer, in output coordinates |
28| `click [left\|right\|middle]`, `down <button>`, `up <button>` | Mouse buttons |
29| `swipe up\|down\|left\|right` | Three-finger flick |
30| `swipe4 up\|down` | Four-finger flick |
31
32## Testing input methods
33
34`examples/testime` sends a preedit string, then commits text, each time an app enables text input:
35
36```sh
37WAYLAND_DISPLAY=<name> go run ./examples/testime -preedit nihon -commit 日本
38```
39
40`-count <n>` exits after n commits; `-delay` sets the time between preedit and commit.
41
42## Colour check
43
44`make color-check` renders `examples/testpattern` on a headless output and checks the colours, in SDR and in HDR (`--headless-hdr`). It needs a GPU and `/dev/udmabuf`, and is not part of `make check`.
45
46On a real screen, compare by eye:
47
48```sh
49WAYLAND_DISPLAY=<name> go run ./examples/testpattern -mode hdr -fullscreen   # or -mode sdr
50```