firec

A cozy, full-screen ASCII fireplace for Linux terminals, written in C.

The animation is embedded in the executable, so playback does not need a video file, Python, or FFmpeg. The last terminal row shows live CPU usage, memory usage, the local time, and the CPU package temperature when a suitable Linux hwmon sensor is available.

The fireplace exposure stays bright enough to keep the masonry visible. When CPU temperature is available, only the flame becomes brighter and shifts from red toward a yellow-white core as the processor approaches its critical temperature. The frame rate does not increase, so the effect does not create a load feedback loop. Systems without a suitable sensor use a neutral flame and simply omit temperature from the status line.

• Linux with /proc/stat and /proc/meminfo
• Optional CPU temperature through /sys/class/hwmon
• A terminal with 24-bit color support
• A C11 compiler and make

make
./fire

Press Ctrl+C to stop. The scene automatically adapts to terminal resizing.

You can also build it directly:

cc -O2 -std=c11 -Wall -Wextra -Wpedantic \
  fire.c temperature.c ui.c -o fire

firec displays one CPU temperature. It prefers package-level sensors such as Package id, Tctl, Tdie, CPU, or Die. On multi-socket systems it uses the hottest package. If only per-core CPU sensors are available, it uses the hottest core. Unrelated sensors such as NVMe temperatures are ignored.

Invalid, unavailable, or faulted sensors are hidden rather than displayed as zero. Sensor discovery is retried automatically if a selected hwmon source temporarily disappears.

make test

This is optional and only needed when replacing the source video. It requires Python 3 and FFmpeg:

python3 generate_fireplace_frames.py input.webm fireplace_frames.h
make

The checked-in fireplace_frames.h already contains everything required for normal builds.

To regenerate the README animation, install Pillow and run:

make preview

The source code is available under the MIT License.

The embedded fireplace frames are adapted from a video by free video library, licensed under CC BY 3.0. Full attribution and transformation details are recorded in FIREPLACE_SOURCE.md. The MIT License does not replace the CC BY 3.0 terms for those frames.