Stupidly Visible Temperature Display

temp.py

#!/usr/bin/env python3
"""
Print the lm-sensors "Package id 0" temperature in a huge terminal font.

Usage:
  ./scripts/package-temp-big.py           # watch, run sensors every 2s, large font
  ./scripts/package-temp-big.py -i 5      # watch every 5s
  ./scripts/package-temp-big.py --scale 3 # even larger
  ./scripts/package-temp-big.py --once    # one-shot
  sensors | ./scripts/package-temp-big.py --stdin

No external Python dependencies. Requires `sensors` from lm-sensors unless using --stdin.
"""

from __future__ import annotations

import argparse
import re
import shutil
import subprocess
import sys
import time
from typing import Iterable

# 7-line block digits. Keep glyphs monospace-friendly.
FONT = {
    "0": [" █████ ", "██   ██", "██  ███", "██ █ ██", "███  ██", "██   ██", " █████ "],
    "1": ["  ██   ", " ███   ", "  ██   ", "  ██   ", "  ██   ", "  ██   ", "██████ "],
    "2": [" █████ ", "██   ██", "     ██", "   ███ ", "  ██   ", " ██    ", "███████"],
    "3": ["██████ ", "     ██", "     ██", " █████ ", "     ██", "     ██", "██████ "],
    "4": ["██   ██", "██   ██", "██   ██", "███████", "     ██", "     ██", "     ██"],
    "5": ["███████", "██     ", "██     ", "██████ ", "     ██", "██   ██", " █████ "],
    "6": [" █████ ", "██   ██", "██     ", "██████ ", "██   ██", "██   ██", " █████ "],
    "7": ["███████", "     ██", "    ██ ", "   ██  ", "  ██   ", " ██    ", "██     "],
    "8": [" █████ ", "██   ██", "██   ██", " █████ ", "██   ██", "██   ██", " █████ "],
    "9": [" █████ ", "██   ██", "██   ██", " ██████", "     ██", "██   ██", " █████ "],
    ".": ["       ", "       ", "       ", "       ", "       ", "  ██   ", "  ██   "],
    "+": ["       ", "   ██  ", "   ██  ", "███████", "   ██  ", "   ██  ", "       "],
    "-": ["       ", "       ", "       ", "███████", "       ", "       ", "       "],
    "°": [" ███   ", "█   █  ", "█   █  ", " ███   ", "       ", "       ", "       "],
    "C": [" █████ ", "██   ██", "██     ", "██     ", "██     ", "██   ██", " █████ "],
    " ": ["   "] * 7,
}

PACKAGE_RE = re.compile(
    r"^\s*Package\s+id\s+0\s*:\s*\+?(-?\d+(?:\.\d+)?)\s*°?C",
    re.IGNORECASE | re.MULTILINE,
)


def run_sensors() -> str:
    if not shutil.which("sensors"):
        raise RuntimeError("`sensors` not found. Install lm-sensors first, e.g. `sudo apt install lm-sensors`.")
    proc = subprocess.run(["sensors"], text=True, capture_output=True, check=False)
    if proc.returncode != 0:
        raise RuntimeError(proc.stderr.strip() or "`sensors` failed")
    return proc.stdout


def parse_package_temp(output: str) -> str:
    match = PACKAGE_RE.search(output)
    if not match:
        raise RuntimeError('Could not find a "Package id 0" temperature in `sensors` output.')
    value = match.group(1)
    # Avoid noisy trailing .0 unless lm-sensors reports a useful decimal.
    if value.endswith(".0"):
        value = value[:-2]
    return value


def read_package_temp(stdin: bool = False) -> str:
    output = sys.stdin.read() if stdin else run_sensors()
    return parse_package_temp(output)


def colour_for_temp(temp: float) -> str:
    if temp >= 90:
        return "\033[1;31m"  # bright red
    if temp >= 75:
        return "\033[38;5;208m"  # orange
    if temp >= 60:
        return "\033[1;33m"  # yellow
    return "\033[1;36m"  # cyan


def render_big(text: str, scale: int = 2) -> str:
    """Render text with simple integer scaling.

    scale=2 is intentionally huge but still fits most terminals for values like 63°C.
    """
    scale = max(1, scale)
    rows: list[str] = []
    for glyph_row in range(7):
        line = ""
        for char in text:
            glyph = FONT.get(char, FONT[" "])
            expanded = "".join(ch * scale for ch in glyph[glyph_row])
            line += expanded + (" " * (2 * scale))
        for _ in range(scale):
            rows.append(line.rstrip())
    return "\n".join(rows)


def print_temp(clear: bool = False, stdin: bool = False, scale: int = 2) -> None:
    temp_s = read_package_temp(stdin=stdin)
    temp_f = float(temp_s)
    label = f"{temp_s}°C"
    if clear:
        print("\033[2J\033[H", end="")
    print(colour_for_temp(temp_f) + render_big(label, scale=scale) + "\033[0m")
    print(f"Package id 0: {temp_s}°C")


def main(argv: Iterable[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description="Show lm-sensors Package id 0 temperature in a huge terminal font.")
    parser.add_argument("--once", action="store_true", help="run sensors once and exit")
    parser.add_argument("-i", "--interval", type=float, default=2.0, help="refresh interval in seconds (default: 2)")
    parser.add_argument("-s", "--scale", type=int, default=2, help="font scale factor (default: 2)")
    parser.add_argument("--stdin", action="store_true", help="parse sensors output from stdin instead of running sensors")
    args = parser.parse_args(argv)

    try:
        if args.stdin and not args.once:
            args.once = True
        if args.stdin:
            print_temp(clear=False, stdin=True, scale=args.scale)
        elif args.once:
            print_temp(clear=False, scale=args.scale)
        else:
            while True:
                print_temp(clear=True, scale=args.scale)
                time.sleep(args.interval)
    except KeyboardInterrupt:
        return 0
    except RuntimeError as exc:
        print(f"error: {exc}", file=sys.stderr)
        return 1
    return 0


if __name__ == "__main__":
    raise SystemExit(main())