bash script for setting the volume on macOS

volume.sh

#!/usr/bin/env bash

MIN_LEVEL=0
MAX_LEVEL=100

if [ "$#" -eq 0 ]; then
  LEVEL=$MAX_LEVEL
else
  LEVEL=$1
fi

if ! [[ "$LEVEL" =~ ^[0-9\.]+$ ]]; then
  case "$LEVEL" in
    *min*)
      LEVEL=$MIN_LEVEL
      ;;
    *max*)
      LEVEL=$MAX_LEVEL
      ;;
    *)
      LEVEL=$MIN_LEVEL
      ;;
  esac
fi

# trunc(value)
LEVEL=$(printf "%.0f\n" "$LEVEL")

# max($MIN_LEVEL, min($LEVEL, $MAX_LEVEL))
if [ "$LEVEL" -lt $MIN_LEVEL ]; then
  LEVEL=$MIN_LEVEL
elif [ "$LEVEL" -gt $MAX_LEVEL ]; then
  LEVEL=$MAX_LEVEL
fi

osascript -e "set volume output volume $LEVEL"