convert-retina.sh

#!/usr/bin/env bash

if ! command -v inkscape &> /dev/null; then
  echo "command 'inkscape' could not be found"
  exit 1
fi

height=$1
if [[ "$height" -lt 1 ]]; then
  echo "$height must be greater than 0"
  exit 1
fi

svg_file=$2
if [[ ! -f "$svg_file" ]]; then
  echo "file: $svg_file does not exist"
  exit 1
fi

filename=${3%%.*}
extension=${3#*.}
if [[ -z "$filename" ]]; then
  filename=${svg_file%%.*}
  extension="png"
fi

output_filename="$filename.txt"
filename_1x="$filename.$extension"
filename_2x="$filename@2x.$extension"
filename_3x="$filename@3x.$extension"

echo -e "$filename_1x" | tee -a "$output_filename"
inkscape --export-height="$((height))"     "$svg_file" --export-filename="$filename_1x" 2> >(tee -a "$output_filename")

echo -e "\n$filename_2x" | tee -a "$output_filename"
inkscape --export-height="$((height * 2))" "$svg_file" --export-filename="$filename_2x" 2> >(tee -a "$output_filename")

echo -e "\n$filename_3x" | tee -a "$output_filename"
inkscape --export-height="$((height * 3))" "$svg_file" --export-filename="$filename_3x" 2> >(tee -a "$output_filename")