add png to ico converter shell script for multi-size ico files

img/icoconv.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+
+# icoconv.sh
+# Copyright 2016 Christopher Simpkins
+# Adapted from shell script by Denilson Sá at https://superuser.com/questions/40623/icons-command-line-generator#40629
+# MIT License
+
+# Dependencies:
+#    1. imagemagick (http://www.imagemagick.org/)
+#    2. icoutils (http://www.nongnu.org/icoutils/)
+
+# Usage: ./icoconv.sh [png filepath]
+
+if [[ -f "$1" ]]; then
+	SOURCE="$1"
+	BASE=`basename "${SOURCE}" .png`
+else
+	echo "[iconconv.sh] ERROR: $1 does not appear to be a valid .png file"
+fi
+
+# Resize png image to 16x16 through 256x256 for the ico file
+convert "${SOURCE}" -thumbnail 16x16 "${BASE}_16.png"
+convert "${SOURCE}" -thumbnail 32x32 "${BASE}_32.png"
+convert "${SOURCE}" -thumbnail 48x48 "${BASE}_48.png"
+convert "${SOURCE}" -thumbnail 64x64 "${BASE}_64.png"
+convert "${SOURCE}" -thumbnail 256x256 "${BASE}_256.png"
+
+if [[ $? -eq 0 ]]; then
+	echo "Image resizes completed successfully."
+else
+	echo "Image resizes failed."
+	exit 1
+fi
+
+# compile all sizes into the ico file
+icotool -c -o "${BASE}.ico" "${BASE}"_{16,32,48,64,256}.png
+
+if [[ $? -eq 0 ]]; then
+	echo "Successful conversion of '$1' to '${BASE}.ico'"
+	rm -f  "${BASE}"_{16,32,48,64,256}.png
+else
+	echo "Conversion to an ico file failed."
+	exit 1
+fi