diff --git a/tools/build_gh_pages.sh b/tools/build_gh_pages.sh
index 009b0092..65f90e46 100755
--- a/tools/build_gh_pages.sh
+++ b/tools/build_gh_pages.sh
@@ -2,10 +2,10 @@
 
 set -e
 
-BUILD="$(mktemp -dt solaar-gh-pages-XXXXXX)"
-cd "$(dirname "$0")"/..
+BUILD="$(/bin/mktemp --directory --tmpdir solaar-gh-pages-XXXXXX)"
+cd "$(/usr/bin/dirname "$0")/.."
 SELF="$PWD"
-SITE="$(readlink -f "$SELF/../gh-pages")"
+SITE="$(/bin/readlink --canonicalize "$SELF/../gh-pages")"
 
 #
 #
@@ -13,10 +13,10 @@ SITE="$(readlink -f "$SELF/../gh-pages")"
 
 add_md() {
 	local SOURCE="$SELF/$1"
-	local TARGET="$BUILD/${2:-$(basename "$1")}"
+	local TARGET="$BUILD/${2:-$(/usr/bin/basename "$1")}"
 
 	LAYOUT=default
-	TITLE=$(grep '^# ' "$SOURCE" -m 1 | cut -c 3-)
+	TITLE=$(/bin/grep --max-count=1 '^# ' "$SOURCE" | /usr/bin/cut --characters=3-)
 	if test -n "$TITLE"; then
 		local TITLE="Solaar - $TITLE"
 		LAYOUT=page
@@ -24,8 +24,8 @@ add_md() {
 		local TITLE=Solaar
 	fi
 
-	mkdir -p "$(dirname "$TARGET")"
-	cat >"$TARGET" <<-FRONTMATTER
+	/bin/mkdir --parents "$(dirname "$TARGET")"
+	/bin/cat >"$TARGET" <<-FRONTMATTER
 		---
 		layout: $LAYOUT
 		title: $TITLE
@@ -33,7 +33,7 @@ add_md() {
 
 	FRONTMATTER
 
-	cat "$SOURCE" >>"$TARGET"
+	/bin/cat "$SOURCE" >>"$TARGET"
 }
 
 fix_times() {
@@ -43,68 +43,80 @@ fix_times() {
 
 	if test -d "$SOURCE"; then
 		for f in "$SOURCE"/*; do
-			f=$(basename "$f")
+			f=$(/usr/bin/basename "$f")
 			fix_times "$1/$f" "$2/$f"
 		done
 	fi
-	touch -r "$SOURCE" "$TARGET"
+	/usr/bin/touch --reference="$SOURCE" "$TARGET"
 }
 
 #
 #
 #
 
-cp -upr "$SELF/jekyll"/* "$BUILD/"
-convert.im6 "$SELF/share/solaar/icons/solaar.svg" -transparent white \
+/bin/cp --archive --update "$SELF/jekyll"/* "$BUILD/"
+# convert the svg logo to png for the web site
+/usr/bin/convert.im6 "$SELF/share/solaar/icons/solaar.svg" -transparent white \
 	-resize 48x48  "$BUILD/images/solaar-logo.png"
-convert.im6 "$SELF/share/solaar/icons/solaar.svg" -transparent white \
-	-resize 32x32 "$BUILD/images/favicon.png"
+/usr/bin/convert.im6 "$SELF/share/solaar/icons/solaar.svg" -transparent white \
+	-resize 16x16 "$BUILD/images/favicon.png"
+
+# optimize the converted pngs
+command -V optipng && optipng -preserve -quiet -o 7 "$BUILD/images"/*.png
+#command -V pngcrush && pngcrush -d "$BUILD/images" -oldtimestamp -q "$BUILD/images"/*.png
 
 add_md docs/devices.md
 add_md docs/installation.md
 
 add_md README.md index.md
-sed -i -e 's#\[docs/\([a-z]*\)\.md\]#[\1]#g' "$BUILD/index.md"
-sed -i -e 's#(docs/\([a-z]*\)\.md)#(\1.html)#g' "$BUILD/index.md"
-sed -i -e 's#(COPYING)#({{ site.repository }}/blob/master/COPYING)#g' "$BUILD/index.md"
+# fix local links to the proper .html files
+/bin/sed --in-place --expression='s#\[docs/\([a-z]*\)\.md\]#[\1]#g' "$BUILD/index.md"
+/bin/sed --in-place --expression='s#(docs/\([a-z]*\)\.md)#(\1.html)#g' "$BUILD/index.md"
+/bin/sed --in-place --expression='s#(COPYING)#({{ site.repository }}/blob/master/COPYING)#g' "$BUILD/index.md"
 
+# remove empty lines, to minimze html sizes
 for l in "$BUILD/_layouts"/*.html; do
-	sed -e '/^$/d' "$l" | tr -d '\t' >"$l="
-	mv "$l=" "$l"
+	/bin/sed --expression='/^$/d' "$l" | /usr/bin/tr --delete '\t' >"$l="
+	/bin/mv "$l=" "$l"
 done
 
-mkdir -p "$SITE/../packages" "$SITE/packages/"
-cp -up "$SELF/dist/debian"/solaar_* "$SITE/../packages/"
-cp -up "$SELF/dist/debian"/solaar-gnome3_* "$SITE/../packages/"
+# create packages/ sub-directory
+/bin/mkdir --parents "$SITE/../packages" "$SITE/packages/"
+/bin/cp --archive --update --target-directory="$SITE/../packages/" "$SELF/dist/debian"/solaar_* || true
+/bin/cp --archive --update --target-directory="$SITE/../packages/" "$SELF/dist/debian"/solaar-gnome3_* || true
 if test -x /usr/bin/dpkg-scanpackages; then
 	cd "$SITE/../packages/"
-	rm -f *.build
-	dpkg-scanpackages -m . > Packages
-	dpkg-scansources . > Sources
+	/bin/rm --force *.build
+	/usr/bin/dpkg-scanpackages --multiversion . > Packages
+	/usr/bin/dpkg-scansources . > Sources
 	add_md docs/debian.md
 	cd -
 fi
 
+# check for the latest released version, and update the jekyll configuration
 if test -x /usr/bin/uscan; then
-	TAG=$(uscan --no-conf --report-status --check-dirname-regex packaging ./packaging/ \
-				| grep 'Newest version' \
-				| grep -ow '[0-9.]*' | head -1)
+	TAG=$(/usr/bin/uscan --no-conf --report-status --check-dirname-regex packaging ./packaging/ \
+				| /bin/grep 'Newest version' \
+				| /bin/grep --only-matching --word-regexp '[0-9.]*' | /usr/bin/head --lines=1)
 	if test -n "$TAG"; then
-		sed -i -e 's#^version: .*$#'"version: $TAG#" "$SELF/jekyll/_config.yml"
-		sed -i -e 's#/archive/[0-9.]*\.tar\.gz$#'"/archive/$TAG.tar.gz#" "$SELF/jekyll/_config.yml"
+		/bin/sed --in-place --expression='s#^version: .*$#'"version: $TAG#" "$SELF/jekyll/_config.yml"
+		/bin/sed --in-place --expression='s#/archive/[0-9.]*\.tar\.gz$#'"/archive/$TAG.tar.gz#" "$SELF/jekyll/_config.yml"
 	fi
 fi
 
-GIT_BACKUP="$(mktemp -ud --tmpdir="$SITE/.." git-backup-XXXXXX)"
-mv "$SITE/.git" "$GIT_BACKUP"
+# Jekyll nukes the .git folder in the target
+# so move it out of the way while building.
+GIT_BACKUP="$(/bin/mktemp --dry-run --directory --tmpdir="$SITE/.." git-backup-XXXXXX)"
+/bin/mv --no-target-directory "$SITE/.git" "$GIT_BACKUP"
 jekyll --kramdown "$BUILD" "$SITE"
-mv "$GIT_BACKUP" "$SITE/.git"
+/bin/mv --no-target-directory "$GIT_BACKUP" "$SITE/.git"
 
-cp -al "$SITE/../packages/" "$SITE/"
+/bin/cp --archive --link "$SITE/../packages/" "$SITE/"
 
+# fix some html formatting
 for p in "$SITE"/*.html; do
-	sed -i -e 's#^[ ]*##g' "$p"
-	sed -i -f- "$p" <<-SED
+	/bin/sed --in-place --expression='s#^[ ]*##g' "$p"
+	/bin/sed --in-place --file=- "$p" <<-SED
 		bstart
 		:eop /<\/p>/ brepl
 		{ N; beop; }
@@ -115,6 +127,7 @@ for p in "$SITE"/*.html; do
 		SED
 done
 
+# set timestmap of the created files to match the sources
 fix_times README.md index.html
 fix_times docs/devices.md devices.html
 fix_times docs/installation.md installation.html