a utility script to pngcrush png files

build/sanitize-png-files.sh

+#!/bin/bash
+# Copyright (c) 2010 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+ALL_DIRS="
+ash/resources
+ui/resources
+chrome/app/theme
+chrome/browser/resources
+chrome/renderer/resources
+webkit/glue/resources
+remoting/resources
+remoting/webapp
+"
+
+function sanitize_file {
+  tput el
+  echo -ne "$1\r"
+  local file=$1
+  local name=$(basename $file)
+  pngcrush -d $TMP_DIR -brute -reduce -rem text -rem mkBT \
+      -rem mkTS $file > /dev/null

[Nico, 2013/01/10 23:47:37]

I asked leiz/msw about the best way to crunch PNG files, and he wrote:

"""PNGCrush alone isn't ideal. You'll also want to strip iTXt, tEXt, zTXt, and
tIME
chunks *and run PNGSlim* for non-trivial additional lossless size reduction.
I've been meaning to write up these instructions for a while, but you can get
the gist from:

crbug.com/76282 and codereview.chromium.org/7782022 and cmd:
pngcrush.exe -reduce -brute -rem iTXt -rem tEXt -rem zTXt -rem tIME"""

It looks like you are not using all these flags. Also, the bug mentioned also
running pngslim.

Finally, should this be a python script, so that windows people can run it? Or
is this supposed to run automatically on some bot?

[oshima, 2013/01/11 00:12:11]

I took the command from chrome/app/theme/README but looks like it wasn't up to
date.
I'll fix them in follow up CL.
I was planning to just run this periodically for the time being.
I'd rather want to automate someone and will look into it first. IIRC, there
was some discussion about it and decided not to, but I'll look into it again.

+  mv "$TMP_DIR/$name" "$file"
+}
+
+function sanitize_dir {
+  local dir=$1
+  for f in $(find $dir -name "*.png"); do
+    sanitize_file $f
+  done
+}
+
+if [ ! -e ../.gclient ]; then
+  echo "$0 must be run in src directory"
+  exit 1
+fi
+
+# Make sure we have pngcrush installed.
+dpkg -s pngcrush > /dev/null 2>&1
+if [ "$?" != "0" ]; then
+  read -p "Couldn't fnd pngcrush. Do you want to install? (y/n)"
+  [ "$REPLY" == "y" ] && sudo apt-get install pngcrush
+  [ "$REPLY" == "y" ] || exit
+fi
+
+# Create tmp directory for crushed png file.
+TMP_DIR=$(mktemp -d)
+
+# Make sure we cleanup temp dir
+trap "rm -rf $TMP_DIR" EXIT
+
+# If no arguments passed, sanitize all directories.
+DIRS=$*
+set ${DIRS:=$ALL_DIRS}
+
+for d in $DIRS; do
+  echo "Sanitizing png files in $d"
+  sanitize_dir $d
+  echo
+done
+