From 4048945e110ef0f373ab890e25af7a7d1dac21a9 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Thu, 12 Feb 2015 06:11:17 +0100
Subject: [PATCH] browser: wget-ifmodified script to download new caniuse data

---
 Makefile              |  3 +++
 tools/wget-ifmodified | 26 ++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100755 tools/wget-ifmodified

diff --git a/Makefile b/Makefile
index d7c1003..4e51768 100644
--- a/Makefile
+++ b/Makefile
@@ -28,6 +28,9 @@ data/countryInfo.txt:
 countries.inc.pl: data/countryInfo.txt
 	tools/mkcountries-geonames data/countryInfo.txt >$@
 
+data/caniuse.json:
+	tools/wget-ifmodified http://caniuse.com/data.json $@
+
 clean:
 	-rm digraphs.inc.pl
 	-rm unicode-char.inc.pl
diff --git a/tools/wget-ifmodified b/tools/wget-ifmodified
new file mode 100755
index 0000000..bae00f1
--- /dev/null
+++ b/tools/wget-ifmodified
@@ -0,0 +1,26 @@
+#!/usr/bin/env sh
+
+set -u
+
+if [ -z "$1" ]
+then
+	echo 'Usage: $0 <url> [<target>]' >&2
+	# download url to target location if modified
+	exit 64 # EX_USAGE
+fi
+
+source=$1
+target=${2:-${source##*/}}
+
+if [ -e "$target" ]
+then
+	modified=$(stat -c%y -L "$target") &&
+	modified=$(date -R -d "$modified")
+	echo download since: $modified
+fi
+
+headers=${modified:+If-Modified-Since: $modified}
+wget -nv --header="$headers" -O "$target.new" "$source" &&
+mv "$target.new" "$target" ||
+rm "$target.new" # clean up failed download (usually empty 304 response)
+
-- 
2.30.0