From c35514be86eaf472906620eeafaa007027d8a67b Mon Sep 17 00:00:00 2001
From: Romain Menke <romainmenke@gmail.com>
Date: Thu, 6 Apr 2017 19:44:41 +0200
Subject: [PATCH] add version flag

---
 guetzli/guetzli.cc | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/guetzli/guetzli.cc b/guetzli/guetzli.cc
index 5f78b30b..ec00f5c5 100644
--- a/guetzli/guetzli.cc
+++ b/guetzli/guetzli.cc
@@ -30,6 +30,9 @@
 
 namespace {
 
+// The current guetzli version
+static const char* const  kVersion = "1.0.1";
+
 constexpr int kDefaultJPEGQuality = 95;
 
 // An upper estimate of memory usage of Guetzli. The bound is
@@ -66,7 +69,7 @@ bool ReadPNG(const std::string& data, int* xsize, int* ysize,
   std::istringstream memstream(data, std::ios::in | std::ios::binary);
   png_set_read_fn(png_ptr, static_cast<void*>(&memstream), [](png_structp png_ptr, png_bytep outBytes, png_size_t byteCountToRead) {
     std::istringstream& memstream = *static_cast<std::istringstream*>(png_get_io_ptr(png_ptr));
-    
+
     memstream.read(reinterpret_cast<char*>(outBytes), byteCountToRead);
 
     if (memstream.eof()) png_error(png_ptr, "unexpected end of data");
@@ -217,6 +220,7 @@ void Usage() {
       "guetzli [flags] input_filename output_filename\n"
       "\n"
       "Flags:\n"
+      "  --version    - Print version.\n"
       "  --verbose    - Print a verbose trace of all attempts to standard output.\n"
       "  --quality Q  - Visual quality to aim for, expressed as a JPEG quality value.\n"
       "                 Default value is %d.\n"
@@ -226,6 +230,12 @@ void Usage() {
   exit(1);
 }
 
+void Version() {
+  fprintf(stdout,
+      "Guetzli %s\n", kVersion);
+  exit(0);
+}
+
 }  // namespace
 
 int main(int argc, char** argv) {
@@ -239,6 +249,9 @@ int main(int argc, char** argv) {
   for(;opt_idx < argc;opt_idx++) {
     if (strnlen(argv[opt_idx], 2) < 2 || argv[opt_idx][0] != '-' || argv[opt_idx][1] != '-')
       break;
+    if (!strcmp(argv[opt_idx], "--version")) {
+      Version();
+    }
     if (!strcmp(argv[opt_idx], "--verbose")) {
       verbose = 1;
     } else if (!strcmp(argv[opt_idx], "--quality")) {