From cc686a769d8063aca8f54b5bfb0d15d73c653b48 Mon Sep 17 00:00:00 2001
From: Robin Richtsfeld <robin.richtsfeld@gmail.com>
Date: Wed, 31 Jan 2018 20:49:10 +0100
Subject: [PATCH] Add version output

---
 BUILD                           | 16 ++++++++++++++++
 butteraugli/butteraugli_main.cc | 28 ++++++++++++++++++++++++----
 version.sh                      | 11 +++++++++++
 3 files changed, 51 insertions(+), 4 deletions(-)
 create mode 100755 version.sh

diff --git a/BUILD b/BUILD
index 5695064..f033099 100755
--- a/BUILD
+++ b/BUILD
@@ -1,3 +1,18 @@
+filegroup(
+    name = "git_files",
+    srcs = glob([".git/**"]),
+)
+
+genrule(
+    name = "gen_version",
+    srcs = [
+        ":git_files",
+        "version.sh"
+    ],
+    outs = ["version.txt"],
+    cmd = "./version.sh $@",
+)
+
 cc_library(
     name = "butteraugli_lib",
     srcs = [
@@ -21,4 +36,5 @@ cc_binary(
         "@jpeg_archive//:jpeg",
         "@png_archive//:png",
     ],
+    data = [":gen_version"],
 )
diff --git a/butteraugli/butteraugli_main.cc b/butteraugli/butteraugli_main.cc
index 80c9510..0ee5274 100755
--- a/butteraugli/butteraugli_main.cc
+++ b/butteraugli/butteraugli_main.cc
@@ -358,13 +358,33 @@ void CreateHeatMapImage(const ImageF& distmap, double good_threshold,
   }
 }
 
+char* ReadVersion(char* argv) {
+  FILE* file = fopen("version.txt", "r");
+  char* buffer = new char[100];
+  fread(buffer, 1, 100, file);
+  fclose(file);
+  return buffer;
+}
+
 // main() function, within butteraugli namespace for convenience.
 int Run(int argc, char* argv[]) {
-  if (argc != 3 && argc != 4) {
+  bool valid_syntax = false;
+
+  if (argc == 2) {
+    if (strcmp(argv[1], "--version") == 0) {
+      fprintf(stdout, "%s version %s\n", argv[0], ReadVersion(argv[0]));
+      return 0;
+    }
+  } else if (argc == 3 || argc == 4) {
+    valid_syntax = true;
+  }
+
+  if (!valid_syntax) {
     fprintf(stderr,
-            "Usage: %s {image1.(png|jpg|jpeg)} {image2.(png|jpg|jpeg)} "
-            "[heatmap.ppm]\n",
-            argv[0]);
+            "Usage:\n"
+            "%s {image1.(png|jpg|jpeg)} {image2.(png|jpg|jpeg)} [heatmap.ppm]\n"
+            "%s --version\n",
+            argv[0], argv[0]);
     return 1;
   }
 
diff --git a/version.sh b/version.sh
new file mode 100755
index 0000000..2eb54a9
--- /dev/null
+++ b/version.sh
@@ -0,0 +1,11 @@
+#!/bin/bash
+
+# .git must not be a symlink
+mv .git .git2
+cp -Lr .git2 .git
+
+(
+git rev-list --count HEAD
+echo ' ('; git rev-parse HEAD
+echo ')'
+) | tr -d '\n' > $@