diff --git a/tools/copyright.js b/tools/copyright.js
index 32208193..48d41111 100644
--- a/tools/copyright.js
+++ b/tools/copyright.js
@@ -10,8 +10,33 @@ const OS = require("os");
 
 const SECTION_START = "AUTOGENERATED COPYRIGHT HEADER START";
 const SECTION_END = "AUTOGENERATED COPYRIGHT HEADER END";
+const IGNORED = [
+    ".git",
+    "cmake/clang",
+    "cmake/version",
+    "third-party",
+]
+
+let abortAllWork = false;
+
+async function isIgnored(path) {
+    let rpath = PATH.relative(process.cwd(), path).replaceAll(PATH.sep, PATH.posix.sep);
+    for (let ignore of IGNORED) {
+        if (ignore instanceof RegExp) {
+            if (ignore.global) {
+                if (!rpath.matchAll(ignore).done) {
+                    return true;
+                }
+            } else {
+                if (rpath.match(ignore) !== null) {
+                    return true;
+                }
+            }
+        } else if (rpath.startsWith(ignore)) {
+            return true;
+        }
+    }
 
-async function git_isIgnored(path) {
     return await new Promise((resolve, reject) => {
         try {
             let proc = CHILD_PROCESS.spawn("git", [
@@ -245,13 +270,24 @@ function makeHeader(file, copyright) {
 
 async function addCopyright(file) {
     try {
+        if (abortAllWork) {
+            return;
+        }
 
         // Async/Promises
+        // Copyright information.
+        let copyright = await generateCopyright(file);
+        let header = undefined;
+        try {
+            header = makeHeader(file, copyright);
+        } catch (ex) {
+            return;
+        }
+        console.log(`Updating file '${file}'...`);
+
+        // File contents.
         let content = await FSPROMISES.readFile(file);
         let eol = (content.indexOf("\r\n") != -1 ? OS.EOL : "\n");
-
-        let copyright = await generateCopyright(file);
-        let header = makeHeader(file, copyright);
         let insert = Buffer.from(header.join(eol) + eol);
 
         // Find the starting point.
@@ -264,7 +300,11 @@ async function addCopyright(file) {
         endHeader = content.indexOf(eol, endHeader);
         endHeader += Buffer.from(eol).byteLength;
 
-        let fd = await FSPROMISES.open(file, "w+");
+        if (abortAllWork) {
+            return;
+        }
+
+        let fd = await FSPROMISES.open(file, "w");
         let fp = [];
         if ((startHeader >= 0) && (endHeader >= 0)) {
             let pos = 0;
@@ -318,7 +358,10 @@ async function addCopyright(file) {
 }
 
 async function addCopyrights(path) {
-    if (await git_isIgnored(path)) {
+    if (abortAllWork) {
+        return;
+    }
+    if (await isIgnored(path)) {
         return;
     }
 
@@ -326,16 +369,20 @@ async function addCopyrights(path) {
 
     let files = await FSPROMISES.readdir(path, { "withFileTypes": true });
     for (let file of files) {
+        if (abortAllWork) {
+            break;
+        }
+
         let fullname = PATH.join(path, file.name);
-        if (await git_isIgnored(fullname)) {
+        if (await isIgnored(fullname)) {
             console.log(`Ignoring path '${fullname}'...`);
             continue;
         }
+
         if (file.isDirectory()) {
-            console.log(`Scanning path '${fullname}'...`);
+            //console.log(`Scanning path '${fullname}'...`);
             promises.push(addCopyrights(fullname));
         } else {
-            console.log(`Updating file '${fullname}'...`);
             promises.push(addCopyright(fullname));
         }
     }
@@ -344,12 +391,36 @@ async function addCopyrights(path) {
 }
 
 (async function () {
-    let file = PROCESS.argv[2];
-    let pathStat = await FSPROMISES.stat(file);
+    PROCESS.on("SIGINT", (ev) => {
+        abortAllWork = true;
+        console.log("Sanely aborting all pending work...");
+    })
+
+    let path = PATH.resolve(PROCESS.argv[2]);
+
+    { // Bootstrap to actually be in the directory where '.git' is.
+        let is_git_directory = false;
+        while (!is_git_directory) {
+            if (abortAllWork) {
+                return;
+            }
+
+            let entries = await FSPROMISES.readdir(PROCESS.cwd());
+            if (entries.includes(".git")) {
+                console.log(`Found .git at '${process.cwd()}'.`);
+                is_git_directory = true;
+            } else {
+                PROCESS.chdir(PATH.resolve(PATH.join(PROCESS.cwd(), "..")));
+            }
+        }
+        path = PATH.normalize(PATH.relative(process.cwd(), path));
+    }
+
+    let pathStat = await FSPROMISES.stat(path);
     if (pathStat.isDirectory()) {
-        await addCopyrights(PATH.resolve(file));
+        await addCopyrights(PATH.resolve(path));
     } else {
-        await addCopyright(PATH.resolve(file));
+        await addCopyright(PATH.resolve(path));
     }
     console.log("Done");
 })();