re-added license header files

Signed-off-by: Natalia Luzuriaga <[email protected]>

example-spdx-headers.md

@@ -0,0 +1,81 @@
+# SPDX License Headers for CC0 1.0 Universal in the top 20 programming languages
+
+## JavaScript
+
+`// SPDX-License-Identifier: CC0-1.0`
+
+## Python
+
+`# SPDX-License-Identifier: CC0-1.0`
+
+## Java
+
+`/* SPDX-License-Identifier: CC0-1.0 */`
+
+## C++
+
+`/* SPDX-License-Identifier: CC0-1.0 */`
+
+## Ruby
+
+`# SPDX-License-Identifier: CC0-1.0`
+
+## PHP
+
+`<?php // SPDX-License-Identifier: CC0-1.0 ?>`
+
+## C\#
+
+`// SPDX-License-Identifier: CC0-1.0`
+
+## Go
+
+`// SPDX-License-Identifier: CC0-1.0`
+
+## TypeScript
+
+`// SPDX-License-Identifier: CC0-1.0`
+
+## Swift
+
+`// SPDX-License-Identifier: CC0-1.0`
+
+## Objective-C
+
+`// SPDX-License-Identifier: CC0-1.0`
+
+## Shell
+
+`# SPDX-License-Identifier: CC0-1.0`
+
+## Kotlin
+
+`/* SPDX-License-Identifier: CC0-1.0 */`
+
+## R
+
+`# SPDX-License-Identifier: CC0-1.0`
+
+## Scala
+
+`/* SPDX-License-Identifier: CC0-1.0 */`
+
+## Lua
+
+`-- SPDX-License-Identifier: CC0-1.0`
+
+## Perl
+
+`# SPDX-License-Identifier: CC0-1.0`
+
+## Haskell
+
+`-- SPDX-License-Identifier: CC0-1.0`
+
+## Groovy
+
+`/* SPDX-License-Identifier: CC0-1.0 */`
+
+## Rust
+
+`// SPDX-License-Identifier: CC0-1.0`

insert_license_headers.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# SPDX-License-Identifier: CC0-1.0
+#
+# This script inserts an SPDX license header at the top of all files in a Git repository
+# that do not already have the header.
+#
+# Usage: ./insert_license_headers.sh
+
+LICENSE_HEADER="// SPDX-License-Identifier: CC0-1.0"
+
+for file in $(git ls-files); do
+    if [ $(head -n 1 $file) != $LICENSE_HEADER ]; then
+        echo "Inserting license header into $file"
+        (echo $LICENSE_HEADER; cat $file) > /tmp/file
+        mv /tmp/file $file
+    fi
+done