Initial structure

Author: adityapatwardhan

.github/CONTRIBUTING.md

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+# Code of Conduct
+
+This project has adopted the [Microsoft Open Source Code of Conduct][conduct-code].
+For more information see the [Code of Conduct FAQ][conduct-FAQ] or contact [opencode@microsoft.com][conduct-email] with any additional questions or comments.
+
+[conduct-code]: http://opensource.microsoft.com/codeofconduct/
+[conduct-FAQ]: http://opensource.microsoft.com/codeofconduct/faq/
+[conduct-email]: mailto:opencode@microsoft.com

CODE_OF_CONDUCT.md

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-# LibPSL-Native
+# libpsl-native
+
+This library provides functionality missing from .NET Core via system calls,
+that are called from from the `CorePsPlatform.cs` file of PowerShell. The
+method to do this is a Platform Invoke, which is C#'s Foreign Function
+Interface to C code (and C++ by way of `extern C`).
+
+## Build
+
+[CMake][] is used to build the project, which results in a `libpsl-native.so`
+library on Linux, and `libpsl-native.dylib` on OS X.
+
+```sh
+cmake -DCMAKE_BUILD_TYPE=Debug .
+make -j
+```
+
+[CMake]: https://cmake.org/cmake/help/v2.8.12/cmake.html
+
+## Test
+
+The [Google Test][] framework is used for unit tests.
+
+Use either `make test` or `ctest --verbose` for more output.
+
+[Google Test]: https://github.com/google/googletest/tree/release-1.7.0
+
+## Notes
+
+Marshalling data from native to managed code is much easier on Linux than it is
+on Windows. For instance, to return a string, you simply return a copy of it on
+the heap. Since only one memory allocator is used on Linux, the .NET runtime
+has no problem later freeing the buffer. Additionally, .NET presumes that the
+codepage "Ansi" on Linux is always UTF-8. So just marshal the string as
+`UnmanagedType.LPStr`.
+
+### C# (Managed)
+
+```c#
+[DllImport("libpsl-native", CharSet = CharSet.Ansi)]
+[return: MarshalAs(UnmanagedType.LPStr)]
+internal static extern string GetSomeString();
+```
+
+### C (Native)
+
+```c
+char *GetSomeString()
+{
+    return strdup("some string");
+}
+```
+
+The CoreFX team has an excellent guide for [UNIX Interop][].
+
+[UNIX Interop]: https://github.com/dotnet/corefx/blob/master/Documentation/coding-guidelines/interop-guidelines.md#unix-shims