msvcrt.lib generator

msvcrt.dll is the generic C runtime library (aka "libc") on Microsoft Windows that has shipped alongside Windows since Windows 95. Unlike other versions of the Microsoft C Runtime, this binary is available on all end user machines and requires no preinstallation or dependency management solution. However, unlike versioned MSVCRT releases (such as msvcrt71.dll), msvcrt.dll does not have a stable API and its exposed functions are not guaranteed backwards compatible by Microsoft. As such, Microsoft - despite linking against this dll themselves for many of their applications - does not provide the required library stub (msvcrt.lib) for developers to dynamically link against msvcrt.dll for their own applications.

The Makefile in this repository will create a version of msvcrt.lib describing the API exposed by the currently installed version of msvcrt.dll, allowing developers to link against the system copy of msvcrt.dll instead of using a specific, versioned release of the MSVC runtime that requires the installation of the VC redistributable package on consumer PCs before applications linked against it can be used.

Note: It is recommended to use the versioned C runtime when and where possible; this script is only provided for the convenience of developers familiar with the pitfalls and caveats that come with using the unversioned copy of msvcrt.dll and the minimal APIs it exposes!

Building msvcrt.lib

To build your own copy of msvcrt.lib, simply launch a copy of the Visual Studio Command Line Tools and cd into the directory you checked out a copy of this repository into, then use the Microsoft Makefile compiler (nmake) to build:

git clone https://github.com/neosmart/msvcrt.lib
cd msvcrt.lib
nmake all

Note that this script currently requires a working installation of the Windows Subsystem for Linux (WSL) installed, and a copy of RunInBash aliased to $.exe to properly generate the .lib file. There are no dependencies/requirements for the resulting file, these are only "build dependencies."

Downloading msvcrt.lib

Builds of msvcrt.lib tagged against the version of Windows they were built on/against can be found on the Releases page of this repository.

Other notes

• The 32-bit and 64-bit copies of msvcrt.dll are virtually identical, but this script generates a separate copy of msvcrt.lib of each for posterity's sake and out of an abundance of caution.
• Since the API of msvcrt.dll is not guaranteed, be sure to test your application thoroughly on all versions of Windows.
• If you do not need the zero-dependency, dynamically-linked binaries that come as a result of linking against the system msvcrt.dll, we do not recommend that you do so.

License

The msvcrt.lib generation script and all utilities included in this repository are licensed under the terms of the MIT Public License and can be freely redistributed accordingly. The msvcrt.lib Makefile script and the GetFileVersionInfo.exe helper utility are developed and maintained by Mahmoud Al-Qudsi mqudsi@neosmart.net of NeoSmart Technologies. This document and thes source code in this repository Copyright NeoSmart Technologies, 2017-2020.