c89stringutils

C89 is missing some nice things. As is MSVC. This adds the string related functionality for:

• Windows
  • MSVC 2005 through MSVC 2026+
  • MinGW
  • Cygwin
  • Open Watcom 2.0 (including DOS target)
• SunOS
• Linux
• *BSD
• macOS

Everything is hidden behind ifdefs so if the compiler/OS supports the function, that function will be used instead of the one provided by this library.

Architecture & Standards

• Strict C89 Compliance: The entire codebase strictly conforms to ISO C90 (C89), preventing compilation issues on extremely old enterprise toolchains.
• Header Guards & C++ Interop: Fully instrumented with extern "C" blocks and robust guards, playing nicely when directly #included into C++ sources.
• Windows Security: Eradicates the inclusion of heavy platform headers like <windows.h>, and actively defaults to MSVC "Safe CRT" variants (e.g., vsprintf_s, _vscprintf) implicitly when building on Microsoft compilers.
• Quality Metrics: Maintains 100% Doxygen documentation and 100% test coverage locally.

Single-File Header-Only Amalgamation (STB-style)

If you don't want to link against a built static or shared library, you can generate a drop-in, STB-style single-header amalgamation!

When building the project via CMake, toggle C89STRINGUTILS_BUILD_AMALGAMATION=ON:

cmake -B build -DC89STRINGUTILS_BUILD_AMALGAMATION=ON

This generates build/c89stringutils/c89stringutils_amalgamation.h.

To use the amalgamation in your project: Drop it into your source tree and define C89STRINGUTILS_IMPLEMENTATION in exactly one .c or .cpp file before including the header:

#define C89STRINGUTILS_IMPLEMENTATION
#include "c89stringutils_amalgamation.h"

int main(void) {
    char* str = NULL;
    asprintf(&str, "Hello %s", "World");
    free(str);
    return 0;
}

String functions implemented

Function	Citation
strcasestr	From MUSL
strncasecmp	Alias for MSVC's _strnicmp
strcasecmp	Alias for MSVC's _stricmp
snprintf	Mostly from WTF_StringExtras
vsnprintf	Mostly from WTF_StringExtras
strnstr	Mostly from WTF_StringExtras
strerrorlen_s	From Safe C Library
asprintf	From libressl-portable

Additionally jasprintf, a version of asprintf that concatenates on successive calls.

Dependencies

• CMake (3.11 for MSVC 2005 or newer versions for other targets)
• C compiler (any that work with CMake, and were released within the last 30 years)

Configure, build, and test

cmake -S . -B build -DBUILD_TESTING=ON
cmake --build build
ctest --test-dir build -C Debug

Advanced CMake Toggles: The build environment seamlessly supports several CDD-style switches out of the box:

• CDD_CHARSET: Unicode or ANSI (Sets UNICODE and _UNICODE defines).
• CDD_THREADING: ON or OFF.
• CDD_LTO: ON or OFF (Validates and sets CMAKE_INTERPROCEDURAL_OPTIMIZATION).
• CDD_MSVC_RTC: RTC1, RTCu, or RTCs (Automatically injects /RTCx flags on MSVC).

Script to automatically build

Build, test, and package for:

• Cygwin;
• MinGW (32-bit and 64-bit);
• MSVC 2005 (32-bit and 64-bit);
• MSVC 2022 / 2026 (32-bit and 64-bit);
• OpenWatcom's DOS target (16-bit).

…by running in Command Prompt: https://github.com/offscale/win-cmake-multi-build

(also handles upload to GitHub Releases)

Instructions for MSVC 2005

With cmake-3.11.4 specified, do:

mkdir build_msvc2005 && cd build_msvc2005
cmake-3.11.4-win64-x64\bin\cmake -DCMAKE_WARN_VS8=OFF -DCMAKE_BUILD_TYPE="Debug" -G "Visual Studio 8 2005" ..
cmake-3.11.4-win64-x64\bin\cmake --build .
cmake-3.11.4-win64-x64\bin\ctest -C Debug

(the last two commands can be run by opening the solution in Visual Studio 2005)

Alternatively with newer versions of CMake (tested 3.26.3):

mkdir build_msvc_nmake2005 && cd build_msvc_nmake2005
cmake -DCMAKE_BUILD_TYPE="Debug" -G "NMake Makefiles" ..
cmake --build .
ctest -C Debug

Instructions for Open Watcom (DOS target)

With v2 from https://github.com/open-watcom/open-watcom-v2/releases installed:

[path]\WATCOM\owsetenv.bat
mkdir build_dos && cd build_dos
cmake -G "Watcom WMake" -D CMAKE_SYSTEM_NAME "DOS" -D CMAKE_SYSTEM_PROCESSOR "I86" ..
cmake --build .
ctest -C Debug

(that test phase might fail if you're running this on a non-DOS host)

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License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.