From d09e13d29daf4223990d8d1ae50013dfcd8e4129 Mon Sep 17 00:00:00 2001
From: Mihir Patel <82491937+LowLevelLore@users.noreply.github.com>
Date: Fri, 18 Jul 2025 15:59:07 +0530
Subject: [PATCH] ANSI color sink on Windows

---
 CMakeLists.txt                            |  1 +
 include/spdlog/sinks/ansicolor_sink-inl.h | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 882aa90e..67cf3a20 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -156,6 +156,7 @@ message(STATUS "Build type: " ${CMAKE_BUILD_TYPE})
 # Static/Shared library
 # ---------------------------------------------------------------------------------------
 set(SPDLOG_SRCS src/spdlog.cpp src/stdout_sinks.cpp src/color_sinks.cpp src/file_sinks.cpp src/async.cpp src/cfg.cpp)
+list(APPEND SPDLOG_SRCS include/spdlog/sinks/ansicolor_sink-inl.h)
 
 if(NOT SPDLOG_USE_STD_FORMAT AND NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
     list(APPEND SPDLOG_SRCS src/bundled_fmtlib_format.cpp)
diff --git a/include/spdlog/sinks/ansicolor_sink-inl.h b/include/spdlog/sinks/ansicolor_sink-inl.h
index 6a23f6c7..74f9937f 100644
--- a/include/spdlog/sinks/ansicolor_sink-inl.h
+++ b/include/spdlog/sinks/ansicolor_sink-inl.h
@@ -10,6 +10,13 @@
 #include <spdlog/details/os.h>
 #include <spdlog/pattern_formatter.h>
 
+#if defined(_WIN32)
+    #include <spdlog/details/windows_include.h>
+    #include <fileapi.h>  // WriteFile
+    #include <io.h>       // _get_osfhandle
+    #include <stdio.h>    // _fileno
+#endif
+
 namespace spdlog {
 namespace sinks {
 
@@ -113,14 +120,30 @@ SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color_mode_(color_mode mode
 template <typename ConsoleMutex>
 SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_ccode_(
     const string_view_t &color_code) const {
+#ifdef _WIN32
+    DWORD bytes_written = 0;
+    HANDLE h =
+        (target_file_ == stdout) ? GetStdHandle(STD_OUTPUT_HANDLE) : GetStdHandle(STD_ERROR_HANDLE);
+    // WriteFile bypasses the extra \r injection
+    WriteFile(h, color_code.data(), static_cast<DWORD>(color_code.size()), &bytes_written, nullptr);
+#else
     details::os::fwrite_bytes(color_code.data(), color_code.size(), target_file_);
+#endif
 }
 
 template <typename ConsoleMutex>
 SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_range_(const memory_buf_t &formatted,
                                                               size_t start,
                                                               size_t end) const {
+#ifdef _WIN32
+    DWORD bytes_written = 0;
+    HANDLE h =
+        (target_file_ == stdout) ? GetStdHandle(STD_OUTPUT_HANDLE) : GetStdHandle(STD_ERROR_HANDLE);
+    WriteFile(h, formatted.data() + start, static_cast<DWORD>(end - start), &bytes_written,
+              nullptr);
+#else
     details::os::fwrite_bytes(formatted.data() + start, end - start, target_file_);
+#endif
 }
 
 template <typename ConsoleMutex>