Core: Add initial process support (Process::SpawnDetached)

src/Nazara/Core/Win32/ProcessImpl.cpp

@@ -0,0 +1,125 @@
+// Copyright (C) 2024 Jérôme "SirLynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Core/Win32/ProcessImpl.hpp>
+#include <Nazara/Core/Error.hpp>
+#include <Nazara/Core/StringExt.hpp>
+#include <Nazara/Core/Win32/Win32Utils.hpp>
+#include <Windows.h>
+#include <Nazara/Core/Debug.hpp>
+
+namespace Nz::PlatformImpl
+{
+	std::wstring BuildCommandLine(const std::filesystem::path& program, std::span<const std::string> arguments)
+	{
+		std::wstring commandLine;
+
+		auto AddProgramName = [&commandLine](const WidePathHolder& program)
+		{
+			if (!program.starts_with(L'"') && !program.ends_with(L'"') && program.find(L' ') != program.npos)
+			{
+				commandLine += L'"';
+				commandLine += program;
+				commandLine += L'"';
+			}
+			else
+				commandLine += program;
+			
+			ReplaceStr(commandLine, L'/', L'\\');
+			commandLine += L' ';
+		};
+
+		// Use a lambda to keep WidePathHolder alive
+		AddProgramName(PathToWideTemp(program));
+
+		for (std::string_view arg : arguments)
+		{
+			commandLine += L' ';
+
+			if (arg.empty())
+			{
+				// Empty argument (ensures quotes)
+				commandLine += LR"("")";
+				continue;
+			}
+
+			// Characters requiring quotes from cmd /?
+			constexpr std::string_view specialChars = "\t &()[]{}^=;!'+,`~%|<>";
+
+			bool requiresQuote = arg.find_first_of(specialChars) != arg.npos;
+
+			if (requiresQuote)
+				commandLine += L'"';
+
+			std::size_t backslashCount = 0;
+			IterateOnWideChars(arg, [&](std::wstring_view characters)
+			{
+				for (wchar_t character : characters)
+				{
+					if (character != L'\\')
+					{
+						// Escape quotes and double their preceding backslashes ('\\\"' => '\\\\\\\"')
+						if (character == L'"')
+							commandLine.append(backslashCount + 1, L'\\');
+
+						backslashCount = 0;
+					}
+					else
+						backslashCount++;
+
+					commandLine.push_back(character);
+				}
+
+				return true;
+			});
+
+			if (requiresQuote)
+			{
+				commandLine.append(backslashCount, L'\\');
+				commandLine += L'"';
+			}
+		}
+
+		return commandLine;
+	}
+
+	Result<Pid, std::string> SpawnDetachedProcess(const std::filesystem::path& program, std::span<const std::string> arguments, const std::filesystem::path& workingDirectory)
+	{
+		DWORD creationFlags = CREATE_UNICODE_ENVIRONMENT | CREATE_NEW_PROCESS_GROUP | DETACHED_PROCESS;
+
+		std::wstring commandLine = BuildCommandLine(program, arguments);
+
+		STARTUPINFOW startupInfo = {
+			.cb = sizeof(startupInfo),
+			.dwX = DWORD(CW_USEDEFAULT),
+			.dwY = DWORD(CW_USEDEFAULT),
+			.dwXSize = DWORD(CW_USEDEFAULT),
+			.dwYSize = DWORD(CW_USEDEFAULT)
+		};
+
+		PROCESS_INFORMATION processInfo;
+		BOOL success = CreateProcessW(
+			nullptr,            // Application name
+			commandLine.data(), // Command line
+			nullptr,            // Process attributes
+			nullptr,            // Thread attributes
+			false,              // Inherit handles
+			creationFlags,      // Creation flags
+			nullptr,            // Environment
+			(!workingDirectory.empty()) ? PathToWideTemp(workingDirectory).data() : nullptr, // Current directory
+			&startupInfo,       // Startup info
+			&processInfo        // Process information
+		);
+
+		if (!success)
+			return Err(Error::GetLastSystemError());
+
+		CloseHandle(processInfo.hThread);
+		CloseHandle(processInfo.hProcess);
+
+		return Pid(processInfo.dwProcessId);
+	}
+}
+
+#include <Nazara/Core/AntiWindows.hpp>

src/Nazara/Core/Win32/ProcessImpl.hpp

@@ -0,0 +1,18 @@
+// Copyright (C) 2024 Jérôme "SirLynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#pragma once
+
+#ifndef NAZARA_CORE_WIN32_PROCESSIMPL_HPP
+#define NAZARA_CORE_WIN32_PROCESSIMPL_HPP
+
+#include <NazaraUtils/Prerequisites.hpp>
+#include <Nazara/Core/Process.hpp>
+
+namespace Nz::PlatformImpl
+{
+	NAZARA_CORE_API Result<Pid, std::string> SpawnDetachedProcess(const std::filesystem::path& program, std::span<const std::string> arguments = {}, const std::filesystem::path& workingDirectory = {});
+}
+
+#endif // NAZARA_CORE_WIN32_PROCESSIMPL_HPP