Added a zen::CreateProc() function for spawning child processes

1 files changed, 119 insertions, 0 deletions

diff --git a/zencore/thread.cpp b/zencore/thread.cpp
index 7f8042ae0..e155d2ab2 100644
--- a/zencore/thread.cpp
+++ b/zencore/thread.cpp
@@ -7,6 +7,7 @@
 #include <zencore/testing.h>
 
 #if ZEN_PLATFORM_WINDOWS
+#	include <shellapi.h>
 #	include <zencore/windows.h>
 #elif ZEN_PLATFORM_LINUX
 #	include <chrono>
@@ -576,6 +577,124 @@ ProcessHandle::Wait(int TimeoutMs)
 //////////////////////////////////////////////////////////////////////////
 
 #if ZEN_PLATFORM_WINDOWS
+static CreateProcResult CreateProcNormal(
+	const std::filesystem::path& Executable,
+	std::string_view			 CommandLine,
+	const CreateProcOptions&	 Options)
+{
+	PROCESS_INFORMATION ProcessInfo{};
+	STARTUPINFO			StartupInfo{.cb = sizeof(STARTUPINFO)};
+
+	const bool			  InheritHandles	= false;
+	void*				  Environment		= nullptr;
+	LPSECURITY_ATTRIBUTES ProcessAttributes = nullptr;
+	LPSECURITY_ATTRIBUTES ThreadAttributes	= nullptr;
+
+	DWORD CreationFlags = 0;
+	if (Options.Flags & CreateProcOptions::Flag_NewConsole)
+	{
+		CreationFlags |= CREATE_NEW_CONSOLE;
+	}
+
+	const wchar_t* WorkingDir = nullptr;
+	if (Options.WorkingDirectory != nullptr)
+	{
+		WorkingDir = Options.WorkingDirectory->c_str();
+	}
+
+	ExtendableWideStringBuilder<256> CommandLineZ;
+	CommandLineZ << CommandLine;
+
+	BOOL Success = CreateProcessW(Executable.c_str(),
+								  CommandLineZ.Data(),
+								  ProcessAttributes,
+								  ThreadAttributes,
+								  InheritHandles,
+								  CreationFlags,
+								  Environment,
+								  WorkingDir,
+								  &StartupInfo,
+								  &ProcessInfo);
+
+	if (!Success)
+	{
+		return nullptr;
+	}
+
+	CloseHandle(ProcessInfo.hThread);
+	return ProcessInfo.hProcess;
+}
+
+static CreateProcResult CreateProcElevated(
+	const std::filesystem::path& Executable,
+	std::string_view			 CommandLine,
+	const CreateProcOptions&	 Options)
+{
+	ExtendableWideStringBuilder<256> CommandLineZ;
+	CommandLineZ << CommandLine;
+
+	SHELLEXECUTEINFO ShellExecuteInfo;
+	ZeroMemory(&ShellExecuteInfo, sizeof(ShellExecuteInfo));
+	ShellExecuteInfo.cbSize		  = sizeof(ShellExecuteInfo);
+	ShellExecuteInfo.fMask		  = SEE_MASK_UNICODE | SEE_MASK_NOCLOSEPROCESS;
+	ShellExecuteInfo.lpFile		  = Executable.c_str();
+	ShellExecuteInfo.lpVerb		  = TEXT("runas");
+	ShellExecuteInfo.nShow		  = SW_SHOW;
+	ShellExecuteInfo.lpParameters = CommandLineZ.c_str();
+
+	if (Options.WorkingDirectory != nullptr)
+	{
+		ShellExecuteInfo.lpDirectory = Options.WorkingDirectory->c_str();
+	}
+
+	if (::ShellExecuteEx(&ShellExecuteInfo))
+	{
+		return ShellExecuteInfo.hProcess;
+	}
+
+	return nullptr;
+}
+#endif // ZEN_PLATFORM_WINDOWS
+
+CreateProcResult CreateProc(
+	const std::filesystem::path& Executable,
+	std::string_view			 CommandLine,
+	const CreateProcOptions&	 Options)
+{
+#if ZEN_PLATFORM_WINDOWS
+	if (Options.Flags & CreateProcOptions::Flag_Elevated)
+	{
+		return CreateProcElevated(Executable, CommandLine, Options);
+	}
+
+	return CreateProcNormal(Executable, CommandLine, Options);
+#else
+	int ChildPid = fork();
+	if (ChildPid < 0)
+	{
+		ThrowLastError("Failed to fork a new child process");
+	}
+	else
+	{
+		if (Options.WorkingDirectory != nullptr)
+		{
+			chdir(Options.WorkingDirectory->c_str());
+		}
+
+		std::string CommandLineZ(CommandLine);
+		if (execl(Executable.c_str(), CommandLineZ.c_str(), nullptr) < 0)
+		{
+			ThrowLastError("Failed to exec() a new process image");
+		}
+	}
+
+	return ChildPid;
+#endif
+}
+
+//////////////////////////////////////////////////////////////////////////
+
+#if ZEN_PLATFORM_WINDOWS
 
 ProcessMonitor::ProcessMonitor()
 {