source-engine/tier0/win32consoleio.cpp
FluorescentCIAAfricanAmerican 3bf9df6b27 1
2020-04-22 12:56:21 -04:00

91 lines
3.1 KiB
C++

//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: Attaches a console for I/O to a Win32 GUI application in a
// reasonably smart fashion
//
//=============================================================================
#include "pch_tier0.h"
#if defined( _WIN32 )
#include <windows.h>
#include <io.h>
#include <fcntl.h>
#include <iostream>
#endif // defined( _WIN32 )
//-----------------------------------------------------------------------------
//
// Attach a console to a Win32 GUI process and setup stdin, stdout & stderr
// along with the std::iostream (cout, cin, cerr) equivalents to read and
// write to and from that console
//
// 1. Ensure the handle associated with stdio is FILE_TYPE_UNKNOWN
// if it's anything else just return false. This supports cygwin
// style command shells like rxvt which setup pipes to processes
// they spawn
//
// 2. See if the Win32 function call AttachConsole exists in kernel32
// It's a Windows 2000 and above call. If it does, call it and see
// if it succeeds in attaching to the console of the parent process.
// If that succeeds, return false (for no new console allocated).
// This supports someone typing the command from a normal windows
// command window and having the output go to the parent window.
// It's a little funny because a GUI app detaches so the command
// prompt gets intermingled with output from this process
//
// 3. If thigns get to here call AllocConsole which will pop open
// a new window and allow output to go to that window. The
// window will disappear when the process exists so if it's used
// for something like a help message then do something like getchar()
// from stdin to wait for a keypress. if AllocConsole is called
// true is returned.
//
// Return: true if AllocConsole() was used to pop open a new windows console
//
//-----------------------------------------------------------------------------
bool SetupWin32ConsoleIO()
{
#if defined( _WIN32 )
// Only useful on Windows platforms
bool newConsole( false );
if ( GetFileType( GetStdHandle( STD_OUTPUT_HANDLE ) ) == FILE_TYPE_UNKNOWN )
{
HINSTANCE hInst = ::LoadLibrary( "kernel32.dll" );
typedef BOOL ( WINAPI * pAttachConsole_t )( DWORD );
pAttachConsole_t pAttachConsole( ( BOOL ( _stdcall * )( DWORD ) )GetProcAddress( hInst, "AttachConsole" ) );
if ( !( pAttachConsole && (*pAttachConsole)( ( DWORD ) - 1 ) ) )
{
newConsole = true;
AllocConsole();
}
*stdout = *_fdopen( _open_osfhandle( reinterpret_cast< intptr_t >( GetStdHandle( STD_OUTPUT_HANDLE ) ), _O_TEXT ), "w" );
setvbuf( stdout, NULL, _IONBF, 0 );
*stdin = *_fdopen( _open_osfhandle( reinterpret_cast< intptr_t >( GetStdHandle( STD_INPUT_HANDLE ) ), _O_TEXT ), "r" );
setvbuf( stdin, NULL, _IONBF, 0 );
*stderr = *_fdopen( _open_osfhandle( reinterpret_cast< intptr_t >( GetStdHandle( STD_ERROR_HANDLE ) ), _O_TEXT ), "w" );
setvbuf( stdout, NULL, _IONBF, 0 );
std::ios_base::sync_with_stdio();
}
return newConsole;
#else // defined( _WIN32 )
return false;
#endif // defined( _WIN32 )
}