PrismLauncher/launcher/WindowsConsole.cpp
Sefa Eyeoglu 91ba4cf75e
chore: reformat
Signed-off-by: Sefa Eyeoglu <contact@scrumplex.net>
2023-08-14 18:16:53 +02:00

129 lines
4.6 KiB
C++

/*
* Prism Launcher - Minecraft Launcher
* Copyright (C) 2022 Rachel Powers <508861+Ryex@users.noreply.github.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, version 3.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*
*/
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <fcntl.h>
#include <io.h>
#include <stdio.h>
#include <windows.h>
#include <iostream>
void RedirectHandle(DWORD handle, FILE* stream, const char* mode)
{
HANDLE stdHandle = GetStdHandle(handle);
if (stdHandle != INVALID_HANDLE_VALUE) {
int fileDescriptor = _open_osfhandle((intptr_t)stdHandle, _O_TEXT);
if (fileDescriptor != -1) {
FILE* file = _fdopen(fileDescriptor, mode);
if (file != NULL) {
int dup2Result = _dup2(_fileno(file), _fileno(stream));
if (dup2Result == 0) {
setvbuf(stream, NULL, _IONBF, 0);
}
}
}
}
}
// taken from https://stackoverflow.com/a/25927081
// getting a proper output to console with redirection support on windows is apparently hell
void BindCrtHandlesToStdHandles(bool bindStdIn, bool bindStdOut, bool bindStdErr)
{
// Re-initialize the C runtime "FILE" handles with clean handles bound to "nul". We do this because it has been
// observed that the file number of our standard handle file objects can be assigned internally to a value of -2
// when not bound to a valid target, which represents some kind of unknown internal invalid state. In this state our
// call to "_dup2" fails, as it specifically tests to ensure that the target file number isn't equal to this value
// before allowing the operation to continue. We can resolve this issue by first "re-opening" the target files to
// use the "nul" device, which will place them into a valid state, after which we can redirect them to our target
// using the "_dup2" function.
if (bindStdIn) {
FILE* dummyFile;
freopen_s(&dummyFile, "nul", "r", stdin);
}
if (bindStdOut) {
FILE* dummyFile;
freopen_s(&dummyFile, "nul", "w", stdout);
}
if (bindStdErr) {
FILE* dummyFile;
freopen_s(&dummyFile, "nul", "w", stderr);
}
// Redirect unbuffered stdin from the current standard input handle
if (bindStdIn) {
RedirectHandle(STD_INPUT_HANDLE, stdin, "r");
}
// Redirect unbuffered stdout to the current standard output handle
if (bindStdOut) {
RedirectHandle(STD_OUTPUT_HANDLE, stdout, "w");
}
// Redirect unbuffered stderr to the current standard error handle
if (bindStdErr) {
RedirectHandle(STD_ERROR_HANDLE, stderr, "w");
}
// Clear the error state for each of the C++ standard stream objects. We need to do this, as attempts to access the
// standard streams before they refer to a valid target will cause the iostream objects to enter an error state. In
// versions of Visual Studio after 2005, this seems to always occur during startup regardless of whether anything
// has been read from or written to the targets or not.
if (bindStdIn) {
std::wcin.clear();
std::cin.clear();
}
if (bindStdOut) {
std::wcout.clear();
std::cout.clear();
}
if (bindStdErr) {
std::wcerr.clear();
std::cerr.clear();
}
}
bool AttachWindowsConsole()
{
auto stdinType = GetFileType(GetStdHandle(STD_INPUT_HANDLE));
auto stdoutType = GetFileType(GetStdHandle(STD_OUTPUT_HANDLE));
auto stderrType = GetFileType(GetStdHandle(STD_ERROR_HANDLE));
bool bindStdIn = false;
bool bindStdOut = false;
bool bindStdErr = false;
if (stdinType == FILE_TYPE_CHAR || stdinType == FILE_TYPE_UNKNOWN) {
bindStdIn = true;
}
if (stdoutType == FILE_TYPE_CHAR || stdoutType == FILE_TYPE_UNKNOWN) {
bindStdOut = true;
}
if (stderrType == FILE_TYPE_CHAR || stderrType == FILE_TYPE_UNKNOWN) {
bindStdErr = true;
}
if (AttachConsole(ATTACH_PARENT_PROCESS)) {
BindCrtHandlesToStdHandles(bindStdIn, bindStdOut, bindStdErr);
return true;
}
return false;
}