如果我有一个本地 C++ windows 程序（即入口点是 WinMain），我如何查看 std::cout 等控制台函数的输出？
Obediah Stane
问问题
103236 次
11 回答
30
查看将控制台 I/O 添加到 Win32 GUI 应用程序。这可以帮助你做你想做的事。
如果您没有或无法修改代码，请尝试此处找到的建议将控制台输出重定向到文件。
编辑：这里有一点线程死灵法。我第一次回答这个问题是在 9 年前，在 SO 的早期，在非仅链接答案的（好）政策生效之前。我将重新发布原始文章中的代码，以弥补我过去的罪过。
guicon.cpp -- 控制台重定向功能
#include <windows.h>
#include <stdio.h>
#include <fcntl.h>
#include <io.h>
#include <iostream>
#include <fstream>
#ifndef _USE_OLD_IOSTREAMS
using namespace std;
#endif
// maximum mumber of lines the output console should have
static const WORD MAX_CONSOLE_LINES = 500;
#ifdef _DEBUG
void RedirectIOToConsole()
{
int hConHandle;
long lStdHandle;
CONSOLE_SCREEN_BUFFER_INFO coninfo;
FILE *fp;
// allocate a console for this app
AllocConsole();
// set the screen buffer to be big enough to let us scroll text
GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &coninfo);
coninfo.dwSize.Y = MAX_CONSOLE_LINES;
SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), coninfo.dwSize);
// redirect unbuffered STDOUT to the console
lStdHandle = (long)GetStdHandle(STD_OUTPUT_HANDLE);
hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
fp = _fdopen( hConHandle, "w" );
*stdout = *fp;
setvbuf( stdout, NULL, _IONBF, 0 );
// redirect unbuffered STDIN to the console
lStdHandle = (long)GetStdHandle(STD_INPUT_HANDLE);
hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
fp = _fdopen( hConHandle, "r" );
*stdin = *fp;
setvbuf( stdin, NULL, _IONBF, 0 );
// redirect unbuffered STDERR to the console
lStdHandle = (long)GetStdHandle(STD_ERROR_HANDLE);
hConHandle = _open_osfhandle(lStdHandle, _O_TEXT);
fp = _fdopen( hConHandle, "w" );
*stderr = *fp;
setvbuf( stderr, NULL, _IONBF, 0 );
// make cout, wcout, cin, wcin, wcerr, cerr, wclog and clog
// point to console as well
ios::sync_with_stdio();
}
#endif
//End of File
guicon.h -- 控制台重定向功能的接口
#ifndef __GUICON_H__
#define __GUICON_H__
#ifdef _DEBUG
void RedirectIOToConsole();
#endif
#endif
// End of File
test.cpp -- 演示控制台重定向
#include <windows.h>
#include <iostream>
#include <fstream>
#include <conio.h>
#include <stdio.h>
#ifndef _USE_OLD_OSTREAMS
using namespace std;
#endif
#include "guicon.h"
#include <crtdbg.h>
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow)
{
#ifdef _DEBUG
RedirectIOToConsole();
#endif
int iVar;
// test stdio
fprintf(stdout, "Test output to stdout\n");
fprintf(stderr, "Test output to stderr\n");
fprintf(stdout, "Enter an integer to test stdin: ");
scanf("%d", &iVar);
printf("You entered %d\n", iVar);
//test iostreams
cout << "Test output to cout" << endl;
cerr << "Test output to cerr" << endl;
clog << "Test output to clog" << endl;
cout << "Enter an integer to test cin: ";
cin >> iVar;
cout << "You entered " << iVar << endl;
#ifndef _USE_OLD_IOSTREAMS
// test wide iostreams
wcout << L"Test output to wcout" << endl;
wcerr << L"Test output to wcerr" << endl;
wclog << L"Test output to wclog" << endl;
wcout << L"Enter an integer to test wcin: ";
wcin >> iVar;
wcout << L"You entered " << iVar << endl;
#endif
// test CrtDbg output
_CrtSetReportMode( _CRT_ASSERT, _CRTDBG_MODE_FILE );
_CrtSetReportFile( _CRT_ASSERT, _CRTDBG_FILE_STDERR );
_CrtSetReportMode( _CRT_ERROR, _CRTDBG_MODE_FILE );
_CrtSetReportFile( _CRT_ERROR, _CRTDBG_FILE_STDERR);
_CrtSetReportMode( _CRT_WARN, _CRTDBG_MODE_FILE );
_CrtSetReportFile( _CRT_WARN, _CRTDBG_FILE_STDERR);
_RPT0(_CRT_WARN, "This is testing _CRT_WARN output\n");
_RPT0(_CRT_ERROR, "This is testing _CRT_ERROR output\n");
_ASSERT( 0 && "testing _ASSERT" );
_ASSERTE( 0 && "testing _ASSERTE" );
Sleep(2000);
return 0;
}
//End of File
于 2008-10-10T15:29:50.243 回答
21
其他一些答案的问题是它们不必要地创建了新FILE实例，这些实例随后被泄露，并可能导致 CRT 清理代码中的调试断言。
freopen_s就是真正需要的：
FILE* fp = nullptr;
freopen_s(&fp, "CONIN$", "r", stdin);
freopen_s(&fp, "CONOUT$", "w", stdout);
freopen_s(&fp, "CONOUT$", "w", stderr);
您可能还想进行一些错误检查和清理。以下是我目前使用的完整解决方案。
重定向控制台标准 IO：
bool RedirectConsoleIO()
{
bool result = true;
FILE* fp;
// Redirect STDIN if the console has an input handle
if (GetStdHandle(STD_INPUT_HANDLE) != INVALID_HANDLE_VALUE)
if (freopen_s(&fp, "CONIN$", "r", stdin) != 0)
result = false;
else
setvbuf(stdin, NULL, _IONBF, 0);
// Redirect STDOUT if the console has an output handle
if (GetStdHandle(STD_OUTPUT_HANDLE) != INVALID_HANDLE_VALUE)
if (freopen_s(&fp, "CONOUT$", "w", stdout) != 0)
result = false;
else
setvbuf(stdout, NULL, _IONBF, 0);
// Redirect STDERR if the console has an error handle
if (GetStdHandle(STD_ERROR_HANDLE) != INVALID_HANDLE_VALUE)
if (freopen_s(&fp, "CONOUT$", "w", stderr) != 0)
result = false;
else
setvbuf(stderr, NULL, _IONBF, 0);
// Make C++ standard streams point to console as well.
ios::sync_with_stdio(true);
// Clear the error state for each of the C++ standard streams.
std::wcout.clear();
std::cout.clear();
std::wcerr.clear();
std::cerr.clear();
std::wcin.clear();
std::cin.clear();
return result;
}
发布控制台：
bool ReleaseConsole()
{
bool result = true;
FILE* fp;
// Just to be safe, redirect standard IO to NUL before releasing.
// Redirect STDIN to NUL
if (freopen_s(&fp, "NUL:", "r", stdin) != 0)
result = false;
else
setvbuf(stdin, NULL, _IONBF, 0);
// Redirect STDOUT to NUL
if (freopen_s(&fp, "NUL:", "w", stdout) != 0)
result = false;
else
setvbuf(stdout, NULL, _IONBF, 0);
// Redirect STDERR to NUL
if (freopen_s(&fp, "NUL:", "w", stderr) != 0)
result = false;
else
setvbuf(stderr, NULL, _IONBF, 0);
// Detach from console
if (!FreeConsole())
result = false;
return result;
}
调整控制台缓冲区的大小：
void AdjustConsoleBuffer(int16_t minLength)
{
// Set the screen buffer to be big enough to scroll some text
CONSOLE_SCREEN_BUFFER_INFO conInfo;
GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &conInfo);
if (conInfo.dwSize.Y < minLength)
conInfo.dwSize.Y = minLength;
SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), conInfo.dwSize);
}
分配新控制台：
bool CreateNewConsole(int16_t minLength)
{
bool result = false;
// Release any current console and redirect IO to NUL
ReleaseConsole();
// Attempt to create new console
if (AllocConsole())
{
AdjustConsoleBuffer(minLength);
result = RedirectConsoleIO();
}
return result;
}
附加到家长控制台：
bool AttachParentConsole(int16_t minLength)
{
bool result = false;
// Release any current console and redirect IO to NUL
ReleaseConsole();
// Attempt to attach to parent process's console
if (AttachConsole(ATTACH_PARENT_PROCESS))
{
AdjustConsoleBuffer(minLength);
result = RedirectConsoleIO();
}
return result;
}
从 WinMain 调用：
链接到/SUBSYSTEM:Windows
int APIENTRY WinMain(
HINSTANCE /*hInstance*/,
HINSTANCE /*hPrevInstance*/,
LPTSTR /*lpCmdLine*/,
int /*cmdShow*/)
{
if (CreateNewConsole(1024))
{
int i;
// test stdio
fprintf(stdout, "Test output to stdout\n");
fprintf(stderr, "Test output to stderr\n");
fprintf(stdout, "Enter an integer to test stdin: ");
scanf("%d", &i);
printf("You entered %d\n", i);
// test iostreams
std::cout << "Test output to std::cout" << std::endl;
std::cerr << "Test output to std::cerr" << std::endl;
std::clog << "Test output to std::clog" << std::endl;
std::cout << "Enter an integer to test std::cin: ";
std::cin >> i;
std::cout << "You entered " << i << std::endl;
std::cout << endl << "Press any key to continue..." << endl;
_getch();
ReleaseConsole();
}
return 0;
};
于 2019-04-26T22:27:43.810 回答
15
您也可以重新打开 cout 和 cerr 流以输出到文件。以下应该适用于此：
#include <iostream>
#include <fstream>
int main ()
{
std::ofstream file;
file.open ("cout.txt");
std::streambuf* sbuf = std::cout.rdbuf();
std::cout.rdbuf(file.rdbuf());
//cout is now pointing to a file
return 0;
}
于 2008-10-10T15:35:59.983 回答
9
实际上，有一个比迄今为止提出的任何解决方案都简单得多的解决方案。您的 Windows 程序将具有 WinMain 函数，因此只需添加此“虚拟”主函数即可
int main()
{
return WinMain(GetModuleHandle(NULL), NULL, GetCommandLineA(), SW_SHOWNORMAL);
}
您现在可以像这样使用 MSVC 进行编译
cl /nologo /c /EHsc myprog.c
link /nologo /out:myprog.exe /subsystem:console myprog.obj user32.lib gdi32.lib
（您可能需要添加更多库链接）
当您运行程序时，任何printf将被写入命令提示符。
如果您使用 gcc (mingw) 为 Windows 编译，则不需要虚拟主函数，只需执行
gcc -o myprog.exe myprog.c -luser32 -lgdi32
（即避免使用-mwindows会阻止写入控制台的标志。当您创建最终的 GUI 版本时，该标志将很有用）同样，如果使用更多 Windows 功能，您可能需要指定更多库）
于 2018-10-09T09:11:13.330 回答
9
如果您将程序的输出发送到文件或管道，例如
myprogram.exe > file.txt
myprogram.exe | anotherprogram.exe
或者您正在从另一个程序调用您的程序并通过管道捕获其输出，那么您不需要更改任何内容。它会正常工作，即使入口点是WinMain.
但是，如果您在控制台或 Visual Studio 中运行程序，则输出不会出现在控制台或 Visual Studio 的“输出”窗口中。如果您想查看“实时”输出，请尝试其他答案之一。
基本上，这意味着标准输出与控制台应用程序一样工作，但它没有连接到您正在运行应用程序的控制台，而且似乎没有简单的方法可以做到这一点（此处提供的所有其他解决方案都连接输出到一个新的控制台窗口，当你运行你的应用程序时会弹出这个窗口，即使是从另一个控制台）。
于 2017-08-01T13:25:52.900 回答
8
在我的 Windows 桌面应用程序项目中，结合使用卢克的答案和罗杰的答案对我有用。
void RedirectIOToConsole() {
//Create a console for this application
AllocConsole();
// Get STDOUT handle
HANDLE ConsoleOutput = GetStdHandle(STD_OUTPUT_HANDLE);
int SystemOutput = _open_osfhandle(intptr_t(ConsoleOutput), _O_TEXT);
FILE *COutputHandle = _fdopen(SystemOutput, "w");
// Get STDERR handle
HANDLE ConsoleError = GetStdHandle(STD_ERROR_HANDLE);
int SystemError = _open_osfhandle(intptr_t(ConsoleError), _O_TEXT);
FILE *CErrorHandle = _fdopen(SystemError, "w");
// Get STDIN handle
HANDLE ConsoleInput = GetStdHandle(STD_INPUT_HANDLE);
int SystemInput = _open_osfhandle(intptr_t(ConsoleInput), _O_TEXT);
FILE *CInputHandle = _fdopen(SystemInput, "r");
//make cout, wcout, cin, wcin, wcerr, cerr, wclog and clog point to console as well
ios::sync_with_stdio(true);
// Redirect the CRT standard input, output, and error handles to the console
freopen_s(&CInputHandle, "CONIN$", "r", stdin);
freopen_s(&COutputHandle, "CONOUT$", "w", stdout);
freopen_s(&CErrorHandle, "CONOUT$", "w", stderr);
//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 console or not.
std::wcout.clear();
std::cout.clear();
std::wcerr.clear();
std::cerr.clear();
std::wcin.clear();
std::cin.clear();
}
于 2017-09-05T08:49:19.247 回答
4
creating a pipe, execute the program console CreateProcess() and read with ReadFile() or writes in console WriteFile()
HANDLE hRead ; // ConsoleStdInput
HANDLE hWrite; // ConsoleStdOutput and ConsoleStdError
STARTUPINFO stiConsole;
SECURITY_ATTRIBUTES segConsole;
PROCESS_INFORMATION priConsole;
segConsole.nLength = sizeof(segConsole);
segConsole.lpSecurityDescriptor = NULL;
segConsole.bInheritHandle = TRUE;
if(CreatePipe(&hRead,&hWrite,&segConsole,0) )
{
FillMemory(&stiConsole,sizeof(stiConsole),0);
stiConsole.cb = sizeof(stiConsole);
GetStartupInfo(&stiConsole);
stiConsole.hStdOutput = hWrite;
stiConsole.hStdError = hWrite;
stiConsole.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
stiConsole.wShowWindow = SW_HIDE; // execute hide
if(CreateProcess(NULL, "c:\\teste.exe",NULL,NULL,TRUE,NULL,
NULL,NULL,&stiConsole,&priConsole) == TRUE)
{
//readfile and/or writefile
}
}
于 2009-01-11T18:06:10.520 回答
3
转到项目>项目属性>链接器>系统并在右侧窗格中，将子系统选项设置为控制台（/SUBSYSTEM：CONSOLE）
然后编译你的程序并从控制台运行它，看看你的命令提示符是否显示你的输出。
于 2017-02-23T17:58:29.303 回答
1
正如那里提到的那样，最简单的解决方案是使用您的项目属性页在和子系统之间来回切换，以随意启用或禁用控制台输出。CONSOLEWINDOWS
您的程序只需要main和WinMain入口点来确保两个配置都在编译。该main函数简单地调用WinMain如下所示：
int main()
{
cout << "Output standard\n";
cerr << "Output error\n";
return WinMain(GetModuleHandle(NULL), NULL, GetCommandLineA(), SW_SHOWNORMAL);
}
于 2019-07-01T11:14:52.703 回答
0
由于没有控制台窗口，这不可能是困难的。（每天学习新东西——我从来不知道控制台功能！）
您可以替换输出调用吗？我会经常使用 TRACE 或 OutputDebugString 将信息发送到 Visual Studio 输出窗口。
于 2008-10-10T15:24:13.517 回答