System("cls") doesn't work in the debugger terminal.

[RabbitSeries]

Environment

• OS and version: Microsoft Windows 11 Pro 10.0.26100 N/A Build 26100
• VS Code: 1.96.2
• C/C++ extension: [email protected]
• OS and version of remote machine (if applicable): NONE
• GDB / LLDB version: GNU gdb (GDB) 14.2

Bug Summary and Steps to Reproduce

Bug Summary:
In terminal std::system( "cls" ); or std::system( "pause" );, such command does not work as expected on windows OS.
However, manually execute the command still works, execute the program without the debugger still works, enable externalConsole works, on linux platform also works.

Steps to reproduce:

Minimal reproduce code:

#include "iostream"
#include "cstdlib"
int main(){
    std::cout << "This line should be cleared." << std::endl;    
    std::system( "cls" );
    std::cout << "This line will be the one and only line left." << std::endl;
    return 0;
}

launch config:

        {
            "name": "C/C++: g++.exe build and debug active file",
            "type": "cppdbg",
            "request": "launch",
            "program": "${fileDirname}\\${fileBasenameNoExtension}.exe",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${fileDirname}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",
            "miDebuggerPath": "D:\\Build_Tool_Lib\\x86_64-14.2.0-release-win32-seh-ucrt-rt_v12-rev0\\mingw64\\bin\\gdb.exe",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                },
                {
                    "description": "Set Disassembly Flavor to Intel",
                    "text": "-gdb-set disassembly-flavor intel",
                    "ignoreFailures": true
                }
            ],
            "preLaunchTask": "C/C++: g++.exe build active file"
        },

Steps to reproduce:

Minimal reproduce code:

#include "iostream"
#include "cstdlib"
int main(){
    std::cout << "This line should be cleared." << std::endl;    
    // std::cout.flush();
    std::system( "cls" );
    std::cout << "This line will be the one and only line left." << std::endl;
    // std::cout.flush();
    return 0;
}

Debugger Configurations

{
            "name": "C/C++: g++.exe build and debug active file",
            "type": "cppdbg",
            "request": "launch",
            "program": "${fileDirname}\\${fileBasenameNoExtension}.exe",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${fileDirname}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",
            "miDebuggerPath": "D:\\Build_Tool_Lib\\x86_64-14.2.0-release-win32-seh-ucrt-rt_v12-rev0\\mingw64\\bin\\gdb.exe",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                },
                {
                    "description": "Set Disassembly Flavor to Intel",
                    "text": "-gdb-set disassembly-flavor intel",
                    "ignoreFailures": true
                }
            ],
            "logging": { "engineLogging": true, "trace": true, "traceResponse": true },
            "preLaunchTask": "C/C++: g++.exe build active file"
        },

Debugger Logs

Unable to find /usr/bin/g++. [ArchLinux] C/C++: g++ build active file task is ignored.
Unable to find /usr/bin/g++. [ArchLinux] [Release] C/C++: g++ build active file task is ignored.
Unable to find /usr/bin/g++. [ArchLinux] C/C++: gcc build active file task is ignored.
Unable to find /usr/bin/g++. [ArchLinux] C/C++: g++ build active file task is ignored.
Unable to find /usr/bin/g++. [ArchLinux] [Release] C/C++: g++ build active file task is ignored.
Unable to find /usr/bin/g++. [ArchLinux] C/C++: gcc build active file task is ignored.
Launch configuration:
{
  "name": "C/C++: g++.exe build and debug active file",
  "type": "cppdbg",
  "request": "launch",
  "program": "D:\\back_up\\ProgrammingEvents\\AdventOfCode\\2024\\Day20\\test.exe",
  "args": [],
  "stopAtEntry": false,
  "cwd": "D:\\back_up\\ProgrammingEvents\\AdventOfCode\\2024\\Day20",
  "environment": [],
  "externalConsole": true,
  "MIMode": "gdb",
  "miDebuggerPath": "D:\\Build_Tool_Lib\\x86_64-14.2.0-release-win32-seh-ucrt-rt_v12-rev0\\mingw64\\bin\\gdb.exe",
  "setupCommands": [
    {
      "description": "Enable pretty-printing for gdb",
      "text": "-enable-pretty-printing",
      "ignoreFailures": true
    },
    {
      "description": "Set Disassembly Flavor to Intel",
      "text": "-gdb-set disassembly-flavor intel",
      "ignoreFailures": true
    }
  ],
  "logging": {
    "engineLogging": true,
    "trace": true,
    "traceResponse": true
  },
  "preLaunchTask": "C/C++: g++.exe build active file",
  "__configurationTarget": 6,
  "configSource": "workspaceFolder",
  "debugType": "debug"
}
Launch configuration:
{
  "name": "C/C++: g++.exe build and debug active file",
  "type": "cppdbg",
  "request": "launch",
  "program": "D:\\back_up\\ProgrammingEvents\\AdventOfCode\\2024\\Day20\\test.exe",
  "args": [],
  "stopAtEntry": false,
  "cwd": "D:\\back_up\\ProgrammingEvents\\AdventOfCode\\2024\\Day20",
  "environment": [],
  "externalConsole": false,
  "MIMode": "gdb",
  "miDebuggerPath": "D:\\Build_Tool_Lib\\x86_64-14.2.0-release-win32-seh-ucrt-rt_v12-rev0\\mingw64\\bin\\gdb.exe",
  "setupCommands": [
    {
      "description": "Enable pretty-printing for gdb",
      "text": "-enable-pretty-printing",
      "ignoreFailures": true
    },
    {
      "description": "Set Disassembly Flavor to Intel",
      "text": "-gdb-set disassembly-flavor intel",
      "ignoreFailures": true
    }
  ],
  "logging": {
    "engineLogging": true,
    "trace": true,
    "traceResponse": true
  },
  "preLaunchTask": "C/C++: g++.exe build active file",
  "__configurationTarget": 6,
  "configSource": "workspaceFolder",
  "debugType": "debug"
}
Launch configuration:
{
  "name": "C/C++: g++.exe build and debug active file",
  "type": "cppdbg",
  "request": "launch",
  "program": "D:\\back_up\\ProgrammingEvents\\AdventOfCode\\2024\\Day20\\test.exe",
  "args": [],
  "stopAtEntry": false,
  "cwd": "D:\\back_up\\ProgrammingEvents\\AdventOfCode\\2024\\Day20",
  "environment": [],
  "externalConsole": false,
  "MIMode": "gdb",
  "miDebuggerPath": "D:\\Build_Tool_Lib\\x86_64-14.2.0-release-win32-seh-ucrt-rt_v12-rev0\\mingw64\\bin\\gdb.exe",
  "setupCommands": [
    {
      "description": "Enable pretty-printing for gdb",
      "text": "-enable-pretty-printing",
      "ignoreFailures": true
    },
    {
      "description": "Set Disassembly Flavor to Intel",
      "text": "-gdb-set disassembly-flavor intel",
      "ignoreFailures": true
    }
  ],
  "logging": {
    "engineLogging": true,
    "trace": true,
    "traceResponse": true
  },
  "preLaunchTask": "C/C++: g++.exe build active file",
  "__configurationTarget": 6,
  "configSource": "workspaceFolder",
  "debugType": "debug"
}

Other Extensions

No response

Additional Information

No response

[RabbitSeries]

This alternative output will work.

#include "iostream"
#include "cstdlib"
int main(){
    std::cout << "This line should be cleared." << std::endl;    
    //std::system( "cls" );
    std::cout << "\033[2J\033[1;1H";
    std::cout << "This line will be the one and only line left." << std::endl;
    return 0;
}

And the folloing is supplement screenshot for the behaviour comparison of system("pause") after launch from debugger and manually execution. Some output characters may even cause the program to stuck for a while (don't know which yet).

[github-actions]

Thank you for reporting this issue. We’ll let you know if we need more information to investigate it. Additionally, if you're working with GDB/LLDB, please note that the code is open source at https://github.com/microsoft/MIEngine/wiki/Contributing-Code . Your contributions are always welcome and appreciated.