无法识别 C++ CreateProcess 'telnet'

Question

当我将 ipconfig 命令传递给进程时，它会将正确的结果存储在文件中。

char cmd[] = "C:\\windows\\system32\\cmd.exe /c ipconfig";
SaveResult("ipconfig1.txt", NULL, cmd);

char appName[] = "C:\\windows\\system32\\cmd.exe";
char cmd2[] = "/c ipconfig";
SaveResult("ipconfig2.txt", appName, cmd2);

但是当我通过 wuauclt 或 telnet

char cmd1[] = "C:\\windows\\system32\\cmd.exe /c telnet";
SaveResult("telnet1.txt", NULL, cmd1);

char appName3[] = "C:\\windows\\system32\\cmd.exe";
char cmd3[] = "/c telnet";
SaveResult("telnet2.txt", appName3, cmd3);

char cmd4[] = "C:\\windows\\system32\\cmd.exe /c wuauclt";
SaveResult("wuauclt1.txt", NULL, cmd4);

char appName5[] = "C:\\windows\\system32\\cmd.exe";
char cmd5[] = "/c wuauclt";
SaveResult("wuauclt2.txt", appName5, cmd5);

我明白了

'wuauclt' is not recognized as an internal or external command, operable program or batch file. 'telnet' is not recognized as an internal or external command, operable program or batch file.

如何解决这个问题，为什么会发生？是否可以通过 cmd.exe telnet 或 wuauclt 启动？

同样在这台 PC 上，wuauclt 和 telnet 在公共(public)控制台中打开，从开始按预期工作。

#include "stdafx.h"
#include "windows.h"

wchar_t *convertCharArrayToLPCWSTR(const char* charArray)
{
    wchar_t* wString = new wchar_t[4096];
    MultiByteToWideChar(CP_ACP, 0, charArray, -1, wString, 4096);
    return wString;
}

void SaveResult(const char *fileName, const char *appName, const char *commandLine)
{
    SECURITY_ATTRIBUTES sa;
    sa.nLength = sizeof(sa);
    sa.lpSecurityDescriptor = NULL;
    sa.bInheritHandle = TRUE;

    HANDLE h = CreateFile(convertCharArrayToLPCWSTR(fileName),
        FILE_APPEND_DATA,
        FILE_SHARE_WRITE | FILE_SHARE_READ,
        &sa,
        OPEN_ALWAYS,
        FILE_ATTRIBUTE_NORMAL,
        NULL);

    PROCESS_INFORMATION pi;
    STARTUPINFO si;
    BOOL ret = FALSE;
    DWORD flags = CREATE_NO_WINDOW;

    ZeroMemory(&pi, sizeof(PROCESS_INFORMATION));
    ZeroMemory(&si, sizeof(STARTUPINFO));
    si.cb = sizeof(STARTUPINFO);
    si.dwFlags |= STARTF_USESTDHANDLES;
    si.hStdInput = NULL;
    si.hStdError = h;
    si.hStdOutput = h;

    ret = CreateProcess(appName==NULL ? NULL : convertCharArrayToLPCWSTR(appName), commandLine == NULL ? NULL : convertCharArrayToLPCWSTR(commandLine), NULL, NULL, TRUE, flags, NULL, NULL, &si, &pi);

    if (ret)
    {
        CloseHandle(pi.hProcess);
        CloseHandle(pi.hThread);
        CloseHandle(h);
    }
}
int main()
{
    char cmd[] = "C:\\windows\\system32\\cmd.exe /c ipconfig";
    SaveResult("ipconfig1.txt", NULL, cmd);

    char appName[] = "C:\\windows\\system32\\cmd.exe";
    char cmd2[] = "/c ipconfig";
    SaveResult("ipconfig2.txt", appName, cmd2);

    char cmd1[] = "C:\\windows\\system32\\cmd.exe /c telnet";
    SaveResult("telnet1.txt", NULL, cmd1);

    char appName3[] = "C:\\windows\\system32\\cmd.exe";
    char cmd3[] = "/c telnet";
    SaveResult("telnet2.txt", appName3, cmd3);

    char cmd4[] = "C:\\windows\\system32\\cmd.exe /c wuauclt";
    SaveResult("wuauclt1.txt", NULL, cmd4);

    char appName5[] = "C:\\windows\\system32\\cmd.exe";
    char cmd5[] = "/c wuauclt";
    SaveResult("wuauclt2.txt", appName5, cmd5);

    return -1;
}

Answer 1

如果您在控制台窗口中输入ipconfig，该进程将显示 IP 信息并退出。

另一方面，如果您在控制台窗口中键入telnet，该进程将显示提示并等待响应。该过程不会自动完成。

当您使用CreateProcess 运行此命令时，CreateProcess 将立即返回，但进程并未完成。然后您尝试关闭 telnet 仍在使用的文件句柄。

您可以使用 WaitForSingleObject 等待进程完成。在 telnet 的情况下，该过程未完成。下面的例子演示了这个问题。

对于 CreateProcess，提供整个命令行作为第二个参数。确保字符缓冲区可写，并在最后释放。

旁注，建议对 Unicode 程序使用宽字符串。将 ANSI 提升为 UTF16 很好，但在这种情况下并没有太大收获。您还可以将 CreateProcessA 与 STARTUPINFOA si = { sizeof(si) }; 一起使用，后者接受 ANSI 字符。

void SaveResult(const wchar_t *fileName, const wchar_t *commandLine)
{
    SECURITY_ATTRIBUTES sa;
    sa.nLength = sizeof(sa);
    sa.lpSecurityDescriptor = NULL;
    sa.bInheritHandle = TRUE;

    HANDLE h = CreateFile(fileName, FILE_WRITE_DATA, FILE_SHARE_WRITE | FILE_SHARE_READ,
        &sa, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
    if(h == INVALID_HANDLE_VALUE)
        return;

    PROCESS_INFORMATION pi = { 0 };
    STARTUPINFO si = { sizeof(si) };
    si.dwFlags |= STARTF_USESTDHANDLES;
    si.hStdInput = NULL;
    si.hStdError = h;
    si.hStdOutput = h;

    wchar_t *writable_cmdline = _wcsdup(commandLine);
    BOOL success = CreateProcess(NULL, writable_cmdline,
        NULL, NULL, TRUE, CREATE_NO_WINDOW, NULL, NULL, &si, &pi);

    bool finished = false;

    //wait for 1 second
    for(int i = 0; i < 10; i++)
    {
        if(WaitForSingleObject(pi.hProcess, 100) <= 0)
        {
            finished = true;
            break;
        }
    }

    if(success)
    {
        CloseHandle(pi.hProcess);
        CloseHandle(pi.hThread);
    }

    CloseHandle(h);
    free(writable_cmdline);

    if(!finished)
        printf("Process didn't finish\n");
}


int main()
{
    SaveResult(L"telnet.txt", L"C:\\windows\\system32\\cmd.exe /c telnet");
    SaveResult(L"ipconfig.txt", L"C:\\windows\\system32\\cmd.exe /c ipconfig");
    return 0;
}