使用 CreateProcess() 创建的 cmd.exe 不从 WriteFile() 读取

Question

I have created a child process with CreateProcess(). an instance of cmd.exe. The first command is passed in the creation of the process and the second is passed through WriteFile(), after the process is created. The first job is done and the second isn't and I don't know the reason why. Please help

The code for creating the process is:

PROCESS_INFORMATION _info;
char cmd[1024];
strcpy(cmd,"C:\\Windows\\system32\\cmd.exe /k echo 1");

    HANDLE _stdin_rd = NULL;
    HANDLE _stdin_wr = NULL;
    HANDLE _stdout_rd = NULL;
    HANDLE _stdout_wr = NULL;
    BOOL br;
    SECURITY_ATTRIBUTES sa;
    sa.nLength = sizeof(SECURITY_ATTRIBUTES);
    sa.bInheritHandle = TRUE;
    sa.lpSecurityDescriptor = NULL;
    br = CreatePipe(&_stdin_rd, &_stdin_wr, &sa, 0);
    br = SetHandleInformation(_stdin_wr, HANDLE_FLAG_INHERIT, 0);
    br = CreatePipe(&_stdout_rd, &_stdout_wr, &sa, 0);
    br = SetHandleInformation(_stdout_rd, HANDLE_FLAG_INHERIT, 0);
    STARTUPINFO si;
    ZeroMemory(&si, sizeof(STARTUPINFO));
    ZeroMemory(&_info, sizeof(PROCESS_INFORMATION));
    si.cb = sizeof(STARTUPINFO);
    si.dwFlags |= STARTF_USESTDHANDLES;
    si.hStdInput = _stdin_rd;
    si.hStdOutput = _stdout_wr;
    si.hStdError = _stdout_wr;
    br = CreateProcess(0, cmd,0,0,TRUE,CREATE_NO_WINDOW,0,0,&si,&_info);
    CloseHandle(_stdout_wr);
    CloseHandle(_stdin_rd);
    CloseHandle(_info.hProcess);
    CloseHandle(_info.hThread);
    printf("process created...\n");

    Sleep(320);
    printf("waited\n\n");

The code for communicating with the process is:

    char bufy[10240];
    char kom[1024];
    long unsigned int prt, ovs=0;
    for(int i=2;i<10;++i){
        if(!ReadFile(_stdout_rd,bufy+ovs,10240-ovs,&prt,0)){
            printf("   ERROR=%d\n",GetLastError());
            break;
        }
        ovs+=prt;
        printf("respond: ");
        bufy[ovs]=0;
        printf("%s\n",bufy);

        sprintf(kom,"/k echo %d",i);
        BOOL odgw = WriteFile(_stdin_wr,kom,strlen(kom),0,0);
        printf("sent(%s): %s\n",odgw?"TRUE":"FALSE",kom);
    }

return 0;

All I get on the output of my program is:

process created...
waited

respond: 1

D:\>
sent(TRUE): /k echo 2

Answer 1

I found the mistake. Commands to be passed afterwards should not begin with /k and should end with \\n . Then the program works. Also, in the creation of the process, there may not be anything after /k , the program will still work.