reactos/base/shell/cmd/ctty.c

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/*
* CTTY.C - ctty (Change TTY) command.
*
* This command redirects the first three standard handles
* stdin, stdout, stderr to another terminal.
*
*
* History:
*
* 14 Aug 1998 (John P Price)
* - Created dummy command.
*
* 2000/01/14 ska
* + Added to change the first three handles to the given device name
* + Supports only redirection of stdin and stdout, e.g.:
* C:\> CTTY COM1 >file
* -or-
* C:\> echo Hallo | CTTY COM1 | echo du
* The CTTY command effects the commands on the _next_ line.
*
* 20 Oct 2016 (Hermes Belusca-Maito)
* Port it to NT.
*/
#include "precomp.h"
#if defined(INCLUDE_CMD_CTTY) && defined(FEATURE_REDIRECTION)
static WORD
CheckTerminalDeviceType(IN LPCTSTR pszName)
{
/* Console reserved "file" names */
static const LPCWSTR DosLPTDevice = L"LPT";
static const LPCWSTR DosCOMDevice = L"COM";
static const LPCWSTR DosPRNDevice = L"PRN";
static const LPCWSTR DosAUXDevice = L"AUX";
static const LPCWSTR DosCONDevice = L"CON";
static const LPCWSTR DosNULDevice = L"NUL";
LPCWSTR DeviceName;
ULONG DeviceNameInfo;
WORD DeviceType = 0; // 0: Unknown; 1: CON; 2: COM etc...
#ifndef _UNICODE // UNICODE means that TCHAR == WCHAR == UTF-16
/* Convert from the current process/thread's codepage to UTF-16 */
DWORD len = strlen(pszName) + 1;
WCHAR *buffer = cmd_alloc(len * sizeof(WCHAR));
if (!buffer)
{
// SetLastError(ERROR_NOT_ENOUGH_MEMORY);
return FALSE;
}
len = (DWORD)MultiByteToWideChar(CP_THREAD_ACP, // CP_ACP, CP_OEMCP
0, pszName, (INT)len, buffer, (INT)len);
DeviceName = buffer;
#else
DeviceName = pszName;
#endif
/*
* Check whether we deal with a DOS device, and if so,
* strip the path till the file name.
* Therefore, things like \\.\CON or C:\some_path\COM1
* are transformed into CON or COM1, for example.
*/
DeviceNameInfo = RtlIsDosDeviceName_U(DeviceName);
if (DeviceNameInfo != 0)
{
DeviceName = (LPCWSTR)((ULONG_PTR)DeviceName + ((DeviceNameInfo >> 16) & 0xFFFF));
if (_wcsnicmp(DeviceName, DosCONDevice, 3) == 0)
{
DeviceType = 1;
}
else
if ( _wcsnicmp(DeviceName, DosLPTDevice, 3) == 0 ||
_wcsnicmp(DeviceName, DosCOMDevice, 3) == 0 ||
_wcsnicmp(DeviceName, DosPRNDevice, 3) == 0 ||
_wcsnicmp(DeviceName, DosAUXDevice, 3) == 0 ||
_wcsnicmp(DeviceName, DosNULDevice, 3) == 0 )
{
DeviceType = 2;
}
// else DeviceType = 0;
}
#ifndef _UNICODE
cmd_free(buffer);
#endif
return DeviceType;
}
/*
* See also redir.c!PerformRedirection().
*
* The CTTY command allows only the usage of CON, COM, AUX, LPT, PRN and NUL
* DOS devices as valid terminal devices. Everything else is forbidden.
*
* CTTY does not set ERRORLEVEL on error.
*/
INT cmd_ctty(LPTSTR param)
{
static SECURITY_ATTRIBUTES SecAttr = { sizeof(SECURITY_ATTRIBUTES), NULL, TRUE };
BOOL Success;
WORD DeviceType;
HANDLE hDevice, hStdHandles[3]; // hStdIn, hStdOut, hStdErr;
/* The user asked for help */
if (_tcsncmp(param, _T("/?"), 2) == 0)
{
ConOutResPaging(TRUE, STRING_CTTY_HELP);
return 0;
}
if (!*param)
{
error_req_param_missing();
return 1;
}
/* Check whether this is a valid terminal device name */
DeviceType = CheckTerminalDeviceType(param);
if (DeviceType == 1)
{
/*
* Special case for CON device.
*
* We do not open CON with GENERIC_READ or GENERIC_WRITE as is,
* but instead we separately open CONIN$ and CONOUT$ with both
* GENERIC_READ | GENERIC_WRITE access.
* We do so because otherwise, opening in particular CON with GENERIC_WRITE
* only would open CONOUT$ with an handle not passing the IsConsoleHandle()
* test, meaning that we could not use the full console functionalities.
*/
BOOL bRetry = FALSE;
RetryOpenConsole:
/*
* If we previously failed in opening handles to the console,
* this means the existing console is almost destroyed.
* Close the existing console and allocate and open a new one.
*/
if (bRetry)
{
FreeConsole();
if (!AllocConsole())
return 1;
}
/* Attempt to retrieve a handle for standard input */
hStdHandles[0] = CreateFile(_T("CONIN$"),
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
&SecAttr,
OPEN_EXISTING,
0,
NULL);
if (hStdHandles[0] == INVALID_HANDLE_VALUE)
{
// TODO: Error
// error_no_rw_device(param);
if (bRetry)
return 1;
bRetry = TRUE;
goto RetryOpenConsole;
}
/* Attempt to retrieve a handle for standard output.
* Note that GENERIC_READ is needed for IsConsoleHandle() to succeed afterwards. */
hStdHandles[1] = CreateFile(_T("CONOUT$"),
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
&SecAttr,
OPEN_EXISTING,
0,
NULL);
if (hStdHandles[1] == INVALID_HANDLE_VALUE)
{
// TODO: Error
// error_no_rw_device(param);
CloseHandle(hStdHandles[0]);
if (bRetry)
return 1;
bRetry = TRUE;
goto RetryOpenConsole;
}
/* Duplicate a handle for standard error */
Success = DuplicateHandle(GetCurrentProcess(),
hStdHandles[1],
GetCurrentProcess(),
&hStdHandles[2],
0, // GENERIC_WRITE,
TRUE,
DUPLICATE_SAME_ACCESS /* 0 */);
if (!Success)
{
// TODO: Error
// error_no_rw_device(param);
CloseHandle(hStdHandles[1]);
CloseHandle(hStdHandles[0]);
return 1;
}
}
else if (DeviceType == 2)
{
/*
* COM and the other devices can only be opened once.
* Since we need different handles, we need to duplicate them.
*/
/* Attempt to retrieve a handle to the device for read/write access */
hDevice = CreateFile(param,
GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE,
&SecAttr,
OPEN_EXISTING,
0, // FILE_FLAG_OVERLAPPED, // 0,
NULL);
if (hDevice == INVALID_HANDLE_VALUE)
{
// TODO: Error
// error_no_rw_device(param);
return 1;
}
/* Duplicate a handle for standard input */
Success = DuplicateHandle(GetCurrentProcess(),
hDevice,
GetCurrentProcess(),
&hStdHandles[0],
GENERIC_READ,
TRUE,
0);
if (!Success)
{
// TODO: Error
// error_no_rw_device(param);
CloseHandle(hDevice);
return 1;
}
/* Duplicate a handle for standard output */
Success = DuplicateHandle(GetCurrentProcess(),
hDevice,
GetCurrentProcess(),
&hStdHandles[1],
GENERIC_WRITE,
TRUE,
0);
if (!Success)
{
// TODO: Error
// error_no_rw_device(param);
CloseHandle(hStdHandles[0]);
CloseHandle(hDevice);
return 1;
}
/* Duplicate a handle for standard error */
Success = DuplicateHandle(GetCurrentProcess(),
hDevice,
GetCurrentProcess(),
&hStdHandles[2],
GENERIC_WRITE,
TRUE,
0);
if (!Success)
{
// TODO: Error
// error_no_rw_device(param);
CloseHandle(hStdHandles[1]);
CloseHandle(hStdHandles[0]);
CloseHandle(hDevice);
return 1;
}
/* Now get rid of the main device handle */
CloseHandle(hDevice);
}
else
{
// FIXME: Localize!
ConOutPrintf(L"Invalid device '%s'\n", param);
return 1;
}
#if 0
/* Now change the file descriptors:
0 := rdonly
1,2 := wronly
if CTTY is called within a pipe or its I/O is redirected,
oldinfd or oldoutfd is not equal to -1. In such case the
old*fd is modified in order to effect the file descriptor
after the redirections are restored. Otherwise a pipe or
redirection would left CTTY in a half-made status.
*/
// int failed;
failed = dup2(f, 2); /* no redirection support */
if(oldinfd != -1)
dos_close(oldinfd);
oldinfd = f;
if(oldoutfd != -1)
dos_close(oldoutfd);
if((oldoutfd = dup(f)) == -1)
failed = 1;
if(failed)
error_ctty_dup(param);
return failed;
#endif
/* Now set the standard handles */
hDevice = GetHandle(0);
if (hDevice != INVALID_HANDLE_VALUE)
CloseHandle(hDevice);
SetHandle(0, hStdHandles[0]);
hDevice = GetHandle(1);
if (hDevice != INVALID_HANDLE_VALUE)
CloseHandle(hDevice);
SetHandle(1, hStdHandles[1]);
hDevice = GetHandle(2);
if (hDevice != INVALID_HANDLE_VALUE)
CloseHandle(hDevice);
SetHandle(2, hStdHandles[2]);
return 0;
}
#endif /* INCLUDE_CMD_CTTY && FEATURE_REDIRECTION */
/* EOF */