source: downloads/tcl8.5.2/win/stub16.c @ 25

/*
 * stub16.c
 *
 *      A helper program used for running 16-bit DOS applications under
 *      Windows 95.
 *
 * Copyright (c) 1996 by Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: stub16.c,v 1.5 2005/11/04 00:06:50 dkf Exp $
 */

#define STRICT

#include <windows.h>
#include <stdio.h>

static HANDLE           CreateTempFile(void);

/*
 *---------------------------------------------------------------------------
 *
 * main
 *
 *      Entry point for the 32-bit console mode app used by Windows 95 to help
 *      run the 16-bit program specified on the command line.
 *
 *      1. EOF on a pipe that connects a detached 16-bit process and a 32-bit
 *      process is never seen. So, this process runs the 16-bit process
 *      _attached_, and then it is run detached from the calling 32-bit
 *      process.
 *
 *      2. If a 16-bit process blocks reading from or writing to a pipe, it
 *      never wakes up, and eventually brings the whole system down with it if
 *      you try to kill the process. This app simulates pipes. If any of the
 *      stdio handles is a pipe, this program accumulates information into
 *      temp files and forwards it to or from the DOS application as
 *      appropriate. This means that this program must receive EOF from a
 *      stdin pipe before it will actually start the DOS app, and the DOS app
 *      must finish generating stdout or stderr before the data will be sent
 *      to the next stage of the pipe. If the stdio handles are not pipes, no
 *      accumulation occurs and the data is passed straight through to and
 *      from the DOS application.
 *
 * Results:
 *      None.
 *
 * Side effects:
 *      The child process is created and this process waits for it to
 *      complete.
 *
 *---------------------------------------------------------------------------
 */

int
main(void)
{
    DWORD dwRead, dwWrite;
    char *cmdLine;
    HANDLE hStdInput, hStdOutput, hStdError;
    HANDLE hFileInput, hFileOutput, hFileError;
    STARTUPINFO si;
    PROCESS_INFORMATION pi;
    char buf[8192];
    DWORD result;

    hFileInput = INVALID_HANDLE_VALUE;
    hFileOutput = INVALID_HANDLE_VALUE;
    hFileError = INVALID_HANDLE_VALUE;
    result = 1;

    /*
     * Don't get command line from argc, argv, because the command line
     * tokenizer will have stripped off all the escape sequences needed for
     * quotes and backslashes, and then we'd have to put them all back in
     * again. Get the raw command line and parse off what we want ourselves.
     * The command line should be of the form:
     *
     * stub16.exe program arg1 arg2 ...
     */

    cmdLine = strchr(GetCommandLine(), ' ');
    if (cmdLine == NULL) {
        return 1;
    }
    cmdLine++;

    hStdInput = GetStdHandle(STD_INPUT_HANDLE);
    hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
    hStdError = GetStdHandle(STD_ERROR_HANDLE);

    if (GetFileType(hStdInput) == FILE_TYPE_PIPE) {
        hFileInput = CreateTempFile();
        if (hFileInput == INVALID_HANDLE_VALUE) {
            goto cleanup;
        }
        while (ReadFile(hStdInput, buf, sizeof(buf), &dwRead, NULL) != FALSE) {
            if (dwRead == 0) {
                break;
            }
            if (WriteFile(hFileInput, buf, dwRead, &dwWrite, NULL) == FALSE) {
                goto cleanup;
            }
        }
        SetFilePointer(hFileInput, 0, 0, FILE_BEGIN);
        SetStdHandle(STD_INPUT_HANDLE, hFileInput);
    }
    if (GetFileType(hStdOutput) == FILE_TYPE_PIPE) {
        hFileOutput = CreateTempFile();
        if (hFileOutput == INVALID_HANDLE_VALUE) {
            goto cleanup;
        }
        SetStdHandle(STD_OUTPUT_HANDLE, hFileOutput);
    }
    if (GetFileType(hStdError) == FILE_TYPE_PIPE) {
        hFileError = CreateTempFile();
        if (hFileError == INVALID_HANDLE_VALUE) {
            goto cleanup;
        }
        SetStdHandle(STD_ERROR_HANDLE, hFileError);
    }

    ZeroMemory(&si, sizeof(si));
    si.cb = sizeof(si);
    if (CreateProcess(NULL, cmdLine, NULL, NULL, TRUE, 0, NULL, NULL, &si,
            &pi) == FALSE) {
        goto cleanup;
    }

    WaitForInputIdle(pi.hProcess, 5000);
    WaitForSingleObject(pi.hProcess, INFINITE);
    GetExitCodeProcess(pi.hProcess, &result);
    CloseHandle(pi.hProcess);
    CloseHandle(pi.hThread);

    if (hFileOutput != INVALID_HANDLE_VALUE) {
        SetFilePointer(hFileOutput, 0, 0, FILE_BEGIN);
        while (ReadFile(hFileOutput, buf, sizeof(buf), &dwRead, NULL) != FALSE) {
            if (dwRead == 0) {
                break;
            }
            if (WriteFile(hStdOutput, buf, dwRead, &dwWrite, NULL) == FALSE) {
                break;
            }
        }
    }
    if (hFileError != INVALID_HANDLE_VALUE) {
        SetFilePointer(hFileError, 0, 0, FILE_BEGIN);
        while (ReadFile(hFileError, buf, sizeof(buf), &dwRead, NULL) != FALSE) {
            if (dwRead == 0) {
                break;
            }
            if (WriteFile(hStdError, buf, dwRead, &dwWrite, NULL) == FALSE) {
                break;
            }
        }
    }

  cleanup:
    if (hFileInput != INVALID_HANDLE_VALUE) {
        CloseHandle(hFileInput);
    }
    if (hFileOutput != INVALID_HANDLE_VALUE) {
        CloseHandle(hFileOutput);
    }
    if (hFileError != INVALID_HANDLE_VALUE) {
        CloseHandle(hFileError);
    }
    CloseHandle(hStdInput);
    CloseHandle(hStdOutput);
    CloseHandle(hStdError);
    ExitProcess(result);
    return 1;
}

static HANDLE
CreateTempFile(void)
{
    char name[MAX_PATH];
    SECURITY_ATTRIBUTES sa;

    if (GetTempPath(sizeof(name), name) == 0) {
        return INVALID_HANDLE_VALUE;
    }
    if (GetTempFileName(name, "tcl", 0, name) == 0) {
        return INVALID_HANDLE_VALUE;
    }

    sa.nLength = sizeof(sa);
    sa.lpSecurityDescriptor = NULL;
    sa.bInheritHandle = TRUE;
    return CreateFile(name, GENERIC_READ | GENERIC_WRITE, 0, &sa,
            CREATE_ALWAYS, FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE,
            NULL);
}