DBMON.C

/*++ 
 
Copyright (c) 1990  Microsoft Corporation 
 
Module Name: 
 
    dbmon.c 
 
Abstract: 
 
    A simple program to print strings passed to OutputDebugString when 
    the app printing the strings is not being debugged. 
 
Author: 
 
    Kent Forschmiedt (kentf) 30-Sep-1994 
 
Revision History: 
 
--*/ 
 
#include <windows.h> 
#include <stdio.h> 
#include <stdlib.h> 
 
int _cdecl 
main( 
    int argc, 
    char ** argv 
    ) 
/*++ 
 
Routine Description: 
 
 
Arguments: 
 
 
Return Value: 
 
 
--*/ 
{ 
    HANDLE AckEvent; 
    HANDLE ReadyEvent; 
    HANDLE SharedFile; 
    LPVOID SharedMem; 
    LPSTR  String; 
    DWORD  ret; 
    DWORD  LastPid; 
    LPDWORD pThisPid; 
    BOOL    DidCR; 
 
    SECURITY_ATTRIBUTES sa; 
    SECURITY_DESCRIPTOR sd; 
 
    sa.nLength = sizeof(SECURITY_ATTRIBUTES); 
    sa.bInheritHandle = TRUE; 
    sa.lpSecurityDescriptor = &sd; 
 
    if(!InitializeSecurityDescriptor(&sd, SECURITY_DESCRIPTOR_REVISION)) { 
        fprintf(stderr,"unable to InitializeSecurityDescriptor, err == %d\n", 
            GetLastError()); 
        exit(1); 
    } 
 
    if(!SetSecurityDescriptorDacl(&sd, TRUE, (PACL)NULL, FALSE)) { 
        fprintf(stderr,"unable to SetSecurityDescriptorDacl, err == %d\n", 
            GetLastError()); 
        exit(1); 
    } 
 
    AckEvent = CreateEvent(&sa, FALSE, FALSE, "DBWIN_BUFFER_READY"); 
 
    if (!AckEvent) { 
        fprintf(stderr, 
                "dbmon: Unable to create synchronization object, err == %d\n", 
                GetLastError()); 
        exit(1); 
    } 
 
    if (GetLastError() == ERROR_ALREADY_EXISTS) { 
        fprintf(stderr, "dbmon: already running\n"); 
        exit(1); 
    } 
 
    ReadyEvent = CreateEvent(&sa, FALSE, FALSE, "DBWIN_DATA_READY"); 
 
    if (!ReadyEvent) { 
        fprintf(stderr, 
                "dbmon: Unable to create synchronization object, err == %d\n", 
                GetLastError()); 
        exit(1); 
    } 
 
    SharedFile = CreateFileMapping( 
                        (HANDLE)-1, 
                        &sa, 
                        PAGE_READWRITE, 
                        0, 
                        4096, 
                        "DBWIN_BUFFER"); 
 
    if (!SharedFile) { 
        fprintf(stderr, 
                "dbmon: Unable to create file mapping object, err == %d\n", 
                GetLastError()); 
        exit(1); 
    } 
 
    SharedMem = MapViewOfFile( 
                        SharedFile, 
                        FILE_MAP_READ, 
                        0, 
                        0, 
                        512); 
 
    if (!SharedMem) { 
        fprintf(stderr, 
                "dbmon: Unable to map shared memory, err == %d\n", 
                GetLastError()); 
        exit(1); 
    } 
 
    String = (LPSTR)SharedMem + sizeof(DWORD); 
    pThisPid = SharedMem; 
 
    LastPid = 0xffffffff; 
    DidCR = TRUE; 
 
    SetEvent(AckEvent); 
 
    for (;;) { 
 
        ret = WaitForSingleObject(ReadyEvent, INFINITE); 
 
        if (ret != WAIT_OBJECT_0) { 
 
            fprintf(stderr, "dbmon: wait failed; err == %d\n", GetLastError()); 
            exit(1); 
 
        } else { 
 
            if (LastPid != *pThisPid) { 
                LastPid = *pThisPid; 
                if (!DidCR) { 
                    putchar('\n'); 
                    DidCR = TRUE; 
                } 
            } 
 
            if (DidCR) { 
                printf("%3u: ", LastPid); 
            } 
 
            printf("%s", String); 
            DidCR = (*String && (String[strlen(String) - 1] == '\n')); 
            SetEvent(AckEvent); 
 
        } 
 
    } 
 
    return 0; 
}