How To Get Message Text from Networking Error Codes

MORE INFORMATION

Sample Code

/*
    The following sample illustrates how to display error text
    associated with Networking related error codes, in addition
    to displaying error text associated with system related error
    codes.

    This sample relies on the following import library:
    User32.lib

*/ 

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

#include <lmerr.h>

void
DisplayErrorText(
    DWORD dwLastError
    );

int
__cdecl
main(
    void
    )
{
    // 
    // display a networking related error string
    // 
    printf("Network related error string follows:\n");
    DisplayErrorText(2226);

    // 
    // display a system related error string
    // 
    printf("\nSystem related error string follows:\n");
    SetLastError(ERROR_FILE_NOT_FOUND);
    DisplayErrorText(GetLastError());

    return 0;
}

void
DisplayErrorText(
    DWORD dwLastError
    )
{
    HMODULE hModule = NULL; // default to system source
    LPSTR MessageBuffer;
    DWORD dwBufferLength;

    // 
    // if dwLastError is in the network range, load the message source
    // 
    if(dwLastError >= NERR_BASE && dwLastError <= MAX_NERR) {
        hModule = LoadLibraryEx(
            TEXT("netmsg.dll"),
            NULL,
            LOAD_LIBRARY_AS_DATAFILE
            );
    }

    // 
    // call FormatMessage() to allow for message text to be acquired
    // from the system or the supplied module handle
    // 
    if(dwBufferLength = FormatMessageA(
        FORMAT_MESSAGE_ALLOCATE_BUFFER |
        FORMAT_MESSAGE_IGNORE_INSERTS |
        FORMAT_MESSAGE_FROM_SYSTEM | // always consider system table
        ((hModule != NULL) ? FORMAT_MESSAGE_FROM_HMODULE : 0),
        hModule, // module to get message from (NULL == system)
        dwLastError,
        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // default language
        (LPSTR) &MessageBuffer,
        0,
        NULL
        ))
    {
        DWORD dwBytesWritten;

        // 
        // Output message string on stderr
        // 
        WriteFile(
            GetStdHandle(STD_ERROR_HANDLE),
            MessageBuffer,
            dwBufferLength,
            &dwBytesWritten,
            NULL
            );

        // 
        // free the buffer allocated by the system
        // 
        LocalFree(MessageBuffer);
    }

    // 
    // if you loaded a message source, unload it
    // 
    if(hModule != NULL)
        FreeLibrary(hModule);
}