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Small program to get server OS name

Posted on 2011-03-01
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1,134 Views
Last Modified: 2012-05-11
I got this small C source code and compiled with GCC, in order to get server OS information, using data stored in ServerMessegeBlock (SMB) APIs.

When I call it with no parameters, the code correctily shows OS from current machine:
    "GetOSName.exe      ENTER"

But when a run the utility passing server name, no information is printed:
    "GetOSName.exe   \\MYSERVER    ENTER"

So, what is wrong with this code ?
#ifndef UNICODE
#define UNICODE
#endif
#pragma comment(lib, "netapi32.lib")

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

int main(int argc, wchar_t *argv[])
{
   DWORD dwLevel = 101;
   LPSERVER_INFO_101 pBuf = NULL;
   NET_API_STATUS nStatus;
   LPTSTR pszServerName = NULL;

   if (argc > 2)
   {
      fwprintf(stderr, L"Usage: %s [\\\\ServerName]\n", argv[0]);
      exit(1);
   }

   // The server is not the default local computer.
   //
   if (argc == 2)
      pszServerName = (LPTSTR) argv[1];

   //
   // Call the NetServerGetInfo function, specifying level 101.
   //
   nStatus = NetServerGetInfo(pszServerName,
                              dwLevel,
                              (LPBYTE *)&pBuf);
   //
   // If the call succeeds,
   //
   if (nStatus == NERR_Success)
   {
      //
      // Check for the type of server.
      //

      printf("sv101_type..........: %d\n", pBuf->sv101_type);
      wprintf(L"sv101_name..........: %s\n", pBuf->sv101_name);
      printf("sv101_platform_id...: %d\n", pBuf->sv101_platform_id);
      printf("sv101_version_major.: %d\n", pBuf->sv101_version_major);
      printf("sv101_version_minor.: %d\n", pBuf->sv101_version_minor);
      wprintf(L"sv101_comment.......: %s\n", pBuf->sv101_comment);


      if ((pBuf->sv101_type & SV_TYPE_DOMAIN_CTRL) ||
         (pBuf->sv101_type & SV_TYPE_DOMAIN_BAKCTRL) ||
         (pBuf->sv101_type & SV_TYPE_SERVER_NT))
         printf("This is a server\n");
      else
         printf("This is a workstation\n");
   }
   //
   // Otherwise, print the system error.
   //
   else
      fprintf(stderr, "A system error has occurred: %d\n", nStatus);
   //
   // Free the allocated memory.
   //
   if (pBuf != NULL)
      NetApiBufferFree(pBuf);

   return 0;
}

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Question by:MarcosBarroso
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10 Comments
 
LVL 4

Expert Comment

by:denissie
ID: 35012397
Hi MacrosBarroso,

Could you please add the output of your program when using the server name?
Do you get the ""A system error has occurred" message?

Thanks.
0
 

Author Comment

by:MarcosBarroso
ID: 35016260
If I use  
    "GetOSName.exe   \\MYSERVER    ENTER"     or
    "GetOSName.exe   MYSERVER    ENTER"

Then i get value 53 returned to variable nStatus:  
    " A system error has occurred: 53"

Thanks

Marcos

0
 

Author Comment

by:MarcosBarroso
ID: 35016433
I think my error is in line 26:
     "pszServerName = (LPTSTR) argv[1];"

Maybe wrong cast or string /pointer type, because if I don't pass any parameter, information about current machine is showed ok.

Marcos


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LVL 33

Accepted Solution

by:
sarabande earned 500 total points
ID: 35016484
error 53 means "bad network path"

the servername passed to NetServerGetInfo must be LPWSTR ( == wchar_t *)  while LPTSTR can be either LPSTR (==char*) or LPWSTR depending on the defined character set of the project. try to pass L"MYSERVER"  to check that issue.

Sara
0
 
LVL 16

Expert Comment

by:sjklein42
ID: 35016503
I'll go out on a limb and make a fool of myself, but doesn't function main have char *argv, not wchar_t:

int main(int argc, char *argv[])

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LVL 33

Expert Comment

by:sarabande
ID: 35016590
a wizard generated win32 console project in Visual Studio has function

   int _tmain(int argc, LPTSTR argv[]);

as main function where the LPTSTR either is char* or wchar_t*

Sara
0
 
LVL 4

Expert Comment

by:denissie
ID: 35021922
The WinAPI "NetServerGetInfo" uses LPWSTR servername as server name's input.
Therefore, you should use unicode.

As might be seen in MSDn code example (http://msdn.microsoft.com/en-us/library/aa370624%28v=vs.85%29.aspx), use "int wmain(int argc, wchar_t *argv[])".

BTW:Your code looks a lot like that code example. Might it be that you've omitted to copy the "int wmain..." line?
Could you change that and try again?

Thanks.
0
 
LVL 16

Expert Comment

by:sjklein42
ID: 35022135
MarcosBarroso:  Did you try my simple change on the "main" line just to see if it works?

sara:  He's using "main", not "_tmain".  I think it makes a difference. The raw "main" is the same in C and C++:

http://en.wikipedia.org/wiki/Main_function
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LVL 16

Expert Comment

by:sjklein42
ID: 35022662
I knew I'd be the fool in this discussion.   Good going sarabande.
0
 
LVL 33

Expert Comment

by:sarabande
ID: 35024967
sjklein42, i like your humour :-)

you rightly stated that marcosborroso used wrong argument wchar_t* as type for second argument.

Sara
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