Solved

Small program to get server OS name

Posted on 2011-03-01
10
1,145 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;
}

Open in new window

0
Comment
Question by:MarcosBarroso
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 3
  • 2
  • +1
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


0
How our DevOps Teams Maximize Uptime

Our Dev teams are like yours. They’re continually cranking out code for new features/bugs fixes, testing, deploying, responding to production monitoring events and more. It’s complex. So, we thought you’d like to see what’s working for us. Read the use case whitepaper.

 
LVL 34

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[])

Open in new window

0
 
LVL 34

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
0
 
LVL 16

Expert Comment

by:sjklein42
ID: 35022662
I knew I'd be the fool in this discussion.   Good going sarabande.
0
 
LVL 34

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
0

Featured Post

Problems using Powershell and Active Directory?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

ADCs have gained traction within the last decade, largely due to increased demand for legacy load balancing appliances to handle more advanced application delivery requirements and improve application performance.
A procedure for exporting installed hotfix details of remote computers using powershell
The goal of this video is to provide viewers with basic examples to understand how to create, access, and change arrays in the C programming language.
This tutorial will walk an individual through the steps necessary to configure their installation of BackupExec 2012 to use network shared disk space. Verify that the path to the shared storage is valid and that data can be written to that location:…

751 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question