Enumerating Running Processes in Win95 and WinNT

Overview

While developing an application, I encountered the need to get
a list of all running processes (programs). Ok, so all advanced
Win32 programmers know that for such a task one uses the
performance data in WinNT or the ToolHelp functions in Win95.
BUT, In my case my application had to run both
under NT and 95, without conditional compilation
, i.e without having two seperate versions of the
executable, one for win95 and one for NT. So, to solve this
problem I wrote a C++ class, calles Win32Process that gets a list
of all currently running applications, in a "platform
independent" way (independent between windows 95 and NT, and
of course it’s using MFC, that’s why I put it in quotes). More
accuratly, the class detects if its running under NT or 95, and
accordingly invokes the correct functions.

More-Over, the code for the class is written in
such a way, that when platform-dependent functions from a dll are
used, these functions are loaded dynamically, so that you do not
have to link statically to a .lib file, thereby making your code
(or at least your project settings) different if compiling on NT
or on 95. for instance, if we are compiling on NT, but we need to
use the Win 95-specific ToolHelp function Process32Next( ), there
is no problem – the project will compile, link and run
successfully.

So, in summary, all you need to do is
drop this class into your current VC++ 5.0 project – without
changing ANY of your current project settings, and then you’ll be
able to enumerate all running processes
without
worrying if the code will be executed/compiled on win95 or NT
.
The class will automatically do this for you.

Using Win32Process.cpp

To use this class, include it’s header where
you want to use it. Then, instantiate it:

Win32Process
m_win32proc;

Then, before using it (for example in
OnInitDialog of you application), Initiate it:

if(!m_win32proc.Init())
	AfxMessageBox(m_win32proc.GetLastError());

The initiation gets the needed function
pointers if running on 95. If running on NT it doesnt do much but
still must be called.
Note that EVERY method returns false if it fails and true if it
succeeds, and to get the cause of the error you simply call
GetLastError( ),
in return for which you get a CString describing the nature of
the error.

Now, to get a list of all the processes, do:

if (!m_win32proc.EnumAllProcesses())
{
	AfxMessageBox(m_win32proc.GetLastError());
	return;
} 

And you’re all set! Now a
CStringArray member in Win32Process.cpp contains all the names of
the currently running processes.
(Note that the AfxMessageBox is just for debugging. When actually
using it you may do anything you like with the error string. (BTW
I havent had an error yet using this class)).

To display these names (for example in a list
box) you may do something like this:

//populate the list box
int size=m_win32proc.GetAllProcessesNames()->GetSize();
for (int i=0;i<size;i++)
	m_ctrlProcLB.AddString(m_win32proc.GetAllProcessesNames()->GetAt(i));

Where the m_ctrlProcLB is a list box in this
case. (See the enclosed Demo)
Simple, isnt it? and remember that you use the same code
regardless if its running on NT or 95. Also, none of your project
settings have to be changed.

It is also possible to check if one certain
process is running using the member
GetProcessStatus( ) as follows:

if (!m_win32proc.GetProcessStatus(&m_strProcessToCheck,&bStatus))
{
	AfxMessageBox(m_win32proc.GetLastError());
	return;
}
if (bStatus)
	AfxMessageBox(m_strProcessToCheck+" is running!");
else
	AfxMessageBox(m_strProcessToCheck+" is NOT running!");

Note that GetProcessStatus(
)
does not return TRUE if
the process is running, but rather, it returns TRUE if it was
successful. You get the info about the process by passing a
pointer to a boolean (see
bStatus above)

The Demo

Enclosed is also a demo program that
exemplifies the usage of this class. The demo is a simple VC++
5.0 project. The demo also shows how you can test whether a
specific process is running, using the Win32Process class.

To use the class, copy the file
Win32Process.cpp and Win32Process.h from the demo directory into
your project directory, and add them to your project.

Download Source Code and Example– 107KB

Last updated: 27 June 1998 

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