/ 
Win32-Process-Info-1.009
River stage zero No dependents
/ Win32::Process::Info

NAME

Win32::Process::Info - Provide process information for Windows 32 systems.

SYNOPSIS

use Win32::Process::Info;
$pi = Win32::Process::Info->new ();
$pi->Set (elapsed_as_seconds => 0);	# In clunks, not seconds.
@pids = $pi->ListPids ();	# Get all known PIDs
@info = $pi->GetProcInfo ();	# Get the max
%subs = $pi->Subprocesses ();	# Figure out subprocess relationships.

NOTICE

This package covers a multitude of sins - as many as Microsoft has invented ways to get process info and I have resources and gumption to code. The key to this mess is the 'variant' argument to the 'new' method (q.v.).

The WMI variant has various problems, known or suspected to be inherited from Win32::OLE. See "BUGS" for the gory details. The worst of these is that if you use fork(), you must disallow WMI completely by loading this module as follows:

use Win32::Process::Info qw{NT};

This method of controlling things must be considered experimental until I can confirm it causes no unexpected insurmountable problems. If I am forced to change it, the change will be flagged prominently in the documentation.

This change is somewhat incompatible with 1.006 and earlier because it requires the import() method to be called in the correct place with the correct arguments. See the import() documentation below for the details.

YOU HAVE BEEN WARNED!

DESCRIPTION

The main purpose of the Win32::Process::Info package is to get whatever information is convenient (for the author!) about one or more Windows 32 processes. "GetProcInfo" is therefore the most-important method in the package. See it for more information.

Unless explicitly stated otherwise, modules, variables, and so on are considered private. That is, the author reserves the right to make arbitrary changes in the way they work, without telling anyone. For methods, variables, and so on which are considered public, the author will make an effort keep them stable, and failing that to call attention to changes.

The following methods should be considered public:

$pi = Win32::Process::Info->new ([machine], [variant], [hash])

This method instantiates a process information object, connected to the given machine, and using the given variant.

The following variants are currently supported:

NT - Uses the NT-native mechanism. Good on any NT, including Windows 2000. This variant does not support connecting to another machine, so the 'machine' argument must be an empty string (or undef, if you prefer).

WMI - Uses the Windows Management Implementation. Good on Win2K, ME, and possibly others, depending on their vintage and whether WMI has been retrofitted.

The initial default variant comes from environment variable PERL_WIN32_PROCESS_INFO_VARIANT. If this is not found, it will be 'WMI,NT', which means to try WMI first, and NT if WMI fails. This can be changed using Win32::Process::Info->Set (variant => whatever).

The hash argument is a hash reference to additional arguments, if any. The hash reference can actually appear anywhere in the argument list, though positional arguments are illegal after the hash reference.

The following hash keys are supported:

  variant => corresponds to the 'variant' argument (all)
  assert_debug_priv => assert debug if available (all) This
	only has effect under WMI. The NT variant always
	asserts debug. You want to be careful doing this
	under WMI if you're fetching the process owner
	information, since the script can be badly behaved
	(i.e. die horribly) for those processes whose
	ExecutablePath is only available with the debug
	privilege turned on.
  host => corresponds to the 'machine' argument (WMI)
  user => username to perform operation under (WMI)
  password => password corresponding to the given
	username (WMI)

ALL hash keys are optional. SOME hash keys are only supported under certain variants. These are indicated in parentheses after the description of the key. It is an error to specify a key that the variant in use does not support.

@values = $pi->Get (attributes ...)

This method returns the values of the listed attributes. If called in scalar context, it returns the value of the first attribute specified, or undef if none was. An exception is raised if you specify a non-existent attribute.

This method can also be called as a class method (that is, as Win32::Process::Info->Get ()) to return default attributes values.

The relevant attribute names are:

elapsed_as_seconds is TRUE to convert elapsed user and kernel times to seconds. If FALSE, they are returned in clunks (that is, hundreds of nanoseconds). The default is TRUE.

variant is the variant of the Process::Info code in use, and should be zero or more of 'WMI' or 'NT', separated by commas. 'WMI' selects the Windows Management Implementation, and 'NT' selects the Windows NT native interface.

machine is the name of the machine connected to. This is not available as a class attribute.

@values = $pi->Set (attribute => value ...)

This method sets the values of the listed attributes, returning the values of all attributes listed if called in list context, or of the first attribute listed if called in scalar context.

This method can also be called as a class method (that is, as Win32::Process::Info->Set ()) to change default attribute values.

The relevant attribute names are the same as for Get. However:

variant is read-only at the instance level. That is, Win32::Process::Info->Set (variant => 'NT') is OK, but $pi->Set (variant => 'NT') will raise an exception. If you set variant to an empty string (the default), the next "new" will iterate over all possibilities (or the contents of environment variable PERL_WIN32_PROCESS_INFO_VARIANT if present), and set variant to the first one that actually works.

machine is not available as a class attribute, and is read-only as an instance attribute. It is not useful for discovering your machine name - if you instantiated the object without specifying a machine name, you will get nothing useful back.

@pids = $pi->ListPids ();

This method lists all known process IDs in the system. If called in scalar context, it returns a reference to the list of PIDs. If you pass in a list of pids, the return will be the intersection of the argument list and the actual PIDs in the system.

@info = $pi->GetProcInfo ();

This method returns a list of anonymous hashes, each containing information on one process. If no arguments are passed, the list represents all processes in the system. You can pass a list of process IDs, and get out a list of the attributes of all such processes that actually exist. If you call this method in scalar context, you get a reference to the list.

What keys are available depends on the variant in use. You can hope to get at least the following keys for a "normal" process (i.e. not the idle process, which is PID 0, nor the system, which is some small indeterminate PID) to which you have access:

CreationDate
ExecutablePath
KernelModeTime
MaximumWorkingSetSize
MinimumWorkingSetSize
Name (generally the name of the executable file)
ProcessId
UserModeTime

You may find other keys available as well, depending on which operating system you're using, and which variant of Process::Info you're using.

This method also optionally takes as its first argument a reference to a hash of option values. The only supported key is:

    no_user_info => 1
	Do not return keys Owner and OwnerSid, even if available.
	These tend to be time-consuming, and can cause problems
	under the WMI variant.
Win32::Process::Info->import ()

The purpose of this static method is to specify which variants of the functionality are legal to use. Possible arguments are 'NT', 'WMI', or both (i.e. ('NT', 'WMI')). Unrecognized arguments are ignored, though this may change if this class becomes a subclass of Exporter. If called with no arguments, it is as though it were called with arguments ('NT', 'WMI'). See "BUGS", below, for why this mess was introduced in the first place.

This method must be called at least once, in a BEGIN block, or no variants will be legal to use. Usually it does not need to be explicitly called by the user, since it is called implicitly when you 'use Win32::Process::Info;'.

If this method is called more than once, the second and subsequent calls will have no effect on what variants are available. The reason for this is will be made clear (I hope!) under "USE IN OTHER MODULES", below.

The only time a user of this module needs to do anything different versus version 1.006 and previous of this module is if this module is being loaded in such a way that this method is not implicitly called. This can happen two ways:

use Win32::Process::Info ();

explicitly bypasses the implicit call of this method. Don't do that.

require Win32::Process::Info;

also does not call this method. If you must load this module using require rather than use, follow the require with

Win32::Process::Info->import ();

passing any necessary arguments.

%subs = $pi->Subprocesses ([pid ...])

This method takes as its argument a list of PIDs, and returns a hash indexed by PID and containing, for each PID, a reference to a list of all subprocesses of that process. If those processes have subprocesses as well, you will get the sub-sub processes, and so ad infinitum, so you may well get back more hash keys than you passed process IDs. Note that the process of finding the sub-sub processes is iterative, not recursive; so you don't get back a tree.

If no argument is passed, you get all processes in the system.

If called in scalar context you get a reference to the hash.

This method works off the ParentProcessId attribute. Not all variants support this. If the variant you're using doesn't support this attribute, you get back an empty hash. Specifically:

NT -> unsupported
WMI -> supported

This method just returns the version number of the Win32::Process::Info object.

USE IN OTHER MODULES

Other modules that use this module are also subject to the effects of the collision between Win32::OLE and the emulated fork call, and to the requirements of the import() method. I will not address subclassing, since I am not sure how well this module subclasses (the variants are implemented as subclasses of this module).

Modules that simply make use of this module (the 'has-a' relationship) should work as before, provided they 'use Win32::Process::Info'. Note that the phrase 'as before' is literal, and means (among other things), that you can't use the emulated fork.

If you as the author of a module that uses Win32::Process::Info wish to allow emulated forks, you have a number of options.

The easiest way to go is

use Win32::Process::Info qw{NT};

if this provides enough information for your module.

If you would prefer the extra information provided by WMI but can operate in a degraded mode if needed, you can do something like

use Win32::Process::Info ();

sub import {
   my $pkg = shift;
   $pkg->SUPER::import (@_);  # Optional (see below)
   Win32::Process::Info->import (@_);
}

The call to $pkg->SUPER::import is needed only if your package is a subclass of Exporter.

Note to users of modules that require this module:

If the above 'rules' are violated, the symptoms will be either that you cannot instantiate an object (because there are no legal variants) or that you cannot use fork (because the WMI variant was enabled by default). The workaround for you is to

use Win32::Process::Info;

before you 'use' the problematic module. If the problem is coexistence with fork, you will of course need to

use Win32::Process::Info qw{NT};

This is why only the first import() sets the possible variants.

ENVIRONMENT

This package is sensitive to a number of environment variables. Note that these are normally consulted only when the package is initialized (i.e. when it's "used" or "required").

PERL_WIN32_PROCESS_INFO_VARIANT

If present, specifies which variant(s) are tried, in which order. The default behavior is equivalent to specifying 'WMI,NT'. This environment variable is consulted when you "use Win32::Process::Info;". If you want to change it in your Perl code you should use the static Set () method.

PERL_WIN32_PROCESS_INFO_WMI_DEBUG

If present and containing a value Perl recognizes as true, causes the WMI variant to assert the "Debug" privilege. This has the advantage of returning more full paths, but the disadvantage of tending to cause Perl to die when trying to get the owner information on the newly-accessible processes.

PERL_WIN32_PROCESS_INFO_WMI_PARIAH

If present, should contain a semicolon-delimited list of process names for which the package should not attempt to get owner information. '*' is a special case meaning 'all'. You will probably need to use this if you assert PERL_WIN32_PROCESS_INFO_WMI_DEBUG.

REQUIREMENTS

It should be obvious that this library must run under some flavor of Windows.

This library uses the following libraries:

Carp
Time::Local
Win32::API (if using the NT-native variant)
Win32API::Registry (if using the NT-native variant)
Win32::ODBC (if using the WMI variant)

As of ActivePerl 630, none of this uses any packages that are not included with ActivePerl. Carp and Time::Local have been in the core since at least 5.004. Your mileage may, of course, vary.

HISTORY

0.010 Released as Win32::Process::Info
0.011 Added Version method
      Fixed warning in NT.pm when -w in effect. Fix provided
          by Judy Hawkins (of Pitney Bowes, according to her
          mailing address), and accepted with thanks.
0.012 Hid attributes beginning with "_".
0.013 Use environment variable PERL_WIN32_PROCESS_INFO_VARIANT
          to specify the default variant list.
      Add a hash reference argument to new (); use this to
          specify username and password to the WMI variant.
      Turn on debug privilege in NT variant. This also resulted
          in dependency on Win32API::Registry.
      Return OwnerSid and Owner in NT variant.
0.014 Remove conditional dependencies from Makefile.PL
      Track changes in Win32::API. Can no longer "require" it.
      WMI variant no longer asserts debug privilege by default.
      Use environment variable PERL_WIN32_PROCESS_INFO_WMI_DEBUG
         to tell the WMI variant whether to assert debug.
      Use environment variable PERL_WIN32_PROCESS_INFO_WMI_PARIAH
         to encode processes to skip when determining the owner.
      Add optional first hash ref argument to GetProcInfo.
      Add Subprocesses method.
1.000 Add assert_debug_priv hash argument to the 'new' method.
      Fix documentation, both pod errors and actual doc bugs.
      When the only thing you've done in two months is add a
          semicolon to a comment, it's probably time to call it
          production code.
1.001 Removed dependency on Win32. We still need it, of course,
      but PPM3 chokes on it, and I figure anyone who IS using
      PPM3 already has it, and anyone who ISN'T is smart enough
      to figure out what's going on - or at least read the Readme.
1.002 Document leaky behavior of WMI variant, and try to make it
      leak less. Document related modules.
1.003 Documented PERL_WIN32_PROCESS_INFO_WMI_DEBUG correctly
      (the docs had a _PRIV on the end).
      Recorded the variant name in the object.
      Clarified (hopefully) the docs on how to use the
      PERL_WIN32_PROCESS_INFO_VARIANT environment variable.
      Added the current status and whereabouts of
      Win32::IProc. Thanks to Eric Bluestein
      (http://www.emblue.com/) for pointing this out.
1.004 Remove commented-out dependencies in Makefile.PL,
      since CPAN's now checking. The only one that really
      counts is Win32, but ActiveState's PPM3 chokes on
      this, or at least did as of January 2001.
1.005 Addressed token handle leak in the NT variant.
1.006 Silently skip non-existent processes in the
      Subprocesses method. Fix provided by Kirk Baucom of
      Itron, and accepted with thanks.
1.007 Provide method to disallow a given variant when the
      package is loaded. This prevents the normal testing,
      which causes problems if fork() is used. Thanks to Malcolm
      Nooning for finding the problem, helping me work out
      the solution, and sharing the results of his
      correspondence with ActiveState.
1.008 Clean up the documentation. The new import()
      documentation, in particular, contained a couple
      abortive attempts to get it right. But the real
      incentive is that the Windows build on ActiveState
      failed because the Makefile was older than
      Makefile.PL (?!?), so I thought I would try sending
      it through again.
1.009 Fix synopsis code so that it compiles as-is.
      Correct the error message generated when new() is
      passed a reference other than a hash reference.

BUGS

The WMI variant leaks memory - badly for 1.001 and earlier. After 1.001 it only leaks badly if you retrieve the process owner information. If you're trying to write a daemon, the NT variant is recommended. If you're stuck with WMI, set the no_user_info flag when you call GetProcInfo. This won't stop the leaks, but it minimizes them, at the cost of not returning the username or SID.

If you intend to use fork (), your script will die horribly unless you load this module as

use Win32::Process::Info qw{NT};

The problem is that fork() and Win32::OLE (used by the WMI variant) do not play at all nicely together. This appears to be an acknowledged problem with Win32::OLE, which is brought on simply by loading the module. See import() above for the consequences of handling things this way.

Bugs can be reported to the author by mail, or through http://rt.cpan.org.

RESTRICTIONS

You can not "require" this library except in a BEGIN block. This is a consequence of the use of Win32::API, which has the same restriction, at least in some versions.

If your code calls fork (), you must load this module as

use Win32::Process::Info qw{NT};

This renders the WMI variant unavailable. See "BUGS".

RELATED MODULES

Win32::Process::Info focuses on returning static data about a process. If this module doesn't do what you want, maybe one of the following ones will.

Win32::PerfLib by Jutta M. Klebe

This module focuses on performance counters. It is a ".xs" module, and requires Visual C++ 6.0 to install. But it's also part of LibWin32, and should come with ActivePerl.

Win32::IProc by Amine Moulay Ramdane

This module is no longer supported, which is a shame because it returns per-thread information as well. As of December 27, 2004, Jenda Krynicky (http://jenda.krynicky.cz/) was hosting a PPM kit in PPM repository http://jenda.krynicky.cz/perl/, which may be usable. But the source for the DLL files is missing, so if some Windows upgrade breaks it you're out of luck.

Win32API::ProcessStatus, by Ferdinand Prantl

This module focuses on the .exe and .dll files used by the process. It is a ".xs" module, requiring Visual C++ 6.0 and psapi.h to install.

pulist

This is not a Perl module, it's an executable that comes with the NT resource kit.

ACKNOWLEDGMENTS

This module would not exist without the following people:

Aldo Calpini, who gave us Win32::API.

Jenda Krynicky, whose "How2 create a PPM distribution" (http://jenda.krynicky.cz/perl/PPM.html) gave me a leg up on both PPM and tar distributions.

Dave Roth, http://www.roth.net/perl/, author of Win32 Perl Programming: Administrators Handbook, which is published by Macmillan Technical Publishing, ISBN 1-57870-215-1

Dan Sugalski sugalskd@osshe.edu, author of VMS::Process, where I got (for good or ill) the idea of just grabbing all the data I could find on a process and smashing it into a big hash.

The folks of Cygwin (http://www.cygwin.com/), especially Christopher G. Faylor, author of ps.cc.

Judy Hawkins of Pitney Bowes, for providing testing and patches for NT 4.0 without WMI.

AUTHOR

Thomas R. Wyant, III (wyant at cpan dot org)

COPYRIGHT

Copyright 2001, 2002, 2003, 2004, 2005 by E. I. DuPont de Nemours and Company, Inc. All rights reserved.

Modifications since version 1.006 copyright 2007 by Thomas R. Wyant, III. All rights reserved.

This module is free software; you can use it, redistribute it and/or modify it under the same terms as Perl itself.