Difference between ProcessID and Handle

[Jarod_24]

Dim p As Diagnostics.Pro cess
Debug.WriteLine (p.Id)
Debug.WriteLine (p.Handle)

What is the difference between a process's ID and Handle

I see that they are different, and i know that the Processid is a uniqe
number given to each process as they are created, but what is the handle?

do all processes have a handle and do you use them for?

[Rob Teixeira [MVP]]

The ID is just a number assigned to the process by the system.
The Handle is a handle to a process "object" maintained by the system. This
object holds a number of pieces of info about the process, and you can use
various kernel, threading, and security API functions to retrieve/set this
data by providing the Handle. Unless you have some bizzar piece of data that
you need that isn't available directly in .NET, you really don't care much
about the Handle.

-Rob Teixeira [MVP]

"Jarod_24" <ja******@hotma il.com> wrote in message
news:29******** *************** *******@news.te ranews.com...

Dim p As Diagnostics.Pro cess
Debug.WriteLine (p.Id)
Debug.WriteLine (p.Handle)

What is the difference between a process's ID and Handle

I see that they are different, and i know that the Processid is a uniqe
number given to each process as they are created, but what is the handle?

do all processes have a handle and do you use them for?

[Jarod_24]

"Rob Teixeira [MVP]" <RobTeixeira@@m sn.com> wrote in message
news:u8******** ******@TK2MSFTN GP09.phx.gbl...

The ID is just a number assigned to the process by the system.
The Handle is a handle to a process "object" maintained by the system. This object holds a number of pieces of info about the process, and you can use various kernel, threading, and security API functions to retrieve/set this
data by providing the Handle. Unless you have some bizzar piece of data that you need that isn't available directly in .NET, you really don't care much
about the Handle.

So a handle is a pointer to the Process-object that the OS creates to
administrate the running process itself; A pointer to a memory-location
perhaps, while the ProcessId is just a uniqe number that each process gets.

What was the point of the processid then?

Both are uniqe, What's the diference about pointing to a memory location or
just using a "number", when you must ask the OS anyway if you are going to
do anything. Then the OS itself internally can/must lookup the
Memory-adress.
-Rob Teixeira [MVP]

"Jarod_24" <ja******@hotma il.com> wrote in message
news:29******** *************** *******@news.te ranews.com...

Dim p As Diagnostics.Pro cess
Debug.WriteLine (p.Id)
Debug.WriteLine (p.Handle)

What is the difference between a process's ID and Handle

I see that they are different, and i know that the Processid is a uniqe
number given to each process as they are created, but what is the handle?
do all processes have a handle and do you use them for?

[Mattias Sjögren]

>So a handle is a pointer to the Process-object that the OS creates

Not necessarily a pointer. You should at least not try to dereference
it.

What was the point of the processid then?

The process ID can easily be shared globally, you can pass it between
processes as a way to identify another process. The ID number is the
same regardless which process you're using it.

Process handles have access rights associated with them. You can for
example have one handle that allows you to change information about a
process, and another that only gives you right to query information.
Also, handle values are usually only useful within the process that
opened the handle. You can't pass a process handle from one
application to another and expect it to be valid at the recieving end.

Mattias

--
Mattias Sjögren [MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
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