Communicate between 2 processes

Question

I am trying to communicate between 2 programs but I can’t find out how.

Process p = Process.Start(Secondprogram.exe, "number = " + number);
p.WaitForExit();
this.Close();

I want to receive the number in my second program and use it there.

Or something like:

Process p = Process.Start(Secondprogram.exe);
Parameter number = 1200;
p.WaitForExit();
this.Close();

And then in my second program:

txtSomething.Text = number;

depends on the program. you could try to read the stream from the Process.... — Ahmed ilyas, May 22 '15 at 09:10
Do you need to communicate only from the first to the second process or also in the reverse direction? — Codor, May 22 '15 at 09:13
Googeling the phrase [c# interprocess communication](https://www.google.de/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=c%23%20interprocess%20communication) immediately gave me this [result](https://msdn.microsoft.com/en-us/library/bb546102%28v=vs.110%29.aspx) — ckruczek, May 22 '15 at 09:14
wouldn't a simple command-line argument suffice in this case? — Random Dev, May 22 '15 at 09:18
Is `number` a command line argument or do you want to "send" it to the other process when it is already running? — Thomas Lielacher, May 22 '15 at 09:18
http://stackoverflow.com/questions/18437474/inter-process-communication-options — Jodrell, May 22 '15 at 09:22
http://stackoverflow.com/questions/528652/what-is-the-simplest-method-of-inter-process-communication-between-2-c-sharp-pro — Jodrell, May 22 '15 at 09:23
http://stackoverflow.com/questions/21101243/c-sharp-interprocess-communication-on-the-same-box — Jodrell, May 22 '15 at 09:23
http://stackoverflow.com/questions/1802475/what-is-the-easiest-way-to-do-inter-process-communication-in-c — Jodrell, May 22 '15 at 09:23
Sorry I did not know the correct search description for my question — robbii15, May 22 '15 at 09:44

oleksii · Accepted Answer · 2015-05-22T09:55:09.820

You have several options:

Using WCF will allow you to switch between bindings easily. So if you have two processes on the same machine you can use a named pipe binding which is a type of inter-process communication. If you later decide to separate processes onto different machines you can just change configuration to, say, tcp binding and everything will continue working
If you are into REST, there will be client-server frameworks, such as as self-hosted ASP NET Web API or Nancy
If it is something dead simple, you can just write to a file and read from a file, combined with a global named mutex to synchronise access
There is also a choice of a memory-mapped file, where one process writes to a file and the other reads from it. It's a bit geeky approach and I have rarely seen this in use.
Or yet another conventional approach is to use a 3-rd party, such as a database or a message queue system

score 1 · Answer 2 · answered May 22 '15 at 09:19

1

You can use the output stream of the first program as input stream of the second one. Check ProcessStartInfo : https://msdn.microsoft.com/fr-fr/library/system.diagnostics.processstartinfo%28v=vs.110%29.aspx

answered May 22 '15 at 09:19

norisknofun

This is an interesting approach. Could you provide an example? I have exacly this kind of situtaiton where I start another process with ProcessStartInfo. Would it also work if I don't wait for the started process to exti? – t3chb0t Feb 27 '16 at 21:40

2 Answers2