How to create a pipe in c under Windows

Question

I am trying to create a pipe in my c program to input data to another program myProgram.exe. All I need to do is to get myProgram running and send "quit" from the main program. The problem is I don't know how I can create a pipe in c.

I got a working Perl example somewhere:

open(myHandle, ".../myProgram.exe");
//... (do something else) ...
printf(myHandle, "quit");
close(myHandle);

Can somebody please help me translate this into c code? Please keep in mind I'm running under Windows so there is no unistd.h available.

Cheers, B

See CreateNamedPipe function. However, for simple message like this it is better to use named event. — Alex F, Nov 03 '14 at 08:38
http://msdn.microsoft.com/en-us/library/windows/desktop/ms682499%28v=vs.85%29.aspx — Hans Passant, Nov 03 '14 at 08:48
Sorry but I don't get it. If I call CreateNamedPipe, how do I specify in which program I want to pipe? Could you please post a code sample? Thanks — b3d, Nov 03 '14 at 09:40

score 4 · Answer 1 · edited May 23 '17 at 12:32

4

I've recently posted a simple example how to create pipes for inter-process communication:

See Create Named Pipe C++ Windows

edited May 23 '17 at 12:32

Community

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answered Nov 03 '14 at 18:55

Lukas Thomsen

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Thanks for the example. I have a simple question: to connect a client to the pipe, do I have to necessarily edit the code in the client program (add the line with CreateFile etc.)? I want to feed my client some input, but in my case I have the client program from somewhere else and I really don't want to change anything in the code there. I hope you understand my question. – b3d Nov 04 '14 at 08:01
Yes you have to do that. If you don't want to change the other application you can create the application with a new handle to STDOUT/STDIN. Check the documentation of attribute of `STARTUPINFO` structure and function `CreateProcess(..)`. – Lukas Thomsen Nov 04 '14 at 20:56
Thanks Lukas. I set the new handlesto STDOUT/STDIN as you suggested. I transmuted this [example](http://msdn.microsoft.com/en-us/library/windows/desktop/ms682499%28v=vs.85%29.aspx). I didn't make any changes in my client program. I managed to get it running and pipe no more than a single command to it. It is not optimal, but for my needs it is enough. – b3d Nov 05 '14 at 08:09

score 0 · Answer 2 · answered Nov 03 '14 at 08:38

Maybe this would help:

http://msdn.microsoft.com/en-us/library/windows/desktop/aa365780(v=vs.85).aspx

There is a lot of information about pipes under windows there.

Also see:

http://msdn.microsoft.com/en-us/library/windows/desktop/aa365781(v=vs.85).aspx

For a list of pipe-related functions in WINAPI

How to create a pipe in c under Windows

2 Answers2