mkfifo() error ---> "Error creating the named pipe.: File exists"

c systems-programming mkfifo
Spyros Rokopanos picture Spyros Rokopanos · Oct 24, 2012 · Viewed 17k times · Source

The mkfifo function takes 2 arguments, path and mode. But I don't know what is the format of the path that it uses. I am writing a small program to create a named pipe and as path in the mkfifo. Using /home/username/Documents for example, but it always returns -1 with the message Error creating the named pipe.: File exists.

I have checked this dir a lot of times and there is no pipe inside it. So I am wondering what is the problem. The mode I use in mkfifo is either 0666 or 0777.

Answer

Olaf Dietsche picture Olaf Dietsche · Oct 24, 2012

You gave mkfifo() the name of an existing directory, thus the error. You must give it the name of a non-existing file, e.g.

mkfifo("/home/username/Documents/myfifo", 0600);

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