Named Pipes (FIFOs) on Unix with multiple readers

user_139117 0
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I have two programs, Writer and Reader.

I have a FIFO from Writer to Reader so when I write something to stdin in Writer, it gets printed out to stdout from Reader.

I tried doing this with TWO Readers open, and I got output to stdout from only one of the two Reader programs. Which Reader program Unix chooses to print stdout from seemed to be arbitrary each time I run this, but once it chooses one of the programs, each output to stdout gets printed from the same Reader program.

Does anyone know why this happens?

If I have two WRITER programs, they both write to the same pipe okay.

fifo unix
5 Answers

The sockets solution works, but becomes complicated if the server crashes. To allow any process to be the server, I use record locks at the end of a temporary file that contains location/length/data changes to the given file. I use a temporary named pipe to communicate append requests to whichever process has the write lock at the end of the temporary file.

user_45889820
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