Two things make me wonder. You write

I can get the writer to print the line to stdout but sqlloader just hangs.

Your code 

print $fifo "$categories{$ky}#";

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doesn't print lines (unless there are line feeds embedded in $categories{$ky}), but you are using line oriented <STDIN> to read the data. That may lead to unexpected blocking.

Second, as far as I understand sqlldr, your command 

"sqlldr control=atpctl.ctl data=atp_fifo.dat userid=someu
+ser/pwd log=loader.log"

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will try to read data from the disk file "atp_fifo.dat". I don't see how that file is connected to the pipe output.

Anno

In reply to Re: writing to and reading from fifo by Anno
in thread writing to and reading from fifo by diomedea

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