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I want netcat to pipe the output of a tcp/ip connection to commands that examine the output and split it into distinct files separated by the strings "msg" and "/msg" from the output, something like

nc host port | while :
split 'msg' '/msg' > timestamp.txt

but I can't get the syntax right. In an ideal world, I'd also like the whole of the output of nc appending to another file, say big_data.txt. Maybe I should use grep?

I know how to send nc output to a file and can work out how to split it, but the file will keep appending for 12 hours each day. Also, I think it's more efficient to split the data as it arrives.

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2 Answers 2

I would not do this with shell scripting1, and definitely not try to do it with a oneliner.

But if you want to pipe data into multiple files/pipes it could be done with the tee command.
Have a look at this SO-question for an example

1 I'd use perl or python

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Why not? I can do this in R with strsplit, make.socket, read.socket and file commands. I was hoping to get it all processed as it arrives, assuming there's some buffer to get a faster solution. Maybe a shell script? –  Yoda May 17 '13 at 13:58

I did it all in R.

    stream_processor <- function(host_,port)
     con2 <- socketConnection(host=host_, port=port_)
    # as non-blocking, may need to loop for input
    while(isIncomplete(con2)) {
        z <- unlist(readLines(con2,1000))
     write(z, file=paste(make.names(date()),'.stream',sep=''))
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