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  • This worked fine. But fifo is closing after write to it. Is this expected behavior? I solved this with grepping fifo in a infinite while loop. But this is not working if I write to pipe with continious stream. For example: I have a shell script printnumbers.sh that looping infinite and printing 1,2,3,... to stdout each second. I am running ./printnumbers.sh > myfifo in one terminal, and in another terminal: while true; do grep -f myfifo numbers.txt | awk '{print $2; system("")}' done This printing to stdout when I stop print to fifo. Commented Dec 4, 2016 at 18:12
  • @mesuutt When the last writer on a pipe closes the pipe, readers get an end-of-file indication. I don't understand the rest of your comment. What are you trying to achieve? As I explain in my answer, grep reads the patterns before it starts processing the text to search. Do you want to search the data again each time a new pattern comes on the pipe? If so you will need to call grep (or awk) in a loop, since it has to read the data again and again each time. Commented Dec 4, 2016 at 18:34
  • Yes I want to search the data again each time a new pattern comes to pipe. Also I read from pipe within a loop. I have a bash script file printnumbers.sh that print numbers each second in infinite loop. Your solution works if I write to pipe as echo 1 > myfifo and print one to stdout but if I write to pipe numbers as: ./printnumbers.sh > myfifo not printing anything to stdout due to stop the ./printnumbers.sh > myfifo. gist.github.com/mesuutt/92e1d6286c442b2003fe2c67d2133d7b Commented Dec 4, 2016 at 19:03