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Top Forums Shell Programming and Scripting Grep causing long delay (batching) whilst piping Post 302211181 by Annihilannic on Wednesday 2nd of July 2008 08:55:37 PM
Old 07-02-2008
Hi Mitch,

I had exactly the same problem with a script I wrote to put timestamps on some tail -f output - I kept getting bunches of lines with the same timestamp instead of them being processed in real time.

I ended up replacing grep with a small perl script:

Code:
./input.sh | perl -nwe '
        BEGIN {
                # From the open() section on the perlfunc man page.
                # Makes output unbuffered.
                select(STDOUT); $| = 1;
        }
        /2008/ && print;
' | ./output.sh

Hope that helps.
 

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