Arch Linux

eirika

Member

From: New York

Registered: 2009-09-14

Posts: 65

Sending output to 2 pipelines in shell script?

I have a large file to process using grep, however the same output of grep
will be used by 2 different programs. Processing the large input file twice
will be a waste of time. Is there a way to duplicate the output data and send it
to 2 separate pipelines?

As a resolution saving the grep output to a temporary file and reading the file twice
will do the job. But I would like to know if there is a possibility to avoid using
tmp files.

mksoft

Member

Registered: 2008-07-03

Posts: 9

Re: Sending output to 2 pipelines in shell script?

The tee command will help you with it, google will have some examples, here's one:
http://linux.byexamples.com/archives/14 … processes/

eirika

Member

From: New York

Registered: 2009-09-14

Posts: 65

Re: Sending output to 2 pipelines in shell script?

The tee command will help you with it, google will have some examples, here's one:
http://linux.byexamples.com/archives/14 … processes/

That's wonderful
However process substitution is not part of the POSIX standard. I think that's why I didn't
see it in some of my scripting textbooks.