topic Re: shell question (intercept stderr output) in Operating System - HP-UX

shell question (intercept stderr output)

Ulrich Deiters — Tue, 11 Mar 2003 17:43:25 GMT

A background process sends messages via stderr to the terminal. How can I duplicate this output to stdout (or elsewhere), so that another process can read the messages, too?

my_prog 2>&1 1>results | tee msgfile 1>&2 |&

with periodic inspection of msgfile works, but is slow. Is there a better way? Thanks in advance for your help.

Re: shell question (intercept stderr output)

Adam J Markiewicz — Tue, 11 Mar 2003 18:16:39 GMT

Hi

1. How about:
mkfifo msgfifo
and than something like
my_prog 2>msgfifo
or more complicated construction with this?
Disadvantage: 'writes' to fifo are blocked until the reader is attached.

2. tail -f msgfile
scans every second a file and prints only what was appended after previous scan.

Good luck

Adam

Re: shell question (intercept stderr output)

Steven E. Protter — Tue, 11 Mar 2003 18:16:56 GMT

Here is an offbeat idea, probably not the best

In another terminal session, run this.

tail -f msgfile

It will show output as it hits the file.

I am sure there is some slick way to do it on the command line, but my way is simple and it would work unless I'm logged in on a console.

SEP