Re: OT: tail -f | while read

[Adam McDaniel <adamm@psynch.com>]

On Thu, Sep 06, 2001 at 09:47:01PM +0200, Martin F Krafft wrote:
> and could someone give me a perl one-liner that takes each such line
> fed into its STDIN, and for each line, calls an external shell script
> with the entire line as argument?
> 

here you go :)

#!/usr/bin/perl
$| = 1;
while (<>)
{
  chomp;
  if (/something/i)
  {
    system("/usr/bin/program $_");
  }
}

----

To use this call it like so

tail -f /var/log/messages | thisprog.pl

and you have your built in grep that supports regexs right there (in the /something/i line, just replace whats between the /'s)

the $_ var is the whole like as outputted from the STDIN that it matched on. Do that with what you want...

i think the reason as to why you were having problems is that grep itself didn't produce its output in the way you were expecting for a second pipe. 

enjoy! :)

-- 
Adam McDaniel
Infrastructure Technology Consultant
M-Tech Mercury Information Technology, Inc.