"Tailing" grep (Was: cat and grep without destroying file)

[Brian Fahrlander]

Michael R. Head wrote:
> On Sun, 2007-09-30 at 17:04 -0500, Brian Fahrlander wrote:
>> While we've got the attention of the most-able on this subject, I'd 
>> like to reopen a discussion about a very similar tool: a 'grep' that 
>> happens on tailing a file.  There have been dozens of times that I'm 
>> looking for a message number in /var/log/mail.log and would love to see 
>> only the lines mentioning that message.
>>
>>      A couple of years ago I asked and got a "maybe you could write 
>> something", but I actually never could.  It's not as easy as it looks.
>>
>>      Any chance you guys have seen this done?
> 
> You can use the "watch" program to effectively achieve this
> functionality.
> 
> watch "grep kernel /var/log/syslog | tail -n 20"

     Thanks; I'll look into that!

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  Brian Fahrländer                 Christian, Conservative, and Technomad
  Evansville, IN                              http://Fahrlander.net/brian
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