Tail and Grep

[Brahnda A. Eleazar]

Peace all,

I was trying to use tail and grep for log monitoring.
Such as this:
tail -f my.log | grep error

It's working in Linux but doesn't seem so in HP-UX 11.23.

Any help?

Thanks,
=adley=

[Suraj K Sankari]

Hi,
What is the output you are getting ?

Suraj

[Nido]

Hi,

>>>>tail -f my.log | grep error
Its working for me on both Linux and HPUX 11.23,11.11.

Anyway tail -f option is ignored when reading from a pipe.
Instead of "-f" option you can put a sleep argument in your script for the desired time.

Cheers!!

[Venkatesh BL]

Looks like with '-f' option waits for further input even after the EOF is reached(see manpage). So, it will show you the pattern, but, won't terminate.

What is the difference you are seeing? Can you post both the outputs?

[Brahnda A. Eleazar]

Peace all,

Thanks for the inputs.

The problem is there is no output.
It simply hung after I pressed ENTER (it's been like this for 5 minutes almost) :)

Well, I asked this because I wanted to monitor IPMON logs.
But, I think I'll just reroute the ipmon logs to a separate file instead. :)

Thanks,
=adley=

[Venkatesh BL]

May be there is no 'error' thus far!

[Brahnda A. Eleazar]

Peace,

I thought about that.
The thing is, I did try to simulate an error attempt.

For example, if the ipf rule is this:
pass in quick on lan8 proto tcp from 10.192.x.y to any port = NNNN keep state
block in log quick on lan8 proto tcp from any to any port = NNNN keep state

I tried attempting to the same port from, say, 10.192.x.z, I did get rejected by ipf. But no logs of the blocking.

But nevermind, I have re-routed the logs to another file instead of syslog.log; so I can tail there instead easily. :)

Really appreciate everyone's help!

Thanks,
=adley=

[Suraj K Sankari]

Hi Again,

>>tail -f my.log | grep error

will open your my.log and waiting for any line which is having error insert into the my.log file.

if your my.log file will not getting any error string then you will not getting any error.

Suraj

[Aneesh Mohan]

see..


# echo "error $(date)" >> /tmp/pv

# tail -f /tmp/pv |grep error
error Thu Jun 18 10:00:49 UTC 2009


Aneesh

[john korterman]

Hi,

perhaps you should try a non-case sensitive search:

# tail -f my.log | grep -i error

regards,
John K.