Hello.

I have a problem with reading a log file the way I want to.

I have many systems reporting errors to a file called "error.log" in a "main" system.
Only two of the systems in the file concerns me. (sys1 and sys2.)
To read the messages for the two systems I use the command:
This gives me only the information about sys1 and sys2.
However, this also gives me more information than I'd like.
Example of information given:
sys1 cooling warning
sys2 door open
sys2 cooling error
sys1 lost connection with hhut1
sys1 gained connection with hhut1
sys2 door closed

Lets say I want to exclude the information about cooling and door. My idea was to use this command:
My guess is that you know this does not work. I also guess that you know why.

Any one that care to help me out?

Hi -

What you posted should basically work fine:

1. You want to use "egrep" (for the "|" functionality)
2. You want all entries in the error log for "sys1" or "sys2"
3. You want to EXCLUDE any entries for "cooling" or "door"

Try this:
Works for me

Yes, what you said works fine, but if you look at my code I also have tail -f, and then it won't work.

You can use sed:

You have to flush the output from grep to let it pass through the second pipe:

This works:
This does NOT work: (not for me anyway)

Thanks.