[SOLVED] display 2nd part of variable in a shell script

sir-lancealot · 03-07-2012, 09:32 PM

ok, linux saavy, still need to sit in a cave for a week and learn sed/awk as it seems that's always the answer! Well I am remotely monitoring mysql, now want to graph the slave status. I have the following one line which works fine;

mysql -P 3306 -h host -e 'show slave status \G' | grep 'Seconds_Behind_Master'
Seconds_Behind_Master: 0

The monitoring app can take the value, graph it, I can trigger alarms, etc. so I need to only display the value, so I want to say just 0 (or whatever the value is. The Seconds_Behind_Master: is always exact so if I need to count characters and say after that is fine, or some other way, I am sure its simple for the right person/people, but I do want to get the scripting down more!

Tnx

grail · 03-08-2012, 12:26 AM

Well you can either put a second grep at the end:

Code:

mysql -P 3306 -h host -e 'show slave status \G' | grep 'Seconds_Behind_Master' | grep -Eo '[0-9]+$'

Or use sed to do something like:

Code:

mysql -P 3306 -h host -e 'show slave status \G' | sed -rn 's/Seconds_Behind_Master: ([0-9]+)/\1/p'

Or maybe with awk:

Code:

mysql -P 3306 -h host -e 'show slave status \G' | awk '/Seconds_Behind_Master/{print $NF}'

sir-lancealot · 03-08-2012, 09:14 PM

showoff ; )

Well the 1st grep I should have gotten first as I use grep alot but there are sooo many extra's. The other 2 I knew the command, but it's like jumping in the ocean & not even knowing how to swim outside the kiddie pool! That's the reason I do try to post, learn and thank those who help since it's the best way to learn I find vs. linux programming, page 1, echo 'hello world' !!

Thanks again!

grail · 03-09-2012, 09:43 AM

No probs

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