bash noob question

sir-lancealot · 01-03-2008, 09:15 AM

ok, I am getting dangerous now, but we have a problem with an apache memory leak and it's taking out the box's. So for now I am babysitting them using a free -m across the network, getting the swap in use, if it's over 300 or so, restarting apache (long story). While the developers track down, I would like to set this up as a script to check, if over 300 send an email, so this;
free -m | awk '/Swap/ {print $3}'
gives me exactly what I want, so now I need to say in a script;

if free -m | awk '/Swap/ {print $3}' > 300
{
email me
}
, then stick that in a cron. I know php, cf, etc. so this will take the right person/people 2 min's to reply vs. me starting at page 1, hello world.

Tnx

helptonewbie · 01-03-2008, 10:14 AM

Code:

#!/bin/bash
MEM_VAL=`free -m | awk '/Swap/ {print $3}'`
if [ ${MEM_VAL} -gt 300 ]; then
echo MEM_VAL=$MEM_VAL | mail -s "Alert Mem Limit" person@mail.com
fi
exit

Something like that might be enough

sir-lancealot · 01-03-2008, 10:34 AM

thanks, I put that in my home, made it executable, and ran it;

./memchk.sh <enter> and it just sat there. I put it on a box that had a swap in use of around 300 (so it would trip it) and it just sat there. A <ctrl>-C showed, (Interrupt -- one more to kill letter)
but it never sent the email.

I also upped the limit to 500 so it wouldn't trip, ran and it went through back to command line, so it must be something missing like a ', ; etc.

But thanks for the quick reply, just need to kick it one more time!

ghostdog74 · 01-03-2008, 10:53 AM

Code:

# free -m | (awk '/Swap/ && $4 > 300' && mail -s "Alert new" root)

helptonewbie · 01-03-2008, 10:58 AM

my bad i edited the above post try that

ghostdog74 · 01-03-2008, 11:05 AM

Quote:

Originally Posted by helptonewbie

Code:

#!/bin/bash
MEM_VAL=`free -m | awk '/Swap/ {print $3}'`
if [ ${MEM_VAL} -gt 300 ]; then
echo MEM_VAL=$MEM_VAL > /tmp/tmpfile
mail -s "Alert Mem Limit" person@mail.com < tempfile
fi
exit

Something like that might be enough

you can just do this. No need to create tempfile. ( btw, the tempfile and tmpfile, different spelling and path.)

Code:

echo MEM_VAL=$MEM_VAL | mail -s "Alert Mem Limit" person@mail.com

helptonewbie · 01-03-2008, 11:09 AM

ah yea that would work, dumb diddy um dumb dumb :-)
I'll re-edit

sir-lancealot · 01-03-2008, 12:17 PM

lol, worked like a charm, thanks both.

Now I can start working on some dangerous bash scripts!

Happy New Year !!!!

:lr:

helptonewbie · 01-03-2008, 01:56 PM

Just for future reference, it wasn't working because the first mail command i gave you didn't contain any text in the main body of the email, i thought that an email with just a subject name should send but it appears not to, hense why i then went and tried a input re-direct into the mail which does work but yes, using a pipe as the input also works so either way would have worked the '|' method is much neater :-)