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- - Script Help - If Statement (https://www.linuxquestions.org/questions/linux-newbie-8/script-help-if-statement-817206/)

genogp

06-30-2010 12:30 PM

Script Help - If Statement

Hi guys i need some help.
Im trying to run a command then grep a log file to see if the command was successful or not. In the log file there are specific words i can grep for to check for success or failure. Then weather it fails or succeeds i will send a mail to myself.

heres what i have;

Code:

#!/bin/bash



STOPSRV='stopServer.sh server1'

STARTSRV='startServer.sh server1'

CHECKA='grep' "Server server1 stopped" SystemOut.log

CHECKB='grep' "open for e-bus" SystemOut.log

MAILSUC='sendEmail -t test@mail.com -f 'host@mail.com' -u hello -s mail.smtp.com:25 -m bye'

MAILFAIL='sendEmail -t test@mail.com -f 'host@mail.com' -u fail -s mail.smtp.com:25 -m fail'



$STOPSRV

sleep 2m

if [[ "$CHECKA" == Server server1 stopped ]]

then $MAILSUC

else $MAILFAIL

fi



$STARTSRV

sleep 2m

if [[ "$CHECKB" == open for e-bus ]]

then $MAILSUC

else $MAILFAIL

fi



exit

Then if statement is were im falling short, and i think im putting the back ticks in the wrong place as well. Please help me

johnshen64

06-30-2010 01:09 PM

quote your multitoken strings and you should be fine.

e.g.

if [[ "$CHECKB" == "open for e-bus" ]]

instead of

if [[ "$CHECKB" == open for e-bus ]]

genogp

06-30-2010 01:29 PM

Thanks the if statement doesnt through an error anymore more but the statement is not working as expected.

The statement will only switch to the "else" therefore the variable "CHECKA" and "CHECKB" are failing.
Ive been starring at this for an hour and i know its something simple but cant put my finger on it :(

catkin

06-30-2010 09:40 PM

The line CHECKA='grep' "Server server1 stopped" SystemOut.log tells bash to set variable CHECKA to grep, to run the command "Server server1 stopped" SystemOut.log and then to unset CHECKA. It should have produced an error message as this experiment at the command prompt shows

Code:

c@CW8:~$ CHECKA='grep' "Server server1 stopped" SystemOut.log

bash: Server server1 stopped: command not found

Presumably your intention was to put the output of grep "Server server1 stopped" SystemOut.log into CHECKA. That could be done with this line

Code:

CHECKA=$( grep "Server server1 stopped" SystemOut.log 2>&1 )

You can figure a lot out for yourself by using echo statements to see what variables contain

Code:

echo "DEBUG: CHECKA: '$CHECKA'"

simon.sweetman

06-30-2010 11:32 PM

Most commands set the exit status, zero indicates success and non-zero indicates failure (different number for each possible type of error). In shell scripts $? is the exit status of the last command.

So if your scripts follow this convention (i.e. using exit 0 when everything is OK and exit 1 , exit 2, etc) you can test exit status after the command like:

Code:

$STOPSRV

ISOK=$?

sleep 2m

if [ $ISOK -eq 0 ]

then $MAILSUC

else $MAILFAIL

fi

Note that $? is stored in ISOK, if you wait till after the sleep statement $? will be the exit status of sleep no your script!

If your scripts don't set exit status correctly, grep does so you can do something like the following

Code:

$STOPSRV

grep "Server server1 stopped" SystemOut.log > /dev/null 2>&1

ISOK=$?

sleep 2m

if [ $ISOK -eq 0 ]

then $MAILSUC

else $MAILFAIL

fi

genogp

07-01-2010 01:49 AM

Many Thanks, guys you provided the solution

grail

07-01-2010 02:39 AM

Please mark as SOLVED once you have your solution.

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