nagios 监控内存脚本

#!/bin/bash
USAGE="

basename $0

[-w|–warning]<percent free> [-c|–critical]<percent free>"
THRESHOLD_USAGE="WARNING threshold must be greater than CRITICAL:

basename $0

$*"
calc=/tmp/memcalc
percent_free=/tmp/mempercent
critical=""
warning=""
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
# print usage
if [[ $# -lt 4 ]]
then
echo ""
echo "Wrong Syntax:

basename $0

$*"
echo ""
echo "Usage: $USAGE"
echo ""
exit 0
fi
# read input
while [[ $# -gt 0 ]]
do
case "$1" in
-w|–warning)
shift
warning=$1
;;
-c|–critical)
shift
critical=$1
;;
esac
shift
done
# verify input
if [[ $warning -eq $critical || $warning -lt $critical ]]
then
echo ""
echo "$THRESHOLD_USAGE"
echo ""
echo "Usage: $USAGE"
echo ""
exit 0
fi
# Total memory available
total=

free -m | head -2 |tail -1 |gawk '{print $2}'

# Total memory used
used=

free -m | head -2 |tail -1 |gawk '{print $3}'

# Calc total minus used
free=

free -m | head -2 |tail -1 |gawk '{print $2-$3}'

# normal values
#echo "$total"MB total
#echo "$used"MB used
#echo "$free"MB free
# make it into % percent free = ((free mem / total mem) * 100)
echo "5" > $calc # decimal accuracy
echo "k" >> $calc # commit
echo "100" >> $calc # multiply
echo "$free" >> $calc # division integer
echo "$total" >> $calc # division integer
echo "/" >> $calc # division sign
echo "*" >> $calc # multiplication sign
echo "p" >> $calc # print
percent=

/usr/bin/dc $calc|/bin/sed 's/^./0./'|/usr/bin/tr "." " "|/usr/bin/gawk {'print $1'}

#percent1=

/usr/bin/dc $calc

#echo "$percent1"
if [[ "$percent" -le  $critical ]]
then
echo "CRITICAL – $free MB ($percent%) Free Memory"
exit 2
fi
if [[ "$percent" -le  $warning ]]
then
echo "WARNING – $free MB ($percent%) Free Memory"
exit 1
fi
if [[ "$percent" -gt  $warning ]]
then
echo "OK – $free MB ($percent%) Free Memory"
exit 0
fi