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chapter19/vmstat_loadmon.bash

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+#!/bin/bash
+#
+# SCRIPT: vmstat_loadmon.bash
+# AUTHOR: Randy Michael
+# DATE: 12/20/2007
+# REV: 1.0.P
+# PLATFORM: AIX, HP-UX, Linux, OpenBSD, and Solaris
+#
+# PURPOSE: This shell script takes two samples of the CPU
+#          usage using the command. The first set of
+#          data is an average since the last system reboot. The
+#          second set of data is an average over the sampling
+#          period, or $INTERVAL. The result of the data acquired
+#          during the sampling period is shown to the user based
+#          on the UNIX operating system that this shell script is
+#          executing on. Different UNIX flavors have differing
+#          outputs and the fields vary too.
+#
+# REV LIST:
+#
+#
+# set -n # Uncomment to check the script syntax without any execution
+# set -x # Uncomment to debug this shell script
+#
+###################################################
+############# DEFINE VARIABLES HERE ###############
+###################################################
+
+SECS=300 # Defines the number of seconds for each sample
+INTERVAL=2  # Defines the total number of sampling intervals
+STATCOUNT=0 # Initializes a loop counter to 0, zero
+OS=$(uname) # Defines the UNIX flavor
+
+###################################################
+##### SET UP THE ENVIRONMENT FOR EACH OS HERE ######
+###################################################
+
+# These "F-numbers" point to the correct field in the
+# command output for each UNIX flavor.
+
+OS=$(uname)
+
+case $OS in
+AIX)
+     F1=14
+     F2=15
+     F3=16
+     F4=17
+     echo -e "\nThe Operating System is $OS\n"
+     ;;
+HP-UX)
+     F1=16
+     F2=17
+     F3=18
+     F4=1 # This "F4=1" is bogus and not used for HP-UX
+     echo -e "\nThe Operating System is $OS\n"
+     ;;
+Linux)
+     F1=13
+     F2=14
+     F3=15
+     F4=16
+     echo -e "\nThe Operating System is $OS\n"
+     ;;
+OpenBSD)
+     F1=17
+     F2=18
+     F3=19
+     F4=1 # This "F4=1" is bogus and not used for Linux
+     echo -e "\nThe Operating System is $OS\n"
+     ;;
+SunOS)
+     F1=20
+     F2=21
+     F3=22
+     F4=1 # This "F4=1" is bogus and not used for SunOS
+     echo -e "\nThe Operating System is $OS\n"
+     ;;
+*)   echo -e "\nERROR: $OS is not a supported operating system\n"
+     echo -e "\n\t...EXITING...\n"
+     exit 1
+     ;;
+esac
+###################################################
+######## BEGIN GATHERING STATISTICS HERE ##########
+###################################################
+
+echo -e "Gathering CPU Statistics using vmstat...\n"
+echo "There are $INTERVAL sampling periods with"
+echo "each interval lasting $SECS seconds"
+echo -e "\n...Please wait while gathering statistics...\n"
+
+# Use "vmstat" to montor the CPU utilization and
+# remove all lines that contain alphabetic characters
+# and blank spaces. Then use the previously defined
+# field numbers, for example F1=20,to point directly
+# to the 20th position, for this example. The syntax
+# for this technique is ==> $.$F1. and points directly
+# to the $20 positional parameter.
+
+vmstat $SECS $INTERVAL | egrep -v '[a-zA-Z]|^$' \
+         | awk '{print $'$F1', $'$F2', $'$F3', $'$F4'}' \
+         | while read FIRST SECOND THIRD FOURTH
+do
+  if ((STATCOUNT == 1)) # Loop counter to get the second set
+  then # of data produced by
+
+      case $OS in # Show the results based on the UNIX flavor
+      AIX|Linux)
+            echo -e "\nUser part is ${FIRST}%"
+            echo "System part is ${SECOND}%"
+            echo "Idle part is ${THIRD}%"
+            echo -e "I/O wait state is ${FOURTH}%\n"
+            ;;
+      HP-UX|OpenBSD|SunOS)
+            echo -e "\nUser part is ${FIRST}%"
+            echo "System part is ${SECOND}%"
+            echo -e "Idle time is ${THIRD}%\n"
+            ;;
+      esac
+  fi
+((STATCOUNT = STATCOUNT + 1)) # Increment the loop counter
+done