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chapter19/iostat_loadmon.bash

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+#!/bin/bash
+#
+# SCRIPT: iostat_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 take 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.
+
+case $OS in
+AIX|HP-UX) SWITCH='-t'
+           F1=3
+           F2=4
+           F3=5
+           F4=6
+           echo -e "\nThe Operating System is $OS\n"
+           ;;
+Linux) SWITCH='-c'
+           F1=1
+           F2=3
+           F3=4
+           F4=6
+           echo -e "\nThe Operating System is $OS\n"
+           ;;
+SunOS) SWITCH='-c'
+           F1=1
+           F2=2
+           F3=3
+           F4=4
+          echo -e "\nThe Operating System is $OS\n"
+          ;;
+OpenBSD) SWITCH='-C'
+          F1=1
+          F2=2
+          F3=3
+          F4=5
+          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 "iostat" to monitor the CPU utilization and
+# remove all lines that contain alphabetic characters
+# and blank spaces. Then use the previously defined
+# field numbers, for example, F1=4,to point directly
+# to the 4th position, for this example. The syntax
+# for this techniques is ==> $.$F1..
+
+iostat $SWITCH $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 "iostat"
+
+    case $OS in # Show the results based on the UNIX flavor
+    AIX)
+         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)
+         echo -e "\nUser part is ${FIRST}%"
+         echo "Nice part is ${SECOND}%"
+         echo "System part is ${THIRD}%"
+         echo -e "Idle time is ${FOURTH}%\n"
+         ;;
+    SunOS|Linux)
+         echo -e "\nUser part is ${FIRST}%"
+         echo "System part is ${SECOND}%"
+         echo "I/O Wait is ${THIRD}%"
+         echo -e "Idle time is ${FOURTH}%\n"
+         ;;
+    esac
+fi
+((STATCOUNT = STATCOUNT + 1)) # Increment the loop counter
+done