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chapter13/float_average.ksh

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+#!/usr/bin/ksh
+#
+# SCRIPT: float_aaverage.ksh
+# AUTHOR: Randy Michael
+# DATE: 03/01/2007
+# REV: 1.1.A
+#
+# PURPOSE: This script is used to average a list of 
+#   floating-point numbers. 
+#      
+# EXIT STATUS:
+#       0 ==> This script completed without error
+#       1 ==> Usage error
+#       2 ==> This script exited on a trapped signal
+#
+# REV. LIST:
+#
+#
+#
+# set -x # Uncomment to debug this script
+# set -n # Uncomment to debug without any command execution
+
+SCRIPT_NAME=`basename $0`
+ARG1="$1"
+ARG2="$2"
+ARG_LIST="$*"
+TOTAL_TOKENS="$#"
+SCALE="0"
+
+########################################################
+################ FUNCTIONS #############################
+########################################################
+
+function usage
+{
+echo "\n\n"
+echo "Numbers to average...\n"
+echo "USAGE: $SCRIPT_NAME [-s scale_value]  N1 N2...N#"
+echo "\nFor an integer result without any significant decimal places..."
+echo "\nEXAMPLE: $SCRIPT_NAME 2048.221 65536 \n"
+echo "OR for 4 significant decimal places"
+echo "\nEXAMPLE: $SCRIPT_NAME -s 4  8.09838 2048 65536 42.632\n"
+echo "Try again...EXITING...\n"
+}
+########################################################
+
+function exit_trap
+{
+echo "\n...EXITING on trapped signal...\n"
+}
+
+########################################################
+################ START OF MAIN #########################
+########################################################
+
+###### Set a Trap ######
+
+trap 'exit_trap; exit 2' 1 2 3 15
+
+########################
+
+if [ $# -lt 2 ]
+then
+    echo "\nIncorrect number of command auguments...Nothing to average..."
+    usage
+    exit 1
+fi
+
+if [ $ARG1 = "-s" ] || [ $ARG1 = "-S" ]
+then
+    echo $ARG2 | grep [[:digit:]] >/dev/null 2>&1
+    if [ $? -ne "0" ]
+    then
+        echo "\nERROR: Invalid argument - $ARG2 ... Must be an integer...\n"
+        usage
+        exit 1
+    fi
+    echo $ARG2 | grep "\." >/dev/null 2>&1
+    if [ $? -ne "0" ]
+    then
+        SCALE="$ARG2"
+        NUM_LIST=`echo $ARG_LIST | cut -f 3- -d " "`
+        (( TOTAL_TOKENS = $TOTAL_TOKENS - 2 ))
+    else
+        echo "\nERROR: Invalid scale - $ARG2 ... Scale must be an integer...\n"
+        usage
+        exit 1
+    fi
+else
+    NUM_LIST=$ARG_LIST
+fi
+
+for TOKEN in $NUM_LIST
+do
+    echo $TOKEN | grep [[:digit:]] >/dev/null 2>&1
+    RC=$?
+    case $RC in
+    0) cat /dev/null
+       ;;
+    *) echo "\n$TOKEN is not a number...Invalid argument list"
+       usage
+       exit 1
+       ;;
+    esac
+done
+
+
+# Build the list of numbers to add for averaging...
+
+ADD=""
+PLUS=""
+for X in $NUM_LIST
+do
+    ADD="$ADD $PLUS $X"
+    PLUS="+"
+done
+
+# Do the math here
+
+AVERAGE=`bc <<EOF
+scale=$SCALE
+(${ADD}) / $TOTAL_TOKENS
+EOF`
+
+########################################################
+
+# Present the result of the average to the user.
+
+echo "\nThe averaging equation: (${ADD}) / $TOTAL_TOKENS"
+echo "\nto a scale of $SCALE is: ${AVERAGE}\n"
+