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chapter14/equate_base_16_to_2.ksh

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+#!/usr/bin/ksh
+#
+# SCRIPT: equate_base_16_to_2.ksh
+# AUTHOR: Randy Michael
+# DATE: 07/07/2007
+# REV: 1.2.P
+#
+# PURPOSE: This script is used to convert a base 16 hexidecimal
+#          number to a base 2 binary representation.
+#          This scripts expects that a base 16 number
+#          is supplied as a single argument.
+#
+# EXIT CODES:
+#               0 - Normal script execution
+#               1 - Usage error
+#
+# REV LIST:
+#
+#
+# set -x # Uncomment to debug this script
+# set -n # Uncomment to check command syntax without any execution
+#
+#################################################
+# DEFINE FILES AND VARIABLES HERE
+#################################################
+
+SCRIPT_NAME=`basename $0`
+
+# Set up the correct echo command usage. Many Linux
+# distributions will execute in Bash even if the
+# script specifies Korn shell. Bash shell requires
+# we use echo -e when we use \n, \c, etc.
+
+case $SHELL in
+*/bin/bash) alias echo="echo -e"
+            ;;
+esac
+
+#################################################
+# DEFINE FUNCTIONS HERE
+#################################################
+
+function usage
+{
+echo "\nUSAGE: $SCRIPT_NAME base_16_number"
+echo "\nEXAMPLE: $SCRIPT_NAME FC23"
+echo "\nWill return the binary base 2 number 64547 ...EXITING...\n"
+}
+
+#################################################
+# BEGINNING OF MAIN
+#################################################
+
+# Check for a single command line argument
+
+if [ $# -ne 1 ]
+then
+     echo "\nERROR: A base 16 number must be supplied..."
+     usage
+     exit 1
+fi
+
+# Check for a hexidecimal number!
+
+case $1 in
++([-0-9]|[a-f]|[A-F])) BASE_16_NUM=$1
+                     ;;
+                  *)   usage
+                     ;;
+esac
+
+BASE_2_NUM=$((16#${BASE_16_NUM}))
+typeset -i2 BASE_2_NUM
+echo $BASE_2_NUM