Binary to Decimal Conversion Shell Script

#!/bin/bash
# SCRIPT:  binary2dec.sh
# USAGE:   binary2dec.sh Binary_Numbers(s)
# PURPOSE: Binary to Decimal Conversion. Takes input as command line
#          arguments.
#                        \\\\ ////
#                       \\  - -  //
#                           @ @
#                   ---oOOo-( )-oOOo---
#
#####################################################################
#                      Script Starts Here                           #
#####################################################################
if [ $# -eq 0 ]
then
    echo "Argument(s) not supplied "
    echo "Usage: binary2dec.sh Binary_Number(s)"
else
    echo -e "\033[1mBINARY             \t\t DECIMAL\033[0m"

    while [ $# -ne 0 ]
    do
         Binary=$1
         Bnumber=$Binary
         Decimal=0
         power=1

         while [ $Binary -ne 0 ]
         do
              rem=$(expr $Binary % 10 )
              Decimal=$((Decimal+(rem*power)))
              power=$((power*2))
              Binary=$(expr $Binary / 10)
         done

         echo -e "$Bnumber             \t\t $Decimal"
         shift
    done

fi

#NOTE: Using bc command you can directly get output at command line.
# Here we're converting the binary number 111 to a base 10 (decimal)
# number.
#
# $ echo 'ibase=2;obase=A;111' | bc
# 7
#
#Note that the obase is "A" and not "10".The reason for this is you've
# set the ibase to 2, so if you now had tried to use "10" as the value
# for the obase, it would stay as "2", because "10" in base 2 is "2".
# So you need to use hex to break out of binary mode or use obase=1010
#
# $ echo 'ibase=2;obase=1010;10000' | bc
# 16
# $ echo 'ibase=2;obase=1010;1000001' | bc
# 65
#
# You can omit obase=A, because default obase is 10(decimal).
# $ echo 'ibase=2;1000001' | bc
# 65
OUTPUT:
# sh binary2dec.sh 100 1111 1111111 1000000
BINARY                           DECIMAL
100                              4
1111                             15
1111111                          127
1000000                          64

# sh binary2dec.sh 1111111111111111111
BINARY                           DECIMAL
1111111111111111111              524287

# sh binary2dec.sh 10000000000000000000
BINARY                           DECIMAL
binary2dec.sh:line 28:[:10000000000000000000:integer expression expected
10000000000000000000

NOTE:My bash can handle upto 9223372036854775807.
But with bc command you can do more.
# echo 'ibase=2;10000000000000000000'|bc
524288
# echo 'ibase=2;110000000000000000000'|bc
1572864