# Base converter

Execution

# cat bconv 
#!/bin/bash

function char2dec {
 case $1 in
  b) echo "2" ;;
  o) echo "8" ;;
  d) echo "10";;
  x) echo "16";;
  *) echo $1  ;;
 esac
}

n=`echo $1 | tr [:lower:] [:upper:]`
ib=`char2dec $2`
ob=`char2dec $3`

echo "obase=$ob;ibase=$ib;$n" | bc -l | tr [:upper:] [:lower:]
# ./bconv 1001100110111 b x
1337