@Geoff,

Thanks for pointing this out!

You’re absolutely right, the leading zero causes the shell arithmetic $((…)) to interpret the input as octal, which breaks the binary-to-decimal conversion for numbers like 01101.

A simple fix would be to strip leading zeros before performing the calculation. For example, you can add a line like this right after reading the input:

Binary=$(echo "$Binary" | sed 's/^0*//')

This removes all leading zeros and ensures $((…)) treats the number correctly as decimal digits of a binary number.

Alternatively, you could update the input validation to disallow leading zeros (except for the number 0 itself), depending on your preference.

Thanks again for bringing this up — it’s a useful enhancement for anyone using the script today!

Enter a binary number:
1101
Decimal Value: 13

Enter a binary number:
01101
Decimal Value: 41

The reason the leading zero throws it off is because $((…)) treats integers that have a leading zero as octal (for consistency with C constants). The script should either disallow leading zero when it checks the input, or strip off leading zeros before doing any calculations.

@Ian,

Can you point us the typo? so that we can correct it..