Bash Commands - Using the [[ ... ]] rather than [ ... ] can prevent many logic errors in scripts.

#!/bin/bash

decimal=15
octal=017
hex=0x0f

if [ "$decimal" -eq "$octal" ]
then
 echo "$decimal equals $octal"
else
 echo "$decimal is not equal to $octal"             # 15 is not equal to 017
fi

if [[ "$decimal" -eq "$octal" ]]
then
 echo "$decimal equals $octal"                           # 15 is equals 017
else
 echo "$decimal is not equal to $octal"
fi

if [ "$decimal" -eq "$hex" ]
then
 echo "$decimal equals $hex"                               # 15 is equals 017
else
 echo "$decimal is not equal to $hex"
fi

exit $?