While the decimal numbering system allows any digit in a number to have any of ten values (0-9), digits in hexadecimal numbers can have 16 (0-F), digits in octal numbers only eight (0-7 ...

The octal number 10 represents the number 8 in decimal. The octal 100 represents 8 × 8, or 64. 1000 is 8 × 8 × 8, or 512. One dollar in base ten would convert over to $1.44 in base eight ...

x\n" 42 42 octal: 52 hex: 2a Because of the notational convention mentioned earlier for non-decimal numbers in the shell, you also can specify an octal or hexadecimal value too: $ printf "%o\n" 0500 ...