expand is a program that converts tab characters into groups of space characters, while maintaining correct alignment. It is available in Unix operating systems and many Unix-like operating systems. For example: $ echo -e "foo bar" | expand | xxd -g 1 -u0000000: 66 6F 6F 20 20 20 20 20 62 61 72 0A foo bar.$ echo -e "foo bar" | xxd -g 1 -u0000000: 66 6F 6F 09 62 61 72 0A foo.bar.$