Read article 41.04 (p. 754-756) in Unix Power Tools.

In short:

• a tab is just one character, the terminal (or printer, or editor, or ... ) does the conversion to spaces
• the standard Unix utilities "expand" and "unexpand" can be used to convert between tabs and spaces - they are available for Win32 too in the Cygwin package
• for more detail, read the man pages (or the source :-) ... ) of "expand" and "unexpand"

Christian Lemburg
Brainbench MVP for Perl
http://www.brainbench.com