netbsd man page for expand

EXPAND(1)						    BSD General Commands Manual 						 EXPAND(1)

NAME
     expand, unexpand -- expand tabs to spaces, and vice versa

SYNOPSIS
     expand [-t tabstop] [-t tab1,tab2,...,tabn] [file ...]
     unexpand [-a] [-t tab1,tab2,...,tabn] [file ...]

DESCRIPTION
     expand processes the named files or the standard input writing the standard output with tabs changed into blanks.	Backspace characters are
     preserved into the output and decrement the column count for tab calculations.  expand is useful for pre-processing character files (before
     sorting, looking at specific columns, etc.) that contain tabs.

     If a single tabstop argument is given, then tabs are set tabstop spaces apart instead of the default 8.  If multiple tabstops are given then
     the tabs are set at those specific columns.

     unexpand puts tabs back into the data from the standard input or the named files and writes the result on the standard output.

     Option (with unexpand only):

     -a    By default, only leading blanks and tabs are reconverted to maximal strings of tabs.  If the -a option is given, then tabs are inserted
	   whenever they would compress the resultant file by replacing two or more characters.

HISTORY
     The expand command appeared in 3.0BSD.

BSD
								 December 20, 2008							       BSD