ultrix man page for expand

expand(1)						      General Commands Manual							 expand(1)

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

Syntax
       expand [-tabstop] [-tabn...] [file...]
       unexpand [-a] [file...]

Description
       The  command  processes the named files or the standard input writing the standard output with tabs changed into blanks.  Backspace charac-
       ters are preserved into the output and decrement the column count for tab calculations.	The command is useful for pre-processing character
       files (before sorting, looking at specific columns, and so forth) 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.

       The command puts tabs back into the data from the standard input or the named files and writes the  result  on  the  standard  output.	By
       default	only  leading blanks and tabs are reconverted to maximal strings of tabs.  If the -a option is given, then tabs are inserted when-
       ever they would compress the resultant file by replacing two or more characters.

Options
       -#   Sets tabstops the specified number of spaces (#) apart.

       -a   When used with unexpand, compresses file by inserting tabs for two or more spaces.

																	 expand(1)