expand(1)							    expand(1)



NAME
  expand, unexpand - Replaces tab characters with spaces or spaces with tab
  characters

SYNOPSIS

  Current syntax

  expand [-t tablist] [file ...]

       unexpand [-a] [-t tablist] [file ...]

  Obsolescent syntax

  expand [-tabstop | -tab1,tab2,...,tabn] [file ...]

       The expand command changes tab characters to spaces in the named
       files, or the standard input, and writes the result to the standard
       output.

       The unexpand command puts tab characters back into the data from the
       standard input, or the named files, and writes the result to the stan-
       dard output.

FLAGS

  -a  Replaces spaces at the beginning of each line with a tab, and inserts
      tab characters wherever their presence compresses the resultant file by
      replacing two or more characters.	 When the -t flag is specified with
      the unexpand command, the -a flag has no effect.	(unexpand command
      only)

  -t tablist
      Specifies the tab stops.	The tablist argument consists of a single
      positive decimal integer or multiple positive decimal integers,
      separated by spaces or commas, in ascending order.  If a single number
      is specified, tabs are set tablist column positions apart instead of
      the default (8).	If multiple numbers are specified, tabs are set at
      those specific column positions.	Tabbing to tab stop position n thus
      causes the next character output to be in the (n+1)th column position
      on that line.

      If expand has to process a tab character at a position beyond the last
      of those specified in a multiple tab stop list, the tab character is
      replaced by a single space in the output.

  -tabstop
      Sets tab stops tabstop spaces apart instead of the default (8).
      (Obsolescent)

  -tab1, tab2, ..., tabn
      Sets tab stops at specified columns.  Columns are measured in bytes.
      (Obsolescent)

DESCRIPTION

  Backspace characters are preserved in the output and decrement the column
  count for tab calculations. The column position count cannot be decremented
  below zero. The expand command is useful for preprocessing character files
  (before sorting, looking at specific columns, and so on.) that contain tab
  characters.

  By default, unexpand converts only spaces that are within sequences of
  spaces and tab characters at the beginnings of lines.	 Use -a to convert
  other sequences of spaces.

EXAMPLES

   1.  To replace tab characters in file with spaces, enter:
	    expand file


   2.  To replace the spaces in file with tab characters, enter:
	    unexpand -a file


RELATED INFORMATION

  Commands:  fold(1).