coreutils: expand invocation

 
 9.2 ‘expand’: Convert tabs to spaces
 ====================================
 
 ‘expand’ writes the contents of each given FILE, or standard input if
 none are given or for a FILE of ‘-’, to standard output, with tab
 characters converted to the appropriate number of spaces.  Synopsis:
 
      expand [OPTION]... [FILE]...
 
    By default, ‘expand’ converts all tabs to spaces.  It preserves
 backspace characters in the output; they decrement the column count for
 tab calculations.  The default action is equivalent to ‘-t 8’ (set tabs
 every 8 columns).
 
    The program accepts the following options.  Also see ⇒Common
 options.
 
 ‘-t TAB1[,TAB2]...’
 ‘--tabs=TAB1[,TAB2]...’
      If only one tab stop is given, set the tabs TAB1 spaces apart
      (default is 8).  Otherwise, set the tabs at columns TAB1, TAB2, ...
      (numbered from 0), and replace any tabs beyond the last tab stop
      given with single spaces.  Tab stops can be separated by blanks as
      well as by commas.
 
      As a GNU extension the last TAB specified can be prefixed with a
      ‘/’ to indicate a tab size to use for remaining positions.  For
      example, ‘--tabs=2,4,/8’ will set tab stops at position 2 and 4,
      and every multiple of 8 after that.
 
      Also the last TAB specified can be prefixed with a ‘+’ to indicate
      a tab size to use for remaining positions, offset from the final
      explicitly specified tab stop.  For example, to ignore the 1
      character gutter present in diff output, one can specify a 1
      character offset using ‘--tabs=1,+8’, which will set tab stops at
      positions 1,9,17,...
 
      For compatibility, GNU ‘expand’ also accepts the obsolete option
      syntax, ‘-T1[,T2]...’.  New scripts should use ‘-t T1[,T2]...’
      instead.
 
 ‘-i’
 ‘--initial’
      Only convert initial tabs (those that precede all non-space or
      non-tab characters) on each line to spaces.
 
    An exit status of zero indicates success, and a nonzero value
 indicates failure.