File: coreutils.info,  Node: expand invocation,  Next: unexpand invocation,  Prev: tr invocation,  Up: Operating on characters

9.2 ‘expand’: Convert tabs to spaces
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‘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 *note 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.