unexpand - convert spaces to tabs

SYNOPSIS

       unexpand  [-tab1[,tab2[,...]]] [-t tab1[,tab2[,...]]] [-a]
       [--tabs=tab1[,tab2[,...]]]  [--all]  [--help]  [--version]
       [file...]

DESCRIPTION

       This  manual  page  documents the GNU version of unexpand.
       unexpand writes the contents of each given  file,  or  the
       standard  input if none are given or when a file named `-'
       is given, to the standard output, with strings of  two  or
       more  space or tab characters converted to as many tabs as
       possible followed by as many spaces  as  are  needed.   By
       default,  unexpand  converts  only initial spaces and tabs
       (those that precede all non space or  tab  characters)  on
       each  line.  It preserves backspace characters in the out-
       put; they decrement the column count for tab calculations.
       By default, tabs are set at every 8th column.

   OPTIONS
       -, -t, --tabs tab1[,tab2[,...]]
              If  only  one  tab stop is given, set the tabs tab1
              spaces apart instead of the default 8.   Otherwise,
              set  the tabs at columns tab1, tab2, etc. (numbered
              from 0) and leave spaces and tabs beyond  the  tab-
              stops  given unchanged.  If the tabstops are speci-
              fied with the -t or --tabs option, they can be sep-
              arated by blanks as well as by commas.  This option
              implies the -a option.

       -a, --all
              Convert all strings of two or more spaces or  tabs,
              not just initial ones, to tabs.

       --help Print  a  usage message and exit with a status code
              indicating success.

       --version
              Print version information on standard  output  then
              exit.