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EXPAND(1)                 BSD General Commands Manual                EXPAND(1)

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

     expand [-t tab1,tab2,...,tabn] [file ...]
     unexpand [-a | -t tab1,tab2,...,tabn] [file ...]

     The expand utility processes the named files or the standard input writing the standard output with
     tabs changed into blanks.  Backspace characters are preserved into the output and decrement the column
     count for tab calculations.  The expand utility is useful for pre-processing character files (before
     sorting, looking at specific columns, etc.) that contain tabs.

     The unexpand utility puts tabs back into the data from the standard input or the named files and writes
     the result on the standard output.

     The following options are available:

     -a      (unexpand only.)  By default, only leading blanks and tabs are reconverted to maximal strings
             of tabs.  If the -a option is given, then tabs are inserted whenever they would compress the
             resultant file by replacing two or more characters.

     -t tab1,tab2,...,tabn
             Set tab stops at column positions tab1, tab2, ..., tabn.  If only a single number is given, tab
             stops are set that number of column positions apart instead of the default number of 8.

     The LANG, LC_ALL and LC_CTYPE environment variables affect the execution of expand and unexpand as
     described in environ(7).

     The expand and unexpand utilities exit 0 on success, and >0 if an error occurs.

     The expand and unexpand utilities conform to IEEE Std 1003.1-2001 (``POSIX.1'').

     The expand command appeared in 3.0BSD.

BSD                            October 13, 2006                            BSD

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