EXPAND(1)                    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

     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 -Sm tab1, tab2, ..., tabn Sm
             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

     The expand and unexpand utilities conform to IEEE Std 1003.1-2001

     The expand utility first appeared in 1BSD.

macOS 12.1                        June 6, 2015                        macOS 12.1