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

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

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

DESCRIPTION
     The expand utility processes the named files or the standard input writ-
     ing the standard output with tabs changed into blanks.  Backspace charac-
     ters 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.

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

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

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

HISTORY
     The expand command appeared in 3.0BSD.

BSD                            October 13, 2006                            BSD