expand, unexpand - expand tabs to spaces, and vice versa
expand [-h] [-tabstop] [-tab1, tab2, ...] [file ...]
unexpand [-h] [-a] [-tabstop] [-tab1, tab2, ...] [file ...]
expand 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. expand is useful for pre-processing character files (before sorting, looking at specific columns, etc.) that contain tabs.
If a single tabstop argument is given, tabs are set tabstop spaces apart instead of the default 8. If multiple tabstops are given then the tabs are set at those specific columns.
unexpand puts tabs back into the data from the standard input or the named files and writes the result on the standard output.
Option (with expand and unexpand):
Print a usage message and exit with a status code indicating success.
Option (with unexpand only):
By default, only leading blanks and tabs are reconverted to maximal strings of tabs. If the -a option is given, tabs are inserted whenever they would compress the resultant file by replacing two or more characters.
This documentation comes from the BSD expand(1) man page.
This program is free and open software. You may use, modify, distribute, and sell this program (and any modified variants) in any way you wish, provided you do not restrict others from doing the same.