EXPAND(1) OpenBSD Reference Manual EXPAND(1)NAME
expand, unexpand - expand tabs to spaces, and vice versa
SYNOPSISexpand [-t tablist] [file ...]
unexpand [-a] [file ...]
DESCRIPTIONexpand 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.
unexpand puts tabs back into the data from the standard input or the
named files and writes the result on the standard output.
The options are as follows:
-a (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.
-t tablist
(expand only) If the argument to -t, tablist, consists of a single
numerical argument, tabs are set tablist spaces apart instead of
the default 8. If multiple -t options are given, then the tabs are
set at those specific columns.
Otherwise the argument to -t may consist of a list of two or more
positive decimal integers, comma separated, in ascending order: in
the event of having to process a <tab> at a position beyond the
last of those specified in a multiple -t list, the <tab> is
replaced by a single <space> character.
This implementation of expand additionally allows tablist to be
specified without using the -t flag, by prefixing tablist with a
dash (-).
EXIT STATUS
The expand and unexpand utilities exit 0 on success or >0 if an error
occurred.
SEE ALSOfold(1)STANDARDS
The expand and unexpand utilities are compliant with the IEEE Std
1003.1-2008 (``POSIX'') specification, with the following exceptions:
o POSIX does not support specifying tabstops without use of the
-t flag.
o POSIX specifies that multiple tabstops may be given separated
by commas or blanks. This implementation supports only comma-
separated tabstops.
o unexpand does not recognise the -t flag.
HISTORY
The expand command appeared in 3.0BSD.
OpenBSD 4.9 November 7, 2010 OpenBSD 4.9
