Defaults on if output is a tty,
disabled otherwise such as when piped or redirected.
-=item -f, --field=(<number>|<regexp>)
+=item -f, --field=(<number> | <regexp>)
Compare values after a given number of whitespace separators,
or matching a regular expression.
Also changes an exponent I<1.602176634e-19> to I<160.2z>.
Short integers are aligned but kept without decimal point.
-=item -t, --interval[=(<seconds>|-<lines>)]
+=item -t, --interval[=(<seconds> | -<lines>)]
Output partial progress every given number of seconds or input lines.
An update can also be forced by sending a I<SIGALRM> alarm signal.
the last is used for values equal to the maximum, the first for minima.
If unspecified, these are green and red respectively (I<31 90 32>).
-=item --spark[=<glyphs>]
+=item --spark[=<characters>]
Replace lines by I<sparklines>,
single characters corresponding to input values.