<i>Time complexity: O(start+n) (with start being the start index and n the total length of the requested range). Note that the lookup part of this command is O(1) so for small strings this is actually an O(1) command.</i><b>Warning:</b> this command was renamed into GETRANGE. SUBSTR will be taken as an alias until the next major release of Redis.<br/><br/><blockquote>Return a subset of the string from offset <i>start</i> to offset <i>end</i>(both offsets are inclusive).Negative offsets can be used in order to provide an offset starting fromthe end of the string. So -1 means the last char, -2 the penultimate andso forth.</blockquote>
<blockquote>The function handles out of range requests without raising an error, butjust limiting the resulting range to the actual length of the string.</blockquote>
