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19 <b>SubstrCommand: Contents
</b><br> <a href=
"#SUBSTR _key_ _start_ _end_">SUBSTR _key_ _start_ _end_
</a><br> <a href=
"#Return value">Return value
</a><br> <a href=
"#Examples">Examples
</a>
22 <h1 class=
"wikiname">SubstrCommand
</h1>
29 #sidebar
<a href=
"StringCommandsSidebar.html">StringCommandsSidebar
</a><h1><a name=
"SUBSTR _key_ _start_ _end_">SUBSTR _key_ _start_ _end_
</a></h1>
30 <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><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>
31 <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>
32 <h2><a name=
"Return value">Return value
</a></h2><a href=
"ReplyTypes.html">Bulk reply
</a><h2><a name=
"Examples">Examples
</a></h2><pre class=
"codeblock python" name=
"code">
33 redis
> set s
"This is a string
"
35 redis
> substr s
0 3
37 redis
> substr s -
3 -
1
39 redis
> substr s
0 -
1
40 "This is a string
"
41 redis
> substr s
9 100000