valkey/doc/SubstrCommand.html

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2010-05-17 22:39:49 +00:00
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<b>SubstrCommand: Contents</b><br>&nbsp;&nbsp;<a href="#SUBSTR _key_ _start_ _end_">SUBSTR _key_ _start_ _end_</a><br>&nbsp;&nbsp;&nbsp;&nbsp;<a href="#Return value">Return value</a><br>&nbsp;&nbsp;&nbsp;&nbsp;<a href="#Examples">Examples</a>
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<h1 class="wikiname">SubstrCommand</h1>
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&iuml;&raquo;&iquest;#sidebar <a href="StringCommandsSidebar.html">StringCommandsSidebar</a><h1><a name="SUBSTR _key_ _start_ _end_">SUBSTR _key_ _start_ _end_</a></h1>
<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>
<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>
<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">
redis&gt; set s &quot;This is a string&quot;
OK
redis&gt; substr s 0 3
&quot;This&quot;
redis&gt; substr s -3 -1
&quot;ing&quot;
redis&gt; substr s 0 -1
&quot;This is a string&quot;
redis&gt; substr s 9 100000
&quot; string&quot;
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