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<?xml version="1.0" encoding="ISO-8859-1"?>
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<refentry id="fn_subseq">
<refmeta>
<refentrytitle>subseq</refentrytitle>
<refmiscinfo>string</refmiscinfo>
</refmeta>
<refnamediv>
<refname>subseq</refname>
<refpurpose>returns substring of a string or sub-vector of a vector</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis id="fsyn_subseq">
<funcprototype id="fproto_subseq">
<funcdef><function>subseq</function></funcdef>
<paramdef><parameter>str</parameter> string or vector </paramdef>
<paramdef><parameter>from</parameter> integer</paramdef>
<paramdef><optional><parameter>to</parameter> integer or NULL</optional></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 id="desc"><title>Description</title>
<para>subseq returns a copy of subsequence of string or vector str using zero-based
indices from (inclusive) and to (exclusive) to delimit the substring or the vector
extracted.
</para>
<para>
If to is omitted or is NULL, then it equals by default to the length of
str, i.e. everything from from to the end of str is returned.
</para>
<para>
If to and from are equal, an empty string ''(empty vector) is returned.
</para>
<para>
If from is greater than to or length of str an error is signalled.
</para>
<para>
If str is NULL then NULL is returned.
</para>
<screen>
subseq('AbracadabrA',0,4) -> 'Abra'
subseq('AbracadabrA',4,8) -> 'cada'
subseq('AbracadabrA',7) -> 'abrA'
subseq(string,0,strchr(string,'/'))
subseq(vector (1, 2, 3), 2) -> vector (3)
subseq(vector (1, 2, 3), 0, 2) -> vector (1, 2)
</screen>
<para>
The last one with string argument returns a copy of the string cut from the first slash,
leaving it and everything following out, and in the case where there
are no slashes present, returns a copy of the whole string.
</para>
</refsect1>
</refentry>
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