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Viewing changes to modules/core/help/en_US/keywords/try.xml

  • Committer: Package Import Robot
  • Author(s): Sylvestre Ledru
  • Date: 2012-08-30 14:42:38 UTC
  • mfrom: (1.4.7)
  • Revision ID: package-import@ubuntu.com-20120830144238-c1y2og7dbm7m9nig
Tags: 5.4.0-beta-3-1~exp1
* New upstream release
* Update the scirenderer dep
* Get ride of libjhdf5-java dependency

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modules/core/help/en_US/keywords/try.xml
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<?xml version="1.0" encoding="UTF-8"?>
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<refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:svg="http://www.w3.org/2000/svg" xmlns:ns5="http://www.w3.org/1999/xhtml" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook" version="5.0-subset Scilab" xml:id="try" xml:lang="en">
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  <refnamediv>
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    <refname>try</refname>
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    <refpurpose>beginning of try block in try-catch control
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      instruction
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    </refpurpose>
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  </refnamediv>
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  <refnamediv xml:id="catch">
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    <refname>catch</refname>
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    <refpurpose>beginning of catch block in try-catch control
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      instruction
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    </refpurpose>
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  </refnamediv>
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  <refsynopsisdiv>
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    <title>Calling Sequence</title>
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    <synopsis>
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      try
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      statements
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      catch
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      statements
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      end
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    </synopsis>
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  </refsynopsisdiv>
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  <refsection>
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    <title>Description</title>
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    <para>
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      The <literal>try</literal>-<literal>catch</literal> control
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      instruction can be used to manage codes that could possibly generate
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      errors.
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    </para>
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    <para>
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      When a <literal>try</literal>-<literal>catch</literal> control
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      instruction is executed, normally only the statements between the
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      <literal>try</literal> and <literal>catch</literal> keywords are executed.
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      However, if an error occurs during execution of any of these statements,
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      the error is recorded, the remaining statements up to the
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      <literal>catch</literal> keyword are skipped and the statements between
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      the <literal>catch</literal> and <literal>end</literal> keywords are
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      executed using the default error handling mode (see <link linkend="errcatch">errcatch</link>).
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    </para>
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    <para>
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      The recorded error can be retrieved using the <link linkend="lasterror">lasterror</link> function.
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    </para>
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    <para>
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      The <literal>catch</literal> statements as well as the
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      <literal>catch</literal> keyword can be omitted if no alternative
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      statements are given.
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    </para>
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    <para>
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      Note that one can also use the <link linkend="execstr">execstr</link> function with
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      <literal>'errcatch'</literal> argument for error handling. This can be
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      particularly useful for handling syntactical errors.
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    </para>
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    <para>
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      Note also that <literal>try-catch</literal> is more or less similar
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      to:
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    </para>
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    <programlisting role=""><![CDATA[ 
 
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    <refnamediv>
 
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        <refname>try</refname>
 
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        <refpurpose>beginning of try block in try-catch control
 
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            instruction
 
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        </refpurpose>
 
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    </refnamediv>
 
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    <refnamediv xml:id="catch">
 
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        <refname>catch</refname>
 
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        <refpurpose>beginning of catch block in try-catch control
 
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            instruction
 
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        </refpurpose>
 
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    </refnamediv>
 
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    <refsynopsisdiv>
 
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        <title>Calling Sequence</title>
 
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        <synopsis>
 
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            try
 
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            statements
 
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            catch
 
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            statements
 
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            end
 
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        </synopsis>
 
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    </refsynopsisdiv>
 
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    <refsection>
 
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        <title>Description</title>
 
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        <para>
 
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            The <literal>try</literal>-<literal>catch</literal> control
 
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            instruction can be used to manage codes that could possibly generate
 
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            errors.
 
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        </para>
 
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        <para>
 
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            When a <literal>try</literal>-<literal>catch</literal> control
 
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            instruction is executed, normally only the statements between the
 
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            <literal>try</literal> and <literal>catch</literal> keywords are executed.
 
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            However, if an error occurs during execution of any of these statements,
 
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            the error is recorded, the remaining statements up to the
 
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            <literal>catch</literal> keyword are skipped and the statements between
 
39
            the <literal>catch</literal> and <literal>end</literal> keywords are
 
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            executed using the default error handling mode (see <link linkend="errcatch">errcatch</link>).
 
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        </para>
 
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        <para>
 
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            The recorded error can be retrieved using the <link linkend="lasterror">lasterror</link> function.
 
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        </para>
 
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        <para>
 
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            The <literal>catch</literal> statements as well as the
 
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            <literal>catch</literal> keyword can be omitted if no alternative
 
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            statements are given.
 
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        </para>
 
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        <para>
 
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            Note that one can also use the <link linkend="execstr">execstr</link> function with
 
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            <literal>'errcatch'</literal> argument for error handling. This can be
 
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            particularly useful for handling syntactical errors.
 
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        </para>
 
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        <para>
 
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            Note also that <literal>try-catch</literal> is more or less similar
 
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            to:
 
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        </para>
 
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        <programlisting role=""><![CDATA[ 
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if execstr("<try instructions>","errcatch")<>0 then
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  <catch instructions>
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end
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 ]]></programlisting>
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    <para>
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      It uses the same internal mechanism as <link linkend="errcatch">errcatch</link>. It is the reason why <link linkend="errcatch">errcatch</link> or
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      <emphasis>execstr(...,"errcatch")</emphasis> cannot be included in
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      <literal>try</literal>-<literal>catch</literal> control structures. This
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      context is detected and produces a specific error message (this error is
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      caught and stored like any other error if it is triggered in the
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      <literal>try</literal> block).
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    </para>
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    <para>
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      However, <literal>try</literal>-<literal>catch</literal> control
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      structures can be nested (see example 2 below).
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    </para>
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  </refsection>
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  <refsection>
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    <title>Examples</title>
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    <programlisting role="example"><![CDATA[ 
 
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        <para>
 
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            It uses the same internal mechanism as <link linkend="errcatch">errcatch</link>. It is the reason why <link linkend="errcatch">errcatch</link> or
 
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            <emphasis>execstr(...,"errcatch")</emphasis> cannot be included in
 
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            <literal>try</literal>-<literal>catch</literal> control structures. This
 
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            context is detected and produces a specific error message (this error is
 
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            caught and stored like any other error if it is triggered in the
 
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            <literal>try</literal> block).
 
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        </para>
 
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        <para>
 
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            However, <literal>try</literal>-<literal>catch</literal> control
 
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            structures can be nested (see example 2 below).
 
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        </para>
 
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    </refsection>
 
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    <refsection>
 
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        <title>Examples</title>
 
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        <programlisting role="example"><![CDATA[ 
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// example 1
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file_path=TMPDIR+'/wrong'
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try
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end 
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 [error_message,error_number]=lasterror(%t)
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 ]]></programlisting>
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    <programlisting role="example"><![CDATA[ 
 
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        <programlisting role="example"><![CDATA[ 
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// example 2 (nested try/catch structures)
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function nestedtry(a,b)
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disp("START")
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nestedtry(1,"a string")
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nestedtry("a string","a string")
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 ]]></programlisting>
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  </refsection>
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  <refsection role="see also">
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    <title>See Also</title>
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    <simplelist type="inline">
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      <member>
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        <link linkend="error">error</link>
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      </member>
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      <member>
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        <link linkend="execstr">execstr</link>
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      </member>
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      <member>
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        <link linkend="if">if</link>
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      </member>
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      <member>
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        <link linkend="lasterror">lasterror</link>
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      </member>
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      <member>
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        <link linkend="errcatch">errcatch</link>
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      </member>
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    </simplelist>
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  </refsection>
 
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    </refsection>
 
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    <refsection role="see also">
 
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        <title>See Also</title>
 
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        <simplelist type="inline">
 
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            <member>
 
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                <link linkend="error">error</link>
 
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            </member>
 
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            <member>
 
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                <link linkend="execstr">execstr</link>
 
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            </member>
 
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            <member>
 
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                <link linkend="if">if</link>
 
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            </member>
 
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            <member>
 
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                <link linkend="lasterror">lasterror</link>
 
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            </member>
 
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            <member>
 
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                <link linkend="errcatch">errcatch</link>
 
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            </member>
 
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        </simplelist>
 
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    </refsection>
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</refentry>