<literal>-</literal> flag:

<screen>
SELECT format('|%10s|', 'foo');
<lineannotation>Result: </lineannotation><computeroutput>|       foo|</computeroutput>

SELECT format('|%-10s|', 'foo');
<lineannotation>Result: </lineannotation><computeroutput>|foo       |</computeroutput>

SELECT format('|%*s|', 10, 'foo');
<lineannotation>Result: </lineannotation><computeroutput>|       foo|</computeroutput>

SELECT format('|%*s|', -10, 'foo');
<lineannotation>Result: </lineannotation><computeroutput>|foo       |</computeroutput>

SELECT format('|%-*s|', 10, 'foo');
<lineannotation>Result: </lineannotation><computeroutput>|foo       |</computeroutput>

SELECT format('|%-*s|', -10, 'foo');
<lineannotation>Result: </lineannotation><computeroutput>|foo       |</computeroutput>
</screen>
    </para>

    <para>
     These examples show use of <parameter>position</parameter> fields:

<screen>
SELECT format('Testing %3$s, %2$s, %1$s', 'one', 'two', 'three');
<lineannotation>Result: </lineannotation><computeroutput>Testing three, two, one</computeroutput>

SELECT format('|%*2$s|', 'foo', 10, 'bar');
<lineannotation>Result: </lineannotation><computeroutput>|       bar|</computeroutput>

SELECT format('|%1$*2$s|', 'foo', 10, 'bar');
<lineannotation>Result: </lineannotation><computeroutput>|       foo|</computeroutput>
</screen>
    </para>

    <para>
     Unlike the standard C function <function>sprintf</function>,
     <productname>PostgreSQL</productname>'s <function>format</function> function allows format
     specifiers with and without <parameter>position</parameter> fields to be mixed
     in the same format string.  A format specifier without a
     <parameter>position</parameter> field always uses the next argument after the
     last argument consumed.
     In addition, the <function>format</function> function does not require all
     function arguments to be used in the format string.
     For example:

<screen>
SELECT format('Testing %3$s, %2$s, %s', 'one', 'two', 'three');
<lineannotation>Result: </lineannotation><computeroutput>Testing three, two, three</computeroutput>
</screen>
    </para>

    <para>
     The <literal>%I</literal> and <literal>%L</literal> format specifiers are particularly
     useful for safely constructing dynamic SQL statements.  See
     <xref linkend="plpgsql-quote-literal-example"/>.
    </para>
   </sect2>

  </sect1>


  <sect1 id="functions-binarystring">
   <title>Binary String Functions and Operators</title>

   <indexterm zone="functions-binarystring">
    <primary>binary data</primary>
    <secondary>functions</secondary>
   </indexterm>

   <para>
    This section describes functions and operators for examining and
    manipulating binary strings, that is values of type <type>bytea</type>.
    Many of these are equivalent, in purpose and syntax, to the
    text-string functions described in the previous section.
   </para>

   <para>
    <acronym>SQL</acronym> defines some string functions that use
    key words, rather than commas, to separate
    arguments.  Details are in
    <xref linkend="functions-binarystring-sql"/>.
    <productname>PostgreSQL</productname> also provides versions of these functions
    that use the regular function invocation syntax
    (see <xref linkend="functions-binarystring-other"/>).
   </para>

   <table id="functions-binarystring-sql">
    <title><acronym>SQL</acronym> Binary String Functions and Operators</title>
    <tgroup cols="1">
     <thead>
      <row>
       <entry role="func_table_entry"><para role="func_signature">
        Function/Operator
       </para>
       <para>
        Description
       </para>
       <para>
        Example(s)
       </para></entry>
      </row>
     </thead>

     <tbody>
      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>binary string</primary>
         <secondary>concatenation</secondary>
        </indexterm>
        <type>bytea</type> <literal>||</literal> <type>bytea</type>