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<HTML>
<HEAD>
  <TITLE>IO::Scalar</TITLE>
</HEAD>
<BODY 
       bgcolor="#FFFFFF" link="#CC3366" vlink="#993366" alink="#FF6666">
<FONT FACE="sans-serif" SIZE=-1><A HREF="http://www.zeegee.com" TARGET="_top"><IMG SRC="icons/zeegee.gif" ALT="ZeeGee Software" ALIGN="RIGHT" BORDER="0"></A><A NAME="__TOP__"><H1>IO::Scalar</H1>
</A><UL>
<LI> <A HREF="#NAME">NAME</A>
<LI> <A HREF="#SYNOPSIS">SYNOPSIS</A>
<LI> <A HREF="#DESCRIPTION">DESCRIPTION</A>
<LI> <A HREF="#PUBLIC_INTERFACE">PUBLIC INTERFACE</A>
<UL>
<LI> <A HREF="#Construction">Construction</A>
<LI> <A HREF="#Input_and_output">Input and output</A>
<LI> <A HREF="#Seeking_telling_and_other_attributes">Seeking/telling and other attributes</A>
</UL>
<LI> <A HREF="#VERSION">VERSION</A>
<LI> <A HREF="#AUTHORS">AUTHORS</A>
<UL>
<LI> <A HREF="#Principal_author">Principal author</A>
<LI> <A HREF="#Other_contributors">Other contributors</A>
</UL>
</UL>
</A>

<P><HR>
<A NAME="NAME"><H2><A HREF="#__TOP__"><IMG SRC="icons/h1bullet.gif" ALT="Top" BORDER="0"></A> NAME</H2></A>


<P>IO::Scalar - IO:: interface for reading/writing a scalar



<P><HR>
<A NAME="SYNOPSIS"><H2><A HREF="#__TOP__"><IMG SRC="icons/h1bullet.gif" ALT="Top" BORDER="0"></A> SYNOPSIS</H2></A>


<P>If you have any Perl5, you can use the basic OO interface...

<FONT SIZE=3 FACE="courier"><PRE>
    use IO::Scalar;
    
    ### Open a handle on a string:
    $SH = new IO::Scalar;
    $SH-&gt;open(\$somestring);
    
    ### Open a handle on a string, read it line-by-line, then close it:
    $SH = new IO::Scalar \$somestring;
    while ($_ = $SH-&gt;getline) { print &quot;Line: $_&quot; }
    $SH-&gt;close;
        
    ### Open a handle on a string, and slurp in all the lines:
    $SH = new IO::Scalar \$somestring;
    print $SH-&gt;getlines; 
     
    ### Open a handle on a string, and append to it:
    $SH = new IO::Scalar \$somestring
    $SH-&gt;print(&quot;bar\n&quot;);        ### will add &quot;bar\n&quot; to the end   
      
    ### Get the current position:
    $pos = $SH-&gt;getpos;         ### $SH-&gt;tell() also works
     
    ### Set the current position:
    $SH-&gt;setpos($pos);          ### $SH-&gt;seek(POS,WHENCE) also works
        
    ### Open an anonymous temporary scalar:
    $SH = new IO::Scalar;
    $SH-&gt;print(&quot;Hi there!&quot;);
    print &quot;I got: &quot;, ${$SH-&gt;sref}, &quot;\n&quot;;      ### get at value
</PRE></FONT>

<P>If your Perl is 5.004 or later, you can use the TIEHANDLE
interface, and read/write scalars just like files:

<FONT SIZE=3 FACE="courier"><PRE>
    use IO::Scalar;
</PRE></FONT>
<FONT SIZE=3 FACE="courier"><PRE>
    ### Writing to a scalar...
    my $s; 
    tie *OUT, 'IO::Scalar', \$s;
    print OUT &quot;line 1\nline 2\n&quot;, &quot;line 3\n&quot;;
    print &quot;s is now... $s\n&quot;
     
    ### Reading and writing an anonymous scalar... 
    tie *OUT, 'IO::Scalar';
    print OUT &quot;line 1\nline 2\n&quot;, &quot;line 3\n&quot;;
    tied(OUT)-&gt;seek(0,0);
    while (&lt;OUT&gt;) { print &quot;LINE: &quot;, $_ }
</PRE></FONT>

<P>Stringification now works, too!

<FONT SIZE=3 FACE="courier"><PRE>
    my $SH = new IO::Scalar \$somestring;
    $SH-&gt;print(&quot;Hello, &quot;);
    $SH-&gt;print(&quot;world!&quot;);
    print &quot;I've got: &lt;$SH&gt;\n&quot;;
</PRE></FONT>


<P><HR>
<A NAME="DESCRIPTION"><H2><A HREF="#__TOP__"><IMG SRC="icons/h1bullet.gif" ALT="Top" BORDER="0"></A> DESCRIPTION</H2></A>


<P>This class implements objects which behave just like FileHandle
(or IO::Handle) objects, except that you may use them to write to
(or read from) scalars.  They can be tiehandle'd as well.  


<P>Basically, this:

<FONT SIZE=3 FACE="courier"><PRE>
    my $s;
    $SH = new IO::Scalar \$s;
    $SH-&gt;print(&quot;Hel&quot;, &quot;lo, &quot;);         # OO style
    $SH-&gt;print(&quot;world!\n&quot;);            # ditto
</PRE></FONT>

<P>Or this (if you have 5.004 or later):

<FONT SIZE=3 FACE="courier"><PRE>
    my $s;
    $SH = tie *OUT, 'IO::Scalar', \$s;
    print OUT &quot;Hel&quot;, &quot;lo, &quot;;           # non-OO style
    print OUT &quot;world!\n&quot;;              # ditto
</PRE></FONT>

<P>Or this (if you have 5.004 or later):

<FONT SIZE=3 FACE="courier"><PRE>
    my $s;
    $SH = IO::Scalar-&gt;new_tie(\$s);
    $SH-&gt;print(&quot;Hel&quot;, &quot;lo, &quot;);         # OO style...
    print $SH &quot;world!\n&quot;;              # ...or non-OO style!
</PRE></FONT>

<P>Causes $s to be set to:    

<FONT SIZE=3 FACE="courier"><PRE>
    &quot;Hello, world!\n&quot; 
</PRE></FONT>


<P><HR>
<A NAME="PUBLIC_INTERFACE"><H2><A HREF="#__TOP__"><IMG SRC="icons/h1bullet.gif" ALT="Top" BORDER="0"></A> PUBLIC INTERFACE</H2></A>



<P><HR>
<A NAME="Construction"><H3><A HREF="#__TOP__"><IMG SRC="icons/h2bullet.gif" ALT="Top" BORDER="0"></A> Construction</H3></A>



<DL>
<P><DT><B><A NAME="item:new">new [ARGS...]</A></B></DT>
<DD>
<I>Class method.</I>
Return a new, unattached scalar handle.  
If any arguments are given, they're sent to open().

<P><DT><B><A NAME="item:open">open [SCALARREF]</A></B></DT>
<DD>
<I>Instance method.</I>
Open the scalar handle on a new scalar, pointed to by SCALARREF.
If no SCALARREF is given, a &quot;private&quot; scalar is created to hold
the file data.


<P>Returns the self object on success, undefined on error.

<P><DT><B><A NAME="item:opened">opened</A></B></DT>
<DD>
<I>Instance method.</I>
Is the scalar handle opened on something?

<P><DT><B><A NAME="item:close">close</A></B></DT>
<DD>
<I>Instance method.</I>
Disassociate the scalar handle from its underlying scalar.
Done automatically on destroy.

</DL>



<P><HR>
<A NAME="Input_and_output"><H3><A HREF="#__TOP__"><IMG SRC="icons/h2bullet.gif" ALT="Top" BORDER="0"></A> Input and output</H3></A>



<DL>
<P><DT><B><A NAME="item:flush">flush</A></B></DT>
<DD>
<I>Instance method.</I>
No-op, provided for OO compatibility.

<P><DT><B><A NAME="item:getc">getc</A></B></DT>
<DD>
<I>Instance method.</I>
Return the next character, or undef if none remain.

<P><DT><B><A NAME="item:getline">getline</A></B></DT>
<DD>
<I>Instance method.</I>
Return the next line, or undef on end of string.  
Can safely be called in an array context.
Currently, lines are delimited by &quot;\n&quot;.

<P><DT><B><A NAME="item:getlines">getlines</A></B></DT>
<DD>
<I>Instance method.</I>
Get all remaining lines.
It will croak() if accidentally called in a scalar context.

<P><DT><B><A NAME="item:print">print ARGS...</A></B></DT>
<DD>
<I>Instance method.</I>
Print ARGS to the underlying scalar.  


<P><B>Warning:</B> Currently, this always causes a &quot;seek to the end of the string&quot;; 
this may change in the future.

<P><DT><B><A NAME="item:read">read BUF, NBYTES, [OFFSET]</A></B></DT>
<DD>
<I>Instance method.</I>
Read some bytes from the scalar.
Returns the number of bytes actually read, 0 on end-of-file, undef on error.

<P><DT><B><A NAME="item:write">write BUF, NBYTES, [OFFSET]</A></B></DT>
<DD>
<I>Instance method.</I>
Write some bytes to the scalar.

<P><DT><B><A NAME="item:sysread">sysread BUF, LEN, [OFFSET]</A></B></DT>
<DD>
<I>Instance method.</I>
Read some bytes from the scalar.
Returns the number of bytes actually read, 0 on end-of-file, undef on error.

<P><DT><B><A NAME="item:syswrite">syswrite BUF, NBYTES, [OFFSET]</A></B></DT>
<DD>
<I>Instance method.</I>
Write some bytes to the scalar.

</DL>



<P><HR>
<A NAME="Seeking_telling_and_other_attributes"><H3><A HREF="#__TOP__"><IMG SRC="icons/h2bullet.gif" ALT="Top" BORDER="0"></A> Seeking/telling and other attributes</H3></A>



<DL>
<P><DT><B><A NAME="item:autoflush">autoflush</A></B></DT>
<DD>
<I>Instance method.</I>
No-op, provided for OO compatibility.

<P><DT><B><A NAME="item:binmode">binmode</A></B></DT>
<DD>
<I>Instance method.</I>
No-op, provided for OO compatibility.

<P><DT><B><A NAME="item:clearerr">clearerr</A></B></DT>
<DD>
<I>Instance method.</I>  Clear the error and EOF flags.  A no-op.

<P><DT><B><A NAME="item:eof">eof</A></B></DT>
<DD>
<I>Instance method.</I>  Are we at end of file?

<P><DT><B><A NAME="item:seek">seek OFFSET, WHENCE</A></B></DT>
<DD>
<I>Instance method.</I>  Seek to a given position in the stream.

<P><DT><B><A NAME="item:tell">tell</A></B></DT>
<DD>
<I>Instance method.</I>
Return the current position in the stream, as a numeric offset.

<P><DT><B><A NAME="item:setpos">setpos POS</A></B></DT>
<DD>
<I>Instance method.</I>
Set the current position, using the opaque value returned by <CODE>getpos()</CODE>.

<P><DT><B><A NAME="item:getpos">getpos</A></B></DT>
<DD>
<I>Instance method.</I>
Return the current position in the string, as an opaque object.

<P><DT><B><A NAME="item:sref">sref</A></B></DT>
<DD>
<I>Instance method.</I>
Return a reference to the underlying scalar.

</DL>



<P><HR>
<A NAME="VERSION"><H2><A HREF="#__TOP__"><IMG SRC="icons/h1bullet.gif" ALT="Top" BORDER="0"></A> VERSION</H2></A>


<P>$Id: Scalar.pm,v 1.122 2000/09/28 06:32:28 eryq Exp $



<P><HR>
<A NAME="AUTHORS"><H2><A HREF="#__TOP__"><IMG SRC="icons/h1bullet.gif" ALT="Top" BORDER="0"></A> AUTHORS</H2></A>



<P><HR>
<A NAME="Principal_author"><H3><A HREF="#__TOP__"><IMG SRC="icons/h2bullet.gif" ALT="Top" BORDER="0"></A> Principal author</H3></A>


<P>Eryq (<I><FILE><A HREF="mailto:eryq@zeegee.com">eryq@zeegee.com</A></FILE></I>).
President, ZeeGee Software Inc (<I><FILE><A HREF="http://www.zeegee.com">http://www.zeegee.com</A></FILE></I>).



<P><HR>
<A NAME="Other_contributors"><H3><A HREF="#__TOP__"><IMG SRC="icons/h2bullet.gif" ALT="Top" BORDER="0"></A> Other contributors</H3></A>


<P>The full set of contributors always includes the folks mentioned
in <A HREF="../IO/Stringy.pm.html#CHANGE_LOG">CHANGE LOG</A>.  But just the same, special
thanks to the following individuals for their invaluable contributions
(if I've forgotten or misspelled your name, please email me!):


<P><I>Andy Glew,</I>
for contributing <CODE>getc()</CODE>.


<P><I>Brandon Browning,</I>
for suggesting <CODE>opened()</CODE>.


<P><I>David Richter,</I>
for finding and fixing the bug in <CODE>PRINTF()</CODE>.


<P><I>Eric L. Brine,</I>
for his offset-using read() and write() implementations. 


<P><I>Richard Jones</I> (<I><FILE><A HREF="mailto:rich@annexia.org">rich@annexia.org</A></FILE></I>),
for his patches to massively improve the performance of <CODE>getline()</CODE>
and add <CODE>sysread</CODE> and <CODE>syswrite</CODE>.

<P><HR>
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