NAME

MemHandle - supply memory-based FILEHANDLE methods

SYNOPSIS

use MemHandle;
use IO::Seekable;

my $mh = new MemHandle;
print $mh "foo\n";
$mh->print( "bar\n" );
printf $mh "This is a number: %d\n", 10;
$mh->printf( "a string: \"%s\"\n", "all strings come to those who wait" );

my $len = $mh->tell();  # Use $mh->tell();
                        # tell( $mh ) will NOT work!
$mh->seek(0, SEEK_SET); # Use $mh->seek($where, $whence)
                        # seek($mh, $where, $whence)
                        # will NOT work!

my $memory = $mh->mem();

Here's the real meat:

my $mh = new MemHandle;
my $old = select( $mh );
.
.
.
print "foo bar\n";
print "baz\n";
&MyPrintSub();
select( $old );

print "here it all is: ", $mh->mem(), "\n";

DESCRIPTION

Generates inherits from IO::Handle and IO::Seekable. It provides an interface to the file routines which uses memory instead. See perldoc IO::Handle, and perldoc IO::Seekable as well as perlfunc for more detailed descriptions of the provided built-in functions:

print
printf
readline
sysread
syswrite
getc
gets

The following functions are provided, but tie doesn't allow them to be tied to the built in functions. They should be used by calling the appropriate method on the MemHandle object.

seek
tell

call them like this:

my $mh = new MemHandle();
.
.
.
my $pos = $mh->tell();
$mh->seek( 0, SEEK_SET );

CONSTRUCTOR

new( [mem] )

Creates a MemHandle, which is a reference to a newly created symbol (see the Symbol package). It then ties the FILEHANDLE to MemHandle::Tie (see "Tying FileHandles" in perltie). Tied methods in MemHandle::Tie translate file operations into reads/writes into a string, which can be accessed by calling MemHandle::mem.

METHODS

seek( POS, WHENCE )

Sets the read/write position to WHENCE + POS. WHENCE is one of the constants which are available from IO::Seekable or POSIX:

SEEK_SET # absolute position from the beginning.
SEEK_CUR # offset from the current location.
SEEK_END # from the end (POS can be negative).

tell()

Returns the current position of the mem-file, similiar to the way tell would. (See perlfunc).

mem( [mem] )

gets or sets the memory. If called with a parameter, it copies it to the memory and sets the position to be immediately after (so if you write more to it, you append the string). Returns the current value of memory.

AUTHOR

"Sheridan C. Rawlins" <scr14@cornell.edu>

SEE ALSO

perl. perlfunc. "Tying FileHandles" in perltie. perldoc IO::Handle. perldoc IO::Seekable. perldoc Symbol.