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 the perlfunc manpage 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 the
        section on "Tying FileHandles" in the perltie manpage). 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 the perlfunc manpage).

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

the perl manpage. the perlfunc manpage. the section on "Tying FileHandles" in the perltie manpage. perldoc IO::Handle. perldoc IO::Seekable. perldoc Symbol.