use ChunkReader;
# create reader, threshold is optional (def. 2048)
my $reader = new ChunkReader (threshold=>1024);
# open file
$reader->open ("c:/test2.txt");
#iterate
while ( my $chunk = $reader->chunk )
{
print "$chunk\n****************\n";
}
####
package ChunkReader;
sub new
{
my $class = shift;
my %args = @_;
$args{threshold} = 2048
unless defined $args{threshold};
return bless {%args}, $class;
}
sub open
{
my $self = shift;
my $file = shift || $self->{file};
my $handle;
open $handle, "<", $file
or die "cannot open '$self->{file}\n'";
$self->{handle} = $handle;
}
sub chunk
{
my $self = shift;
my $handle = $self->{handle} || die "File not open!\n";
my $chunk = $self->{lastline};
# reset last line
$self->{lastline} = undef;
while ( my $line = <$handle> )
{
if ( ( length($chunk) + length($line) ) > $self->{threshold} )
{
# unless we already read a chunk
# (when a single line is bigger than the threshold)
unless ( $chunk )
{
#return the line
return $line;
}
else
{
# save the last line for further use
# and return the chunk
$self->{lastline} = $line;
return $chunk;
}
}
else
{
# append line and keep going
$chunk .= $line;
}
}
#end of file
return $chunk;
}
1;
##
##
use ChunkReader;
# create reader, threshold is optional (def. 2048)
my $reader = new ChunkReader ();
# open file
$reader->open ("c:/test2.txt");
while ( $reader->chunk )
{
print "$_****************\n";
}
##
##
package ChunkReader;
sub new
{
my $class = shift;
my %args = @_;
$args{threshold} = 2048
unless defined $args{threshold};
return bless {%args}, $class;
}
sub open
{
my $self = shift;
my $file = shift || $self->{file};
my $handle;
open $handle, "<", $file
or die "cannot open '$self->{file}\n'";
$self->{handle} = $handle;
}
sub chunk
{
my $self = shift;
my $handle = $self->{handle} || die "File not open!\n";
my $chunk = $self->{lastline};
# reset last line
$self->{lastline} = undef;
while ( my $line = <$handle> )
{
if ( ( length($chunk) + length($line) ) > $self->{threshold} )
{
# unless we already read a chunk
# (when a single line is bigger than the threshold)
unless ( $chunk )
{
#return the line
return bless \$line, ChunkReader::Chunk;
}
else
{
# save the last line for further use
# and return the chunk
$self->{lastline} = $line;
return bless \$chunk, ChunkReader::Chunk;
}
}
else
{
# append line and keep going
$chunk .= $line;
}
}
#end of file
return bless \$chunk, ChunkReader::Chunk;
}
package ChunkReader::Chunk;
use overload
(
q{bool} => sub { return ${$_[0]} },
q{""} => sub { return ${$_[0]} },
q{0+} => sub { 0 + ${$_[0]} },
fallback => 1,
);
sub DESTROY
{
$_ = ${$_[0]};
}
1;
__END__