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t/lib/IO/String.pm  view on Meta::CPAN

sub seek
{
    my($self,$off,$whence) = @_;
    my $buf = *$self->{buf} || return 0;
    my $len = length($$buf);
    my $pos = *$self->{pos};

    _init_seek_constants() unless defined $SEEK_SET;

    if    ($whence == $SEEK_SET) { $pos = $off }
    elsif ($whence == $SEEK_CUR) { $pos += $off }
    elsif ($whence == $SEEK_END) { $pos = $len + $off }
    else                         { die "Bad whence ($whence)" }
    print "SEEK(POS=$pos,OFF=$off,LEN=$len)\n" if $DEBUG;

    $pos = 0 if $pos < 0;
    $self->truncate($pos) if $pos > $len;  # extend file
    *$self->{pos} = $pos;
    return 1;
}

sub pos
{
    my $self = shift;
    my $old = *$self->{pos};
    if (@_) {
	my $pos = shift || 0;
	my $buf = *$self->{buf};
	my $len = $buf ? length($$buf) : 0;
	$pos = $len if $pos > $len;
	*$self->{pos} = $pos;
    }
    return $old;
}

sub getpos { shift->pos; }

*sysseek = \&seek;
*setpos  = \&pos;
*tell    = \&getpos;



sub getline
{
    my $self = shift;
    my $buf  = *$self->{buf} || return;
    my $len  = length($$buf);
    my $pos  = *$self->{pos};
    return if $pos >= $len;

    unless (defined $/) {  # slurp
	*$self->{pos} = $len;
	return substr($$buf, $pos);
    }

    unless (length $/) {  # paragraph mode
	# XXX slow&lazy implementation using getc()
	my $para = "";
	my $eol = 0;
	my $c;
	while (defined($c = $self->getc)) {
	    if ($c eq "\n") {
		$eol++;
		next if $eol > 2;
	    }
	    elsif ($eol > 1) {
		$self->ungetc($c);
		last;
	    }
	    else {
		$eol = 0;
	    }
	    $para .= $c;
	}
	return $para;   # XXX wantarray
    }

    my $idx = index($$buf,$/,$pos);
    if ($idx < 0) {
	# return rest of it
	*$self->{pos} = $len;
	$. = ++ *$self->{lno};
	return substr($$buf, $pos);
    }
    $len = $idx - $pos + length($/);
    *$self->{pos} += $len;
    $. = ++ *$self->{lno};
    return substr($$buf, $pos, $len);
}

sub getlines
{
    die "getlines() called in scalar context\n" unless wantarray;
    my $self = shift;
    my($line, @lines);
    push(@lines, $line) while defined($line = $self->getline);
    return @lines;
}

sub READLINE
{
    goto &getlines if wantarray;
    goto &getline;
}

sub input_line_number
{
    my $self = shift;
    my $old = *$self->{lno};
    *$self->{lno} = shift if @_;
    return $old;
}

sub truncate
{
    my $self = shift;
    my $len = shift || 0;
    my $buf = *$self->{buf};
    if (length($$buf) >= $len) {
	substr($$buf, $len) = '';
	*$self->{pos} = $len if $len < *$self->{pos};
    }
    else {
	$$buf .= ($self->pad x ($len - length($$buf)));
    }
    return 1;
}

sub read
{
    my $self = shift;