Should be on systems where seek($fh, $amount, SEEK_CUR) works correctly, you'd have to backup over all the characters read. So if the length($entire_string) is 10 (including LF or CRLF), that'd be: seek($fh, -10, SEEK_CUR). I do seem to recall that it behaves unexpectedly (for a unix nerd) in windows, but my experience was in foxpro, not perl — that definitely shouldn't count.