chomp() is multi-platform(not exactly true). It will delete <CR><NL> and <NL>, even on Windows. These line endings even if mixed will not matter. BTW: To normalize line endings to the current platform: while(<>){chomp;print;} Works on Unix or Windows.

Updated: In my testing and actual experience, Perl programs appear to do well under either Unix or Windows, even with mixed line endings on either platform. Perl itself also apparently doesn't have any problems. I have run the above while() code many times on several Unix platforms with great success. On my Win XP machine, there is an issue with old style Mac endings (which uses just <CR>), however I never work with files like that so I hadn't seen this before and had to write a special test case using bin mode to make a file like that.