sysread is really only something you'll need to use when munging a binary file.

read is really only something you'll need to use when munging a binary file.

sysread is only needed when you need unbuffered IO (e.g. when you use select) or when you want partial reads from pipes and sockets.

the part of Perl that reads lines from files has had (from what I've heard) a great deal of attention paid to it over the last twenty or so years

Actually, I heard it's quite slow, in part due to the minuscule 4k buffer. I'm not saying that reading 8k chunks and breaking them down into lines on the user side is any faster.