Often, a guy's friends are mostly male and they (especially when younger) spend more time with friends than girlfriends... Guys get pretty close to each other in these friendships -- this is safest when they've grown up together; you wouldn't try to "get close" to some guy you just met. Even if you liked the guy a lot it's a little too pink to let him on to that. But if you and a bud have been close for a long time then it's cool and it's safe.
And in those cases you can tell him that you love him -- in certain ways at least. You wouldn't say, Ben, I love you. In fact you couldn't really ever say the i love you without something after it. But if you follow it up with a few choice guy-words, you're cool -- there's the famous I love you man or maybe I love you dude! and so on...
And it's done with a sort of acknowledged smile and joke about how it's kind of funny that you're two guys saying something like that to each other. Because even if you've been tight for years and years and you really mean it, you can't say it sincerely, it'd just be too weird -- that "fag" thing is lurking out there -- so you've got to keep it light...
...hugs, for example, that start as firm handshakes and end up with hard pats on the back that don't last too long... you don't just warmly hold him, or embrace softly... that's risky stuff... so be sure it's a little rough. Men and women can't be friends, a guy can't love another guy, these are the rules that are out there -- you can violate them, and people do, but it's a transgressive thing to do.