Hey folks: Deep linked by http://wiki.apache.org/hadoop/CodeReviewChecklist is the rule that line length should be ideally maximum 80 chars. (Sun coding guidelines.) In general, it's a good idea and it works for many many languages...
Now the caveat. As most of you know, I've been hacking on HADOOP-9902 off and on for a year now. [For those that don't, this is an almost complete rewrite of most of the major shell code that we ship with Hadoop. The stuff that was missed I'll pick it up after this gets committed.] As part of this, I recently reformatted the last patch to fit that 80 character requirement as best I could. The result is... not good. Not good at all. In many ways, it actually hurt readability even beyond the lack of indentation that Bash Beautifier doesn't support for line continuation. (That case statement in bin/hadoop is painful to look at and makes me cry.) Barring anymore feedback, it's pretty much ready to commit. But before that happens, do we want to specify that bash has different line length requirements? Say 120 chars? Most of the problems stem from our usage of REALLY LONG env var names that can't really be changed at this point without *massively* screwing backward compatibility. (Hello, YARN_RESOURCEMANAGER_OPTS... I'm talking about you!). Bouncing the idea around a few folks, they all seem to agree that 80 is just too hard for bash given our general use case, but I think it'd be good to have something official. Thoughts? Thanks.
