Case insensitivity for files in a unix-ish environment seems like a great idea, until you're searching PATH for an executable called "head", and both HEAD and

Case insensitivity for files in a unix-ish environment seems like a great idea, until you're searching PATH for an executable called "head", and both HEAD and head exist. Do you go for first match, or best match, falling back to case-insensitivity? Bonus points for the confusion that ensues when some of the file systems being checked are case sensitive and some are only case preserving.