command is handled as a shell function. This avoids the following
peculiar behaviour when /usr/bin is on a case-insensitive filesystem:
# READ foo
(... long pause, depending upon the amount of swap space available ...)
sh: Resource temporarily unavailable.
Reported by: I can't remember; someone on IRC.
MFC after: 1 week
implement any of the useless POSIX-required ``regular shell builtin''
utilities, saving one frag and one inode each. The script moves to
usr.bin/alias which is alphabetically the first of these commands.