This allows one to set the environment of the specified user either from
login.conf alone (-L) or both login.conf and ~/.login_conf if present (-U).
This is a supporting feature to allow service(8) to pull in the environment
of the "daemon" class before invoking the rc script.
This is a part of D21481.
Submitted by: Andrew Gierth < andrew_tao173.riddles.org.uk>
apart a string, and supports some text substitutions. This can be
used to provide all the flexibility (and more!) that was lost by recent
changes to how the kernel parses #!-lines in shell scripts.
The '-P' option provides a way to specify an alternate set of directories
to use when searching for the 'utility' program to run. This way you can
be sure what directories are used for that search, without changing the
value of PATH that the user has set. Note that on FreeBSD 6.0, this
option is worthless unless the '-S' option is also used.
Approved by: re (blanket `env')
