> > "Utilities other than the special built-ins (see Special Built-In > Utilities) shall be invoked in a separate environment that consists of the > following...[includes redirections specified to the utility]...The > environment of the shell process shall not be changed by the utility" > > > http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_12 > The utility here in question is the external command (/bin/true in my example), which doesn't do the expansion itself. In this case, it's not the utility affecting the environment, it's the expansion performed by the (sub)shell itself before the exec*() that has an effect on the environment.
They're different from word expansions. > The bash manual calls it a word, which is one of the sources of my confusion. "The general format for redirecting output is: [n]>word" https://linux.die.net/man/1/bash
