Re: Question about expansion: redirection(<) vs command(cat)

Bart Schaefer <[email protected]> Tue, 13 Jan 2026 13:18:59 -0800

Newsgroups	gmane.comp.shells.zsh.devel,gmane.comp.shells.zsh.user
Message-ID	<CAH+w=7a_=uqSdRJuHtNzn-+BR72ice5zm-hQaXRt_H+4ucDNmQ@mail.gmail.com>

On Tue, Jan 13, 2026 at 11:09 AM Jim <[email protected]> wrote:
>
> The following produced the expected output.
> Array=(${(f)"$(< /usr/share/zsh/5.9/scripts/newuser)"}) ; print $?
>
> But when expansion is required the following fails.
> Array=(${(f)"$(< /usr/share/zsh/<->.*/scripts/newuser)"}) ; print $?

The issue here is that the token "$(<" is a special case of "$(" and
not a special case of "<" redirection.  Docs under "Command
Substitution":

  The substitution '$(cat FOO)' may be replaced by the faster '$(<FOO)'.
  In this case FOO undergoes single word shell expansions (_parameter
  expansion_, _command substitution_ and _arithmetic expansion_), but not
  filename generation.  No subshell is created.

Note "but not filename generation".