On Wed, Jun 16, 2021 at 01:38:55PM +0200, Ævar Arnfjörð Bjarmason wrote: > > + # We need to use "$*" to get field-splitting, but we want to > > + # disable globbing, since we are matching against an arbitrary > > + # $arg, not what's in the filesystem. Using "set -f" accomplishes > > + # that, but we must do it in a subshell to avoid impacting the > > + # rest of the script. The exit value of the subshell becomes > > + # the function's return value. > > + ( > > + set -f > > + for pattern_ in $* > > + do > > + case "$arg" in > > + $pattern_) > > + exit 0 > > + ;; > > + esac > > + done > > + exit 1 > > + ) > > } > > Why not just start with a ret=1, set ret=0 if we have a match and break > from the loop, and then do a "set +f" afterwards? I.e. is there an > actual need for the subshell here. My thought was that the subshell takes us back to the original state, regardless of what it was. As opposed to "set +f" which takes us back to a particular state. But it is unlikely that we'd have done a global "set -f" before calling this, so maybe that is being overly conservative. > I'm mildly paranoid about a new "set -<flag>" in the codebase for vague > fears of portability (as noted in my linked message), but whatever shell > supports "set -<flag>" surely supports the inverse with "set +<flag>", > no? Yes, I think we can assume that if it supports one, it supports the other. -Peff
