On Tue, Jun 18, 2019 at 06:15:46PM +0200, Johannes Schindelin wrote:
> > And looking through this patch series, I see a gazillion of *new*
> > process substitutions $(test_something...) and $(basename $whatever).
> > Can't we do something about it?
>
> I wish there was. Unix shell scripting has not evolved much in the past,
> what, 3 decades? So I don't really see a way to "pass variables by
> reference" to shell functions, short of calling `eval` (which buys
> preciously little as it _also_ has to spawn a new process [*1*]).
Really? An eval can impact the caller's state, so it _can't_ happen in a
sub-process in most cases.
E.g., if I run this:
-- >8 --
#!/bin/sh
# usage: test_oid_to_path <var> <oid>
# to set the variable <var> in the caller's environment to the path of <oid>
test_oid_to_path() {
path="${2%${2#??}}/${2#??}"
eval "$1=\$path"
}
test_oid_to_path foo 1234abcd
echo foo: $foo
-- >8 --
it all happens in a single process, under both bash and dash.
-Peff
