Re: (shellcheck) SC2103

In article <20250305103210.358@kylheku.com>,
Kaz Kylheku  <643-408-1753@kylheku.com> wrote:

On 2025-03-05, Kenny McCormack <gazelle@shell.xmission.com> wrote:

All testing done with shellcheck version 0.10.0 and bash under Linux.
>
Shellcheck says that you should replace code like:
>
    cd somedir
    do_something
    cd .. # (Or, cd -, which is almost, but not exactly the same thing)
>
with
>
    (
    cd somedir
    do_something
    )

>
That obviously won't work if do_something has to set a variable
that is then visible to the rest of the script.

That's actually mentioned in the rationale on the web page.
That if you need to set a variable, you can't use subshells.

Forking a process just to preserve a current working directory
is wasteful; we wouldn't do that in a C program, where we might
open the current directory to be saved, and then fchdir back to it.
>
However, most of the actions in a shell script fork and exec
something anyway.

Yes, but those would be the cheap form of fork(), where if it is quickly
followed by an exec(), you don't have to do COW.

Note that, in Linux, fork() is actually an alias for vfork().

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