Re: why does </proc/self/environ not work in bash?

[Chet Ramey]

On 2/12/24 12:44 PM, Zachary Santer wrote:
> On Mon, Feb 12, 2024 at 10:14 AM Chet Ramey <chet.ramey@case.edu 
> <mailto:chet.ramey@case.edu>> wrote:
>
>     A system call tracer helps here. You'll find that the shell forks,
>     sets up the redirection by opening /proc/self/environ, then execs tr,
>     which reads the open file descriptor it inherits through execve.
>
> It seems you'd be losing nothing in terms of optimization by evaluating the 
> word representing the file that's being redirected to or from before the 
> fork takes place, which would avoid this little bit of weirdness:

POSIX makes that explicitly unspecified. Is it worth breaking backwards
compatibility for?


--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/

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