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From: Roman Perepelitsa <roman.perepelitsa@gmail.com>
To: Bart Schaefer <schaefer@brasslantern.com>
Cc: Zsh hackers list <zsh-workers@zsh.org>
Subject: Re: Possible bug: HASH_CMDS has no observable effect
Date: Sat, 12 Sep 2020 10:49:05 +0200	[thread overview]
Message-ID: <CAN=4vMr0ucdLxfb+GMevBVT-=u1oNRr+Tc9EEVKizkeQC5tL7A@mail.gmail.com> (raw)
In-Reply-To: <CAH+w=7YDbOLz8Vp9v1tuweX9rGynS19GQ3FDiSryvqX=iz2sNA@mail.gmail.com>

On Sat, Sep 12, 2020 at 10:35 AM Bart Schaefer
<schaefer@brasslantern.com> wrote:
> This eliminates the search
> overhead for any external command you might use in the future.  In
> order to avoid the expense of a useless search when for example you
> make a typo, the assumption is made that if the command is not already
> in the cache then it must not be in any part of the path that has
> previously been searched.  The whole search-and-cache process is
> short-circuited.

Doesn't this search happen anyway? When I type `rsync`, it gets
resolved as /usr/bin/rsync and gets executed. This requires searching
for rsync in all path directories. I believe this is done in execute()
in Src/exec.c. Wouldn't it be better to search for `rsync` in the
parent shell (before forking) and hash the result? This would make the
behavior of HASH_CMDS match the documentation (and my intuition),
would make the invocation of newly installed commands faster, and
wouldn't slow anything down. Am I missing something?

Roman.


  reply	other threads:[~2020-09-12  8:49 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-11  8:21 Roman Perepelitsa
2020-09-11 14:48 ` Phil Pennock
2020-09-11 15:01   ` Roman Perepelitsa
2020-09-11 16:10     ` Phil Pennock
2020-09-11 16:33       ` Roman Perepelitsa
2020-09-11 21:10         ` Bart Schaefer
2020-09-12  7:02           ` Roman Perepelitsa
2020-09-12  8:35             ` Bart Schaefer
2020-09-12  8:49               ` Roman Perepelitsa [this message]
2020-09-12 20:41                 ` Bart Schaefer
2020-09-12 20:43                   ` Bart Schaefer
2020-09-13  9:31                   ` Roman Perepelitsa
2020-09-13 22:24                     ` Bart Schaefer

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