From: Maxime Devos <maximedevos@telenet.be>
To: "Arun Isaac" <arunisaac@systemreboot.net>,
"Ludovic Courtès" <ludo@gnu.org>
Cc: Guix Devel <guix-devel@gnu.org>
Subject: Re: Move switch-symlinks to (guix build utils)
Date: Mon, 06 Jun 2022 14:20:51 +0200 [thread overview]
Message-ID: <6eca3fbfe370f650dfddd5eaf5fbe7193a80cd91.camel@telenet.be> (raw)
In-Reply-To: <87czfmm3pm.fsf@systemreboot.net>
[-- Attachment #1: Type: text/plain, Size: 995 bytes --]
Arun Isaac schreef op ma 06-06-2022 om 16:57 [+0530]:
> Could we implement symlink/remove-old without catch and throw? Something
> like:
>
> --8<---------------cut here---------------start------------->8---
> (define (symlink/remove-old target link)
> "Make a symbolic link named LINK pointing to TARGET. If LINK already
> exists, it will be removed first. This is not an atomic operation."
> (when (file-exists? link)
> (delete-file link))
> (symlink target link))
> --8<---------------cut here---------------end--------------->8---
file-exists? does not check if the file exists -- for a broken symlink,
it will return #false instead of #true.
Also, this introduces additional non-atomicity (though in this
particular case, this does not seem to be a problem). It would also
make things a tiny bit slower, because file-exists? makes an additional
syscall.
For these three reasons, I would go for the more robust catch+throw.
Greetings,
Maxime.
[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 260 bytes --]
next prev parent reply other threads:[~2022-06-06 12:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-01 7:34 Move switch-symlinks to (guix build utils) Arun Isaac
2022-06-01 12:09 ` Maxime Devos
2022-06-02 15:06 ` Arun Isaac
2022-06-02 15:13 ` Maxime Devos
2022-06-03 16:38 ` Ludovic Courtès
2022-06-03 17:09 ` Maxime Devos
2022-06-03 19:30 ` Ludovic Courtès
2022-06-03 19:30 ` Ludovic Courtès
2022-06-03 23:55 ` bokr
2022-06-04 10:17 ` Maxime Devos
2022-06-06 11:27 ` Arun Isaac
2022-06-06 12:20 ` Maxime Devos [this message]
2022-06-08 20:12 ` Arun Isaac
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
List information: https://guix.gnu.org/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6eca3fbfe370f650dfddd5eaf5fbe7193a80cd91.camel@telenet.be \
--to=maximedevos@telenet.be \
--cc=arunisaac@systemreboot.net \
--cc=guix-devel@gnu.org \
--cc=ludo@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this public inbox
https://git.savannah.gnu.org/cgit/guix.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).