unofficial mirror of help-gnu-emacs@gnu.org
 help / color / mirror / Atom feed
From: Eli Zaretskii <eliz@gnu.org>
To: help-gnu-emacs@gnu.org
Subject: Re: Function to find symlink target
Date: Sat, 28 May 2022 19:08:57 +0300	[thread overview]
Message-ID: <83pmjxljvq.fsf@gnu.org> (raw)
In-Reply-To: <87leuloe7v.fsf@dataswamp.org> (message from Emanuel Berg on Sat,  28 May 2022 17:43:00 +0200)

> From: Emanuel Berg <incal@dataswamp.org>
> Date: Sat, 28 May 2022 17:43:00 +0200
> 
> > How big is a symlink?
> >
> > $ touch a.txt
> > $ ln -s a.txt a-sy.txt
> > $ du -b a-sl.txt
> > 5
> >
> > 5 bytes. The path to a.txt
>               ^ relative
> 
> Yes, if one places the symlink in some another dir than the
> target then the size increases.
> 
> Observe
> 
> $ cd
> $ mkdir -p test/sl
> $ cd !:2
> $ touch a
> $ ln -s a b
> $ cd
> $ ln -s test/sl/a l
> 
> then compare
> 
> $ du -b test/sl/b
> 1	test/slb/
> 
> $ du -b l
> 9	l
> 
> Lesson: There is a lot of space to save by placing symlinks correctly!

Actually, for short enough symlinks (like shorter than 60 bytes),
there are no disk space savings at all, regardless of the actual
length of the reference target.

You evidently assume that a symlink is stored in some particular way
on disk, but the reality is different from your assumption.  What 'ls'
and 'du' show you is largely an illusion.



  reply	other threads:[~2022-05-28 16:08 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-18 20:55 Function to find symlink target Jean Louis
2022-05-18 23:00 ` Emanuel Berg
2022-05-22 13:52   ` Jean Louis
2022-05-22 18:02     ` Emanuel Berg
2022-05-23  9:05       ` Jean Louis
2022-05-23 20:46         ` Emanuel Berg
2022-05-24  0:59           ` Emanuel Berg
2022-05-24  1:09             ` Michael Heerdegen
2022-05-24  2:14               ` Emanuel Berg
2022-05-24  2:27                 ` Michael Heerdegen
2022-05-24  8:04                   ` Emanuel Berg
2022-05-24  8:52                     ` Michael Heerdegen
2022-05-25  5:54                       ` Michael Heerdegen
2022-05-27  2:25                         ` Jean Louis
2022-05-27  3:31                           ` Michael Heerdegen
2022-05-27  8:00                             ` Jean Louis
2022-05-27 14:47                           ` Emanuel Berg
2022-05-28  6:43                             ` Jean Louis
2022-05-28 15:29                               ` Emanuel Berg
2022-05-28 15:43                                 ` Emanuel Berg
2022-05-28 16:08                                   ` Eli Zaretskii [this message]
2022-05-28 16:46                                     ` Emanuel Berg
2022-05-28 16:55                                       ` Eli Zaretskii
2022-05-28 17:05                                         ` Emanuel Berg
2022-05-31  6:27                                 ` Jean Louis
2022-05-31 12:24                                   ` Emanuel Berg
2022-05-31  6:31                                 ` Jean Louis
2022-05-31 12:16                                   ` Emanuel Berg
2022-06-01  7:43                                     ` Jean Louis
2022-06-02  0:40                                       ` Emanuel Berg
2022-06-02  5:15                                         ` Jean Louis
2022-06-05  5:40                                           ` Emanuel Berg
2022-05-25  5:05                 ` Jean Louis
2022-05-25 22:33                   ` Emanuel Berg
2022-05-29  2:01                     ` Emanuel Berg
2022-05-19 23:14 ` Nick Dokos
2022-05-20  0:42   ` Emanuel Berg
2022-05-23  8:17   ` Jean Louis
2022-05-23 22:49     ` Michael Heerdegen
2022-05-23 22:57       ` Emanuel Berg
2022-05-24  0:59         ` Michael Heerdegen

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://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=83pmjxljvq.fsf@gnu.org \
    --to=eliz@gnu.org \
    --cc=help-gnu-emacs@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.
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).