Groups > linux.debian.user > #190532

Re: File permission confusion [Debian 9.1 with MATE]

From	Dan Purgert <dan@djph.net>
Newsgroups	linux.debian.user
Subject	Re: File permission confusion [Debian 9.1 with MATE]
Date	2018-01-02 12:10 +0100
Message-ID	<v3sCd-8f9-3@gated-at.bofh.it> (permalink)
References	<v36BI-1CT-13@gated-at.bofh.it> <v374J-23k-3@gated-at.bofh.it> <v3bBn-4OS-7@gated-at.bofh.it> <v3d0t-5Us-1@gated-at.bofh.it> <v3da9-5YQ-1@gated-at.bofh.it>
Organization	A noiseless patient Spider

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<tomas@tuxteam.de> wrote:
>
> On Mon, Jan 01, 2018 at 06:11:59PM -0000, Dan Purgert wrote:
>
> [...]
>
>> Note that "write" permissions on a file only really comes into play when
>> you're messing with a file in an editor (e.g. vim, emacs, nano,
>> whatever).  It does not necessarily prevent one from doing something
>> like:
>> 
>>    -rw-r----- [...] somefile.txt
>>    $ mv anotherfile.txt somefile.txt
>> 
>> Because you're not modifying "the file", but rather its parent
>> directory.  It's a very, very fine distinction, to be sure.
>
> And that's the point... a program "messing" with the file might
> well choose to copy the file to some other name, modify that copy,
> and then, at the end, remove the original and rename the new
> version to the original name: this is actually a common pattern
> to achieve some form of "atomicity": when you want either all
> the changes "committed to disk" or none (in case of failure).

Exactly.  Though reading it again, it was a poor turn of phrase to have
said "messing" with the file. 

>
> As long as the basic difference between a file and its "name"
> (i.e. the directory entry "pointing" to the file) is not understood,
> this fine difference between writing to the file and modifying
> (e.g. deleting) the directory entry will seem mysterious.
>
> Otherwise... nice tutorial.

Thanks.  chmod and chattr actually have really nice manpages :)

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|_|O|_| Registered Linux user #585947
|_|_|O| Github: https://github.com/dpurgert
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Thread

File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-01 12:30 +0100
  Re: File permission confusion [Debian 9.1 with MATE] Mark Fletcher <mark27q1@gmail.com> - 2018-01-01 12:40 +0100
  [ADDENDUM] File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-01 12:40 +0100
    Re: File permission confusion [Debian 9.1 with MATE] "Thomas Schmitt" <scdbackup@gmx.net> - 2018-01-01 13:10 +0100
      Re: File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-01 18:00 +0100
        Re: File permission confusion [Debian 9.1 with MATE] Dan Purgert <dan@djph.net> - 2018-01-01 19:30 +0100
          Re: File permission confusion [Debian 9.1 with MATE] <tomas@tuxteam.de> - 2018-01-01 19:40 +0100
            Re: File permission confusion [Debian 9.1 with MATE] Dan Purgert <dan@djph.net> - 2018-01-02 12:10 +0100
        Re: File permission confusion [Debian 9.1 with MATE] "Thomas Schmitt" <scdbackup@gmx.net> - 2018-01-01 19:40 +0100
          Re: File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-02 15:10 +0100
        Re: File permission confusion [Debian 9.1 with MATE] Eduardo M KALINOWSKI <eduardo@kalinowski.com.br> - 2018-01-02 13:40 +0100
          Re: File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-02 15:20 +0100
            Re: File permission confusion [Debian 9.1 with MATE] "Thomas Schmitt" <scdbackup@gmx.net> - 2018-01-02 16:40 +0100
              Re: File permission confusion [Debian 9.1 with MATE] Brian <ad44@cityscape.co.uk> - 2018-01-02 19:40 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Greg Wooledge <wooledg@eeg.ccf.org> - 2018-01-02 19:40 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Brian <ad44@cityscape.co.uk> - 2018-01-02 19:50 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-02 20:40 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Brian <ad44@cityscape.co.uk> - 2018-01-02 21:10 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Curt <curty@free.fr> - 2018-01-02 22:20 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Dan Purgert <dan@djph.net> - 2018-01-02 21:30 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Brian <ad44@cityscape.co.uk> - 2018-01-02 21:50 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Dan Purgert <dan@djph.net> - 2018-01-03 00:20 +0100
                Re: File permission confusion [Debian 9.1 with MATE] "Thomas Schmitt" <scdbackup@gmx.net> - 2018-01-02 21:10 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Brian <ad44@cityscape.co.uk> - 2018-01-02 21:40 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Richard Hector <richard@walnut.gen.nz> - 2018-01-06 06:20 +0100
    Re: [ADDENDUM] File permission confusion [Debian 9.1 with MATE] Brian <ad44@cityscape.co.uk> - 2018-01-01 13:10 +0100
    Re: [ADDENDUM] File permission confusion [Debian 9.1 with MATE] Brian <ad44@cityscape.co.uk> - 2018-01-01 20:40 +0100
  Re: File permission confusion [Debian 9.1 with MATE] David Wright <deblis@lionunicorn.co.uk> - 2018-01-01 17:30 +0100
    Re: File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-01 18:30 +0100
      Re: File permission confusion [Debian 9.1 with MATE] Michael Stone <mstone@debian.org> - 2018-01-01 18:40 +0100
        Re: File permission confusion [Debian 9.1 with MATE] Richard Owlett <rowlett@cloud85.net> - 2018-01-01 18:50 +0100
          Re: File permission confusion [Debian 9.1 with MATE] Michael Stone <mstone@debian.org> - 2018-01-01 19:10 +0100
            Re: File permission confusion [Debian 9.1 with MATE] <tomas@tuxteam.de> - 2018-01-01 19:20 +0100
              Re: File permission confusion [Debian 9.1 with MATE] Michael Stone <mstone@debian.org> - 2018-01-01 19:40 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Greg Wooledge <wooledg@eeg.ccf.org> - 2018-01-02 15:30 +0100
                Re: File permission confusion [Debian 9.1 with MATE] Michael Stone <mstone@debian.org> - 2018-01-02 23:50 +0100
          Re: File permission confusion [Debian 9.1 with MATE] <tomas@tuxteam.de> - 2018-01-01 19:20 +0100

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