"a file which at this time has no name"

From	Ivan Shmakov <oneingray@gmail.com>
Newsgroups	comp.unix.shell
Subject	"a file which at this time has no name"
Date	2012-03-14 23:48 +0700
Organization	Aioe.org NNTP Server
Message-ID	<86pqcf86x1.fsf_-_@gray.siamics.net> (permalink)
References	<55e8c993-a9ca-4e30-a85c-18430f2eb025@db5g2000vbb.googlegroups.com> <86pqcfbvud.fsf@gray.siamics.net> <0844dc91-9a86-4c72-be7f-39fd85fc1f0d@t16g2000yqt.googlegroups.com>

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>>>>> Paul Branon <paulbranon@googlemail.com> writes:

 >> Not necessarily.  If named

 > How do you create a file with no name?

	By removing the filename after the file is created.  Like:

$ f=$(mktemp -t) 
$ exec 5<> "$f"
$ echo Hello, world! >&5 
$ perl -w read.perl <&5 
Hello, world!
$ rm -v -- "$f" 
removed `/tmp/tmp.iaiCmrwfHE'
$ perl -w read.perl <&5 
Hello, world!
$ echo And one more time... >&5 
$ perl -w read.perl <&5 
Hello, world!
And one more time...
$ 

	So, I can open a temporary file, remove its name, and still be
	able to read from and write to it.

	Since I don't know how to set the file's "offset" in pure Shell,
	I had to use the following simplistic Perl script to read the
	file from its very first (or, rather, zeroth) byte to the last.

$ cat < read.perl 
seek (\*STDIN, 0, 0)
    or die ();
{
    local ($/) = "";
    my $a
        = <STDIN>
        // die ();
    print ($a);
}
$ 

-- 
FSF associate member #7257

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Thread

empty file is simply an inode with sort of null pointers Andre Aitken <andre.aitken.a@gmail.com> - 2012-03-13 21:46 -0700
  Re: empty file is simply an inode with sort of null pointers Ivan Shmakov <oneingray@gmail.com> - 2012-03-14 12:22 +0700
    Re: empty file is simply an inode with sort of null pointers Paul Branon <paulbranon@googlemail.com> - 2012-03-14 08:54 -0700
      Re: empty file is simply an inode with sort of null pointers Janis Papanagnou <janis_papanagnou@hotmail.com> - 2012-03-14 17:17 +0100
        Re: empty file is simply an inode with sort of null pointers Aragorn <stryder@telenet.be.invalid> - 2012-03-15 03:36 +0100
          Re: empty file is simply an inode with sort of null pointers Stephane Chazelas <stephane_chazelas@yahoo.fr> - 2012-03-15 08:19 +0000
          Re: empty file is simply an inode with sort of null pointers Barry Margolin <barmar@alum.mit.edu> - 2012-03-15 10:59 -0400
            Re: empty file is simply an inode with sort of null pointers Aragorn <stryder@telenet.be.invalid> - 2012-03-19 07:22 +0100
          Re: empty file is simply an inode with sort of null pointers William Ahern <william@wilbur.25thandClement.com> - 2012-03-18 23:57 -0700
      "a file which at this time has no name" Ivan Shmakov <oneingray@gmail.com> - 2012-03-14 23:48 +0700
        Re: lseek(2) operators in shells Stephane Chazelas <stephane_chazelas@yahoo.fr> - 2012-03-14 17:11 +0000
          Re: lseek(2) operators in shells Casper H.S. Dik <Casper.Dik@OrSPaMcle.COM> - 2012-03-14 17:44 +0000
          Re: lseek(2) operators in shells Kaz Kylheku <kaz@kylheku.com> - 2012-03-14 18:10 +0000
            Re: lseek(2) operators in shells "Chris F.A. Johnson" <cfajohnson@gmail.com> - 2012-03-14 15:20 -0400
              Re: lseek(2) operators in shells Kaz Kylheku <kaz@kylheku.com> - 2012-03-14 19:46 +0000
                Re: lseek(2) operators in shells Janis Papanagnou <janis_papanagnou@hotmail.com> - 2012-03-15 00:14 +0100
                Re: lseek(2) operators in shells "Mirko K." <mirkok.lists@googlemail.com> - 2012-03-15 00:45 +0100
                Re: lseek(2) operators in shells Janis Papanagnou <janis_papanagnou@hotmail.com> - 2012-03-15 01:11 +0100
                Re: lseek(2) operators in shells Kaz Kylheku <kaz@kylheku.com> - 2012-03-15 00:27 +0000
                Re: lseek(2) operators in shells "Mirko K." <mirkok.lists@googlemail.com> - 2012-03-15 01:35 +0100
                Re: lseek(2) operators in shells Kaz Kylheku <kaz@kylheku.com> - 2012-03-15 00:42 +0000
                Re: lseek(2) operators in shells Headless /body <devnull@NotReallyAn.example.com> - 2012-03-14 22:49 -0400
                Re: lseek(2) operators in shells Stephane Chazelas <stephane_chazelas@yahoo.fr> - 2012-03-15 08:17 +0000
                Re: lseek(2) operators in shells Janis Papanagnou <janis_papanagnou@hotmail.com> - 2012-03-15 09:32 +0100
                Re: lseek(2) operators in shells Janis Papanagnou <janis_papanagnou@hotmail.com> - 2012-03-15 09:26 +0100
              Re: lseek(2) operators in shells Barry Margolin <barmar@alum.mit.edu> - 2012-03-14 15:48 -0400
                Re: lseek(2) operators in shells Headless /body <devnull@NotReallyAn.example.com> - 2012-03-14 22:58 -0400
            Re: lseek(2) operators in shells Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-14 20:28 +0000
              Re: lseek(2) operators in shells Guillaume Dargaud <use_the_contact_form@www.gdargaud.net> - 2012-03-15 08:43 +0100
                dereferencing links to man(1) pages Ivan Shmakov <oneingray@gmail.com> - 2012-03-15 15:03 +0700
                Re: dereferencing links to man(1) pages Stephane Chazelas <stephane_chazelas@yahoo.fr> - 2012-03-15 13:36 +0000
                Re: dereferencing links to man(1) pages Dan Espen <despen@verizon.net> - 2012-03-15 10:02 -0400
                Re: lseek(2) operators in shells Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-15 12:40 +0000
              Re: lseek(2) operators in shells Barry Margolin <barmar@alum.mit.edu> - 2012-03-15 10:56 -0400
                Re: lseek(2) operators in shells Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-15 15:13 +0000
                Re: lseek(2) operators in shells Barry Margolin <barmar@alum.mit.edu> - 2012-03-15 13:09 -0400
                Re: lseek(2) operators in shells Ben Bacarisse <ben.usenet@bsb.me.uk> - 2012-03-15 17:29 +0000
        Re: "a file which at this time has no name" Paul Branon <paulbranon@googlemail.com> - 2012-03-15 05:27 -0700
          Re: "a file which at this time has no name" Ivan Shmakov <oneingray@gmail.com> - 2012-03-15 20:46 +0700
            Re: "a file which at this time has no name" "Mirko K." <mirkok.lists@googlemail.com> - 2012-03-15 22:29 +0100
              Re: "a file which at this time has no name" William Ahern <william@wilbur.25thandClement.com> - 2012-03-15 17:55 -0700
              Re: "a file which at this time has no name" pacman@kosh.dhis.org (Alan Curry) - 2012-03-16 01:09 +0000
                Re: "a file which at this time has no name" Ivan Shmakov <oneingray@gmail.com> - 2012-03-16 09:33 +0700
                Re: "a file which at this time has no name" pacman@kosh.dhis.org (Alan Curry) - 2012-03-16 09:51 +0000
                Re: "a file which at this time has no name" "Mirko K." <mirkok.lists@googlemail.com> - 2012-03-16 18:27 +0100
              Re: "a file which at this time has no name" Casper H.S. Dik <Casper.Dik@OrSPaMcle.COM> - 2012-03-16 14:39 +0000
  Re: empty file is simply an inode with sort of null pointers Kaz Kylheku <kaz@kylheku.com> - 2012-03-14 17:30 +0000

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