Re: Is there a "blackhole" /dev/null directory?
From: Mika Lawando
Date: Thu Feb 14 2008 - 07:15:46 EST
Jasper Bryant-Greene schrieb:
On Thu, 2008-02-14 at 10:30 +0100, rzryyvzy wrote:
/dev/null is often very useful, specially if programs force to save data in some file. But some programs like to creates different temporary file names, so /dev/null could no more work.
What is with a "/dev/null"-directory?
I mean a "blackhole pseudo directory" which eats every write to null.
Here is how it could work:
mount -t nulldir nulldir /dev/nulldir
Now if a program does a create(2),
it creates in the memory the file with its fd.
Then if a program does a write(2) to the fd, it eats the writes and give out fakely it has written the number of bytes.
When the program calls does a close(2) of the fd, then the complete inode is deleted in the memory.
The directory should be permanently empty except for the inodes with open file descriptors. So only inode information would be temporary saved in this "nulldir tmpfs" directory.
Is there already existing a possibility to create a null directory?
This could be done fairly trivially with FUSE, and IMHO is a good use
for FUSE because since you're just throwing most data away, performance
is not a concern.
Unfortunately performance is a concern because if not I would write on
the hard disk the files, and then remove them with a cronjob.
But from the point of view of the time of developpment, FUSE is a good
idea, because its possible to write a filesystem quickly in Perl.
--
Best regards,
Mika
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