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Date: Tue, 04 Mar 2008 15:48:06 -0800
From: Brian Dessent <brian AT dessent DOT net>
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Subject: Re: writing to /proc file system
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NightStrike wrote:

> I'm pretty sure it's not writable on any system, let alone cygwin.
> It's not a real filesystem per se.  It's instead a read-only gateway
> into the kernel.

What?  No.  The entire /proc/sys tree on Linux is writable, which allows
you to tune a great number of kernel parameters at runtime, including
networking stack parameters, filesystems, cacheing, memory management,
etc.  In fact this forms the basis for the entire sysctl settings
system.  For example you can clear all disk caches with "echo 3 >
/proc/sys/vm/drop_caches".  More at:

<http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.24.y.git;a=blob;f=Documentation/filesystems/proc.txt;h=dec99455321fdf86018ca5b2b62936103fd73031;hb=HEAD#l873>
<http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.24.y.git;a=blob;f=Documentation/sysctl/kernel.txt;h=8984a53962716f3f528964d6c318a9e7dcdf8a47;hb=HEAD>
<http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.24.y.git;a=blob;f=Documentation/sysctl/fs.txt;h=aa986a35e9945071abed471776565a2cf4644787;hb=HEAD>
<http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.24.y.git;a=blob;f=Documentation/sysctl/vm.txt;h=6f31f0a247d03137b85955bf59d06a666e34b1a0;hb=HEAD>

Brian

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