Re: [9fans] size on /proc files?

[David Presotto <presotto@closedmind.org>]

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We're equally stupid, though we could to a bit better.  The register
files and status files show the real lengths but the text and mem
file don't.  I'll see what I can do.

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From: Aharon Robbins <arnold@skeeve.com>
To: 9fans@cse.psu.edu
Subject: [9fans] size on /proc files?
Date: Sun, 30 Mar 2003 13:36:14 +0300
Message-ID: <200303301036.h2UAaEFZ031353@localhost.localdomain>

Just out of curiousity, what does ls -l on special files in /proc report?
On linux, e.g., /proc/filesystems shows up as a regular file, but of size
zero.  Yet when you cat it you get information.

This behavior broke the current gawk, where I'd rewritten the get_a_record
routines; they had a check:

	if (S_ISREG(sbuf.st_mode) && total > sbuf.st_size)
		flag |= AT_EOF;

I had to change this to

	if (S_ISREG(sbuf.st_mode) && sbuf.st_size > 0
	    && total > sbuf.st_size) ....

I am annoyed at the Linux behavior, but understand that the contents
of these "files" can change dynamically, making the reporting of a size
for stat difficult or impossible.

So, I was just curious how Plan 9 handles it.

Thanks,

Arnold Robbins