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To: Josef Karthauser <joe@tao.org.uk>
Cc: Dag-Erling Smorgrav <des@ofug.org>, freebsd-fs@FreeBSD.ORG,
	adf@idi.ntnu.no
Subject: Re: parsing problem with /proc/N/status 
In-reply-to: Your message of "Sat, 18 Aug 2001 14:19:40 BST."
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Date: Sun, 19 Aug 2001 01:24:21 +0200
From: Arne Dag Fidjestøl <adf@idi.ntnu.no>
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> > newline).  If we have to go down that road, I'd rather just encode
> > whitespace and unprintables in octal notation (like ls -B does).

Unprintables vary with locales, so octal encoding should probably be 
limited to ascii-whitespace?

> Sounds fair.  I don't particularly care, but as it stands it's next
> to useless as it's unparsable.

Provided that there is a known number of space-seperated fields it is 
still parsable.  See attached program for a lightly-tested example.

-adf

#include <sys/types.h>
#include <sys/uio.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

#define PSTATUS "/proc/curproc/status"


/*
 * return number of characters in progname, or -1 on error.
 */
int
getprognamelen(const char *status, size_t len)
{
    const char *s = status + len;
    int nspc = 14;		/* number of field-seperating-spaces */

    for (; s > status && nspc; s--)
	if (*s == ' ')
	    nspc--;

    return nspc ? -1 : s - status + 1;
}

int
main()
{
    char buf[1024];
    int i,f,sz;

    f = open(PSTATUS, O_RDONLY);
    if (f != -1) {
	sz = read(f, buf, sizeof(buf));
	close(f);
    }else
	err(1, PSTATUS);

    i = getprognamelen(buf, sz);
    if (i != -1)
	printf("getprogname -> '%.*s' [%d]\n", i, buf, i);
    else
	printf("getprogname failed\n");

    return 0;
}



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