Date: Mon, 9 Mar 2009 22:48:39 +0100 From: Timothy Redaelli <timothy@redaelli.eu> To: freebsd-hackers@freebsd.org Subject: lockf: Invalid argument on pipe Message-ID: <ac9bf7980903091448w1c3b8405la2a0084e5a947a05@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Hi,
Why can't I do a lockf on a file descriptor that does not point a real
file (such as stderr, stdout, or a character device)?
Since it works under NetBSD, Linux, Solaris. For portability between
systems I hope I can do it under FreeBSD.
The following code is simple, but It reproduce the problem.
Under non-FreeBSD systems, It will block before the puts. Instead
under FreeBSD the lockf calls return error and, so, the lock does not
works.
Any suggest?
<snip>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
int main(int argc, char *argv[]) {
char tmp[256];
if (lockf(2, F_LOCK, 0) == -1)
perror("lock");
snprintf (tmp, 256, "%s XXX", argv[0]);
if (!argv[1] || strcmp(argv[1], "XXX"))
system(tmp);
puts("You should see it only after ctrl+c");
return EXIT_SUCCESS;
}
<end snip>
--
Timothy Redaelli
IT Consultant
Email: timothy@redaelli.eu
Mobile: +39 (338) 1187273
WWW: http://www.redaelli.eu/
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?ac9bf7980903091448w1c3b8405la2a0084e5a947a05>