bin/142913: [patch] netstat(1) -w should produce error message if fed a negative value

Efstratios Karatzas <gpf.kira at> gpf.kira at
Sun Jan 17 17:40:02 UTC 2010

>Number:         142913
>Category:       bin
>Synopsis:       [patch] netstat(1) -w should produce error message if fed a negative value
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Jan 17 17:40:00 UTC 2010
>Originator:     Efstratios Karatzas <gpf.kira at>
>Release:        FreeBSD 8.0-STABLE i386
FreeBSD Eternal_Crusader 8.0-STABLE FreeBSD 8.0-STABLE #0: Thu Jan 7 04:08:09 EET 2010     root at bt:/usr/obj/usr/src/sys/GENERIC i386
netstat(1) -w should produce an error message and exit when fed a negative numerical value or a non numerical value at all, in which case atoi simply returns 0. This is the way iostat(8) handles this situation.

If we do not check for a negative value, then we will waste a lot of time sleeping before we are finally awaken. 
If I'm not mistaken, we 'll wake up when the timer underflows and eventually turns 0.

> netstat -w -1
> netstat -w abc
> netstat -w -30941
apply my patch. all we need is a check if the value we are fed is a positive integer greater than 1. This way, an error message also occurs if we were not able to parse an integer since atoi(3) returns 0 in that case.

version of the file I used:

__FBSDID("$FreeBSD: src/usr.bin/netstat/main.c,v 1.103 2010/01/11 03:00:17 delphij Exp $");

Patch attached with submission follows:

--- main.c	2010-01-17 17:30:56.000000000 +0200
+++ main.orig.c	2010-01-17 17:29:52.000000000 +0200
@@ -469,8 +469,6 @@
 		case 'w':
 			interval = atoi(optarg);
-			if (interval < 1)
-				errx(1, "wait time < 1");
 			iflag = 1;
 		case 'x':


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