CentOS - Dec 2010 - whats wrong with my internet connection checker script?

$ true && true || echo hi
$ true && false || echo hi
hi
$ false && true || echo hi
hi
$ false && false || echo hi
hi
$ ping -W 1 -c 4 google.com >& /dev/null | grep -q "100% packet
loss" && ping -W 1 -c 4 www.yahoo.com >& /dev/null | grep -q
"100% packet loss" || echo "no internet connection"
no internet connection
$
ping -W 1 -c 4 google.com >& /dev/null | grep "100% packet
loss"
$
ping -W 1 -c 4 www.yahoo.com >& /dev/null | grep "100% packet
loss"
$



...both sides "false", because they have no output, because google.com
and www.yahoo.com is reachable.
how come it writes "no internet connection"? [at the longest line]
i just want a "oneliner" that checks if theres "internet
connection" or no. :\

where did i screw up? 8)

On Sun, 26 Dec 2010, S Mathias wrote:
> To: centos at centos.org
> From: S Mathias <smathias1972 at yahoo.com>
> Subject: [CentOS] whats wrong with my internet connection checker script?
> 
> $ true && true || echo hi
> $ true && false || echo hi
> hi
> $ false && true || echo hi
> hi
> $ false && false || echo hi
> hi
> $ ping -W 1 -c 4 google.com >& /dev/null | grep -q "100% packet
loss" && ping -W 1 -c 4 www.yahoo.com >& /dev/null | grep -q
"100% packet loss" || echo "no internet connection"
> no internet connection
> $
> ping -W 1 -c 4 google.com >& /dev/null | grep "100% packet
loss"
> $
> ping -W 1 -c 4 www.yahoo.com >& /dev/null | grep "100% packet
loss"
> $
Would a bash script be more simple, rather than trying to do 
all the piping stuff on one line?

Keith

-- 
In theory, theory and practice are the same;
in practice they are not.

This email was sent from my laptop with Centos 5.5

perfect! thank you Oliver Grawert! :) made my day :) it's working! :


ping -W 1 -c 4 google.com >& /dev/null && ping -W 1 -c 4
www.yahoo.com >& /dev/null || echo "no internet connection"