Am 02.12.2014 um 19:05 schrieb James B. Byrne: > I am attempting to get a script borrowed from DJB to work on my CentOS-6.6 > box. Simplified it looks like this: > > tcpdump -l -n -e port 53 \ > | awk '{if ($14 ~ /A.*?/) print $15}' \ > | while read domain ; do echo $domain ; done ; > > The sticking point is the 'while read' construct. Run just as 'tcpdum | awk' > I get this: > > english.stackexchange.com. > www.urbandictionary.com. > www.urbandictionary.com. > www.urbandictionary.com. > www.urbandictionary.com. > api.mywot.com. > a.udimg.com. > a.udimg.com. > fonts.googleapis.com. > . . . > > Run with the 'while read $domain ; do echo ' pipe nothing appears whatsoever. > What am I doing wrong? while read domain; do echo ${domain} done < <(tcpdump -l -n -e port 53 | awk '{if ($14 ~ /A.*?/) print $15}') The "echo ${domain}" part is certainly just a simplification of a more complex command to run on the variable. Else it would be pointless as awk is printing out the domain field 15. Alexander