Robert Heller wrote:
At Fri, 3 Dec 2010 12:57:59 -0800 (PST) CentOS mailing list centos@centos.org wrote:
I have the need to know how many connection the server has, i run this command but i don't know how to sum all the results and get a final number. any ideas?
netstat -an | grep -E 'tcp|udp' | awk '{print $6}' | sort | uniq -c | sort -n
  1 CLOSE_WAIT   1 FIN_WAIT_2   1 LAST_ACK   1 TIME_WAIT   4 SYN_SENT  15  37 LISTEN  44 ESTABLISHED
<the above script> | awk '{print $1;}' | tr '\n' '+'|sed 's/+$//g'|bc
The awk prints just the number, the tr replaces the newlines with +'s, the sed strips off the trailing + (from the last newline), and bc does the math.
Why do people use awk without using it? netstat -an | awk '{if ($0 ~ /tcp|udp/){ print $6;}END { print NF;}' gets you the number of lines at the end. Or, to be more elegant, netstat -an | \ awk '{if ($0 ~ /tcp|udp/) { array[$6] += 1; } END { for ( i in array ) { print i; sum += array[i]; } print sum; }'
mark "me? like awk? yell at Larry Wall in '94 for proselytizing perl in comp.language.awk?"