[CentOS] Total Number of conecctions

Fri Dec 3 21:27:14 UTC 2010
m.roth at 5-cent.us <m.roth at 5-cent.us>

Robert Heller wrote:
> At Fri, 3 Dec 2010 12:57:59 -0800 (PST) CentOS mailing list
> <centos at 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?"