unix shell basic

need some help badly.

if i had a file with content of few lines like the followings.

1183724770.651 0.049 137.157.56.169 200 415 GET http://venus/client/clients.xml "text/xml"
1183724770.651 0.049 141.183.101.250 200 415 GET http://venus/client/clients.xml "text/xml"

using what command can i actually to achieve 2 things
-capture the data value in field 5 of every line then add them up
-in field 7, eg. http://venus/client/clients.xml "text/xml", how to cut the field in order just to extract http://venus/

can someone advise?

one way:

#!/bin/ksh
awk '{ total+=$5} END { print total} '  inputfile
awk '{print $7} ' inputfile |  | read link && b=${link%/*} && echo ${b%/*}