function str_extract() {
 pattern=$1
 # Extract
 res=`grep "$pattern" $log | sed "s/$pattern//g"`
 # Drop trailing ...
 res=`echo $res | sed 's/[.][.][.]//g'`
 # Trim
 res=`echo $res | sed 's/^ *//g' | sed 's/ *$//g'`
 echo  $res
}

  download=`str_extract "Download: "`
  upload=`str_extract "Upload: "`

Retrieving speedtest.net configuration...
Testing from Telecomunicazioni S.p.A. ...
Retrieving speedtest.net server list...
Selecting best server based on ping...
Hosted by Coolnetwork (Arezzo) [26.09 km]: 111.547 ms
Testing download speed................................................................................
Download: 2.06 Mbit/s
Testing upload speed...............................................................................................
.Upload: 1.81 Mbit/s
Share results

"2.06" #correct
".1.81" #wrong preceding dot