awk 如何讓連續的行能相加

-ex.txt

 0.0

 0.0

 24.0

 0.0

 0.0

 0.0

 0.0

 24.0

 0.0

 1.0

 2.0

-output

 48.0

 3.0

use 'awk'

awk '{ if ( $1 == "" ) { printf("%f\n",tot); tot=0 } else tot+=$1 }' ex.txt