print go version from built binary

goversion.bash

#!/bin/bash -e

# usage
#   $0 path/to/go/built/binary

usage() {
        echo "Usage"
        echo "  $0 path/to/go/built/binary"
        exit 2
}

obj=$1

if  [ -z $obj ] || [ ! -e $obj ];then
        echo "No such file"
        usage
fi

v=(`go tool nm -size $obj | grep 'runtime.buildVersion' | awk '{print $1,$2}'`)
addr=${v[0]}
size=${v[1]}

start=`objdump -s $obj | grep $addr | awk '{hex=$2; printf "0x%s%s%s%s\n",substr(hex,7,2),substr(hex,5,2),substr(hex,3,2),substr(hex,1,2);}'`
end=`printf "%d+%d\n" $start $size | bc`

objdump -s --start-address=$start --stop-address=$end $obj | grep go | sed -e 's/.*\(go.*\).*/\1/' -e 's/\.\.\+//g'