相关疑难解决方法(0)

假设我有以下字符串:

something1:    +12.0   (some unnecessary trailing data (this must go))
something2:    +15.5   (some more unnecessary trailing data)
something4:    +9.0   (some other unnecessary data)
something1:    +13.5  (blah blah blah)

我该如何简单地把它变成

+12.0,+15.5,+9.0,+13.5

在bash？