I've used sed to replace variables on \*.go files using `sed -i 's/\<old_name\>/newName/g' *.go`
My objective is to eliminate golinter errors.
How can strings with common patterns, e.g. replace 1 with 2

1. `fmt.Printf("blah blah blah")` or `fmt.Printf("yadda yadda yadda")`
2. `fmt.Println("blah blah blah")` or `fmt.Println("yadda yadda yadda")`

In this case, we do NOT want to replace: 
1. `fmt.Printf("print speed= %d",speed)` //So the key here is the ending pattern should be `")`. 
2. log.Printf statements //only replace "fmt."
Any pointers on this?