I have the following file

```
aaa1.bbb1.ccc toto
aaa1.bbb1.ddd. titi
aaa2.bbb2.ccc
aaa2.bbb2.eee tza
aaa2.bbb2.ddd.

```

I want to add at the beginning of each line a string. This string will be "OK" if the first filed of the line finish with `.` and the string will be "NOK" if the first filed of the line do not finish with `.`

The delimiters of the fields is the space

so based on the above example, the ouput of the command will be:

```
NOK aaa1.bbb1.ccc toto
OK aaa1.bbb1.ddd. titi
NOK aaa2.bbb2.ccc
NOK aaa2.bbb2.eee aza
OK aaa2.bbb2.ddd.

```

How I can do that?