I've just been made into checking all my output files with gawk which I avoid as much as I can. 
How does 

```
gawk 'NF \!= 6' file

```

differ from 

```
gawk 'NF != 6' file 

```

that is, how does the backslash change the meaning of this expression?

Should it output lines with number of fields different than 6 and ending with backslash?

I'm getting the following error on my files:

```
gawk:    ^ backslash not last character on line

```

Anybody?