Question: I am using ack to search for instances of the PHP function "split(" that has now been deprecated. Unfortunately, it is bringing up instances of preg\_split (which is still valid), how can I ignore these results, whilst still searching for "split("? 

```
ack --type=php split\\\(

```

Thanks.

Answer: 
```
ack --type=php '[^_]split\('

```

Since `preg_split()` has an underscore before the split, just use a negated match for the underscore.
Well a solution could be to do more search/replace not for split but split preceded by:

* ;
* space
* tab