Question: These are not installed on Android 4.2.1 by default, so is it possible to cross-compile the source for e.g. [GNU](http://ftp.gnu.org/gnu/grep/) `grep` or `find` and have it run on Android? ( Preferably **without having to root** the device or installing some app off [PLAY](https://play.google.com/store) e.g. busybox.) Are there any missing dependencies that will prevent this? I am developing on Ubuntu 10.0.04

Answer: 
Well, you can't.

If you want to have criteria used in Where clause of your SQL query, you need to write them directly as a linq.Expression so that entity may parse it and transform it into SQL, not an external function.

Somthing like this works :

```
DateTime date = DateTime.Now.AddDays(ageFrom);
all = from item in all
      where item.BirthDay > date
      select item;

```
Assuming you can apply filters on the result: 

You can apply normal filters ( in `linq` expressions ) and than apply your functions on the result. Of course, you need to `refactor` your methods. 

Something like this :

```
var result= Users.Where(s=>s.Name).ToList();
result= MyFilter(result);

```