Redirect output to a file

I'm trying to redirect the output of a command to a file so that it can be served. Is this possible?

```
route /domains {
root * /var/www/localhost
exec /bin/ls /var/www > /var/www/localhost/domains {
pass_thru
}
file_server /domains
}
```
The /var/www/localhost/domains file exists but never gets populated and there are no errors on the server.