How to check short in Gerber file

Try importing the gerber into a tool such as CAM350, GerbView or Viewmate and give it a try there. In general a DRC check in the board file will report errors such as shorts.

Ok. I already use it, but I want to control gerber files. No brd file. 

For example, Import the  cadence netlist in CAM350, GerbView or Viewmate and to do a check. 

I want to do this because is possible don't have drs error (or not see it) in allegro, but in reality there is the error.

But in I want to other check on gerber file (production file) in order to intercept these cases.

Ok. I already use it, but I want to control gerber files. No brd file. 

For example, Import the  cadence netlist in CAM350, GerbView or Viewmate and to do a check. 

I want to do this because is possible don't have drs error (or not see it) in allegro, but in reality there is the error.

But in I want to other check on gerber file (production file) in order to intercept these cases.

The ODB++ Viewer is only a viewer, if you want to check anything you need a licensed tool which which are not free...

Most CAM type tools will require an IPC-D-356 netlist file and the various Nc-drill files besides the Gerber artwork files

Ok. I can valuated buy licensed tool. But I have to understand if it works. For example CAM350 can do it? Is there a tutorial or a document?  

Below is an example process that applies to most CAM tools:

Import the Gerber artwork files in the correct order to match the stackup section of the IPC-D-356 netlist file.

Import the NC-Drill files, ensure the start & end layers for buried and blind vias are set correctly.

Import the IPC-D-356 netlist file.

Run the net-list comparison tool...