# RFC 36: Allow specification of intended driver on GDALOpen

Authors: Ivan Lucena

Contact: ivan.lucena@pmldnet.com

Status: Proposed

## Summary

This document proposes a mechanism to explicitly tell GDAL what driver should open a particular dataset.

## Justification

By selecting the driver, users can optimize processing time and avoid incorrect or undesirable driver selection due to the driver probing mechanism.

## Concept

The idea is to pass to GDALOpen a string containing the token "driver=" followed by the driver name and a comma separating it from the file-name.

[driver=driver-name,]file-name

Examples:

$ gdalinfo driver=nitf:imagefile01.ntf

In that case no probing is necessary, since the user has indicated to use the specific driver. If for some reason that process fails the function returns NULL and no other attempt is made to open the file by another driver.

## Implementation

The amount of code is minimal and there is already a proposed patch on ticket #3043.

## Utilization

Any application that uses GDAL API or any GDAL command line tool's user that, at one point, wants to force the use of a particular driver to open a datasets.

## Backward Compatibility Issues

That optional entry on GDALOpen process should not affect the current logic.

## Testing

- Extra tests would be added to the test script

## Issues

For gdalbuildvrt and gdaltindex it will not be possible to use the driver selection with wildcard, as in "driver=gtiff,*.tif".