1.. _rfc-36:
2
3================================================================================
4RFC 36: Allow specification of intended driver on GDALOpen
5================================================================================
6
7Authors: Ivan Lucena
8
9Contact: ivan.lucena@pmldnet.com
10
11Status: Proposed
12
13Summary
14-------
15
16This document proposes a mechanism to explicitly tell GDAL what driver
17should open a particular dataset.
18
19Justification
20-------------
21
22By selecting the driver, users can optimize processing time and avoid
23incorrect or undesirable driver selection due to the driver probing
24mechanism.
25
26Concept
27-------
28
29The idea is to pass to GDALOpen a string containing the token "driver="
30followed by the driver name and a comma separating it from the
31file-name.
32
33[driver=driver-name,]file-name
34
35Examples:
36
37$ gdalinfo driver=nitf:imagefile01.ntf
38
39In that case no probing is necessary, since the user has indicated to
40use the specific driver. If for some reason that process fails the
41function returns NULL and no other attempt is made to open the file by
42another driver.
43
44Implementation
45--------------
46
47The amount of code is minimal and there is already a proposed patch on
48ticket #3043.
49
50Utilization
51-----------
52
53Any application that uses GDAL API or any GDAL command line tool's user
54that, at one point, wants to force the use of a particular driver to
55open a datasets.
56
57Backward Compatibility Issues
58-----------------------------
59
60That optional entry on GDALOpen process should not affect the current
61logic.
62
63Testing
64-------
65
66-  Extra tests would be added to the test script
67
68Issues
69------
70
71For gdalbuildvrt and gdaltindex it will not be possible to use the
72driver selection with wildcard, as in "driver=gtiff,*.tif".
73