Thanks, Frank.<div><br></div><div>I understand the purist argument against this, though I think that 90% of the time you can look at a connection string for a data source and determine what the output driver should be. I'd like to see this feature in the future, but I understand that it would need a caveat that it may not always work or return the expected result. Maybe a "GuessOutputDriver(...)" function would be the appropriate way to name it.</div>
<div><br></div><div><br></div><div><br><br><div class="gmail_quote">On Wed, Oct 6, 2010 at 8:47 AM, Frank Warmerdam <span dir="ltr"><<a href="mailto:warmerdam@pobox.com">warmerdam@pobox.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im">Joel Odom wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Is there a canonical way to pick an OGR driver based on a file name or on a generalized connect string? (For example, if the file name ends in ".shp", it would select the Shapefile driver.) Thanks.<br>
</blockquote>
<br></div>
Joel,<br>
<br>
No.<br>
<br>
I really wanted to send this out with just that one word answer, but I<br>
can't help myself but elaborate.<br>
<br>
First, I think file format identification based on filename extension is<br>
a terrible idea, and I curse those operating systems that try to build it<br>
into the graphical shell. Likewise a pox on applications that carry on<br>
this tradition.<br>
<br>
Second, there are a number of OGR file formats that have no dependency on<br>
extension. For example GML, DGN, DXF, PCIDSK. For these formats any<br>
extension is fine and only letting people pick a file if it has some<br>
particular is offensive to me.<br>
<br>
Third, there are lots of database connection formats that aren't extension<br>
based. Typically these can be identified based on a prefix string like<br>
MYSQL: though not always.<br>
<br>
Despite my feelings on this matter, on the GDAL side of the house we actually<br>
provide a metadata item on drivers allowing specification of a preferred<br>
extension which applications can use. We also have an "identify" mechanism<br>
that will try to efficiently identify what format a file or dataset name<br>
string is without necessarily actually opening it.<br>
<br>
Unfortunately, the OGR world is less sophisticated in this regard and lacks<br>
these two mechanisms. This is one reason I'd like to have a "grand<br>
unification" of GDAL and OGR one day.<br>
<br>
Best regards,<br><font color="#888888">
-- <br>
---------------------------------------+--------------------------------------<br>
I set the clouds in motion - turn up | Frank Warmerdam, <a href="mailto:warmerdam@pobox.com" target="_blank">warmerdam@pobox.com</a><br>
light and sound - activate the windows | <a href="http://pobox.com/~warmerdam" target="_blank">http://pobox.com/~warmerdam</a><br>
and watch the world go round - Rush | Geospatial Programmer for Rent<br>
<br>
</font></blockquote></div><br><br clear="all"><br>-- <br><a href="http://www.operationliberate.com/">http://www.operationliberate.com/</a><br>
</div>