[Gdal-dev] "Old-Style" ESRI .PRJ files -- Access Violation on
cmichaelis at happysquirrel.com
Fri Dec 9 22:25:07 EST 2005
I've got a question more related to OGR than to GDAL itself... but as
I'm using OGR through GDAL I figured the question may be appropriate
here. Apologies if it's not!
I've been reading the previous list messages on the various ESRI .prj
file formats, and I think I've just run into my first "old-style"
projection file. I have up until now been using .ImportFromWkt() to load
projections, and it works perfectly for the WKT-style projection files.
Based on previous posts, I think that .ImportFromESRI() should be able
to read these old-style PRJ files as well as the WKT. Am I correct in
Now... to test it, I simply changed "ImportFromWkt" to "ImportFromESRI"
in my code. No matter whether I try to read a new or old-style .prj
file, this function call results in an access violation in GDAL13.dll.
Does anyone out there have a similar experience with this? I'd be
eternally grateful for any advice. I put together a simple C++ test
program to try to figure out what I was doing wrong; code follows below.
Thanks in advance for any help, and thanks in advance for reading my
--Chris Michaelis of MapWindow.org
My troublesome PRJ file:
29 30 0.0 /* 1st standard parallel
45 30 0.0 /* 2nd standard parallel
-96 0 0.0 /* central meridian
23 0 0.0 /* latitude of projection's origin
0.0 /* false easting (meters)
0.0 /* false northing (meters)
The source code I'm trying to read this with: (takes the .prj file as a
command-line argument -- this is on Windows, if "_tmain" and the
reference to the gdal DLL above doesn't give that away)
int _tmain(int argc, _TCHAR* argv)
OGRSpatialReference oSRS, rSRS;
char *pszProj4 = NULL;
FILE * prjFile;
char * pszWKT = NULL;
prjFile = fopen(argv, "rb");
printf("Couldn't open file.\n");
fseek (prjFile, 0, SEEK_END);
long lSize = ftell (prjFile);
pszWKT = (char*) malloc (lSize);
if (pszWKT == NULL)
printf("Couldn't allocate mem.\n");
printf("INPUT = %s\n", pszWKT);
oSRS.importFromESRI( &pszWKT ); // Crashes Here. ImportFromWkt works
fine (for WKT, but not old-style of course)
oSRS.exportToProj4( &pszProj4 );
printf( "OUTPUT Proj4 = %s\n", pszProj4 );
// Clean up the allocated strings here...
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