[gdal-dev] How to write WKB as string?

[Even Rouault]

Le mercredi 14 octobre 2015 19:18:20, Roger André a écrit :
> <grin>  Yes Even, exportToWkb() was something I tried, but I thought there
> might be an easy way to get the ASCII form of the WKB, rather than the
> straight binary that I got when I wrote out to a text file.

Ah I missed that part.

The following should help:

http://www.gdal.org/cpl__string_8h.html:

char * 	CPLBinaryToHex (int nBytes, const GByte *pabyData) 
CPL_WARN_UNUSED_RESULT
 	Binary to hexadecimal translation. More...
 
GByte * 	CPLHexToBinary (const char *pszHex, int *pnBytes) 
CPL_WARN_UNUSED_RESULT

Even more compact with base64 encoding:

char * 	CPLBase64Encode (int nBytes, const GByte *pabyData) 
CPL_WARN_UNUSED_RESULT
 
int 	CPLBase64DecodeInPlace (GByte *pszBase64)

> 
> Norman, thanks for the links. I'll go peruse them.
> 
> On Wed, Oct 14, 2015 at 10:10 AM, Norman Vine <nhv at cape.com> wrote:
> > On Oct 14, 2015, at 12:59 PM, Roger André <randre at gmail.com> wrote:
> > 
> > Hi All,
> > 
> > I have a tool which currently exports geometry using the ExportToWkt()
> > function.  It works great, but I'd like to try reducing the size of my
> > output files by using a format like the string representation of WKB that
> > shp2pgsql produsces when creating SQL insert files.  Is there a export
> > function available in GDAL that I could use for this?
> > 
> > I'm looking at http://www.gdal.org/classOGRGeometry.html currently, but
> > have not yet spotted what I'm looking for.
> > 
> > Thanks,
> > 
> > 
> > see
> > http://www.gdal.org/ogr__api_8h.html#ad5c94ae76c09774dba8725c24daeefd6
> > or
> > http://www.gdal.org/classOGRGeometry.html#a9a3ad2f9b55285be500ca6ac5dc75d
> > 1d

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