The ZIP archive shpsort.zip contains a utility (console) program
to sort shapefiles by multiple fields (including the "SHAPE"
pseudofield).

The ZIP file contains a Windows executable, compiled with Microsoft's
C compiler (part of Visual Studio 7) on a Windows 2000 box.  If you
would like to compile the program for another platform, you will also
need to fetch the shapelib sources from http://shapelib.maptools.org/.
An example GCC command line (assuming shapelib has been compiled with
its makefile, and shpsort has been extracted to a directory beneath
the shapelib sources):

$ gcc -o shpsort shpsort.c ../shpopen.o ../dbfopen.o -I..

This utility is not supported and is distributed AS IS, NO WARRANTY.