Sqlite: How To Build a Loadable Extension Shared Library on Linux

Details copy from http://www.sqlite.org/cvstrac/wiki?p=LoadableExtensions

How To Build a Loadable Extension Shared Library on Linux
0. untar latest sqlite3 source code in a new directory
1. cd to the newly untarred sqlite directory
2. Comment out the line in Makefile.in to enable loadable extensions:
# TCC += -DSQLITE_OMIT_LOAD_EXTENSION=1
3. ./configure LIBS=-ldl && make sqlite3
4. export LD_LIBRARY_PATH="`pwd`:$LD_LIBRARY_PATH"
5. gcc -I`pwd` -shared src/test_loadext.c -o half.so
6. ./sqlite3
SQLite version 3.3.17
Enter ".help" for instructions
sqlite> .load half.so testloadext_init
sqlite> select half(7);
3.5