sqlite3-preload - Execute SQLite statements when an SQLite database is opened

This is a small hack to enable the execution of certain SQLite PRAGMA(s) when an application opens an SQLite database but does not support user-defined SQL commands.

My use case is to make Asterisk's CEL SQLite logging run in something other than fully synchronous mode. Until upstream exposes an option to control this behavior, I will LD_PRELOAD this .so file to provide that behavior myself.

Use make. I am not going to use autotools on a project this small.

# Optional: Specify an exact version of libsqlite3
export SQLITE3_LIBRARY=[/path/to/]libsqlite3.so.0

export LD_PRELOAD=/path/to/sqlite3-preload.so
export SQLITE3_INIT_SQL=/path/to/sqlite3.sql
exec /path/to/program-using-sqlite3

When your program calls sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2(), this module will hook those function calls and check the SQLITE3_INIT_SQL environment variable. If it is unset, the function call opening the database will be passed thru to SQLite3 with no modification.

However, if SQLITE3_INIT_SQL is set, the contents of the file will be read and passed to sqlite3_exec(). If any errors occur reading the file or executing its contents, the error will be printed to stderr, any newly opened database handles will be closed, and an SQLITE_CANTOPEN error will be returned to the application.

Chase Venters ([email protected])

Public domain