SQLite

# define SQLITE_OPEN_LIBRARY(A)  dlopen(A, RTLD_NOW | RTLD_GLOBAL)
# define SQLITE_FIND_SYMBOL(A,B) dlsym(A,B)
# define SQLITE_CLOSE_LIBRARY(A) dlclose(A)
#endif

/*
** Attempt to load an SQLite extension library contained in the file
** zFile.  The entry point is zProc.  zProc may be 0 in which case the
** name of the entry point is derived from the filename.

**
** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
**
** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with 
** error message text.  The calling function should free this memory
** by calling sqlite3_free().
**
** The entry point name is derived from the filename according to the
** following steps:
**
**    * Convert the name to lower case
**    * Remove the path prefix from the name
**    * Remove the first "." and all following characters from the name
**    * If the name begins with "lib" remove the first 3 characters
**    * Remove all characters that are not US-ASCII alphanumerics
**      or underscores
**    * Remove any leading digits and underscores from the name
**    * Append "_init" to the name
**
** So, for example, if the input filename is "/home/drh/libtest1.52.so"
** then the entry point would be computed as "test1_init".
**
** The derived entry point name is limited to a reasonable number of
** characters (currently 200).
*/
int sqlite3_load_extension(
  sqlite3 *db,          /* Load the extension into this database connection */
  const char *zFile,    /* Name of the shared library containing extension */
  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
  char **pzErrMsg       /* Put error message here if not 0 */
){
#ifdef SQLITE_LIBRARY_TYPE
  SQLITE_LIBRARY_TYPE handle;
  int (*xInit)(sqlite3*,char**,const sqlite3_api_routines*);
  char *zErrmsg = 0;
  SQLITE_LIBRARY_TYPE *aHandle;

  if( zProc==0 ){
    int i, j, n;
    char *z;
    char zBuf[200];
    n = strlen(zFile);
    for(i=n-1; i>0 && zFile[i-1]!='/'; i--){}
    for(j=i; zFile[j] && zFile[j]!='.'; j++){}
    if( j-i > sizeof(zBuf)-10 ) j = i + sizeof(zBuf) - 10;
    memcpy(zBuf, &zFile[i], j - i);
    zBuf[j - i] = 0;
    z = zBuf;
    for(i=j=0; z[i]; i++){
      int c = z[i];
      if( (c & 0x80)!=0 || (!isalnum(c) && c!='_') ) continue;
      z[j++] = tolower(c);
    }
    z[j] = 0;
    if( strncmp(z, "lib", 3)==0 ){
      z += 3;
    }
    while( z[0] && !isalpha(z[0]) ){
      z++;
    }
    strcat(z, "_init");
    zProc = z;
  }

  handle = SQLITE_OPEN_LIBRARY(zFile);
  if( handle==0 ){
    if( pzErrMsg ){
      *pzErrMsg = sqlite3_mprintf("unable to open shared library [%s]", zFile);
    }

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test_schema.c,v 1.3 2006/06/16 06:17:47 danielk1977 Exp $
*/

/* The code in this file defines a sqlite3 module that provides
** a read-only view of the current database schema. There is one
** row in the schema table for each column in the database.
*/
#define SCHEMA \
"CREATE TABLE x("                                                            \
  "database,"          /* Name of database (i.e. main, temp etc.) */         \
  "tablename,"         /* Name of table */                                   \
  "cid,"               /* Column number (from left-to-right, 0 upward) */    \
  "name,"              /* Column name */                                     \

}

#else

/*
** Extension load function.
*/
int schema_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  sqlite3_create_module(db, "schema", &schemaModule, 0);
  return 0;
}

#endif

# 2006 July 14
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is in-memory database backend.
#
# $Id: loadext.test,v 1.1 2006/06/14 10:38:03 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl



if {$::tcl_platform(platform) eq "windows"} {
  set testextension testloadext.dll
} else {
  set testextension libtestloadext.so
}





if {![file exists $testextension]} {





  puts "Skipping loadext tests: Test extension not built..."

  finish_test
  return

}

# Test that loading the extension produces the expected results - adding
# the half() function to the specified database handle.
#
do_test loadext-1.1 {
  catchsql {
    SELECT half(1.0);
  }
} {1 {no such function: half}}
do_test loadext-1.2 {
  sqlite3_load_extension db $testextension
  catchsql {
    SELECT half(1.0);
  }
} {0 0.5}

# Test that a second database connection (db2) can load the extension also.
#
do_test loadext-1.3 {
  sqlite3 db2 test.db
  catchsql {
    SELECT half(1.0);
  } db2
} {1 {no such function: half}}
do_test loadext-1.4 {
  sqlite3_load_extension db2 $testextension
  catchsql {
    SELECT half(1.0);
  } db2
} {0 0.5}

# Close the first database connection. Then check that the second database
# can still use the half() function without a problem.

db2 close
sqlite3 db test.db

# Try to load an extension for which the file does not exist.
#
do_test loadext-2.1 {
  set rc [catch {
    sqlite3_load_extension db "xx${testextension}"
  } msg]
  list $rc $msg
} [list 1 [subst -nocommands \
  {unable to open shared library [xx${testextension}]}
]]

# Try to load an extension for which the file is not a shared object
#
do_test loadext-2.2 {
  set fd [open "xx${testextension}" w]
  puts $fd blah
  close $fd
  set rc [catch {
    sqlite3_load_extension db "xx${testextension}"
  } msg]
  list $rc $msg
} [list 1 [subst -nocommands \
  {unable to open shared library [xx${testextension}]}
]]

# Try to load an extension for which the file is present but the
# entry point is not.
#
do_test loadext-2.3 {
  set rc [catch {

  set rc [catch {
    sqlite3_load_extension db $testextension testbrokenext_init
  } msg]
  list $rc $msg
} {1 {error during initialization: broken!}}

finish_test