text: /*-------------------------------------------------------------------------
   *
   * dynloader.c
   *	  Dynamic Loader for Postgres for Linux, generated from those for
   *	  Ultrix.
   *
   *	  You need to install the dld library on your Linux system!
   *
   * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   *
   * IDENTIFICATION
   *	  $PostgreSQL: pgsql/src/backend/port/dynloader/bsdi.c,v 1.28 2006/03/05 15:58:35 momjian Exp $
   *
   *-------------------------------------------------------------------------
   */
  #include "postgres.h"
  #ifndef HAVE_DLOPEN
  
  extern char my_exec_path[];
  
  void *
  pg_dlopen(char *filename)
  {
  	static int	dl_initialized = 0;
  
  	/*
  	 * initializes the dynamic loader with the executable's pathname. (only
  	 * needs to do this the first time pg_dlopen is called.)
  	 */
  	if (!dl_initialized)
  	{
  		if (dld_init(dld_find_executable(my_exec_path)))
  			return NULL;
  
  		/*
  		 * if there are undefined symbols, we want dl to search from the
  		 * following libraries also.
  		 */
  		dl_initialized = 1;
  	}
  
  	/*
  	 * link the file, then check for undefined symbols!
  	 */
  	if (dld_link(filename))
  		return NULL;
  
  	/*
  	 * If undefined symbols: try to link with the C and math libraries! This
  	 * could be smarter, if the dynamic linker was able to handle shared libs!
  	 */
  	if (dld_undefined_sym_count > 0)
  	{
  		if (dld_link("/usr/lib/libc.a"))
  		{
  			elog(WARNING, "could not link C library");
  			return NULL;
  		}
  		if (dld_undefined_sym_count > 0)
  		{
  			if (dld_link("/usr/lib/libm.a"))
  			{
  				elog(WARNING, "could not link math library");
  				return NULL;
  			}
  			if (dld_undefined_sym_count > 0)
  			{
  				int			count = dld_undefined_sym_count;
  				char	  **list = dld_list_undefined_sym();
  
  				/* list the undefined symbols, if any */
  				do
  				{
  					elog(WARNING, "\"%s\" is undefined", *list);
  					list++;
  					count--;
  				} while (count > 0);
  
  				dld_unlink_by_file(filename, 1);
  				return NULL;
  			}
  		}
  	}
  
  	return (void *) strdup(filename);
  }
  
  char *
  pg_dlerror()
  {
  	return dld_strerror(dld_errno);
  }
  
  #endif   /* not HAVE_DLOPEN */
  