Function load_libraries

src/backend/utils/init/miscinit.c:1836–1883

* load the shared libraries listed in 'libraries' * * 'gucname': name of GUC variable, for error reports * 'restricted': if true, force libraries to be in $libdir/plugins/ */

 * 'restricted': if true, force libraries to be in $libdir/plugins/
 */
static void
load_libraries(const char *libraries, const char *gucname, bool restricted)
{
	char	   *rawstring;
	List	   *elemlist;
	ListCell   *l;

	if (libraries == NULL || libraries[0] == '\0')
		return;					/* nothing to do */

	/* Need a modifiable copy of string */
	rawstring = pstrdup(libraries);

	/* Parse string into list of filename paths */
	if (!SplitDirectoriesString(rawstring, ',', &elemlist))
	{
		/* syntax error in list */
		list_free_deep(elemlist);
		pfree(rawstring);
		ereport(LOG,
				(errcode(ERRCODE_SYNTAX_ERROR),
				 errmsg("invalid list syntax in parameter \"%s\"",
						gucname)));
		return;
	}

	foreach(l, elemlist)
	{
		/* Note that filename was already canonicalized */
		char	   *filename = (char *) lfirst(l);
		char	   *expanded = NULL;

		/* If restricting, insert $libdir/plugins if not mentioned already */
		if (restricted && first_dir_separator(filename) == NULL)
		{
			expanded = psprintf("$libdir/plugins/%s", filename);
			filename = expanded;
		}
		load_file(filename, restricted);
		ereport(DEBUG1,
				(errmsg_internal("loaded library \"%s\"", filename)));
		if (expanded)
			pfree(expanded);
	}

	list_free_deep(elemlist);
	pfree(rawstring);
}

/*
 * process any libraries that should be preloaded at postmaster start