SELECT sys.format_path(NULL);
sys.format_path(NULL)
NULL
SET @mypath := CONCAT(@@global.datadir, 'foo/bar.foo');
SELECT sys.format_path(@mypath);
sys.format_path(@mypath)
@@datadir/foo/bar.foo
SET @mypath := CONCAT(@@global.tmpdir, 'foo/bar.foo');
SELECT sys.format_path(@mypath);
sys.format_path(@mypath)
@@tmpdir/foo/bar.foo
SET @mypath := CONCAT(@@global.innodb_log_group_home_dir, 'foo/bar.foo');
SELECT sys.format_path(@mypath);
sys.format_path(@mypath)
@@innodb_log_group_home_dir/foo/bar.foo
SELECT sys.format_path('/foo/bar/baz.foo');
sys.format_path('/foo/bar/baz.foo')
/foo/bar/baz.foo
