1test [ arg ... ]
2[ [ arg ... ] ]
3       Like the system version of test.  Added for  compatibility;  use
4       conditional  expressions  instead  (see the section `Conditional
5       Expressions').  The main  differences  between  the  conditional
6       expression  syntax  and the test and [ builtins are:  these com-
7       mands are not handled syntactically, so  for  example  an  empty
8       variable  expansion  may cause an argument to be omitted; syntax
9       errors cause status 2 to be returned instead of a  shell  error;
10       and  arithmetic  operators  expect integer arguments rather than
11       arithmetic expressions.
12
13       The command attempts to implement POSIX and its extensions where
14       these are specified.  Unfortunately there are intrinsic ambigui-
15       ties in the  syntax;  in  particular  there  is  no  distinction
16       between  test  operators  and  strings  that resemble them.  The
17       standard attempts to resolve these for small  numbers  of  argu-
18       ments  (up  to  four);  for five or more arguments compatibility
19       cannot be relied on.  Users are urged wherever possible  to  use
20       the `[[' test syntax which does not have these ambiguities.
21