How to compare $arg0 with string literal?

[Aleksey Midenkov]

On Fri, Mar 27, 2015 at 7:25 PM, Doug Evans <dje@google.com> wrote:
> On Thu, Mar 26, 2015 at 11:35 PM, Aleksey Midenkov <midenok@gmail.com> wrote:
>> On Thu, Mar 26, 2015 at 9:28 PM, Doug Evans <dje@google.com> wrote:
>>> Such things are not supported in gdb's own scripting language.
>>> However, with a bit of Python-provided magic ($_streq):
>>>
>>> define logging
>>>     if $argc == 1
>>>         if $_streq("$arg0", "off")
>>>             set logging off
>>>             set logging file gdb.log
>>>         else
>>>             if $_streq("$arg0", "stop")
>>>                 set logging off
>>>             else
>>>                 set logging $arg0
>>>             end
>>>         end
>>>     else
>>>         set logging $arg0 $arg1
>>>     end
>>>     show logging
>>> end
>>>
>>> Note that gdb's if/else syntax is a pain.
>>
>> Sure thing, gdb's syntax could be a bit richer... Also, if I get this
>> error message does that mean that my gdb is not Python-powered?
>>
>> (gdb)  p $_streq("off", "off")
>> Invalid data type for function to be called.
>
> I'd use "py print 42" or some such as a more direct test of whether
> python is present.
>
> btw, which version of gdb are you using?

That host where this error occurs is always outdated. 7.2-60.el6_4.1
On my local machine is latest version and $_streq() works.
On 7.2 'py print' :

(gdb) py print 42
42
(gdb) py prind 42
  File "<string>", line 1
    prind 42
          ^
SyntaxError: unexpected EOF while parsing
Error while executing Python code.