How to compare $arg0 with string literal?

[Doug Evans]

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?