[PATCH 3/3] compositor: dump command line options

[Tiago Vignatti]

On 03/20/2012 05:06 AM, Pekka Paalanen wrote:
> On Tue, 20 Mar 2012 00:57:49 -0300
> Tiago Vignatti<tiago.vignatti at linux.intel.com>  wrote:
>
>>>> +	if (help) {
>>>> +		dump_options(core_options, ARRAY_LENGTH(core_options));
>>>> +		argv[argc] = strdup("--help");
>>>> +		argc++;
>>>
>>> How do you know there is space in argv[] to add that?
>>> Also, doesn't strdup() leak here?
>>>
>>> Hm, so if there was a --help originally, there must be space to add it
>>> back... I wonder if it made sense to handle --help specially in option
>>> parser, and let it indicate "help encountered" with an error code
>>> return. We are going to need the error code return anyway.
>>
>> you're right. So argv is at stack and can be referenceable, so maybe we
>> can use the following to get the address back:
>>
>> +       if (help) {
>> +               dump_options(core_options, ARRAY_LENGTH(core_options));
>> +               argv[argc] = argv[argc - 1] + strlen(argv[argc - 1]) +1;
>> +               strcpy(argv[argc], "--help");
>> +               argc++;
>> +       }
>>
>> is there a cleaner way maybe to get?
>
> I agree with Bill's comment that a simple argv[argc] = "--help"; is
> right, if you want to go there. By space I meant space for a pointer in
> argv, not the space for the string.
>
> After all, argv is an array of pointers, and the pointers point to
> char arrays where-ever, and the char arrays need not be consecutively
> packed in memory (or at least I would never assume that, certainly
> after a parse_options() call they are not packed anymore).
>
> I would also never try to write to strings pointed to by argv.

right right, that works as well.

Tiago