[PATCH] mesg.c: make tty variable use only dynamic memory

[gotrunks at gmail.com]

On Tue, Mar 22, 2011 at 6:52 AM, Denys Vlasenko
<vda.linux at googlemail.com> wrote:
> On Tuesday 22 March 2011 00:47, Tito wrote:
>> attached as drop in replacement file a alternative version with:
>> 1) better command line options checking (catches yx error)
>> 2) size reduction
>>       function                                             old     new   delta
>>       fchmod                                                 -      31     +31
>>       __fchmod                                               -      31     +31
>>       bb_perror_nomsg_and_die                                -       9      +9
>>       mesg_main                                            174     158     -16
>>       chmod                                                 31       -     -31
>>       __chmod                                               31       -     -31
>>       ------------------------------------------------------------------------------
>>       (add/remove: 4/2 grow/shrink: 0/1 up/down: 71/-78)             Total: -7 bytes
>> 3) better error messages
>> 4) no dynamically allocated memory
>>
>> it is just a proof of concept and little tested but seems to work.
>> If there is interest I can make a patch.
>> Hints, critics and improvements are welcome.
>
> Thanks, I used your idea while making USE_TTY_GROUP thing configurable.
>

You can save 2 bytes reversing some logic:

xfstat(STDERR_FILENO, &sb, "stderr");
if (c != 0) {
	m = (c == 'y') ? sb.st_mode | S_IWGRP_OR_S_IWOTH
				   : sb.st_mode & ~(S_IWGRP|S_IWOTH);
	if (fchmod(STDERR_FILENO, m) != 0)
		bb_perror_nomsg_and_die();
} else
	puts((sb.st_mode & (S_IWGRP|S_IWOTH)) ? "is y" : "is n");

return EXIT_SUCCESS;




function                                             old     new   delta
mesg_main                                            155     153      -2
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-2)    Total: -2 bytes



Regards,
-- 
Pere