I did more test on david code and found a problem.
-bash$ mk -f mkfile_david
-bash$ o.test_dirread -a /usr/bin |wc
1084 4336 27266
-bash$ o.test_dirread /usr/bin |wc
1084 4336 27266
-bash$ ls /usr/bin |wc
1108 1108 9719
option -a is for dirreadall.
1108 - 1084 entries are lost.
they are:
o.test_dirread /usr/bin | awk '{print $1}' | sort >/tmp/a
ls /usr/bin | sort >/tmp/b
diff /tmp/a /tmp/b
-bash$ diff /tmp/a /tmp/b
21a22
> SplitForks
240a242,246
> easy_install-2.6
> easy_install-2.7
> efax
> efix
> egrep
461a468,473
> kcc
> kdestroy
> kextutil
> keytool
> kgetcred
> kill.d
675a688,694
> piconv
> piconv5.16
> piconv5.18
> pidpersec.d
> pkgbuild
> pkill
> pl
880a900,904
> spfquery5.18
> splain
> splain5.16
> splain5.18
> split
sorry if I make a mistake, but I suspect readdir_r() has a buffer,
which can make a problem in using dup().
Kenji Arisawa.
> 2017/04/09 13:18、arisawa <[email protected]> のメール：
>
> thanks david.
>
> using dup() is very nice idea!
> your code works with
> CFLAGS=-D__DARWIN_64_BIT_INO_T # manual is wrong
> and a fix:
> // buf = ((char*)buf) + d_reclen(buf);
> buf = (struct dirent *)(((char*)buf) + d_reclen(buf));
> and adding
> #define NAME_MAX 256
> in somewhere.
>
> now /dev is readable.
>
> one problem is left.
>
> my test code:
> fd = open(dirname,OREAD);
> if(fd < 0)
> fatal("%s open error",dirname);
> while((n = dirread(fd, &db)) > 0){
> print("#DBG n=%d\n",n);
> for(i = 0; i < n; i++)
> print("%s %s %s \n", db[i].name, db[i].uid, db[i].gid);
> }
> close(fd);
> shows for dirname=$HOME
> ...
> arch root 501
> bin root 501
> ...
> but they should be
> arch arisawa staff
> bin arisawa staff
> this problem comes from _p9dir() that is used in dirpackage().
>
> Kenji Arisawa
>
>
>> 2017/04/08 18:07、David Arroyo <[email protected]> のメール：
>>
>> Ignore my previous post, I was tired and forgot about dup(). How about
>> something like this? (attached)
>>
>> I only tested this on Ubuntu, I don't have an OS X machine. I still went
>> with readdir_r because the AIX and Solaris man pages for readdir were
>> vague about its behavior when called from multiple threads (glibc, musl,
>> FreeBSD look pretty safe).
>>
>> Cheers,
>> David
>>
>> On Sat, Apr 8, 2017, at 03:27 AM, David Arroyo wrote:
>>> This should be doable with some combination of fdopendir(3) and
>>> readdir(3). I'm not sure how to avoid leaking memory through the
>>> returned DIR pointer and any memory allocated with by readdir(3).
>>> This is usually free'd by closedir(3), which we can't use without
>>> closing the underlying file.
>>>
>>> It should be OK to use free() on the return value of fdopendir, and
>>> stick to the uglier readdir_r(3) interface. I can definitely see why
>>> Russ went with the simpler system-specific interfaces on this.
>>>
>>> David
>>>
>>> On Sat, Apr 8, 2017, at 02:46 AM, Ori Bernstein wrote:
>>>> On Sat, 8 Apr 2017 15:21:47 +0900, arisawa <[email protected]> wrote:
>>>>
>>>>> but how to?
>>>>>
>>>>> unix doesn’t have something like fdreaddir(int fd).
>>>>> my guess: russ unwillingly used a low level function such as
>>>>> int getdirentries(int fd, char *buf, int nbytes, long *basep).
>>>>>
>>>>> readdirall() might be OK in regular usage.
>>>>
>>>> I don't use OSX regularly, although I do maintain the syscall
>>>> layer for Myrddin on it.
>>>>
>>>> Getdirentries64 exists, and rudimentary testing doesn't show
>>>> any difficulties with using it.
>>>>
>>>> --
>>>> Ori Bernstein
>>>>
>>>
>> <posix-dirread.patch>
>
