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From: wij <wyniijj5@gmail.com>
Newsgroups: comp.lang.c
Subject: Re: encapsulating directory operations
Date: Sat, 07 Jun 2025 04:04:24 +0800
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On Fri, 2025-06-06 at 19:26 +0200, Bonita Montero wrote:
> Am 06.06.2025 um 19:24 schrieb Scott Lurndal:
> > Bonita Montero <Bonita.Montero@gmail.com> writes:
> > > Am 06.06.2025 um 16:10 schrieb Scott Lurndal:
> > > > Bonita Montero <Bonita.Montero@gmail.com> writes:
> > > > > Am 03.06.2025 um 20:25 schrieb Scott Lurndal:
> > > >=20
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 The fchownat() functio=
n shall be equivalent to the chown() and lchown()
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 functions except in th=
e case where path specifies a relative path. In
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 this case the file to =
be changed is determined relative to the directory
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 associated with the fi=
le descriptor fd instead of the current working
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 directory. If the acce=
ss mode of the open file description associated
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 with the file descript=
or is not O_SEARCH, the function shall check
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 whether directory sear=
ches are permitted using the current permissions
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 of the directory under=
lying the file descriptor. If the access mode is
> > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 O_SEARCH, the function=
 shall not perform the check.
> > > > > > >=20
> > > > > > > And why is this relevant for directory_iterator or
> > > > > > > recursive_directory_iterator ?
> > > > > >=20
> > > > > > Why are you asking this question on comp.lang.c?
> > > > >=20
> > > > > Because you can have it easier than with opendir() / readdir().
> > > >=20
> > > > Personally, I'd use nftw to iterate over a path.
> > > >=20
> > > > https://pubs.opengroup.org/onlinepubs/9799919799/functions/nftw.htm=
l
> > >=20
> > > That would be much nicer with a lambda which can take the context
> > > of the calling function.
> > >=20
> >=20
> > That's a matter of opinion.
>=20
> It results in much less code.=C2=A0

That is illusion, particularly in this case (about directory).
Most serious programs will 'invent' their own functions, even their own
'sugar syntax'... result would be better than 'directory_iterator'.
In general, no need for such things as 'directory_iterator' in C-library.

> Just like a lambda passed
> to std::sort() which takes context of the calling function.
>=20
> > In any case, nftw is a C function and C doesn't support lamda functions=
..
>=20
> Lambdas without capture can be converted to C function-pointers.