is_subdir

[André Hänsel]

Hi,

is there a function like is_subdir in PHP?

It's not, is it?

Is there a way to achieve its functionality (which is probably clearly
explained by its name ;)) in PHP?

Regards,
André

[Chung Leong]

Re: is_subdir


André Hänsel wrote:

Hi,
>
is there a function like is_subdir in PHP?
>
It's not, is it?
>
Is there a way to achieve its functionality (which is probably clearly
explained by its name ;)) in PHP?
>
Regards,
André

If you mean a function that tells you whether a directory is a
sub-directory in another, that answer is no. You can approximate it
from getting the absolute path of both with realpath() and then compare
them.

[André Hänsel]

Re: is_subdir

Chung Leong schrieb:

André Hänsel wrote:

is there a function like is_subdir in PHP?

>
If you mean a function that tells you whether a directory is a
sub-directory in another, that answer is no. You can approximate it
from getting the absolute path of both with realpath() and then compare
them.

Unfortunately this doesn't work. When I have such a structure...
/
|-- collection
| `-- dir -/dir
`-- dir
`-- subdir

....then /collection/dir/subdir is a subdir of /collection but the
realpath solution says no, because it dereferences the symlinks.

Regards,
André

[ImOk]

Re: is_subdir

is_dir ("./mysubdir/mysubsubdir" )

or Windows

is_dir (".\\mysubdir\\ mysubsubdir" )

.. means the current working directory.

Chung Leong wrote:

André Hänsel wrote:

Hi,

is there a function like is_subdir in PHP?

It's not, is it?

Is there a way to achieve its functionality (which is probably clearly
explained by its name ;)) in PHP?

Regards,
André

>
If you mean a function that tells you whether a directory is a
sub-directory in another, that answer is no. You can approximate it
from getting the absolute path of both with realpath() and then compare
them.

[André Hänsel]

Re: is_subdir

ImOk schrieb:

is_dir ("./mysubdir/mysubsubdir" )

That only determines if ./mysubdir/mysubsubdir is a directory. It makes
no statement about whether it is a subdirectory of another directory.

is_dir('../../nosubdir) will return true (if the dir exits, of course),
although it is no subdir of the working dir.

[Mel]

Re: is_subdir

On 2006-07-10 03:49:12 +1000, "André Hänsel" <andre@webkr.de said:

ImOk schrieb:

>is_dir ("./mysubdir/mysubsubdir" )

>
That only determines if ./mysubdir/mysubsubdir is a directory. It makes
no statement about whether it is a subdirectory of another directory.
>
is_dir('../../nosubdir) will return true (if the dir exits, of course),
although it is no subdir of the working dir.

Wouldn't you just try to open it as a directory from the context of the
parent and if it opens, then it's a subdir?

[André Hänsel]

Re: is_subdir

Mel schrieb:

On 2006-07-10 03:49:12 +1000, "André Hänsel" <andre@webkr.de said:
>

ImOk schrieb:

is_dir ("./mysubdir/mysubsubdir" )

That only determines if ./mysubdir/mysubsubdir is a directory. It makes
no statement about whether it is a subdirectory of another directory.

is_dir('../../nosubdir) will return true (if the dir exits, of course),
although it is no subdir of the working dir.

>
Wouldn't you just try to open it as a directory from the context of the
parent and if it opens, then it's a subdir?

If there were no ".."s in the world, that would work.
I would have to get some kind of temporary chroot, but that would
probably also dereference the symlinks.

But another idea:
There connot be an escaped slash in a path, can it?
What does a path like "dir\/subdir" mean?
a) a subdirectory of the current path named "dir/subdir"
b) a directory named "dir\" with a subdirectory named "subdir"
I think, it's answer b.

If that is true, it will be safe to just explode the path by "/",
traverse it and convert every "." to nothing and every ".." to "go one
step up" (if I am not already in /).

Right?

[ImOk]

Re: is_subdir

I am totally confused by this thread. What in the world are you trying
to do?
In my experience of development when the code starts getting weird,
then the original premise must be re-evaluated. Maybe you can write the
logic in pseudocode and post it here.

André Hänsel wrote:

Mel schrieb:

On 2006-07-10 03:49:12 +1000, "André Hänsel" <andre@webkr.de said:

ImOk schrieb:
>is_dir ("./mysubdir/mysubsubdir" )
>
That only determines if ./mysubdir/mysubsubdir is a directory. It makes
no statement about whether it is a subdirectory of another directory.
>
is_dir('../../nosubdir) will return true (if the dir exits, of course),
although it is no subdir of the working dir.

Wouldn't you just try to open it as a directory from the context of the
parent and if it opens, then it's a subdir?

>
If there were no ".."s in the world, that would work.
I would have to get some kind of temporary chroot, but that would
probably also dereference the symlinks.
>
But another idea:
There connot be an escaped slash in a path, can it?
What does a path like "dir\/subdir" mean?
a) a subdirectory of the current path named "dir/subdir"
b) a directory named "dir\" with a subdirectory named "subdir"
I think, it's answer b.
>
If that is true, it will be safe to just explode the path by "/",
traverse it and convert every "." to nothing and every ".." to "go one
step up" (if I am not already in /).

Right?