C / C++ / MFC

9-May-05 19:50

Changing file attributes for a file is no problem (e.g. using the SetFileAttributes() function).

Is there an equivalent for doing this for a directory?

Thanks in advance, hfr
Sigh | :sigh:

PS: if using SetFileAttributes() for a directory I get a HRESULT of 2 which means: file not found

David Crow10-May-05 2:19

10-May-05 2:19

This works for me:

if (! SetFileAttributes("c:\\ResOrg", FILE_ATTRIBUTE_READONLY))
{
    DWORD dwError = GetLastError();
}

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

hfrmobile10-May-05 3:22

10-May-05 3:22

Hi thanks for your reply!

Sorry, I was a bit inaccurately...

I am using RAPI version of SetFileAttributes() --> CeSetFileAttributes() because I need to do this on a remote device (on a Pocket PC running Windows CE)

It seems that there is a difference between SetFileAttributes() and CeSetFileAttributes().

CeSetFileAttributes() works fine for files but not for directories. The only thing I have found about this issue is that the .NET Compact Framework does not support changing attributes on directories... (files are supported).

Since the project is written in VC++ this should not matter...

CeSetFileAttributes() always returns false and CeGetLastError() returns 0x2 (file not found...)

Any idea why CeSetFileAttributes() does not work for directories?

thx

D'Oh! | :doh:

David Crow10-May-05 4:46

10-May-05 4:46

rubicon_hfr wrote:
Any idea why CeSetFileAttributes() does not work for directories?

No. I've no experience with CE or the .Net framework. What folder attribute are you wanting to alter? If I am reading the documentation correctly, it states that an application cannot change the attributes of a directory in the RAM file system. Does that apply to your situation?

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

hfrmobile10-May-05 5:08

10-May-05 5:08

I assume you mean ROM, not RAM?

Of course I do not try to alter attributes of a directory which is located in ROM. In this case I'll expect a "access denied" error...

I'd like to change directory's attributes which are located in RAM or on a storage card.

I can delete or rename the directories but I cannot change the "r" or "h" attribute...

David Crow10-May-05 5:15

10-May-05 5:15

rubicon_hfr wrote:
I assume you mean ROM, not RAM?

No, RAM was the intended word. See here.

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

hfrmobile10-May-05 9:05

10-May-05 9:05

Very interesting... thx!

This code (see comments) demonstrates what happens:

<br />
CeRapiInit();<br />
<br />
// "\\CF-Card\\Temp"<br />
// "\\SD-MMCard\\Temp"<br />
// "\\Temp\\Test"<br />
CString strFileName = "\\SD-MMCard\\Temp";<br />
<br />
wchar_t wcFileName[256];<br />
mbstowcs(wcFileName, strFileName, strFileName.GetLength()+1);<br />
<br />
DWORD dwAttributes = CeGetFileAttributes(wcFileName); // works always<br />
HRESULT hr = CeGetLastError();<br />
<br />
dwAttributes |= FILE_ATTRIBUTE_READONLY;<br />
<br />
// hr = 0x00000002 "The system cannot find the file specified." if dir is in RAM<br />
// hr = 0x00000005 "Access is denied." if dir is on storage card<br />
// this problems only occur using RAPI<br />
CeSetFileAttributes(wcFileName, dwAttributes);<br />
hr = CeGetLastError();<br />
<br />
CeRapiUninit();<br />

RAM: "The system cannot find the file specified." (ok, since MSDN says it is not supported

Storage Cards: "Access is denied." (also not supported? Cry | :((

)

hfrmobile12-May-05 21:00

12-May-05 21:00

FYI: Conclusion - setting file attributes for directories

I tried something and here are the results:

CeGetFileAttributes()
Worked for all devices.

CeSetFileAttributes()
Not worked on a PPC2002 device (Pocket PC)
Worked on a WM2003 device (Smartphone)

So it seems that this is only supported for devices using WM2003 or higner...

DTW

Jaymahinda9-May-05 18:39

Jaymahinda

9-May-05 18:39

I want to find a working Dynamic time warping algorithm in c++ to compare voice.

about "delete"

simon wan9-May-05 15:56

simon wan

9-May-05 15:56

......
char* p= new char[100];
...
//should I use
// delete p;
//or
// delete[] p;

PJ Arends9-May-05 16:09

PJ Arends

9-May-05 16:09

delete[]

new -> delete
new[] -> delete[]

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04

Within you lies the power for good - Use it!

Honoured as one of The Most Helpful Members of 2004

Jörgen Sigvardsson10-May-05 1:46

Jörgen Sigvardsson

10-May-05 1:46

I'd like to stress PJ's point that you should *always* use delete [] with new []. Otherwise strange things will happen. Trust me. Smile | :)

--
Schni Schna Schnappi! Schnappi Schnappi Schnapp!

Nemanja Trifunovic10-May-05 3:58

Nemanja Trifunovic

10-May-05 3:58

I'd suggest he (almost) never uses new[] and delete[] and make use of container classes instead. Here is why[^]

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

hfrmobile12-May-05 21:05

12-May-05 21:05

I allways used delete regardless if used new or new[]

...it worked fine (and I see no reason why it should not...)

<br />
byte buffer[4] = new byte[4]; // 4 bytes<br />
DWORD dw4Bytes = new DWORD[1]; // 4 bytes<br />
<br />
...<br />
<br />
delete buffer;  // releases 4 bytes<br />
delete dw4Bytes; // releases 4 bytes<br />

Nemanja Trifunovic13-May-05 3:56

Nemanja Trifunovic

13-May-05 3:56

rubicon_hfr wrote:
...it worked fine (and I see no reason why it should not...)

Because for one thing, your example is not exception-safe. If in the "..." code an exception is thrown, you'll end up with a memory leak.

My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.

hfrmobile16-May-05 20:35

just finished my 2d game engine

16-May-05 20:35

Because for one thing, your example is not exception-safe. If in the "..." code an exception is thrown, you'll end up with a memory leak.

Since the topic has the subject "about delete" I only mention that there is no difference between delete and delete[].

You may assume that "..." stands for the following:

<br />
try<br />
{<br />
  // do something meaningful<br />
}<br />
catch (...)<br />
{<br />
}<br />

Of course you can use finally to free memory... Rose | [Rose]

Or you just use a wrapper class which ctor does this for you (so you can't forget)...

Or use managed C++ Laugh | :laugh:

tom_dx9-May-05 14:56

tom_dx

9-May-05 14:56

at least to an extent were its working Smile | :)

took me 30min - 1hr to write it, had 1 bug but fixed it with debugging in under 3 sec. flat!!! Smile | :)

so exciting but I came across a wierd error, when i just used "D3DXVECTOR3(x, y, 0)" in one of the location parameters in the ID3DXSPRITE interface, Draw() to be exact, it wouldn't accept it, but then i tried "&D3DXVECTOR3(x, y, 0)" and it worked, what am i misunderstanding here, D3DXVECTOR3 is type struct by the way D'Oh! | :doh:

IM PROUD TO BE A GMAIL;

Re: just finished my 2d game engine

Christian Graus9-May-05 15:22

Christian Graus

9-May-05 15:22

tom_dx wrote:
but then i tried "&D3DXVECTOR3(x, y, 0)" and it worked, what am i misunderstanding here, D3DXVECTOR3 is type struct by the way

Simple, a struct is completely different to a pointer.

tom_dx wrote:
IM PROUD TO BE A GMAIL;

So was I, until my mail started to disappear.

Christian Graus - Microsoft MVP - C++

Re: just finished my 2d game engine

tom_dx10-May-05 12:20

tom_dx

10-May-05 12:20

whoops

have to break out my C++ reference Smile | :)

IM PROUD TO BE A GMAIL;

Looking for calendar control

David Crow9-May-05 10:20