Unhandled exception using directory_iterator

[Silvio Reis Junior]

Hello friends!
I'm trying to use directory_iterator but when I try to list recursivelly an
entire drive or a big directory I get an unhandled exception.
I'm trying to figure out if I did something wrong but the code is very
similar to the example on the boost web page.
Here is the code:

//-------------------------------------------------------------------
VOID CFileSearch::InternalSearch( path RootDir )
{
directory_iterator EndDirItr;
for ( directory_iterator DirItr( RootDir ); DirItr != EndDirItr;
++DirItr )
{
if ( is_regular( DirItr->status() ) )
{
_tprintf( "FILE: %s\n", DirItr->path().string().c_str() );
}
else if ( is_directory( DirItr->status() ) )
{
_tprintf( "DIR : %s\n", DirItr->path().string().c_str() );
InternalSearch( DirItr->path() );
}
}
}

//-------------------------------------------------------------------
VOID CFileSearch::Search( string RootDir )
{
path TempRootDir = system_complete( path( RootDir, native ) );
if ( exists( TempRootDir ) == true )
{
InternalSearch( TempRootDir );
}
}

//-------------------------------------------------------------------
CFileSearch FileSearch;
FileSearch.Search( "c:\\" );

Is there something wrong in the above code?
Thank you in advance.
Silvio.

[Ovanes Markarian]

Hi!

Just a question:
Did you run your code in debugger to see why it fails?


And an idea from the scratch, what happens if the directory found is either
. or ..? May be you should skip them?



Best Regards,
Ovanes

Post by Silvio Reis Junior
Hello friends!
I'm trying to use directory_iterator but when I try to list recursivelly
an entire drive or a big directory I get an unhandled exception.
I'm trying to figure out if I did something wrong but the code is very
similar to the example on the boost web page.
//-------------------------------------------------------------------
VOID CFileSearch::InternalSearch( path RootDir )
{
directory_iterator EndDirItr;
for ( directory_iterator DirItr( RootDir ); DirItr != EndDirItr;
++DirItr )
{
if ( is_regular( DirItr->status() ) )
{
_tprintf( "FILE: %s\n", DirItr->path().string().c_str() );
}
else if ( is_directory( DirItr->status() ) )
{
_tprintf( "DIR : %s\n", DirItr->path().string().c_str() );
InternalSearch( DirItr->path() );
}
}
}
//-------------------------------------------------------------------
VOID CFileSearch::Search( string RootDir )
{
path TempRootDir = system_complete( path( RootDir, native ) );
if ( exists( TempRootDir ) == true )
{
InternalSearch( TempRootDir );
}
}
//-------------------------------------------------------------------
CFileSearch FileSearch;
FileSearch.Search( "c:\\" );
Is there something wrong in the above code?
Thank you in advance.
Silvio.
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[dizzy]

Post by Silvio Reis Junior
Hello friends!

Hi

Post by Silvio Reis Junior
I'm trying to use directory_iterator but when I try to list recursivelly an
entire drive or a big directory I get an unhandled exception.
I'm trying to figure out if I did something wrong but the code is very
similar to the example on the boost web page.

I have used directory_iterator many times for recursive traversals, no issues
so far.

Post by Silvio Reis Junior
//-------------------------------------------------------------------
VOID CFileSearch::InternalSearch( path RootDir )
{
directory_iterator EndDirItr;
for ( directory_iterator DirItr( RootDir ); DirItr != EndDirItr;
++DirItr )
{
if ( is_regular( DirItr->status() ) )
{
_tprintf( "FILE: %s\n", DirItr->path().string().c_str() );
}
else if ( is_directory( DirItr->status() ) )
{
_tprintf( "DIR : %s\n", DirItr->path().string().c_str() );
InternalSearch( DirItr->path() );
}
}
}

So you have a recursive algorithm. One thing that comes straight into my mind
(especially for big structures) is the depth of the calls. Try to rewrite it
iteratively and see if it still happens. Also, not sure on Windows (which you
seem to be using) but on POSIX doing that is surely a problem because
directory_iterator does follow symbolik links and thus one can easily create
an infinite depth loop.

I also sugest that if your intentation is to recurse then just use
recursive_directory_iterator directly (still pay attention to symlinks,
call .no_push() on them so recursive_directory_iterator does not follow them
through).

[Ovanes Markarian]

This is what I was going to mention in my post with . and .. special
directories. With the approach used the infinite loop should happen already
with the first occurence of .-directory, which would recurse in the same
directory and find the first item (.-dir again).


Greetings,
Ovanes

Post by dizzy

Post by Silvio Reis Junior
Hello friends!

Hi

Post by Silvio Reis Junior
I'm trying to use directory_iterator but when I try to list recursivelly

an

Post by Silvio Reis Junior
entire drive or a big directory I get an unhandled exception.
I'm trying to figure out if I did something wrong but the code is very
similar to the example on the boost web page.

I have used directory_iterator many times for recursive traversals, no issues
so far.

Post by Silvio Reis Junior
//-------------------------------------------------------------------
VOID CFileSearch::InternalSearch( path RootDir )
{
directory_iterator EndDirItr;
for ( directory_iterator DirItr( RootDir ); DirItr != EndDirItr;
++DirItr )
{
if ( is_regular( DirItr->status() ) )
{
_tprintf( "FILE: %s\n", DirItr->path().string().c_str() );
}
else if ( is_directory( DirItr->status() ) )
{
_tprintf( "DIR : %s\n", DirItr->path().string().c_str() );
InternalSearch( DirItr->path() );
}
}
}

So you have a recursive algorithm. One thing that comes straight into my mind
(especially for big structures) is the depth of the calls. Try to rewrite it
iteratively and see if it still happens. Also, not sure on Windows (which you
seem to be using) but on POSIX doing that is surely a problem because
directory_iterator does follow symbolik links and thus one can easily create
an infinite depth loop.
I also sugest that if your intentation is to recurse then just use
recursive_directory_iterator directly (still pay attention to symlinks,
call .no_push() on them so recursive_directory_iterator does not follow them
through).
--
"Linux is obsolete" -- AST
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[dizzy]

Post by Ovanes Markarian
This is what I was going to mention in my post with . and .. special
directories. With the approach used the infinite loop should happen already
with the first occurence of .-directory, which would recurse in the same
directory and find the first item (.-dir again).

No because boost::filesystem directory iterators do not expose (ie
automatically skip) "." and "..".

[Silvio Reis Junior]

Hello folks!
Sorry for the late reply. I found what was wrong.
boost::filesystem directory_iterator throws an exception when access is
denied for a folder.
So I need to create a check for this before recursing into any folder.

Thanks for the replies!
Silvio

Post by Ovanes Markarian

Post by Ovanes Markarian
This is what I was going to mention in my post with . and .. special
directories. With the approach used the infinite loop should happen

already

Post by Ovanes Markarian
with the first occurence of .-directory, which would recurse in the same
directory and find the first item (.-dir again).

No because boost::filesystem directory iterators do not expose (ie
automatically skip) "." and "..".
--
"Linux is obsolete" -- AST
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Boost-users mailing list
http://lists.boost.org/mailman/listinfo.cgi/boost-users

[Igor R.]

The exception doesn't have some message saying "access denied"?

Hello folks!> Sorry for the late reply. I found what was wrong. > boost::filesystem directory_iterator throws an exception when access is denied for a folder.> So I need to create a check for this before recursing into any folder.> Thanks for the replies!> Silvio

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[Silvio Reis Junior]

I haven't seen it. Just unhandled exception.

Post by Igor R.
The exception doesn't have some message saying "access denied"?
------------------------------

Post by Silvio Reis Junior
Hello folks!
Sorry for the late reply. I found what was wrong.
boost::filesystem directory_iterator throws an exception when access is

denied for a folder.

Post by Silvio Reis Junior
So I need to create a check for this before recursing into any folder.
Thanks for the replies!
Silvio

------------------------------
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[Ovanes Markarian]

Yes, directory iterator does not explain the error cause. I did the same
experience as well. But in some other context. As far as I remember it was
smth like trying to traverse the directory path which did not exist.
Directory iterator also threw an exception with directory iterator string.

Post by Silvio Reis Junior
I haven't seen it. Just unhandled exception.

Post by Igor R.
The exception doesn't have some message saying "access denied"?