On Apr 10, 2013, at 8:37 PM, Thiago Macieira <[email protected]> wrote:

> Yes, there's a way. To tell you the truth, I was wondering if it could be 
> done 
> in C++ with only the Standard Library. I've recently done that (qtchooser) 
> and 
> it wasn't very pleasant. And especially there's one snag for Windows: listing 
> directories. Somehow, after all these years this is not a standard API in the 
> C or C++ standard libraries, so you'd have to write the POSIX code and the 
> Win32 code for it.

Actually if you look in the QFileEngine it is quite easy to extract that code 
out for listing directories and make is NOT dependent on Qt but only C or stuff 
that comes with Visual Studio. I know because I had to do it for a project. The 
GPL license made me chuck it though. So in reality this should not be a show 
stopper. I'd be happy to donate the code that I did have. It mimics the Qt API 
as much as it could.

  And I have lots of questions as to why any of this is even necessary but 
those are for another conversation.

Cheers
---
Mike J


/*

    Implementation of POSIX directory browsing functions and types for Win32.

    Author:  Kevlin Henney ([email protected], [email protected])
    History: Created March 1997. Updated June 2003.
    Rights:  See end of file.

*/

#include "dirent.h"
#include <errno.h>
#include <io.h> /* _findfirst and _findnext set errno iff they return -1 */
#include <stdlib.h>
#include <string.h>

#ifdef __cplusplus
extern "C"
{
#endif

struct DIR
{
    long                handle; /* -1 for failed rewind */
    struct _finddata_t  info;
    struct dirent       result; /* d_name null iff first time */
    char                *name;  /* null-terminated char string */
};

DIR *opendir(const char *name)
{
    DIR *dir = 0;

    if(name && name[0])
    {
        size_t base_length = strlen(name);
        const char *all = /* search pattern must end with suitable wildcard */
            strchr("/\\", name[base_length - 1]) ? "*" : "/*";

        if((dir = (DIR *) malloc(sizeof *dir)) != 0 &&
           (dir->name = (char *) malloc(base_length + strlen(all) + 1)) != 0)
        {
            strcat(strcpy(dir->name, name), all);

            if((dir->handle = (long) _findfirst(dir->name, &dir->info)) != -1)
            {
                dir->result.d_name = 0;
            }
            else /* rollback */
            {
                free(dir->name);
                free(dir);
                dir = 0;
            }
        }
        else /* rollback */
        {
            free(dir);
            dir   = 0;
            errno = ENOMEM;
        }
    }
    else
    {
        errno = EINVAL;
    }

    return dir;
}

int closedir(DIR *dir)
{
    int result = -1;

    if(dir)
    {
        if(dir->handle != -1)
        {
            result = _findclose(dir->handle);
        }

        free(dir->name);
        free(dir);
    }

    if(result == -1) /* map all errors to EBADF */
    {
        errno = EBADF;
    }

    return result;
}

struct dirent *readdir(DIR *dir)
{
    struct dirent *result = 0;

    if(dir && dir->handle != -1)
    {
        if(!dir->result.d_name || _findnext(dir->handle, &dir->info) != -1)
        {
            result         = &dir->result;
            result->d_name = dir->info.name;

        }
    }
    else
    {
        errno = EBADF;
    }

    return result;
}

void rewinddir(DIR *dir)
{
    if(dir && dir->handle != -1)
    {
        _findclose(dir->handle);
        dir->handle = (long) _findfirst(dir->name, &dir->info);
        dir->result.d_name = 0;
    }
    else
    {
        errno = EBADF;
    }
}

#ifdef __cplusplus
}
#endif

/*

    Copyright Kevlin Henney, 1997, 2003. All rights reserved.

    Permission to use, copy, modify, and distribute this software and its
    documentation for any purpose is hereby granted without fee, provided
    that this copyright and permissions notice appear in all copies and
    derivatives.

    This software is supplied "as is" without express or implied warranty.

    But that said, if there are any problems please get in touch.

*/

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