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POSIX Directory Browsing API for Windows

The functions and types specified in POSIX for iterating over directory entries have been defined here as wrappers for porting to and common use on Windows platforms. The values of errno set in the event of errors are the most significant difference between the POSIX definition and the wrapper API.

In addition to this documentation file, the software is provided in the dirent.h header file and the dirent.c C source file. To use the API ensure that the path to the dirent.h header is either somewhere standard or is provided to the compiler as an additional option. Ensure also that the dirent.c file is compiled and the object file is either referenced explicitly in the link or included in a referenced library. The source code also compiles cleanly as C++, but it retains C linkage.

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<dirent.h>

typedef ... DIR;struct dirent{    char *d_name;};DIR           *opendir(const char *name);int            closedir(DIR *dir);struct dirent *readdir(DIR *dir);void           rewinddir(DIR *dir);

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DIR *opendir(const char *name);

Description

The opendir function opens the directory specified by name, which may use either / or \ as a directory separator but should not contain any wildcards. On success it associates a DIR stream with the open directory. A non-null DIR stream may be used in subsequent calls to readdir,rewinddir and closedir.

A successful result will position the DIR stream at the first directory entry, ready for reading. Note that a truly empty directory (one without even . or .. entries) will not open successfully.

Returns

A pointer to the DIR structure for the opened directory on success, otherwise null on failure.

Errors

ENOENT   No such directory.
EINVAL   Invalid argument or directory name.
ENOMEM   Not enough memory to perform the operation.

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int closedir(DIR *dir);

Description

The closedir function closes the directory stream associated with dir, freeing resources as necessary and invalidating the dir pointer.

Returns

Returns 0 on successful completion, otherwise -1.

Errors

EBADF    Invalid directory stream.

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struct dirent *readdir(DIR *dir);

Description

The readdir function is used to iterate through the directory stream dir. It advances it one entry at a time, details of which it returns as its result.

On NTFS and FAT file systems, except for drive root directories, the caller is guaranteed that the . and .. entries will be included in the directory stream. On FATX file systems the . and .. entries are not included.

Returns

Returns a pointer to the directory details on success, in which d_name is the file name of the current entry, otherwise null on error or end of stream.

Errors

ENOENT   No more entries.
EBADF    Invalid directory stream.

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void rewinddir(DIR *dir);

Description

The rewindir function can be used to reset the directory stream dir to the start. Sensible results cannot be guaranteed if the directory name used in the initial call to opendir was a relative path name and the program has since changed its current working directory.

Returns

No error status is returned.

Errors

EBADF    Invalid directory stream.

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For Unix/Linux based systems:

You can use opendir / readdir / closedir.

Sample code which searches a directory for entry ``name'' is:

   len = strlen(name);   dirp = opendir(".");   while ((dp = readdir(dirp)) != NULL)           if (dp->d_namlen == len && !strcmp(dp->d_name, name)) {                   (void)closedir(dirp);                   return FOUND;           }   (void)closedir(dirp);   return NOT_FOUND;

Source code from the above man pages.

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For a windows based systems:

you can use the Win32 API FindFirstFile / FindNextFile / FindClose functions.

The following C++ example shows you a minimal use of FindFirstFile.

#include <windows.h>#include <tchar.h>#include <stdio.h>void _tmain(int argc, TCHAR *argv[]){   WIN32_FIND_DATA FindFileData;   HANDLE hFind;   if( argc != 2 )   {      _tprintf(TEXT("Usage: %s [target_file]\n"), argv[0]);      return;   }   _tprintf (TEXT("Target file is %s\n"), argv[1]);   hFind = FindFirstFile(argv[1], &FindFileData);   if (hFind == INVALID_HANDLE_VALUE)    {      printf ("FindFirstFile failed (%d)\n", GetLastError());      return;   }    else    {      _tprintf (TEXT("The first file found is %s\n"),                 FindFileData.cFileName);      FindClose(hFind);   }}

Source code from the above msdn pages.