int ff_findnext( FF_FindData_t *pxFindData );
Finds the next file or directory within an embedded FAT file system directory. ff_findnext() can only be called after first calling ff_findfirst(). ff_findfirst() finds the first file in the directory, ff_findnext() then finds all subsequent files in the directory.
The same instance of the FF_FindData_t object must be passed into ff_findnext() as was passed into ff_findfirst().
FF_FindData_t contains the fields shown in the table below:
|
Field
|
Description
|
| pcFileName | The name of the file |
| ulFileSize | The length of the file in bytes |
| ucAttributes |
The file's attributes, which is a bitwise OR of the following
bit definitions:
|
Parameters:
| pxFindData | A pointer to a structure that is used to store information required to scan a directory, and to pass out details of the files contained in the directory. |
If a file or directory was found then 0 is returned. If an error occurs a non-zero value is returned.
Example usage:
void DIRCommand( const char *pcDirectoryToScan ) { FF_FindData_t *pxFindStruct; const char *pcAttrib; *pcWritableFile = "writable file", *pcReadOnlyFile = "read only file", *pcDirectory = "directory"; /* FF_FindData_t can be large, so it is best to allocate the structure dynamically, rather than declare it as a stack variable. */ pxFindStruct = ( FF_FindData_t * ) pvPortMalloc( sizeof( FF_FindData_t ) ); /* FF_FindData_t must be cleared to 0. */ memset( pxFindStruct, 0x00, sizeof( FF_FindData_t ) ); /* The first parameter to ff_findfist() is the directory being searched. Do not add wildcards to the end of the directory name. */ if( ff_findfirst( pcDirectoryToScan, pxFindStruct ) == 0 ) { do { /* Point pcAttrib to a string that describes the file. */ if( ( pxFindStruct->ucAttributes & FF_FAT_ATTR_DIR ) != 0 ) { pcAttrib = pcDirectory; } else if( pxFindStruct->ucAttributes & FF_FAT_ATTR_READONLY ) { pcAttrib = pcReadOnlyFile; } else { pcAttrib = pcWritableFile; } /* Print the files name, size, and attribute string. */ FreeRTOS_printf( ( "%s [%s] [size=%d]", pxFindStruct->pcFileName, pcAttrib, pxFindStruct->ulFileSize ) ); } while( ff_findnext( pxFindStruct ) == 0 ); } /* Free the allocated FF_FindData_t structure. */ vPortFree( pxFindStruct ); } Example use of the ff_findfirst() API function create a directory listing