header_file.h
long f_read( const void *pvBuffer, long lSize, long lItems, F_FILE *pxFileHandle );
Reads data from the current read/write position of an open FAT file. The current file
read/write position is incremented by the number of bytes read.
A file can only be read if it was opened with one of the following
option strings: "r", "r+", "w+" or "a+" (see f_open()).
Parameters:
pvBuffer
|
A pointer to the buffer into which the read data will be
copied.
|
lSize
|
The size in bytes of the item being read from the file.
|
lItems
|
The number of items being read from the file (the size
of each item being set by the lSize parameter).
|
pxFileHandle
|
The handle of the file from which the data is being read.
The handle is returned by the call to f_open() used to
originally open the file.
|
Returns:
Any value
|
The returned value is the number of items that were
successfully read from the file.
|
See also
f_getc()
Example usage:
int vSampleFunction( char *pcFileName, char *pucBuffer, long lBufferSize )
{
F_FILE *pxFile;
long lSize, lRead = 0L;
pxFile = f_open( pcFileName, "r" );
if( pxFile != NULL )
{
lSize = f_filelength( pcFileName );
if( lSize > lBufferSize )
{
lSize = lBufferSize;
}
lRead = f_read( pucBuffer, 1, lSize, pxFile );
if( lRead == lSize )
{
}
f_close( pxFile );
}
return lSize;
}
Example use of the f_read() API function
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