Reported by David Cuartielles, Feb 17, 2010

<p>Hey there, I just got the MicroSD module for Arduino and 
used the SDuFAT
library on it. I think I found and fixed one bug, made one change 
that
probably makes it better and have a couple of requests so here
goes:</p><p> </p><p>1 - File SDuFAT.cpp in 
function append(const char*
filename), the original code exits the function with
statement:</p><p>return print("hola.txt",
data);</p><p> </p><p>I think you meant to 
write:</p><p>return
print(filename, data);</p><p> </p><p>I 
changed it and now your example
code works (for cases W and A) even with files which are not named
"hola.txt".</p><p> </p><p>2 - File 
SDuFAT.cpp in function
del(const char* filename), the code just reads all of a file's 
sectors and
dumps a zero at the start of each. This is OK for small files. 
However, I
am using a whole 2 Gb SD card containing one big file with 0x03 at 
the end
for generic logging data storage. Deleting the whole thing is 
probably
going to take a couple of centuries and is unnecessary 99% of the 
time
since the card will practically never fill up. So, I changed the 
line where
the zero gets written to the start of the sector 
from:</p><p>buffer[0] =
EOF;</p><p> </p><p>to</p><p>if 
(buffer[0] == EOF) {</p><p> 
return 0;</p><p>} else {</p><p>  buffer[0] =
EOF;</p><p>}</p><p> </p><p>in 
order to only delete the written part of
the file.</p><p> </p><p>I could have made 
some grave error (I 'm a
Java programmer so C++ is totally new to me) but if I got things 
right, I
think both these changes are in line with the spirit of the library 
which
should be updated for useability asap. Change 2 might perhaps need a
separate function or whatever.</p><p> 
</p><p>Now, the feature
requests. Could you please add a couple of functions for 
repositioning the
file counter? Right now, if we have a file and want to overwrite its 
data
we have to delete it using "del" (might be time consuming 
and
unnecessary). Could you please add a couple of functions for dumping 
the
counter at an arbitrary position in the file (or at the very least,
something like rewind() for going to the first byte and starting to 
write
from there onwards)? I looked at function print(const char* 
filename, char*
data) which looks like a good candidate for that sort of thing and 
it looks
like the lines:</p><p>// check where to start writing in 
the file<br />//
these calls will init sector and length<br />int offset1 = 
0;<br />long
file1Length = usedBytes(filename);<br />offset1 = (int) 
(file1Length %
BYTESPERSECTOR);<br />sectors = file1Length /
BYTESPERSECTOR;</p><p> </p><p>are what I 
should be playing with but I
'm not confident with C++ and I 'm afraid of breaking
things.</p><p> </p><p>Thanks.</p>