Adding position() function to File class and replacing FILE_TRUNCATE and FILE_APPEND with FILE_WRITE (SD library). Updating examples and keywords.txt accordingly.

Author: damellis

libraries/SD/File.cpp

@@ -55,6 +55,10 @@ boolean File::seek(uint32_t pos) {
   return SD.file.seekSet(pos);
 }
 
+uint32_t File::position() {
+  return SD.file.curPosition();
+}
+
 uint32_t File::size() {
   return SD.file.fileSize();
 }

libraries/SD/SD.cpp

@@ -297,6 +297,9 @@ boolean callback_openPath(SdFile& parentDir, char *filePathComponent,
   if (isLastComponent) {
     SDClass *p_SD = static_cast<SDClass*>(object);
     p_SD->file.open(parentDir, filePathComponent, p_SD->fileOpenMode);
+    if (p_SD->fileOpenMode == FILE_WRITE) {
+      p_SD->file.seekSet(p_SD->file.fileSize());
+    }
     p_SD->c = -1;
     // TODO: Return file open result?
     return false;

libraries/SD/SD.h

@@ -21,8 +21,7 @@
 #include <utility/SdFatUtil.h>
 
 #define FILE_READ O_READ
-#define FILE_TRUNCATE (O_WRITE | O_CREAT | O_TRUNC)
-#define FILE_APPEND (O_WRITE | O_CREAT | O_APPEND)
+#define FILE_WRITE (O_READ | O_WRITE | O_CREAT | O_SYNC)
 
 class File : public Stream {
 public:
@@ -34,6 +33,7 @@ class File : public Stream {
   virtual int available();
   virtual void flush();
   boolean seek(uint32_t pos);
+  uint32_t position();
   uint32_t size();
   void close();
   operator bool();

libraries/SD/examples/Datalogger/Datalogger.pde

@@ -59,8 +59,9 @@ void loop()
     }
   }
 
-  // open the file:
-  File dataFile = SD.open("datalog.txt", FILE_APPEND);
+  // open the file. note that only one file can be open at a time,
+  // so you have to close this one before opening another.
+  File dataFile = SD.open("datalog.txt", FILE_WRITE);
 
   // if the file is available, write to it:
   if (dataFile) {

libraries/SD/examples/Files/Files.pde

@@ -46,7 +46,7 @@ void setup()
 
   // open a new file and immediately close it:
   Serial.println("Creating example.txt...");
-  myFile = SD.open("example.txt", FILE_TRUNCATE);
+  myFile = SD.open("example.txt", FILE_WRITE);
   myFile.close();
 
   // Check to see if the file exists: 

libraries/SD/examples/ReadWrite/ReadWrite.pde

@@ -39,7 +39,7 @@ void setup()
   Serial.println("initialization done.");
 
   // open a file:
-  myFile = SD.open("test.txt", FILE_TRUNCATE);
+  myFile = SD.open("test.txt", FILE_WRITE);
 
   // if the file opened okay, write to it:
   if (myFile) {

libraries/SD/keywords.txt

@@ -19,11 +19,12 @@ remove	KEYWORD2
 rmdir	KEYWORD2
 open	KEYWORD2
 close	KEYWORD2
-
+seek	KEYWORD2
+position	KEYWORD2
+size	KEYWORD2	
 
 #######################################
 # Constants (LITERAL1)
 #######################################
 FILE_READ	LITERAL1
-FILE_TRUNCATE	LITERAL1
-FILE_APPEND	LITERAL1
+FILE_WRITE	LITERAL1