MDK-ARM Keil, MDK-ARM Datasheet - Page 52

• Manufacturer Part Number: MDK-ARM
• Description: KIT REALVIEW MCU DEVELOPMENT
• Manufacturer: Keil
• Type: Compiler and IDEr

Specifications of MDK-ARM

• For Use With/related Products: ARM MCUs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

52
File I/O Routines
Once the file system has been configured, we can manipulate files.
To create a file, open a file on the volume and define a handler to it. This
handler, with which we can read and write to the file, is a pointer to the open file.
#include <stdio.h>
FILE *Fptr;
Include the
file and check that it has opened. fopen() requires a string for the file name and
an access attribute, which can be “w” write, “a” append, or “r” read.
Fptr = fopen ("Test.txt","w");
If the file cannot be created or opened, a NULL pointer is returned.
if (Fptr == NULL)
}
Once you have finished using the file, you must close it by calling fclose(). Up to
this point, all data written to the file is buffered in the heap space. When you
close the file, the data is written to the physical storage media. Consider this
carefully if you have multiple file streams or are storing large streams of data.
fclose (Fptr);
Once we have created a file, a number of functions help us work with it.
Function
fopen
fclose
fflush
Function
feof
ferror
fseek
ftell
rewind
…;
stdio.h
Description
Creates a new file or opens an existing file.
Writes buffered data to a file and then closes the file.
Writes buffered data to a file.
Description
Reports whether the end of the file stream has been reached.
Reports whether there is an error in the file steam.
Moves the file stream in pointer to a new location.
Gets the current location of the file pointer.
Moves the file stream in file pointer to the beginning of the file.
library to define our file handler as type FILE. Next, create a
{
// error handler
Chapter 3. RL-Flash Introduction