This example application shows, using a P.I.P.S. (P.I.P.S. Is POSIX on the Symbian platform) program, the restrictions on file access that are imposed by the Symbian platform Security model.
It shows that programs can access their own directories, but cannot,
without platform security capabilities not available to ordinary programs,
access the directories of other programs, or the system binary directory sys/bin.
This example defines an executable file with no platform security
capabilities. The program first creates its own secure directory that
it can write to and read from. It then attempts to use a file in a
private directory of another program, and then in sys/bin, and shows that these attempts are denied.
Click on the following link to download the example: FileAccessExample.zip
Click: browse to view the example code.
The following sections provide more information about the steps that the example performs.
Create a secure directory
The example creates an empty secure directory for the program by using the mkdir(const char *,mode_t) function.
This empty secure directory is created in C:\private\E80000C9, as 0xE80000C9 is a unique identifier for the program (as specified
by the third UID in its project file).
Write and read a file in the private directory
The example writes and reads a file in the secure directory using the fopen(const char *, const char *) and other file stream functions.
Write and read a file in the private directory of another program
The example attempts to write and read a file in the secure directory of another program.
The fopen() function is expected to return NULL, indicating that access is not possible, as the program has insufficient
platform security capabilities.
Write and read a file in the sys/bin directory
The example attempts to write and
read a file in the system's sys/bin directory,
where program binaries are stored.
Again, the fopen() function is expected to return NULL, indicating
that access is not possible, as the program has insufficient platform
security capabilities.
mkdir(const char *,mode_t)
fopen(const char *, const char *)
The example builds an executable called fileaccessexample.exe in the standard locations.
To run the example, start fileaccessexample.exe from the file system or from your
IDE. After launching the executable, depending on the emulator you
are using, you may need to navigate away from the application launcher
or shell screen to view the console.