Persistent Storage

[stavrospapa]

Dear Developers,

since the private folder for each app is wiped-out on uninstall,
is there a really persistent and hidden folder for storing log files? (or maybe a registry)

thanks!
Stavros

[symbianyucca]

AFAIK, not really.

[yogpan]

Dear Developers,

since the private folder for each app is wiped-out on uninstall,
is there a really persistent and hidden folder for storing log files? (or maybe a registry)

thanks!
Stavros

Hi,
What kind of data you want to be persistent. The thing is whenever you uninstall the application whatever you have installed through your pkg file will be remmoved from the device.However, if you would have created any file in your application programmatically and not mentioned in the pkg file then on uninstalling that file will remain in the device untill removed manually.

[stavrospapa]

hi!

need to keep persistent a file that I create within my program, not through the pkg file.

AFAIK, private folder gets wipped out on uninstall.
and c:\data folder is freely accessible...

thanks

[yogpan]

Hi,
Yes you are correct. In case you are creating any file in your private folder of your application it will not remain there as during uninstallation it will remove the folder. But the other data space is still available but then your file is not secure and can be deleted manually also.

[stavrospapa]

thanks!
yes, "c:\" seems to be working fine.
the thing is that, how good practice is to store files there?
Such as files used in software licensting?

stavros

[yogpan]

Hi,
In C:\ directly ?? Not a good idea.. See the issue is anything stored under the pretext of persistent should be data caged that is secured from other applications in a sense that tommorow it should not happen some other application just manipulates with your file programmatically.

[sriky27]

Hi,

Why don't you use RFileLogger which usually stores the log files under c:\Logs folder where you could mention the folder under Logs to be used for logging. In this case even if your folder is removed c:\Logs will be there to store your logs.

[stavrospapa]

hi!
its documentation says that its not reliable, and requires some manual work.

anyhow, the situation does not change
and a proven method for hidding sensitive information
from other apps (even in the case of uninstalling the program)
remains, since the private folder is wiped-out.

and hiding files in the file system in arbitrary locations is like hiding behind your finger!

thanks 2 all
Stavros

[yogpan]

Hi,
Thats correct, but I guess if you are anyways uninstalling the application itself whats the use of keeping the data related to the application on the device, it is basically to keep the device clean from any unwanted footprints the application leaves after being uninstalled.

[skumar_rao]

hi!
its documentation says that its not reliable, and requires some manual work.

anyhow, the situation does not change
and a proven method for hidding sensitive information
from other apps (even in the case of uninstalling the program)
remains, since the private folder is wiped-out.

and hiding files in the file system in arbitrary locations is like hiding behind your finger!

thanks 2 all
Stavros

1. RFileLogger is not a solution.
2. You may not able to do what you want to do. [as told by yucca in #2 post]

[kiran10182]

I have few suggestions:

• Store such licensing files on public paths and give them some kind of system names. E.g: KernelLicense or something like that. Do not give common extension to such files. And you should store your data with some encryption algorithm so that it cannot be understood by end users.
• Keep your licensing strategy on some external server and authenticate your users with that server with GPRS connection.
• Use some SMS based licensing mechanism for above point in case you do not want to use GPRS connection.

[yogpan]

Hi,
good points suggested by Kiran but I guess the first point is still a vunerable option as the user can still delete the file or it can get wiped out on factory reset. Storing the information on some other location is a better option. May be you have to do some extra efforts in your application but your purpose can be solved with this approach.

[jas76]

Hi,

I had exactly same requirements discussed here http://discussion.forum.nokia.com/fo...d.php?t=143663 . How unfortunate is that 10 years in development and symbian hasn't provide any mechanism to handle obvious requirement for any application's trial period.

Yogpan

but I guess if you are anyways uninstalling the application itself whats the use of keeping the data related to the application on the device

If you give trial period to user he may uninstall and reinstall application to reuse trial period that's the reason developers need a mecahnism to store something persistently to avoid reuse of trial period.

Stavrospapa,

If you are looking because of same reason I explained above there could be workaround. I found one but due to sensitivity I can not share (not allowed from my company to share any license related detail though the project is abondend). Only hint I can give is look something that is stored systemwide in data caging.

This could have been easily handled by symbian team to provide a API by which it can be checked if an Application with UID xxxx is ever installed on phone or not.

[wizard_hu_]

How unfortunate is that 10 years in development and symbian hasn't provide any mechanism to handle obvious requirement for any application's trial period.

Can you name any other operating system which has "support" for trials?

If you give trial period to user he may uninstall and reinstall application to reuse trial period that's the reason developers need a mecahnism to store something persistently to avoid reuse of trial period.

There is no such thing as "persistent" from this point of view. Phone can be re-formatted, re-flashed. PC can be re-installed, but in the age of VirtualPC, VMWare, VirtualBox things are getting easier than that.