Store Files Persistent; Cannot write to hardlinked folder?

[Frank_W]

Hi, I hardlink an external folder for my application, but I cannot access it.

.adef-File:
requires:{
dir:
{
[rw] /home/root/ar_extern /home/data
}
}

.cdef-File:
requires:{
dir:
{
[rw] /home/root/ar_extern /home/data
}
}

Original Folder is in /home/root/ar_extern
ls -lsa /home/root/
0 drwxr-xr-x 4 root root 376 Jun 19 14:08 .
0 drwxr-xr-x 3 root root 224 Jan 1 1970 …
4 -rw------- 1 root root 2536 Jun 19 15:02 .ash_history
0 drwxrwxrwx 2 root root 160 Jun 19 14:39 ar_extern
0 drwxr-xr-x 2 root root 384 Jun 19 12:20 backup_ar

Hard Link is properly created:
ls -lsa /legato/systems/current/appsWriteable/initTests/h
ome/
0 dr-x—r-x 3 root root 224 Jun 19 14:42 .
0 dr-x—rwx 10 root root 672 Jun 19 14:42 …
0 drwxrwxrwx 2 root root 160 Jun 19 14:39 data

As you can see, access rights are 777, so everyone should be able to do anything.

In SourceCode (.cpp) I tried the following paths:

• home/data/ag_ids.json
• /home/data/ag_ids.json
• ./home/data/ag_ids.json

None of those created a file

The writeFile works, when writing to “ag_ids.json”, the file is created in the root folder.
Storing files in the root-Folder of the application /legato/system/current/appsWritable/initTests/ works but is removed whenever I reinstall my app. I need the file to be persistent

Any idea what I might do wrong or are there any further questions?

Legato Framework Version: 18.10.02

Thank you and best regards

Frank

[jyijyi]

Here says you can use unsandboxed application to create file

File IO operations

What is the correct way to create a file from within a Legato application ? We need to create and save a configuration file during the application initialization, however, any and all attempts to create, open, read, write, and even close the file fail. The result is always a null file pointer or a return value of LE_FAULT. I have tried : a) FILE *fp = fopen( filename, “rw”) b) int fd = open(filename, O_RDWR); c) int fd = le_flock_open(filename, LE_FLOCK_READ); d) int fd = le_atomFile_Open…

[Frank_W]

Thanks for the answer, but an unboxed application raises some potential threats for the system that I would like to avoid. That’s why I only want 1 shared folder.

[jyijyi]

Here suggests to create file outside sandbox and give app access to it in adef file,

How to write data to a file outside sandbox

Hi Alegato, Could you please elaborate your answer a bit more? I’ve tried to create file outside sandbox and give app access to it in adef file, but it still says that my file is read only

[Frank_W]

Thanks jyijyi, I fixed it by creating a second app that is not sandboxed. Not perfect, but it works