Hiya, Is it possible for an app to get read and write access to the /tmp directory to store intermediate and volatile data files? I’ve tried require:'ing the /tmp directory into my app in the adef file - both as sandboxed and unsandboxed. I’ve also tried simply creating a file in /tmp as an unsan…

Hi Dave, May I ask which Legato/product you are using? In my case, I can read/write to /tmp/test.txt whenever app is not run inside sandbox, as expected I don’t even need to specify in requires section. Thx

Hi Lotam, I’ve been testing against a WP7702 with Legato 18.05.1 installed. I was also somewhat confused about not being able to write to /tmp in an unsandboxed app. Quite literally, all my code does is the following: #include "legato.h" #include "interfaces.h" /* include auto-generated api inte…

Hi Dave, Thanks for the code snippet. It works quite well on my WP77 18.05.1 as I marked “sandboxed: false” in .adef. Below the .adef and test log: executables: { helloWorld = ( helloComponent ) } processes: { envVars: { LE_LOG_LEVEL = DEBUG } run: { ( helloWorld ) } } sandboxed…

Hi, I’m having the same issue with sandboxed apps. If the app is not sandboxed the access to /tmp is no problem, but a sandboxed app cannot open the required file in read mode. In the .adef requires: { dir: { /tmp /tmp /proc /proc /home /home } file: { …

you can see here: [image] Opening Files in Sandboxed App I read through it and tried changing the permissions, but i still can’t even read the file. Do i need to add something else except requires: { file: { /tmp/test.txt /tmp/ } } in order to read it?

Unfortunatelly, that doesn’t work, because /tmp/alive does not exist when the app tries to start and therefore, the requires condition is not fulfilled which means that the whole app cannot start properly. So I don’t even get to the point where fopen is called. Also, after the file has been created …

you can create the file in the init script: [image] Adding scripts to run at startup Legato Linux distribution (Yocto project) I just tried on WP76 R9, I found that modifying mount_early is not working. Instead I modify /etc/init.d/startlegato.sh, and I can add my command…

Can startlegato.sh be included into the package that is being installed via /legato/systems/current/bin/update? Because we don’t want to have to add specific files manually to the device. Also this wouldn’t solve the problem, that the file can obviously not be read.

modified startlegato.sh should be stored in /mnt/flash/ufs/etc/init.d/startlegato.sh then why don’t you add an unsandboxed application to create the file during each power on?

We already have this kind of process. The file however, as mentioned above, cannot be accessed in read-mode for some reason. Please try it in one of your test apps. Maybe I’m doing something wrong or missed something that prevents me from accessing the file from a sandboxed app. Because I just tried…

App access to /tmp

Legato Application Framework

jyijyi March 2, 2023, 4:45pm 6

you can see here:

Topic		Replies	Views
How to write to /tmp from legato app Legato Application Framework	1	219	March 22, 2023
Opening Files in Sandboxed App Uncategorized	3	1028	November 30, 2020
SD card access, path/directory Uncategorized	35	1687	February 27, 2020
Problem in Acessing files from sandbox Uncategorized	8	68	January 27, 2026
How to write data to a file outside sandbox Legato Application Framework	13	5051	October 21, 2021

App access to /tmp

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