I have two Android system users configured.

$ pm list users
Users:
	UserInfo{0:Owner:13} running
	UserInfo{10:security space:13} running
	UserInfo{999:XSpace:800010} running

When the mobile is running at Android 8.1, I can access the secondary user's space /storage/emulated/10 easily in adb shell. But after I upgrade to Android 9, I can no longer do it:

$ ls /storage/emulated/10
ls: /storage/emulated/10: Permission denied

Any ideas how I can access my second user's space in adb shell? Btw, my /sdcard/ always points to the first user's space /storage/emulated/0 at adb shell regardless what my current user is at mobile UI. The adb shell connection remains the same when I switch users at mobile UI too. When I switch users at mobile UI level, my adb connection remains the same. And I do see the current user changes with the following command:

$ dumpsys activity | grep mCurrentUser
    mCurrentUser=0
$ dumpsys activity | grep mCurrentUser
    mCurrentUser=10

I have an issue with file permission in Termux. For instance, I installed c4droid and copied the Termux /include and /lib folders content in the /c4droid folder where the headers are being looked for at compilation. I changed the owner and group to the correct name and mode to 777, but at compilation, it says "cannot open ****.h permission denied". Same thing with a worldlist that comes from the SD card that I put on a folder meant to be used with hydra, not only have I have to use root access to unzip the file and move it around, but hydra itself can't open it. What is this so important thing that I am missing about Termux and filed ownership and permissions?

I'm using Android 6. I'm trying to copy a file from /storage/emulated/0/test.txt to /cache/SH_DIR/ via an Android user application, and I'm getting the following error: java.io.FileNotFoundException: /cache/SH_DIR/test.txt: open failed: EACCES (Permission denied) When I build the application as a system application (included as part of AOSP), I'm able to copy the file to /cache/SH_DIR/. Do I need to modify the SEpolicy to allow a user application to copy files to /cache/SH_DIR/? Any help would be appreciated.

How to modify the files in subfolders of android/data on android 14, I tried shizuku + ZArchiver or FV file explorer and it doesn't work, i connected my phone to my computer and tried to edit files from there also using adb and it doesn't work, I tried the files app by Marc and used splitscreen but even that doesn't work. Is there a way to modify (specifically push files into android/data) **not just read** the files, as even before trying shizuku or all these I could already view the files and copy them out of android/data, but I couldn't copy anything in, or edit or delete anything. To clarify I am talking about the /sdcard/android/data folder not /data/data and I need a way push files in, I could already view and pull files out from before

I've tried different file managers on this Android TV 10, but none of them is able to write on the external memory. In the past and other Android TVs, I have written on external storage without this hassle. On Settings, I've granted "Storage" permissions to all the file managers. For example, CX Explorer showed an overlay window with information about the process to grant access to SD in a supposed next window, but no window was open to do these actions. Has Google imposed restrictions on writing on Android TV 10? What can I do?

I know it sounds like a recurring topic, but I would really like to know how to modify the contents of the Data folder in Android 14. I am currently using a Xiaomi 14T that has HyperOS (1.0.8.0.UNEMIXM) and Android 14 UP1A.231005.007. I have used tools like Shizuku and they have not worked for me, nor can I get that menu to appear to give permissions to a certain file explorer, since the Data folder simply does not appear. For example, I have used Super File Manager Explorer, which allows me to see the Data folder, and all the content of the applications but it does not let me edit, delete or add anything. I do not want to become an expert in programming, because I am not, therefore I will not try to move or do strange processes that can damage my device, also I do not want to Root it because I have no idea how to do it, nor because of the issue of updating it manually and that method is known to leave smartphones in a loop, so Root is not an option. Does anyone know of a safe way to edit the data folder? I'm not very experienced in this area, but I thought of deleting the default "Files" app on the device, but I'm sure that would cause more than one problem. As I said, Shizuku didn't work for me with either the wireless or wired method.

How to prevent an app clearing its own data . Thats the 3rd time WhatsApp deleted its own data against Users wish. There can be a zillon reasons which I don't care . If the user does not clear data - then the data should be there. Is there anyway to implement that ? If I am rooted how about if I do this : busybox chattr +a +u /data/data/com.whatsapp You can append but cant delete files. will the app crash ? what happens. I want to ask before crashing anything that works. what if you do just +u u set : When such a file is deleted, its data is saved enabling the user to ask for its undeletion. In the latter case , if the app were to del. its data , I'd be able to restore it ? P.S. this is not your internal storage f2fs but its an ext4 file system since the data folder is linked to my SD card Partition.

I have a Samsung Galaxy A50 phone with Android 9 (I don't want to upgrade! Upgrade is not a matter of this question!) and an old file manager app of a great value (built not by me) that works just fine except it can't write to the external SD card inserted into the phone. A built-in app that came with the phone can write to the external SD card. On the other hand, the same phone model with Android 11 allows this very app to write to external SD card using the same mounting point (/storage/ALPHANUMERIC-SD-CARD-ID). I have read that the app has to request WRITE_EXTERNAL_STORAGE permission and this requires an access to the source code. This app wasn't built by me, so I can't change it. * Does it all mean that this behaviour was fixed in Android 11? * May be there are some hidden settings to enable external SD card write access?

I have a rooted Android 11. Using Termux, or Es File Explorer, I can see all the 284 directories in /data/data. Unfortunately, many file explorer apps (*with* root privileges, such as Total Commander, ZArchiver) can only see 2 folders : com.google.android.gms (don't know why), and their own data folder. I thought this was related to this , but apparently no since I granted the root privileges to both apps... How could I see all the folders in /data/data using (for example) Total Commander? Doing a chmod 755 in Termux? Or maybe there is a problem with these apps as if they they don't use root privileges if at least one folder/file is visible in "normal user" mode?

Via *Settings > Apps > Fayr > Permissions*, I can set various permissions for the Android app Fayr (i.e., Calendar, Camera, Contacts, Location, Notifications), and all of them have been set to permission granted. However, the one permission that the app actually requires to work properly is not even visible and, thus, cannot be granted: '*Files and media*'. Whenever I start Fayr, I receive the information "*Error! To access files or photos, enable access to local storage*". Through third-party permission manager apps (e.g., App Permission Manager or Permissions Manager Dashboard), I can see that the permission '*Files and media*' is listed for Fayr, yet these apps cannot activate that permission either. What is the correct way to solve this issue? (My Android info: One UI version: 6.0, Android version: 14)

I am using Samsung Galaxy S10+ on Android 12. From F-Droid, I have downloaded and installed Emacs. It can run directly on Android, not via Termux. In the internal storage of my phone, I have created a file /storage/emulated/0/WE_test01.txt. By using the X-plore text editor, I have written 2 lines:

asd
123

Then, this file is to be opened by Emacs. I hit on the Emacs icon and typed C-x C-f, and in the bottom line /storage/emulated/0/WE_test01.txt. The response of Emacs is > File is not readable What have I done wrong?

Something is basically pretty messed up on my phone. It looks like everything is running. But sometimes I can't open something or something crashes. The logcat shows a lot of permission denied. A simple example is com.oneplus.calculator: I don't notice anything wrong when operating it. But in the Logcat I see:

09-25 14:42:35.662 29331 13606 E libEGL  : error opening cache file /data/user_de/0/com.oneplus.calculator/code_cache/com.android.skia.shaders_cache: Permission denied (13)
09-25 14:42:35.675 29331 13606 E libEGL  : error opening cache file /data/user_de/0/com.oneplus.calculator/code_cache/com.android.opengl.shaders_cache: Permission denied (13)

When comparing the DAC (Direct Access Control) with a healthy phone, I don't see any differences:

drwx------ 4 u0_a153 u0_a153 3488 2023-09-25 10:05 com.oneplus.calculator
    drwxrws--x 2 u0_a153 u0_a153_cache 3488 1971-12-27 23:26 cache
    drwxrws--x 2 u0_a153 u0_a153_cache 3488 2022-01-03 14:49 code_cache
        -r-------- 1 u0_a153 u0_a153_cache 113084 2023-07-10 15:31 com.android.opengl.shaders_cache
        -r-------- 1 u0_a153 u0_a153_cache  45136 2023-07-10 15:31 com.android.skia.shaders_cache

dumpsys package com.oneplus.calculator: userId=10153 ps -A | grep calculator: u0_a153 27212 993 6770376 106716 do_epoll_wait 0 S com.oneplus.calculator In some cases it helps to simply delete the file in question. If it is recreated automatically then logcat is clean. Since DAC looks the same afterwards, I am assuming there is something else preventing the access. I am quite lost when it comes to checking file/ambient capabilities, MAC and further permission control of the Android framework. How can I debug this? Is it possible to get more detailed information exactly what permission is denied? Android 13, OnePlus 8 Pro IN2023 Any help would be appreciated, many thanks,
Zweikeks

Can anyone tell me what the file and folders are in the picture below? I can't do anything or delete these files and folders. They are coming into my external sd-card. If I format the sdcard they are removed. If I take this sdcard out of my phone and put it into my PC I'm still unable to do anything with the files and folder.

SOLVED (see accepted answer) ------------------- So this one is weird. Everything was working fine untill I rebooted my phone earlier today. For some reason, since this reboot, apps are unable to access my SD card storage. As far as I know, no update was applied with this reboot. I do not recall tinkering or changing anything related to this recently. **Symptoms** - SD card is still visible in the storage tab of the settings (there is no available option to unmount or eject it) or in select cases when choosing a folder from an app, however the content does not show up past the root. - My music player (Oto music) sends an error message "Cannot play this file" while trying to play a song from the SD card - File explorer will not show the SD card directory at all - Resillio Sync has a synced folder on the SD card. It now says "Can't open the destination folder". If I try adding a new synced folder on the SD card and select the root of the SD card, I get the message "Android OS restricts access to this folder" - Google file is stuck in a loop trying to get permissions to access the card - SD card works just fine on another phone. - Other SD cards have the same problem with my phone, not just this one - SD card does not show up when using file transfer with a Windows PC - Rebooting the phone did nothing - Removing the card and putting it back in again did nothing - Formatting the card did nothing - I factory reset the phone. It worked, but the problem came back at the first reboot. **Current state of investigations** I have reset the phone a second time and reboot it every time I install an app, uninstall or disable a system app or change some settings. So far the SD card is still accessible so I know what it's not: - it's not the fault of disabling system apps - it's not related to using a work profile (Insular) - still haven't found an app that causes it I have no idea what could cause this, all I know is it's related to my phone in particular and it appeared out of nowhere. I am using Android 13 on ColorOS. Thanks to anyone who can help.

no matter where I placed the file... on Chrome download folder on Edge download folder I run OS Android 13 / Galaxy S21 sample: href="file:///storage/emulated/0/Download/MEGA Downloads/A_current_Trip/aaa.pdf" I get: about:blank#blocked I read many suggestions. None worked for me. It works perfect on Android 8.1 any help is appreciated.

I'm unable to delete the files with [wrong character encoding in names](https://android.stackexchange.com/q/249146/94084) on my phone. I plug it into my Windows PC and try to delete it in File Explorer. It says the files are write-protected:  [This guide](https://www.youtube.com/watch?v=I79JQewqs00) tells me to

su
restorecon -v -R /data/media

The output is

u0_a82@j1x3g:/ $ su
root@j1x3g:/ # restorecon -v -R /data/media
Function: selinux_compare_spd_ram , priority  , priority version is VE=SEPF_SM-J120H_5.1.1_0069
SELinux: Loaded file_contexts from /file_contexts
SELinux: Skipping restorecon_recursive(/data/media)
root@j1x3g:/ #

But the deletion still doesn't work. Nevertheless I can do this via adb. Do you know why this happens?

I previously posted on the Linux stack exchange about my problem: https://unix.stackexchange.com/questions/731882/termux-bash-permission-denied Suffice to say I've realized that executable files can be run in Termux's home folder (at least that's what I assume ~ is), as well as in ~/storage, but when I move my compiled file hello and hello.cpp into ~/storage/shared the files no longer have permission to be executed:

~/storage $ clang++ hello.cpp -o hello
~/storage $ ls -l
total 60
lrwxrwxrwx 1 u0_a347 u0_a347    24 Jan 15 12:21 dcim -> /storage/emulated/0/DCIM
lrwxrwxrwx 1 u0_a347 u0_a347    28 Jan 15 12:21 downloads -> /storage/emulated/0/Download
-rwx------ 1 u0_a347 u0_a347 53544 Jan 16 14:44 hello
-rw------- 1 u0_a347 u0_a347    88 Jan 16 14:44 hello.cpp
lrwxrwxrwx 1 u0_a347 u0_a347    26 Jan 15 12:21 movies -> /storage/emulated/0/Movies
lrwxrwxrwx 1 u0_a347 u0_a347    25 Jan 15 12:21 music -> /storage/emulated/0/Music
lrwxrwxrwx 1 u0_a347 u0_a347    28 Jan 15 12:21 pictures -> /storage/emulated/0/Pictures
lrwxrwxrwx 1 u0_a347 u0_a347    19 Jan 15 12:21 shared -> /storage/emulated/0
~/storage $ ./hello
hello world
~/storage $ mv hello hello.cpp shared
~/storage $ ls -l
total 0
lrwxrwxrwx 1 u0_a347 u0_a347 24 Jan 15 12:21 dcim -> /storage/emulated/0/DCIM
lrwxrwxrwx 1 u0_a347 u0_a347 28 Jan 15 12:21 downloads -> /storage/emulated/0/Download
lrwxrwxrwx 1 u0_a347 u0_a347 26 Jan 15 12:21 movies -> /storage/emulated/0/Movies
lrwxrwxrwx 1 u0_a347 u0_a347 25 Jan 15 12:21 music -> /storage/emulated/0/Music
lrwxrwxrwx 1 u0_a347 u0_a347 28 Jan 15 12:21 pictures -> /storage/emulated/0/Pictures
lrwxrwxrwx 1 u0_a347 u0_a347 19 Jan 15 12:21 shared -> /storage/emulated/0
~/storage $ cd shared
~/storage/shared $ ls -l
total 150
drwxrws--- 2 u0_a234  media_rw  3452 Aug  9 21:45 Alarms
drwxrws--x 6 media_rw media_rw  3452 Oct  4 19:30 Android
drwxrws--- 2 u0_a234  media_rw  3452 Aug  9 21:45 Audiobooks
drwxrws--- 3 u0_a234  media_rw  3452 Oct  4 17:58 DCIM
drwxrws--- 6 u0_a234  media_rw  3452 Jan  4 20:33 Documents
drwxrws--- 2 u0_a234  media_rw  3452 Jan 16 13:13 Download
drwxrws--- 3 u0_a234  media_rw  3452 Aug  9 21:45 Movies
drwxrwsr-x 4 media_rw media_rw  3452 Aug  9 21:45 Music
drwxrws--- 2 u0_a234  media_rw  3452 Aug  9 21:45 Notifications
drwxrws--- 3 u0_a234  media_rw  3452 Aug  9 21:45 Pictures
drwxrws--- 2 u0_a234  media_rw  3452 Aug  9 21:45 Podcasts
drwxrws--- 2 u0_a234  media_rw  3452 Aug  9 21:45 Recordings
drwxrws--- 2 u0_a234  media_rw  3452 Aug  9 21:45 Ringtones
-rw-rw---- 1 u0_a234  media_rw 53544 Jan 16 14:44 hello
-rw-rw---- 1 u0_a234  media_rw    88 Jan 16 14:44 hello.cpp
~/storage/shared $

I've heard that external sd cards are mounted with a noexec flag, but this is internal storage on my Galaxy Tab S7 FE, so I haven't found anything related to internal storage. What I'm hoping to be able to do is write C/C++ (and other compiled languages) in another app (say, Acode) in any folder, then using Termux, compile them, and run them. So far I can run HTML/CSS/JS files natively in Acode and I can run Python files stored in ~/storage/shared, but I'm hoping to increase the flexibility of this setup more.

I've just bought a TvBox with Android 10 in it, and i've soon discovered that no app can write on the external HDD/flashdrives i attach to the USB port (seen as */storage/* ). This is a problem 'cause the internal storage of the TvBox isn't enough for the apps i want to use (KODI is a good example: it generate a lot of thumbnails, taking up much space, but i can't configure it to use the HDD folder 'cause it can't write to it) or 'cause i'd like to use a wifi connection to update the files in the HD (the file manager which provide the connection cannot do anything on the HD). While i'm not an android/linux expert, i'm not afraid on using ADB, rooting the device if necessary, etc, so i'm asking what should i do to obtain writing permission on every external device i may plug in the USB port.

I have just installed termux in my Android 6 phone and have given storage permissions so I can read, write or compile from the terminal in the folder /sdcard/myC/ by using clang -o birthday birthday.c -lm. However, when I try to run the executable, I get -bash: ./birthday: Permission denied. I have tried compiling and running in multiple places, i.e. /sdcard/data/com.termux, and have tried the command termux-setup-storage that ensures the permissions are granted to read/write. I have tried to chmod the program as well. I should be doing something wrong because apparently, the app is really good.

We're building our own ROM from AOSP, and the ROM will have a third-party app installed to /system/priv-app but we need to give that app read and write access to the main external storage without any user input. The ROM is based on Android 11, API level 30. However, we found no such permissions that could allow us to grant the app external storage access, and it seems like whatever permissions like WRITE_EXTERNAL_STORAGE, READ_EXTERNAL_STORAGE, etc. either have no effect or doesn't function as expected in Android 11. We found MANAGE_EXTERNAL_STORAGE, but this also needs user input via ACTION_MANAGE_ALL_FILES_ACCESS_PERMISSION intent. Are there any hidden permissions to allow us such thing? Or is there any other solution that can achieve the same effect?