I am trying to save a bmp into file in my C++ android app (I am working with chromium project).
FILE* fp = fopen("/myimage.bmp", "wb"); // result: fp==NULL, errno==30
FILE* fp = fopen("/Pictures/myimage.bmp", "wb"); // result: fp==NULL, errno==2
Phone is Nexus 5x having no sdcard. android.permission.WRITE_EXTERNAL_STORAGE and android.permission.WRITE_INTERNAL_STORAGE are set.
Looks like I am using invalid path? Which path would be valid? It is a debug output, so I need any path that would work.
If you're accessing your internal storage of your application then the root path of your application storage is
String ROOT_PATH = "/data/data/" + "com.your.package.name" + "/";
So in case of accessing your file from your internal storage you have to declare the file path like this.
FILE* fp = fopen(ROOT_PATH + "myimage.bmp", "wb");
But this doesn't ensure your problem to be solved as #CommonsWare suggested,
"the root path of your application storage is" -- the path varies by
OS version, user account (primary vs. secondary), and possibly device
manufacturer. NEVER HARDCODE PATHS. If NDK code needs to write to a
location, Java code should be passing in the path, where that is
derived from a method (e.g., getFilesDir()).
So I'm referring to his comment again in your question.
You cannot write to / on any Linux-based system without
superuser-level privileges. "I am working with chromium project" --
then figure out where Chromium writes files, and write your files
there.
These are some valuable insights suggested by #CommonsWare which might help you. Thanks.
Related
I am looking for a solution for copying all the files from a specific directory on the hard drive, to a specific or non specific directory on my android phone, once this device is connected.
I would like these files to be automatically moved (or at least copied) to my phone once I connect it to the computer and run the .py file.
I have windows 7 and python 2.7
I was trying this from another answer but I can't understand because there is few explanation, therefore I cannot get it to work.
edit: I have figured out how to transfer files between to folders but I want to my phone. So how can I fix the error of my system not finding the path of my phone, that'll fix my problem I believe. The code works fine the problem is the path.
Here is my code:
import os
import shutil
sourcePath = r'C:\Users\...\What_to_copy_to_phone'
destPath = r'Computer\XT1032\Internal storage'
for root, dirs, files in os.walk(sourcePath):
#figure out where we're going
dest = destPath + root.replace(sourcePath, '')
#if we're in a directory that doesn't exist in the destination folder
#then create a new folder
if not os.path.isdir(dest):
os.mkdir(dest)
print 'Directory created at: ' + dest
#loop through all files in the directory
for f in files:
#compute current (old) & new file locations
oldLoc = root + '\\' + f
newLoc = dest + '\\' + f
if not os.path.isfile(newLoc):
try:
shutil.copy2(oldLoc, newLoc)
print 'File ' + f + ' copied.'
except IOError:
print 'file "' + f + '" already exists'
I am sorry I am being handful but I thought I had solved it.
In theory, there is no way to access your phone's internal memmory with a drive letter, because, Android connects as an MTP device, and not as a Mass Storage device. But, there are some weird solutions:
Root the phone and get a application which enables "Mass Storage" .
If you can not root and if(only if) both the computer are on the same network, run FTP server in you phone, and you get access for file copy by ftp.
But for you case I recommend adb- adb push C:\src /phone_destination is the best solution.You can google and easily find out way to do this in python.
Google offers adb-sync, which is also available in python. This allows backup/synchronization of files on android device to PC.
The following github repo provides instructions on how to setup the process ie: enable USB Debugging, etc... however I suggest installing 15 second adb installer as opposed to downloading/installing the massive Android SDK just to get adb.
adb-sync: https://github.com/google/adb-sync
15 Sec ADB installer: https://forum.xda-developers.com/showthread.php?t=2588979
A little late to answer, but I use SSH certs and crontab to run a ping command against my local IP and pipe that to an scp recursive copy. It will copy any changes over. No issue yet, and it's been running 4 years straight. I can't for the life of me find the command line that's running.
I have spent many hours trying to find/create files for an app I am writing. When I pull the application directory name I get: /data/data/com.example.android.[myapp]/files. I am using File(getFilesDir():
File fileDir = new File(getFilesDir() + File.separator);
Log.i(TAG, "File directory: "+fileDir);
When I try to find this path I find many application folders here: Android/data/com but no /data/data folder under Android. There are many other application folders there but not mine. I see the same results whether I use Android Files app or Windows Explorer over USB. I've also tried to look using Eclipse DDMS tab. I see a data folder with a (+) to the left but when I click, it does not expand.
I have also tried creating the directory and file manually with Windows explorer and my app still can't find neither the Android/data/com.example... nor the Android/data/data/com.example... paths.
Also puzzling to me is when the app creates the path and file and write to it (using MODE_WORLD_WRITEABLE) I get no exceptions thrown but then I am unable to read it back or see it with either of the tools mentioned above. I have set the manifest permissions to WRITE_INTERNAL_STORAGE and WRITE_INTERNAL_STORAGE for the app.
Obviously, I am making a very basic mistake.
I am on Android 4.1.2 (API 16).
Sincerely,
ScratchingMyHead
To get the path of my application directory, Try this code sample
PackageManager m = getPackageManager();
String s = getPackageName();
try {
PackageInfo p = m.getPackageInfo(s, 0);
s = p.applicationInfo.dataDir;
} catch (NameNotFoundException e) {
Log.w("yourtag", "Error Package name not found ", e);
}
When I try to find this path I find many application folders here: Android/data/com but no /data/data folder under Android.
That is because you are looking on external storage, not internal storage where your files are. Use DDMS on an emulator to examine internal storage.
I've also tried to look using Eclipse DDMS tab. I see a data folder with a (+) to the left but when I click, it does not expand.
That would sound like what you will get when testing on hardware, as neither you nor DDMS have access to the contents of /data on production hardware.
This code works in the simulator but not on my Android device:
local path = system.pathForFile("chinese_rules.db")
print("PATH:: " .. tostring( path ) )
When I run this code on my Galaxy S4 path returns nil.
My first thought was that it was some typo (case sensitivity) but I can't find any typo:
http://i59.tinypic.com/wlpu14.png
I can't find any reason why it should receive nil. This causes a problem as I can't load my database.
I have also tried this with the same result:
local path = system.pathForFile("chinese_rules.db", system.ResourceDirectory)
I have been able to load a path and load databases like this before.
Corona Build: 2013.2100 (2013.12.7)
Further reading the documentation I don't see that .db is a restricted file type:
Corona allows direct loading of images and audio files using the
appropriate APIs, but it has limited access to resource files on
Android using the file I/O APIs. Specifically, the following types can
not be read from the resources directory: .html, .htm., .3gp, .m4v,
.mp4,.png, .jpg, and .ttf.
http://docs.coronalabs.com/api/library/system/pathForFile.html
I found out the reason for the problem:
We are two that are working on this project and he had setup to use expansion files so two files was created (the main APK and the OBB expansion file) which I didn't notice and I only loaded the main APK file and I guess the database is in the OBB file. After setting not to use an expansion file the app works.
usesExpansionFile = false
I'm trying to test the Expansion Pack Files (OBB) In Android following the guide here:
http://developer.android.com/google/play/expansion-files.html
I'm in the step where I need to test my app on my Nexus 4.
I generated my .obb file with jobb and adb-pushed it in the device in this location:
/mnt/shell/emulated/0/Android/obb/my.package/main.1.my.package.obb
When the app run it doesn't find the file.
Method:
Helpers.doesFileExist(context, fileName, xf.mFileSize, false)
return false for my file.
I debugged and found out it is looking for the file in:
/storage/emulated/0/Android/obb/my.package/main.1.my.package.obb
Specifically this is the path returned by:
Helpers.generateSaveFileName(c, fileName)
The /storage/emulated/0, returned by Environment.getExternalStorageDirectory() doesn't exist browsing the device with adb shell.
But it DOES at runtime, inside the app, I also checked what it contains: it contains almost the same things I found in /mnt/shell/emulated/0, it contains the Android/obb dir, which is empty.
How I found out the path /mnt/shell/emulated/0/Android/obb/my.package/main.1.my.package.obb where I placed my obb file:
$ adb shell
$ ls -ld sdcard
lrwxrwxrwx root root 2013-10-16 17:34 sdcard -> /storage/emulated/legacy
$ ls -ld /storage/emulated/legacy
lrwxrwxrwx root root 2013-10-16 17:34 legacy -> /mnt/shell/emulated/0
And inside that I already found the Android/obb directory, empty.
So the question is: where should I put my obb file for it to be in the right position at runtime?
I did everything said there:
created a draft application in the Market to get the public key
generated a random array of 20 byte (salt)
integrated play_licensing/library and play_apk_expansion/download_library
wrote my Service / Receiver
did the check using the Helpers etc.. exactly like the documentation say.
I suppose everything works but I can't just yet release on Play Store! I need to test locally and I'll have the need to change my obb file pretty often in this initial phase of development.
I can't test on the Emulator because I use 3D and device camera.
Since Android 4.2 multi users support have been added.
To support that Android mount an emulated disk for each users acting as a sandbox layer around the actual filesystem: this let Android handle gracefully either sharing of files between users either personal files.
Long story short:
/storage/emulated
is the emulated filesystem.
if you enter that directory from adb shell you may see a
/storage/emulated/obb
directory. Sometimes it doesn't show up, for some reason (see below for what to do if this happen)
It's not in /Android/obb but that's the right directory where to place your app package / obb file!
If you don't see that directory try looking in:
/mnt/shell/emulated/obb
You should be able to put your file there.
It will be correctly picked up at runtime ending at the
/storage/emulated/0/Android/obb/my.package/main.1.my.package.obb
path.
I think the Android documentation should explain this.
(I answer my own question because I found out how to solve it while writing it.)
For me the correct location is : mnt/sdcard/Android/obb/nameofyourpackage/
NOT "/mnt/shell"
I am trying to write a file in the internal storage directory of my application with the following step :
1) Initializing my "jni library" in Acivity Class :
MyLib mylib = new MyLib();
2) Give the internal storage path by calling getFilesDir in my Activity Class:
mylib.setSavePath(getFilesDir());
3) Call a method mylib.save() from my library which is doing the following in c++:
Open the file which i want to write with :
fp = fopen(pathtotheinternalstorage+filename,"w");
if (!fp) {
SetError(XML_ERROR_FILE_NOT_FOUND, filename, 0);
return _errorID;
}
The file path is correct : /data/data/com.myapp/files/myfile.xml
But fopen fails, i dont know what i am doing wrong.
If i write with some java code (openFileOutput), it is working well.
Thanks for your help.
More information would be helpful. Based on the path, I'm assuming you're on a Linux box. I would first check the permissions of the path. A few suggestions below
1) Try opening a file in your home directory and see if you have the same issue.
2) Try setting the file world writable using chmod 777 and see if that fixes the problem. Remember setting world writable is really INSECURE and you should change it to something more restrictive once you've found the problem.
I found the answer, i was using a library that was redefinig fopen to read inside asset folder.
#define fopen(name, mode) android_fopen(name, mode)
now it s working