Comparing sdcard paths - android

Device 1
/sdcard attached to real sd card
/mnt/sdcard attached to real sd card
Device 2
/sdcard attached to internal memory
/mnt/sdcard attached to internal memory
/external_storage(something like this) to real sd card
.
.
/sdcard and /mnt/sdcard seems to have the same location. Always ?
My question is, how do I know if they attached to same directory ?
I tried new File(path1).equals(new File(path2)); but it return false. Only way I see is, create a hidden file with unique id and check the existence in both paths.
PS : I'm aware of Environment.getExternalStorageDirectory(). But I need these paths for some specific purpose.

/sdcard and /mnt/sdcard are not always the same. There are many paths that can exsist such as:
/emmc
/mnt/sdcard/external_sd
/mnt/external_sd
/sdcard/sd
/mnt/sdcard/bpemmctest
/mnt/sdcard/_ExternalSD
/mnt/sdcard-ext
/mnt/Removable/MicroSD
/Removable/MicroSD
/mnt/external1
/mnt/extSdCard
/mnt/extsd
/mnt/usb_storage <-- usb flash mount
/mnt/extSdCard <-- usb flash mount
/mnt/UsbDriveA <-- usb flash mount
/mnt/UsbDriveB <-- usb flash mount
There should be no reason that you would need a direct path hard coded to the internal or external memory when they make functions available for that. Anything that you are hard coding will be the same as what you get back from the functions that you have listed only the will be for that specific devices.
This will give you a string of the absolute path to a file on the external storage:
String myPath = sdcardEnvironment.getExternalStorageDirectory().getAbsolutePath() + "/folder file is in/file you want path to";
And this will get you the path your applications internal storage:
this.getApplicationContext().getFilesDir()
You cannot always access the external SD card from code because of the way that newer versions of android partition itself. Here is statement directly from android dev site:
It's possible that a device using a partition of the internal storage for the external storage may also offer an SD card slot. In this case, the SD card is not part of the external storage and your app cannot access it

new File("/sdcard").getCanonicalPath().equals(new File("/mnt/sdcard").getCanonicalPath())
Omitted are exception handling and other niceties. Note, however, that ObieMD5 is correct, and you should not be doing this, as you can see from the list of paths in the answer above.
Also note that this method will only resolve symlinks; if your device uses mount instead to have the same space accessible from two locations, this method will not work.

attached to real sd card
The Android SDK, at present, has no concept of "real sd card". There is external storage. The definition of where external storage resides is up to the device manufacturer.
attached to internal memory
Those paths at best refer to external storage, and at worst do not exist.
/sdcard and /mnt/sdcard seems to have the same location. Always ?
No. Those paths may not even exist on some devices, as there is no requirement that they exist, and modern devices do not use those paths. Always use methods on Environment or Context to find locations on external storage.

Related

Android Adoptable Storage - find out if internal SD is mounted

When thinking about this question I asked, I wondered: Is there really no way of finding out if a adopted SD is present?
With a Motorola G3 there were two paths returned by getExternalFilesDirs() when an external SD was present, but only one (the emulated one, thats always present) when formatting the SD as internal. Other devices seem to behave similar.
So, if I am looking to know if there is a internal SD present, where would I need to look? Is there anything (non manufacturer specific) provided, so e.g. I could check, if the user expects to use the internal emulated Environment.getExternalStorageDirectory() because he has mounted a internal SD?

Accessing folder paths with %System_Variables% in Android

I am struggling with the following issue. In a configuration file I need to access the general path for the external memory card.
This is usually done by reading the %SDCARD% system variable.
However, the makers of my phone created two partitions of the internal memory, and the second partition is mounted as "sdcard". This results in the %SDCARD%" variable returning the path to the second partition of the internal memory, rather than the externally inserted SD Card.
The SD Card is actually mounted "sdcard-ext". Is there a system variable that returns the generic path to this volume to be used in a generic path, such as
folder = "%SDCARD-EXT%/Subfolder1/Subfolder2"
to access Subfolder2 on the external card?
Thank you in advance for the help!
This is usually done by reading the %SDCARD% system variable.
Android does not use environment variables much, and Linux does not use the % syntax, last I checked.
This results in the %SDCARD%" variable returning the path to the second partition of the internal memory, rather than the externally inserted SD Card.
That is specific to this device from this manufacturer, whatever that device and manufacturer happen to be.
The SD Card is actually mounted "sdcard-ext".
That is specific to this device from this manufacturer, whatever that device and manufacturer happen to be.
Is there a system variable that returns the generic path to this volume to be used in a generic path
That is a question that only the device manufacturer can answer, as Android does not have sdcard-ext, and environment variables, to the extent that there are any, are beyond the Android SDK.

Get the right external storage from Android devices

I tried to figure out the the right external storage (additional sdcard with more space ) location of an Android device.
I know from different user, that the location is not always the same.
The method Environment.getExternalStorageDirectory returns me always mnt/sdcard.
I have the following variants are reported from users:
mnt/sdcard/tflash
mnt/sdcard/external_sd
mnt/sdcard
How can I determine the real location of an external sd-card?
Environment.getExternalStorageState() returns path to internal SD mount point like "/mnt/sdcard"
No, Environment.getExternalStorageDirectory() refers to whatever the device manufacturer considered to be "external storage". On some devices, this is removable media, like an SD card. On some devices, this is a portion of on-device flash. Here, "external storage" means "the stuff accessible via USB Mass Storage mode when mounted on a host machine", at least for Android 2.x and above.
But the question is about external SD. How to get a path like "/mnt/sdcard/external_sd" (it may differ from device to device)?
Android has no concept of "external SD", aside from external storage, as described above.
If a device manufacturer has elected to have external storage be on-board flash and also has an SD card, you will need to contact that manufacturer to determine whether or not you can use the SD card (not guaranteed) and what the rules are for using it, such as what path to use for it.
How can I determine the real location of an external sd-card?
=> Environment.getExternalStorageDirectory() gives you the exact location of your external storage device. Path may be different because it depends on the consideration of manufacturer.
For example: I found /sdcard on some HTC devices and /mnt/sdcard on some samsung devices.
So Environment.getExternalStorageDirectory() is the correct way.

How to access USB Path in android?

I am connected android device and PC via USB cable. My Internal SD Card location Path as /mnt/sdcard. But my External USB device path as /mnt/userdata1. I am try to use this code to find only the Internal SD Card Path Environment.getExternalStorageDirectory(). I am using this code to access only in the internal SD Card path. How to access the external USB Path.
For example Screenshot is here...
Example
In this example contains Internal Memory, External SD card and USB Storage. How to find this path ( Internal Memory, External SD card and USB Storage) programmatically. In this code Environment.getExternalStorageDirectory() is viewed files from all Internal Memory Files only. So how to access others path ( External SD card and USB Storage ) Please guide me with code. Thanks..
If I understand correctly, what you are calling "external" USB path is actually the mount point for your SD card on your computer. Most likely, your SD card has label userdata1. Therefore when it's mounted on the computer, it gets /mnt/userdata1 mount point. However this is not strictly necessary and it can be any mount point at all. In fact, if you connect it to another computer, it can easily be another mount point.
Because this path is determined by the computer operating system, you'll need to find this path on your computer (note that this can be different every time you connect your phone to your PC, so you'll need to do it every time).
From your question and path structure (/mnt/userdata1) I'm guessing you're using linux or some other unix version. Therefore you could run mount on your PC to see the list of the mounted devices. For example, here's the output on my mac:
$ mount
/dev/disk0s2 on / (hfs, local, journaled)
devfs on /dev (devfs, local, nobrowse)
map -hosts on /net (autofs, nosuid, automounted, nobrowse)
map auto_home on /home (autofs, automounted, nobrowse)
/dev/disk1s1 on /Volumes/ALEKS540 (msdos, local, nodev, nosuid, noowners)
Note the last line in the output - this is my connected android phone with the SD card mounted to the computer. On macs, the mount points are created under /Volumes instead of /mnt. Other than than, ALEKS540 is the label of my SD card, hence it's mounted this way.
Internally on the phone, it's still mounted as /mnt/sdcard.
From the point of view of Android, there may be three storage types:
Internal memory it's always mounted under / on the device and contains everything except the SD card and USB storage below.
SD card - this is referred to as "external storage" and is usually mounted as /mnt/sd, but not always. Environment.getExternalStorageDirectory() will return the path of SD card mount point.
USB storage - this is only supported on very few devices (those that support USB host mode for external storage). This will be mounted somewhere under /mnt, but the exact location will vary. You will need to use Android NDK to interrogate and iterate mounted devices to find the one you're after.

Programmatically accessing internal storage (not SD card) on Verizon HTC Droid Incredible (Android)

I'm trying to find information on how to programmatically access the HTC Droid Incredible's supposed 8GB of Internal Storage Memory.
To determine the External Storage (SD Card) Location, I'm using the command:
android.os.Environment.getExternalStorageDirectory().
I've not been able to find any corollary for Internal phone Storage.
In examining HTC/Google Nexus One, Motorola Droid, and HTC Dream/G1 phones, there (as would be expected) does not appear to be any Mount Point for such Arbitrary Internal Storage.
On these phones the Internal Storage is divided amongst /data, /system, and /cache partitions.
The Incredible's Internal Storage is certainly not going to be located in /system. /cache is also unlikely given that it is globally non-readable/non-executable.
I'd read in reviews that the phone will still be limited to 512MB or so for apps, suggesting that it is not simply a subdirectory of /data.
I do not have access to a Droid Incredible unit myself, of course.
There is more information here: Droid Incredible storage mount points. It seems that Droid Incredible mounts its internal storage to /emmc, supposedly mounted r/w. It is not yet verified whether the WRITE_EXTERNAL_STORAGE permission is necessary in order to gain r/w access - I'm trying to get this information from Google Code
I will probably solve this by allowing the user two options to store the data:
SD-Card
Droid Incredible-only Internal storage
Edit: It seems that the WRITE_EXTERNAL_STORAGE permission is sufficient: according to droidForums both /sdcard and /emmc has the same GID of 1015.
Edit2: According to Google Group Thread the Incredible returns /sdcard as the result value of Environment.getExternalStorageDirectory(). Therefore, the user needs to decide whether he wants to use /sdcard or /emmc. The auto-detection of Incredible may be based on existence of the /emmc path.
As you're aware access to internal storage is usually limited to certain directories for each application by permissions. This is to stop one application reading data from another and from accessing system files without using the APIs. This makes sense since, for example, if you had an internet banking application you wouldn't want other apps to be able to access any of its cached data.
Each application gets to store data in a directory under /data/data. However, normally you don't specify the paths explicitly but used methods like Context.openFileOutput() which creates the file in the appropriate subdirectory of your application's directly.
I agree with you that it is unlikely that the majority of the 8GB of the Incredible's storage will be used for the /data partition.
So if they are going to have a separate partition to allow music and photos to be stored easily on the phone's internal storage then they will have to do it in a way that's compatible with existing applications. This means using Environment.getExternalStorageDirectory() but since the Incredible also supports SD cards then you're right in that it's not obvious how this might work.
There is a thread on the Android Developers Google Group discussing this exact question. Whilst there isn't an answer (at the time of writing) for how the Incredible works there's a post which says the Samsung Galaxy solves the same problem in this way:
The internal storage is mounted at /sdcard
If an SD card is also available this can be found at /sdcard/sd
This seems a sensible solution since it will be compatible with existing applications, including those which have mistakenly hard coded /sdcard instead of using Environment.getExternalStorageDirectory().
So my advice would be to use Environment.getExternalStorageDirectory() when you're looking for large areas for storage - either SD card or internal to the phone - and hope that each phone returns something sensible.
Just simply use this:
String primary_sd = System.getenv("EXTERNAL_STORAGE");
if(primary_sd != null)
Log.i("EXTERNAL_STORAGE", primary_sd);
String secondary_sd = System.getenv("SECONDARY_STORAGE");
if(secondary_sd != null)
Log.i("SECONDARY_STORAGE", secondary_sd)

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