error with pymtp to work on python 3 - android

I want to access a android device from python to download some photos.
libmtp works from the CLI.
Than pymtp. It's been around for a while but it's designed for python 2 and i'm using python 3. Meanwhile fixed several minor issues but i'm stuck at an error from function get_filelisting
specially this section:
ret = []
next = files
while next:
ret.append(next.contents)
if (next(next.contents) is None):
break
next = next(next.contents)
The error is related to the "next".
That section looks strange to me, i've been coding in python for a while but i'm new to ctypes. Tried a lot of variants, they all failed. The "next" could be confusing with python buildin function so i renamed it to nextpointer and came to this code:
ret = []
nextpointer = files
while nextpointer:
ret.append(nextpointer.contents)
nextpointer = nextpointer.contents.next
It seems to work but did it work by accident ? does it have any design flaws ? Could anyone with experience on python ctypes confirm this a solution ? Any suggestion welcome.

From python2.7 documentation
next(iterator[, default])
Retrieve the next item from the iterator by calling its next() method. If default is given, it is returned if the iterator is
exhausted, otherwise StopIteration is raised.
from python3 documentation
next(iterator[, default])
Retrieve the next item from the iterator by calling its __next__() method. If default is given, it is returned if the iterator is
exhausted, otherwise StopIteration is raised.
Notice that next() method was removed from python3 but the function still exists.
This is all I can say about the next function and .next()/__next__() methods.
I downloaded the pymtp module and get_filelisting() is slightly different from what you posted in your ported code, here it is:
ret = []
next = files
while next:
ret.append(next.contents)
if (next.contents.next == None):
break
next = next.contents.next
If none of this helped you (which probably didn't :D), the version of pymtp library that I am using is 0.0.6 download using pip.

Related

Titanium Hyperloop access to android.os.SystemProperties

I have been trying a ( i hope) simple bit of Android hyperloop code directly within a titanium project (using SDK 7.0.1.GA and hyperloop 3).
var sysProp = require('android.os.SystemProperties');
var serialNumber = sysProp.get("sys.serialnumber", "none");
But when the app is run it reports
Requested module not found:android.os.SystemProperties
I think this maybe due to the fact that when compiling the app (using the cli) it reports
hyperloop:generateSources: Skipping Hyperloop wrapper generation, no usage found ...
I have similar code in a jar and if I use this then it does work, so I am wondering why the hyperloop generation is not being triggered, as I assume that is the issue.
Sorry should have explained better.
This is the jar source that I use, the extraction of the serial number was just an example (I need access to other info manufacturer specific data as well), I wanted to see if I could replicate the JAR functionality using just hyperloop rather that including the JAR file. Guess if it's not broke don't fix it, but was curious to see if it could be done.
So with the feedback from #miga and a bit of trial and error, I have come up with a solution that works really well and will do the method reflection that is required. My new Hyperloop function is
function getData(data){
var result = false;
var Class = require("java.lang.Class");
var String = require("java.lang.String");
var c = Class.forName("android.os.SystemProperties");
var get = c.getMethod("get", String.class, String.class);
result = get.invoke(c, data, "Error");
return result;
}
Where data is a string of the system property I want.
I am using it to extract and match a serial number from a Samsung device that is a System Property call "ril.serialnumber" or "sys.serialnumber". Now I can use the above function to do what I was using the JAR file for. Just thought I'd share in case anyone else needed something similar.
It is because android.os.SystemProperties is not class you can import. Check the android documentation at https://developer.android.com/reference/android/os/package-summary.html
You could use
var build = require('android.os.Build');
console.log(build.SERIAL);
to access the serial number.

What is the purpose of using double underscore ( __ ) before the start and after the end of an file name in c?

I'm studying the android kernel as a beginner. I can read the messages thrown from the macro ERROR() inside the function main() at system/core/init/init.c using dmesg command through adb. I observed that after calling the function open_devnull_stdio() inside main(), dmesg no longer displays the messages thrown by ERROR().
To find the reason, I started digging into the declaration of open_devnull_stdio() inside system/core/init/util.c and I found this line I can't understand
static const char *name = "/dev/__null__";
Actually there was no file named __null__ inside /dev/ in the device, but there was a file named null and I was able to grab it using adb pull and it was a 0 byte (empty) file.
So why is a file name wrapped with double underscore (__) ?
Here is the link for the util.c
There is no special purpose of using double underscore before the start, after the end or both in C. From the point of view of C the file name is just a string, the operating system is free to interpret in whatever way it chooses. From the point of view of Linux, the same applies. Underscores in file names are just characters. They are not treated differently from the letters b and t.
If I guessed right and I'm reading the same file as you (it might be a good idea to link to the source code you're reading) then it should be pretty obvious what the code does on the lines after the one you mentioned. The next lines are:
if (mknod(name, S_IFCHR | 0600, (1 << 8) | 3) == 0) {
fd = open(name, O_RDWR);
unlink(name);
Which creates the null device which is then opened and immediately deleted again.
I suspect this is done so that programs can run without access to the root filesystem and still be able to open the equivalent of /dev/null.
I don't know the answer but I have an idea:
The following page shows an "strace" output where /dev/__null__ is used:
https://gist.github.com/tetsu-koba/1522515
Under Linux device files have a 33-bit (?) number which identifies the device. (At least under old Linux versions) you could delete some file in /dev and you could restore it or even create it in another directory (!) when you know the 33-bit number! (So you can delete the device /dev/sda2 and create the device (not file!) /home/myuser/sda2 instead.)
The trace in the link above shows the following three lines:
mknod("/dev/__null__", S_IFCHR|0600, makedev(1, 3)) = 0
open("/dev/__null__", O_RDWR|O_LARGEFILE) = 3
unlink("/dev/__null__") = 0
These lines will create the device file /dev/__null__ (with the 33-bit number identifying /dev/null). Then it opens that file and then it removes the file again.
Maybe this is done because the tool shall be able to run both on Linux installations where the device file "/dev/null" is present (in this case the file should not be overwritten) and on installations where that file is missing (in this case a replacement file must be created using the known 33-bit number).
As other people have pointed out this just tells it's the "null device", not a regular file called "null". null is supposed to act like an information sink, not like a normal file where you dump your data to. Hope this helps.

cordova.file.* (all directories) are null

I'm working on Ionic mobile app development.
My requirement is to create client side logger to track issues in app. I used the methods mentioned in https://github.com/pbakondy/filelogger, and I could able to create the log file in both Android and iOS.
For the first time when I open the app, it creates the log file in cordova.file.dataDirectory, when I close and reopen the app in i*OS, I'm trying to read the content of the file which was created using the below
$fileLogger.getLogfile().then(function (loggerContent) {
var temp =loggerContent;
});
But the application says
{
"applicationDirectory":null,
"applicationStorageDirectory":null,
"dataDirectory":null,
"cacheDirectory":null,
"externalApplicationStorageDirectory":null,
"externalDataDirectory":null,
"externalCacheDirectory":null,
"externalRootDirectory":null,
"tempDirectory":null,
"syncedDataDirectory":null,
"documentsDirectory":null,
"sharedDirectory":null
}
So I couldn't able to find the file where i saved my logs.
Please help me resolve this issue or if you could recommend me a different method to get around this issue, that would be great!
Thanks for the answers
There is a check list here and should solve your problem :
1-Be sure that the cordova-file-plugin is installed and works in your test environment.
2-Be sure that the cordova.js file is refrenced by your html and before your code usage.
3-Be sure to call your codes after device_ready state :
check this
4-Call your function after a short delay (use setTimeOut in Javascirpt)
Ali's item 4 is very important:
I had a similiar problem on different platforms: cordova.file.dataDirectory was null.
I tracked cordova.file.dataDirectory over the lifecycle and it was first accessed by my Ionic 2 code BEFORE the device ready event was fired.
My "mistake": I wanted to load data during the constructor(!) of a service. Seems too early.

Android Read Result From MySQL

My code used to work, it does not work anymore, I tried troubleshooting and can't figure out why.
I have this piece of code in my PHP:
$android_id_01 = $_GET['pmysql_room_id'];
$android_id_02 = "";
$f = fopen("00_android_id_01.txt", "w");
fwrite($f, print_r($android_id_01, true));
fclose($f);
$f = fopen("00_android_id_02.txt", "w");
fwrite($f, print_r($android_id_02, true));
fclose($f);
For troubleshooting I created two android IDs ($android_id_01 and $android_id_02) which are both empty (The first one is From Android and the second one I created directly from PHP).
Now when I launch my Android device, the PHP file is executed from server side and both the text files are created empty and identical. Now my code only works when I use $android_id_02 and not $android_id_01 from the code below:
if ($android_id == '')
{
//my code
}
(Yes when I use either one of the $android_id_01 OR $android_id_02 I rename it to $android_id and comment out the other one)
My question is, although this was working yesterday, why does it work with $android_id_02 = ""; and not $android_id_01 = $_GET['pmysql_room_id']; even though they are both empty????
I don't know what changed from yesterday to today.
Ok after a bit of troubleshooting I found a solution, strange though.
On the server side "display_errors" under PHP settings must be turned off. Somehow having this on interferes with the json_encode sent back to android client. (even though my code is not generating any errors)

C++ Builder WSDL client for Android

I'm having a confusing problem. I'm trying to make a Web cleint that uses WSDL.
I'm using C++ RAD Studio 10 Seattle, but the same problem occured in RAD Studio XE8(older version).
1.I create a Multi-Device Application, add one Edit component and one Button.
2.I create a WSDL Importer by changing the location of the WSDL file to : "http://www.w3schools.com/webservices/tempconvert.asmx?WSDL" and leave all other setting to default.
3.On ButtonClick event of the button I write two lines of code :
_di_TempConvertSoap Converter = GetTempConvertSoap(true,
"http://www.w3schools.com/webservices/tempconvert.asmx?WSDL");
Edit1->Text = Converter->CelsiusToFahrenheit("32");
So after these three steps I have one unit, which is the main Unit with the Form and with the button event. And one file "tempconvert.cpp" that the WSDL Importer has generated. It quite actually just translates the WSDL code to a C++ one and defines the method to communicate with the server. In my case I have two methods : FahrenheitToCelsius() and CelsiusToFahrenheit(), in the example I use CelsiusToFahrenheit().
I compile it to 32-bit Windows platform, run it and when I click the button, the result "89.6" appears in the text of the Edit component. So this is working as expected.
But when I change the target platform to "Android" and use my mobile phone "Samsung GT-I8262" with Android 4.1.2 and run the project, it just stops and exits. I debugged the problem and it stops at the first command in "tempconvert.cpp" in RegTypes() method.
// ************************************************************************
//
// This routine registers the interfaces and types exposed by the WebService.
// ************************************************************************ //
static void RegTypes()
{
/* TempConvertSoap */
InvRegistry()->RegisterInterface(__delphirtti(TempConvertSoap), L"http://www.w3schools.com/webservices/", L"utf-8");
InvRegistry()->RegisterDefaultSOAPAction(__delphirtti(TempConvertSoap), L"http://www.w3schools.com/webservices/%operationName%");
InvRegistry()->RegisterInvokeOptions(__delphirtti(TempConvertSoap), ioDocument);
/* TempConvertSoap.FahrenheitToCelsius */
InvRegistry()->RegisterMethodInfo(__delphirtti(TempConvertSoap), "FahrenheitToCelsius", "",
"[ReturnName='FahrenheitToCelsiusResult']", IS_OPTN);
/* TempConvertSoap.CelsiusToFahrenheit */
InvRegistry()->RegisterMethodInfo(__delphirtti(TempConvertSoap), "CelsiusToFahrenheit", "",
"[ReturnName='CelsiusToFahrenheitResult']", IS_OPTN);
/* TempConvertHttpPost */
InvRegistry()->RegisterInterface(__delphirtti(TempConvertHttpPost), L"http://www.w3schools.com/webservices/", L"utf-8");
InvRegistry()->RegisterDefaultSOAPAction(__delphirtti(TempConvertHttpPost), L"");
}
#pragma startup RegTypes 32
Does someone have any idea why this might be happening? I tried on two other Samsung phones and it didn't work. The error that shuts the program down is "Segmentation fault(11)", and more precisely it stops at the following line of code in "System.pas" file :
u_strFromUTF8(PUChar(Dest), MaxDestChars, DestLen, MarshaledAString(Source), SourceBytes, ErrorConv);
Here is some info that I've found about the function:
u_strFromUTF8 - function that converts a UTF-8 string to UTF-16.
UCHAR is a Byte(in Delphi), so PUCHAR is a pointer to Byte.
I cannot se what could possibly go wrong with this function which apparently only converts a string.
So my question is why does the project work on Windows 32 bit version, but on Android it throws Segmentation fault(11)?
I hope I could find a solution for this problem. I will keep looking.
Thank you,
Zdravko Donev :)
UPDATE:
I disassembled the line:
InvRegistry()->RegisterInterface(__delphirtti(TempConvertSoap), L"http://www.w3schools.com/webservices/", L"utf-16");
to get :
TInvokableClassRegistry *Class = InvRegistry();
TTypeInfo *Info = __delphirtti(TempConvertSoap);
UnicodeString Namespace = "http://www.w3schools.com/webservices/";
UnicodeString WSDLEncoding = "utf-8";
Class->RegisterInterface(Info, Namespace, WSDLEncoding);
And I saw that the problem occurs when calling InvRegistry() function, but I still haven't found the problem as I cannot reach the source code of the function.
I found a solution.
I deleted the line
#pragma startup RegTypes 32
and called the method RegTypes() on my own when I create the form and it worked.

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