Programs & Examples On #Zodb

ZODB is an object database for Python. Originally part of the ZOPE web application framework project, it can be used stand-alone, and provides an easier persistance alternative to relational databases for object oriented python software.

"Server Tomcat v7.0 Server at localhost failed to start" without stack trace while it works in terminal

I was facing similar problem this weekend. Tried all the above mentioned tricks, but none of them worked of me. (Working in Eclipse LUNA)

Then i analysed that just before creating a particular servlet, i was running Apache Tomcat v7.0 successfully. Which was "RefreshServlet" as shown below :

RefreshServlet.java

So that practicing servlets to understand the "AutoRefresh" functioning. When i remove this servlet from my application, it works fine, but when i try to add and run this servlet, it gives the same error "Apache Tomcat v7.0 failed to start"

Don't know why, but only removing this servlet works fine for me to run the rest of my application.

So, the bottom line suggestion from me would be that if not any other trick is working, then try removing any latest servlet or any class you just created before getting this error and it may work fine for you too for the rest of the application.

Any further explanation would be appreciated. Thanks

Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2

You state in the comments that the returned JSON is this:

{ 
  "dstOffset" : 3600, 
  "rawOffset" : 36000, 
  "status" : "OK", 
  "timeZoneId" : "Australia/Hobart", 
  "timeZoneName" : "Australian Eastern Daylight Time" 
}

You're telling Gson that you have an array of Post objects:

List<Post> postsList = Arrays.asList(gson.fromJson(reader,
                    Post[].class));

You don't. The JSON represents exactly one Post object, and Gson is telling you that.

Change your code to be:

Post post = gson.fromJson(reader, Post.class);

java.lang.IllegalArgumentException: No converter found for return value of type

In my case, I forgot to add library jackson-core.jar, I only added jackson-annotations.jar and jackson-databind.jar. When I added jackson-core.jar, it fixed the problem.

Display text from .txt file in batch file

Try this: use Find to iterate through all lines with "Current date/time", and write each line to the same file:

for /f "usebackq delims==" %i in (`find "Current date" log.txt`) do (echo %i > log-time.txt)
type log-time.txt

Set delims= to a character not relevant in the date/time lines. Use %%i in batch files.

Explanation (update):

Find extracts all lines from log.txt containing the search string.

For /f loops through each line the command inside (...) generates.

As echo > log-time.txt (single > !) overwrites log-time.txt every time it's executed, only the last matching line remains in log-time.txt

How to get progress from XMLHttpRequest

_x000D_
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<body>_x000D_
<p id="demo">result</p>_x000D_
<button type="button" onclick="get_post_ajax();">Change Content</button>_x000D_
<script type="text/javascript">_x000D_
 function update_progress(e)_x000D_
 {_x000D_
   if (e.lengthComputable)_x000D_
   {_x000D_
     var percentage = Math.round((e.loaded/e.total)*100);_x000D_
     console.log("percent " + percentage + '%' );_x000D_
   }_x000D_
   else _x000D_
   {_x000D_
    console.log("Unable to compute progress information since the total size is unknown");_x000D_
   }_x000D_
 }_x000D_
 function transfer_complete(e){console.log("The transfer is complete.");}_x000D_
 function transfer_failed(e){console.log("An error occurred while transferring the file.");}_x000D_
 function transfer_canceled(e){console.log("The transfer has been canceled by the user.");}_x000D_
 function get_post_ajax()_x000D_
 {_x000D_
    var xhttp;_x000D_
    if (window.XMLHttpRequest){xhttp = new XMLHttpRequest();}//code for modern browsers} _x000D_
   else{xhttp = new ActiveXObject("Microsoft.XMLHTTP");}// code for IE6, IE5    _x000D_
    xhttp.onprogress = update_progress;_x000D_
  xhttp.addEventListener("load", transfer_complete, false);_x000D_
  xhttp.addEventListener("error", transfer_failed, false);_x000D_
  xhttp.addEventListener("abort", transfer_canceled, false);    _x000D_
    xhttp.onreadystatechange = function()_x000D_
    {_x000D_
      if (xhttp.readyState == 4 && xhttp.status == 200)_x000D_
      {_x000D_
         document.getElementById("demo").innerHTML = xhttp.responseText;_x000D_
      }_x000D_
    };_x000D_
   xhttp.open("GET", "http://it-tu.com/ajax_test.php", true);_x000D_
   xhttp.send();_x000D_
 }_x000D_
</script>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Result

How does Google calculate my location on a desktop?

They use a combination of IP geolocation, as well as comparing the results of a scan for nearby wireless networks with a database on their side (which is built by collecting GPS coordinates alongside wifi scan data when Android phone users use their GPS)

java.lang.IllegalStateException: Only fullscreen opaque activities can request orientation

I resolved this issue by removing android:screenOrientation="portrait" and added below code into my onCreate

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}

while my theme properties are

<item name="android:windowIsTranslucent">true</item>
<item name="android:windowDisablePreview">true</item>

Vue-router redirect on page not found (404)

@mani's Original answer is all you want, but if you'd also like to read it in official way, here's

Reference to Vue's official page:

https://router.vuejs.org/guide/essentials/history-mode.html#caveat

SQL-Server: Error - Exclusive access could not be obtained because the database is in use

I think you just need to set the db to single user mode before attempting to restore, like below, just make sure you're using master

USE master
GO
ALTER DATABASE AdventureWorksDW
SET SINGLE_USER

How to check if text fields are empty on form submit using jQuery?

you need to add a handler to the form submit event. In the handler you need to check for each text field, select element and password fields if there values are non empty.

$('form').submit(function() {
     var res = true;
     // here I am checking for textFields, password fields, and any 
     // drop down you may have in the form
     $("input[type='text'],select,input[type='password']",this).each(function() {
         if($(this).val().trim() == "") {
             res = false; 
         }
     })
     return res; // returning false will prevent the form from submitting.
});

Setting DataContext in XAML in WPF

There are several issues here.

  1. You can't assign DataContext as DataContext="{Binding Employee}" because it's a complex object which can't be assigned as string. So you have to use <Window.DataContext></Window.DataContext> syntax.
  2. You assign the class that represents the data context object to the view, not an individual property so {Binding Employee} is invalid here, you just have to specify an object.
  3. Now when you assign data context using valid syntax like below
   <Window.DataContext>
      <local:Employee/>
   </Window.DataContext>

know that you are creating a new instance of the Employee class and assigning it as the data context object. You may well have nothing in default constructor so nothing will show up. But then how do you manage it in code behind file? You have typecast the DataContext.

    private void my_button_Click(object sender, RoutedEventArgs e)
    {
        Employee e = (Employee) DataContext;
    }
  1. A second way is to assign the data context in the code behind file itself. The advantage then is your code behind file already knows it and can work with it.

    public partial class MainWindow : Window
    {
       Employee employee = new Employee();
    
       public MainWindow()
       {
           InitializeComponent();
    
           DataContext = employee;
       }
    }
    

How can I check if a value is of type Integer?

if (x % 1 == 0)
    // x is an integer

Here x is a numeric primitive: short, int, long, float or double

How to get substring of NSString?

Here's a slightly less complicated answer:

NSString *myString = @"abcdefg";
NSString *mySmallerString = [myString substringToIndex:4];

See also substringWithRange and substringFromIndex

The type or namespace cannot be found (are you missing a using directive or an assembly reference?)

This error comes because compile does not know where to find the class..so it occurs mainly when u copy or import item ..to solve this .. 1.change the namespace in the formname.cs and formname.designer.cs to the name of your project .

Logging best practices


Update: For extensions to System.Diagnostics, providing some of the missing listeners you might want, see Essential.Diagnostics on CodePlex (http://essentialdiagnostics.codeplex.com/)


Frameworks

Q: What frameworks do you use?

A: System.Diagnostics.TraceSource, built in to .NET 2.0.

It provides powerful, flexible, high performance logging for applications, however many developers are not aware of its capabilities and do not make full use of them.

There are some areas where additional functionality is useful, or sometimes the functionality exists but is not well documented, however this does not mean that the entire logging framework (which is designed to be extensible) should be thrown away and completely replaced like some popular alternatives (NLog, log4net, Common.Logging, and even EntLib Logging).

Rather than change the way you add logging statements to your application and re-inventing the wheel, just extended the System.Diagnostics framework in the few places you need it.

It seems to me the other frameworks, even EntLib, simply suffer from Not Invented Here Syndrome, and I think they have wasted time re-inventing the basics that already work perfectly well in System.Diagnostics (such as how you write log statements), rather than filling in the few gaps that exist. In short, don't use them -- they aren't needed.

Features you may not have known:

  • Using the TraceEvent overloads that take a format string and args can help performance as parameters are kept as separate references until after Filter.ShouldTrace() has succeeded. This means no expensive calls to ToString() on parameter values until after the system has confirmed message will actually be logged.
  • The Trace.CorrelationManager allows you to correlate log statements about the same logical operation (see below).
  • VisualBasic.Logging.FileLogTraceListener is good for writing to log files and supports file rotation. Although in the VisualBasic namespace, it can be just as easily used in a C# (or other language) project simply by including the DLL.
  • When using EventLogTraceListener if you call TraceEvent with multiple arguments and with empty or null format string, then the args are passed directly to the EventLog.WriteEntry() if you are using localized message resources.
  • The Service Trace Viewer tool (from WCF) is useful for viewing graphs of activity correlated log files (even if you aren't using WCF). This can really help debug complex issues where multiple threads/activites are involved.
  • Avoid overhead by clearing all listeners (or removing Default); otherwise Default will pass everything to the trace system (and incur all those ToString() overheads).

Areas you might want to look at extending (if needed):

  • Database trace listener
  • Colored console trace listener
  • MSMQ / Email / WMI trace listeners (if needed)
  • Implement a FileSystemWatcher to call Trace.Refresh for dynamic configuration changes

Other Recommendations:

Use structed event id's, and keep a reference list (e.g. document them in an enum).

Having unique event id's for each (significant) event in your system is very useful for correlating and finding specific issues. It is easy to track back to the specific code that logs/uses the event ids, and can make it easy to provide guidance for common errors, e.g. error 5178 means your database connection string is wrong, etc.

Event id's should follow some kind of structure (similar to the Theory of Reply Codes used in email and HTTP), which allows you to treat them by category without knowing specific codes.

e.g. The first digit can detail the general class: 1xxx can be used for 'Start' operations, 2xxx for normal behaviour, 3xxx for activity tracing, 4xxx for warnings, 5xxx for errors, 8xxx for 'Stop' operations, 9xxx for fatal errors, etc.

The second digit can detail the area, e.g. 21xx for database information (41xx for database warnings, 51xx for database errors), 22xx for calculation mode (42xx for calculation warnings, etc), 23xx for another module, etc.

Assigned, structured event id's also allow you use them in filters.

Q: If you use tracing, do you make use of Trace.Correlation.StartLogicalOperation?

A: Trace.CorrelationManager is very useful for correlating log statements in any sort of multi-threaded environment (which is pretty much anything these days).

You need at least to set the ActivityId once for each logical operation in order to correlate.

Start/Stop and the LogicalOperationStack can then be used for simple stack-based context. For more complex contexts (e.g. asynchronous operations), using TraceTransfer to the new ActivityId (before changing it), allows correlation.

The Service Trace Viewer tool can be useful for viewing activity graphs (even if you aren't using WCF).

Q: Do you write this code manually, or do you use some form of aspect oriented programming to do it? Care to share a code snippet?

A: You may want to create a scope class, e.g. LogicalOperationScope, that (a) sets up the context when created and (b) resets the context when disposed.

This allows you to write code such as the following to automatically wrap operations:

  using( LogicalOperationScope operation = new LogicalOperationScope("Operation") )
  {
    // .. do work here
  }

On creation the scope could first set ActivityId if needed, call StartLogicalOperation and then log a TraceEventType.Start message. On Dispose it could log a Stop message, and then call StopLogicalOperation.

Q: Do you provide any form of granularity over trace sources? E.g., WPF TraceSources allow you to configure them at various levels.

A: Yes, multiple Trace Sources are useful / important as systems get larger.

Whilst you probably want to consistently log all Warning & above, or all Information & above messages, for any reasonably sized system the volume of Activity Tracing (Start, Stop, etc) and Verbose logging simply becomes too much.

Rather than having only one switch that turns it all either on or off, it is useful to be able to turn on this information for one section of your system at a time.

This way, you can locate significant problems from the usually logging (all warnings, errors, etc), and then "zoom in" on the sections you want and set them to Activity Tracing or even Debug levels.

The number of trace sources you need depends on your application, e.g. you may want one trace source per assembly or per major section of your application.

If you need even more fine tuned control, add individual boolean switches to turn on/off specific high volume tracing, e.g. raw message dumps. (Or a separate trace source could be used, similar to WCF/WPF).

You might also want to consider separate trace sources for Activity Tracing vs general (other) logging, as it can make it a bit easier to configure filters exactly how you want them.

Note that messages can still be correlated via ActivityId even if different sources are used, so use as many as you need.


Listeners

Q: What log outputs do you use?

This can depend on what type of application you are writing, and what things are being logged. Usually different things go in different places (i.e. multiple outputs).

I generally classify outputs into three groups:

(1) Events - Windows Event Log (and trace files)

e.g. If writing a server/service, then best practice on Windows is to use the Windows Event Log (you don't have a UI to report to).

In this case all Fatal, Error, Warning and (service-level) Information events should go to the Windows Event Log. The Information level should be reserved for these type of high level events, the ones that you want to go in the event log, e.g. "Service Started", "Service Stopped", "Connected to Xyz", and maybe even "Schedule Initiated", "User Logged On", etc.

In some cases you may want to make writing to the event log a built-in part of your application and not via the trace system (i.e. write Event Log entries directly). This means it can't accidentally be turned off. (Note you still also want to note the same event in your trace system so you can correlate).

In contrast, a Windows GUI application would generally report these to the user (although they may also log to the Windows Event Log).

Events may also have related performance counters (e.g. number of errors/sec), and it can be important to co-ordinate any direct writing to the Event Log, performance counters, writing to the trace system and reporting to the user so they occur at the same time.

i.e. If a user sees an error message at a particular time, you should be able to find the same error message in the Windows Event Log, and then the same event with the same timestamp in the trace log (along with other trace details).

(2) Activities - Application Log files or database table (and trace files)

This is the regular activity that a system does, e.g. web page served, stock market trade lodged, order taken, calculation performed, etc.

Activity Tracing (start, stop, etc) is useful here (at the right granuality).

Also, it is very common to use a specific Application Log (sometimes called an Audit Log). Usually this is a database table or an application log file and contains structured data (i.e. a set of fields).

Things can get a bit blurred here depending on your application. A good example might be a web server which writes each request to a web log; similar examples might be a messaging system or calculation system where each operation is logged along with application-specific details.

A not so good example is stock market trades or a sales ordering system. In these systems you are probably already logging the activity as they have important business value, however the principal of correlating them to other actions is still important.

As well as custom application logs, activities also often have related peformance counters, e.g. number of transactions per second.

In generally you should co-ordinate logging of activities across different systems, i.e. write to your application log at the same time as you increase your performance counter and log to your trace system. If you do all at the same time (or straight after each other in the code), then debugging problems is easier (than if they all occur at diffent times/locations in the code).

(3) Debug Trace - Text file, or maybe XML or database.

This is information at Verbose level and lower (e.g. custom boolean switches to turn on/off raw data dumps). This provides the guts or details of what a system is doing at a sub-activity level.

This is the level you want to be able to turn on/off for individual sections of your application (hence the multiple sources). You don't want this stuff cluttering up the Windows Event Log. Sometimes a database is used, but more likely are rolling log files that are purged after a certain time.

A big difference between this information and an Application Log file is that it is unstructured. Whilst an Application Log may have fields for To, From, Amount, etc., Verbose debug traces may be whatever a programmer puts in, e.g. "checking values X={value}, Y=false", or random comments/markers like "Done it, trying again".

One important practice is to make sure things you put in application log files or the Windows Event Log also get logged to the trace system with the same details (e.g. timestamp). This allows you to then correlate the different logs when investigating.

If you are planning to use a particular log viewer because you have complex correlation, e.g. the Service Trace Viewer, then you need to use an appropriate format i.e. XML. Otherwise, a simple text file is usually good enough -- at the lower levels the information is largely unstructured, so you might find dumps of arrays, stack dumps, etc. Provided you can correlated back to more structured logs at higher levels, things should be okay.

Q: If using files, do you use rolling logs or just a single file? How do you make the logs available for people to consume?

A: For files, generally you want rolling log files from a manageability point of view (with System.Diagnostics simply use VisualBasic.Logging.FileLogTraceListener).

Availability again depends on the system. If you are only talking about files then for a server/service, rolling files can just be accessed when necessary. (Windows Event Log or Database Application Logs would have their own access mechanisms).

If you don't have easy access to the file system, then debug tracing to a database may be easier. [i.e. implement a database TraceListener].

One interesting solution I saw for a Windows GUI application was that it logged very detailed tracing information to a "flight recorder" whilst running and then when you shut it down if it had no problems then it simply deleted the file.

If, however it crashed or encountered a problem then the file was not deleted. Either if it catches the error, or the next time it runs it will notice the file, and then it can take action, e.g. compress it (e.g. 7zip) and email it or otherwise make available.

Many systems these days incorporate automated reporting of failures to a central server (after checking with users, e.g. for privacy reasons).


Viewing

Q: What tools to you use for viewing the logs?

A: If you have multiple logs for different reasons then you will use multiple viewers.

Notepad/vi/Notepad++ or any other text editor is the basic for plain text logs.

If you have complex operations, e.g. activities with transfers, then you would, obviously, use a specialized tool like the Service Trace Viewer. (But if you don't need it, then a text editor is easier).

As I generally log high level information to the Windows Event Log, then it provides a quick way to get an overview, in a structured manner (look for the pretty error/warning icons). You only need to start hunting through text files if there is not enough in the log, although at least the log gives you a starting point. (At this point, making sure your logs have co-ordinated entires becomes useful).

Generally the Windows Event Log also makes these significant events available to monitoring tools like MOM or OpenView.

Others --

If you log to a Database it can be easy to filter and sort informatio (e.g. zoom in on a particular activity id. (With text files you can use Grep/PowerShell or similar to filter on the partiular GUID you want)

MS Excel (or another spreadsheet program). This can be useful for analysing structured or semi-structured information if you can import it with the right delimiters so that different values go in different columns.

When running a service in debug/test I usually host it in a console application for simplicity I find a colored console logger useful (e.g. red for errors, yellow for warnings, etc). You need to implement a custom trace listener.

Note that the framework does not include a colored console logger or a database logger so, right now, you would need to write these if you need them (it's not too hard).

It really annoys me that several frameworks (log4net, EntLib, etc) have wasted time re-inventing the wheel and re-implemented basic logging, filtering, and logging to text files, the Windows Event Log, and XML files, each in their own different way (log statements are different in each); each has then implemented their own version of, for example, a database logger, when most of that already existed and all that was needed was a couple more trace listeners for System.Diagnostics. Talk about a big waste of duplicate effort.

Q: If you are building an ASP.NET solution, do you also use ASP.NET Health Monitoring? Do you include trace output in the health monitor events? What about Trace.axd?

These things can be turned on/off as needed. I find Trace.axd quite useful for debugging how a server responds to certain things, but it's not generally useful in a heavily used environment or for long term tracing.

Q: What about custom performance counters?

For a professional application, especially a server/service, I expect to see it fully instrumented with both Performance Monitor counters and logging to the Windows Event Log. These are the standard tools in Windows and should be used.

You need to make sure you include installers for the performance counters and event logs that you use; these should be created at installation time (when installing as administrator). When your application is running normally it should not need have administration privileges (and so won't be able to create missing logs).

This is a good reason to practice developing as a non-administrator (have a separate admin account for when you need to install services, etc). If writing to the Event Log, .NET will automatically create a missing log the first time you write to it; if you develop as a non-admin you will catch this early and avoid a nasty surprise when a customer installs your system and then can't use it because they aren't running as administrator.

How can I select from list of values in SQL Server

Simplest way to get the distinct values of a long list of comma delimited text would be to use a find an replace with UNION to get the distinct values.

SELECT 1
UNION SELECT 1
UNION SELECT 1
UNION SELECT 2
UNION SELECT 5
UNION SELECT 1
UNION SELECT 6

Applied to your long line of comma delimited text

  • Find and replace every comma with UNION SELECT
  • Add a SELECT in front of the statement

You now should have a working query

Download files from SFTP with SSH.NET library

My version of @Merak Marey's Code. I am checking if files exist already and different download directories for .txt and other files

        static void DownloadAll()
    {
        string host = "xxx.xxx.xxx.xxx";
        string username = "@@@";
        string password = "123";string remoteDirectory = "/IN/";
        string finalDir = "";
        string localDirectory = @"C:\filesDN\";
        string localDirectoryZip = @"C:\filesDN\ZIP\";
        using (var sftp = new SftpClient(host, username, password))
        {
            Console.WriteLine("Connecting to " + host + " as " + username);
            sftp.Connect();
            Console.WriteLine("Connected!");
            var files = sftp.ListDirectory(remoteDirectory);

            foreach (var file in files)
            {

                string remoteFileName = file.Name;

                if ((!file.Name.StartsWith(".")) && ((file.LastWriteTime.Date == DateTime.Today)))
                { 

                    if (!file.Name.Contains(".TXT"))
                    {
                        finalDir = localDirectoryZip;
                    } 
                    else 
                    {
                        finalDir = localDirectory;
                    }


                    if (File.Exists(finalDir  + file.Name))
                    {
                        Console.WriteLine("File " + file.Name + " Exists");
                    }else{
                        Console.WriteLine("Downloading file: " + file.Name);
                          using (Stream file1 = File.OpenWrite(finalDir + remoteFileName))
                    {
                        sftp.DownloadFile(remoteDirectory + remoteFileName, file1);
                    }
                    }
                }
            }



            Console.ReadLine();

        }

What is the best way to extract the first word from a string in Java?

To simplify the above:

text.substring(0, text.indexOf(' ')); 

Here is a ready function:

private String getFirstWord(String text) {

  int index = text.indexOf(' ');

  if (index > -1) { // Check if there is more than one word.

    return text.substring(0, index).trim(); // Extract first word.

  } else {

    return text; // Text is the first word itself.
  }
}

Storing files in SQL Server

You might read up on FILESTREAM. Here is some info from the docs that should help you decide:

If the following conditions are true, you should consider using FILESTREAM:

  • Objects that are being stored are, on average, larger than 1 MB.
  • Fast read access is important.
  • You are developing applications that use a middle tier for application logic.

For smaller objects, storing varbinary(max) BLOBs in the database often provides better streaming performance.

String to Dictionary in Python

Use ast.literal_eval to evaluate Python literals. However, what you have is JSON (note "true" for example), so use a JSON deserializer.

>>> import json
>>> s = """{"id":"123456789","name":"John Doe","first_name":"John","last_name":"Doe","link":"http:\/\/www.facebook.com\/jdoe","gender":"male","email":"jdoe\u0040gmail.com","timezone":-7,"locale":"en_US","verified":true,"updated_time":"2011-01-12T02:43:35+0000"}"""
>>> json.loads(s)
{u'first_name': u'John', u'last_name': u'Doe', u'verified': True, u'name': u'John Doe', u'locale': u'en_US', u'gender': u'male', u'email': u'[email protected]', u'link': u'http://www.facebook.com/jdoe', u'timezone': -7, u'updated_time': u'2011-01-12T02:43:35+0000', u'id': u'123456789'}

error running apache after xampp install

www.example.com:443:0 server certificate does NOT include an ID which matches the server name

I was getting this error when trying to start Apache, there is no error with Apache. It's an dependency error on windows 8 - probably the same for 7. Just right click and run as Admin :)

If you're still getting an error check your Antivirus/Firewall is not blocking Xampp or port 443.

python requests file upload

Client Upload

If you want to upload a single file with Python requests library, then requests lib supports streaming uploads, which allow you to send large files or streams without reading into memory.

with open('massive-body', 'rb') as f:
    requests.post('http://some.url/streamed', data=f)

Server Side

Then store the file on the server.py side such that save the stream into file without loading into the memory. Following is an example with using Flask file uploads.

@app.route("/upload", methods=['POST'])
def upload_file():
    from werkzeug.datastructures import FileStorage
    FileStorage(request.stream).save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
    return 'OK', 200

Or use werkzeug Form Data Parsing as mentioned in a fix for the issue of "large file uploads eating up memory" in order to avoid using memory inefficiently on large files upload (s.t. 22 GiB file in ~60 seconds. Memory usage is constant at about 13 MiB.).

@app.route("/upload", methods=['POST'])
def upload_file():
    def custom_stream_factory(total_content_length, filename, content_type, content_length=None):
        import tempfile
        tmpfile = tempfile.NamedTemporaryFile('wb+', prefix='flaskapp', suffix='.nc')
        app.logger.info("start receiving file ... filename => " + str(tmpfile.name))
        return tmpfile

    import werkzeug, flask
    stream, form, files = werkzeug.formparser.parse_form_data(flask.request.environ, stream_factory=custom_stream_factory)
    for fil in files.values():
        app.logger.info(" ".join(["saved form name", fil.name, "submitted as", fil.filename, "to temporary file", fil.stream.name]))
        # Do whatever with stored file at `fil.stream.name`
    return 'OK', 200

How to write the Fibonacci Sequence?

On the much shorter format:

def fibbo(range_, a, b):
    if(range_!=0):
        a, b = b, a+b
        print(a)
        return fibbo(range_-1, a, b)
    return

fibbo(11, 1, 0)

Can I check if Bootstrap Modal Shown / Hidden?

its an old question but anyway heres something i used incase someone was looking for the same thing

if (!$('#myModal').is(':visible')) {
    // if modal is not shown/visible then do something
}

CodeIgniter Active Record - Get number of returned rows

Just gotta read the docs son!

$query->num_rows();

SSH to Elastic Beanstalk instance

I have been playing with this as well.

  1. goto your elastic beanstalk service tab
  2. on your application overview goto action --> edit configuration
  3. add the name of a key as it appears in your EC2 tab (for the same region) to the existing keypair box and hit apply changes

The service will be relaunched so make a coffee for 5 mins

On your ec2 tab for the same region you'll see your new running instance. ssh to the public dns name as ec2-user using the key added in 3 e.g. ssh [email protected]

How do I find the location of my Python site-packages directory?

As others have noted, distutils.sysconfig has the relevant settings:

import distutils.sysconfig
print distutils.sysconfig.get_python_lib()

...though the default site.py does something a bit more crude, paraphrased below:

import sys, os
print os.sep.join([sys.prefix, 'lib', 'python' + sys.version[:3], 'site-packages'])

(it also adds ${sys.prefix}/lib/site-python and adds both paths for sys.exec_prefix as well, should that constant be different).

That said, what's the context? You shouldn't be messing with your site-packages directly; setuptools/distutils will work for installation, and your program may be running in a virtualenv where your pythonpath is completely user-local, so it shouldn't assume use of the system site-packages directly either.

Expected response code 220 but got code "", with message "" in Laravel

For me the problem was the port. I first incorrectly used port 465, which works for SSL but not TLS. So the key thing was changing the port to 587.

webpack: Module not found: Error: Can't resolve (with relative path)

changing templateUrl: '' to template: '' fixed it

how to set background image in submit button?

Typically one would use one (or more) image tags, maybe in combination with setting div background images in css to act as the submit button. The actual submit would be done in javascript on the click event.

A tutorial on the subject.

How to use regex in String.contains() method in Java

matcher.find() does what you needed. Example:

Pattern.compile("stores.*store.*product").matcher(someString).find();

How to have multiple colors in a Windows batch file?

If you have a modern Windows (that has powershell installed), the following may work fine as well

call :PrintBright Something Something

  (do actual batch stuff here)

call :PrintBright Done!
goto :eof


:PrintBright
powershell -Command Write-Host "%*" -foreground "White"

Adjust the color as you see fit.

Create hyperlink to another sheet

In my implementation, the cell I was referencing could have been several options. I used the following format where 'ws' is the current worksheet being edited

For each ws in Activeworkbook.Worksheets
    For i…
       For j...
...
ws.Cells(i, j).Value = "=HYPERLINK(""#'" & SHEET-REF-VAR & "'!" & CELL-REF-VAR & """,""" & SHEET-REF-VAR & """)"

XPath selecting a node with some attribute value equals to some other node's attribute value

I think this is what you want:

/grand/parent/child[@id="#grand"]

iOS 7 UIBarButton back button arrow color

UINavigationBar *nbar = self.navigationController.navigationBar;

if (floor(NSFoundationVersionNumber) > NSFoundationVersionNumber_iOS_6_1) {
   //iOS 7
   nbar.barTintColor = [UIColor blueColor]; // bar color
   //or custom color 
   //[UIColor colorWithRed:19.0/255.0 green:86.0/255.0 blue:138.0/255.0 alpha:1];

   nbar.navigationBar.translucent = NO;

   nbar.tintColor = [UIColor blueColor]; //bar button item color

} else {
   //ios 4,5,6
   nbar.tintColor = [UIColor whiteColor];
   //or custom color
   //[UIColor colorWithRed:19.0/255.0 green:86.0/255.0 blue:138.0/255.0 alpha:1];

}

Casting LinkedHashMap to Complex Object

You can use ObjectMapper.convertValue(), either value by value or even for the whole list. But you need to know the type to convert to:

POJO pojo = mapper.convertValue(singleObject, POJO.class);
// or:
List<POJO> pojos = mapper.convertValue(listOfObjects, new TypeReference<List<POJO>>() { });

this is functionally same as if you did:

byte[] json = mapper.writeValueAsBytes(singleObject);
POJO pojo = mapper.readValue(json, POJO.class);

but avoids actual serialization of data as JSON, instead using an in-memory event sequence as the intermediate step.

SQL DELETE with INNER JOIN

Add .* to s in your first line.

Try:

DELETE s.* FROM spawnlist s
INNER JOIN npc n ON s.npc_templateid = n.idTemplate
WHERE (n.type = "monster");

VBA Count cells in column containing specified value

Do you mean you want to use a formula in VBA? Something like:

Dim iVal As Integer
iVal = Application.WorksheetFunction.COUNTIF(Range("A1:A10"),"Green")

should work.

Recover unsaved SQL query scripts

I use the free file searching program Everything, search for *.sql files across my C: drive, and then sort by Last Modified, and then browse by the date I think it was probably last executed.

It usually brings up loads of autorecovery files from a variety of locations. And you don't have to worry where the latest version of SSMS/VS is saving the backup files this version.

enter image description here

Repeat each row of data.frame the number of times specified in a column

Another possibility is using tidyr::expand:

library(dplyr)
library(tidyr)

df %>% group_by_at(vars(-freq)) %>% expand(temp = 1:freq) %>% select(-temp)
#> # A tibble: 6 x 2
#> # Groups:   var1, var2 [3]
#>   var1  var2 
#>   <fct> <fct>
#> 1 a     d    
#> 2 b     e    
#> 3 b     e    
#> 4 c     f    
#> 5 c     f    
#> 6 c     f

One-liner version of vonjd's answer:

library(data.table)

setDT(df)[ ,list(freq=rep(1,freq)),by=c("var1","var2")][ ,freq := NULL][]
#>    var1 var2
#> 1:    a    d
#> 2:    b    e
#> 3:    b    e
#> 4:    c    f
#> 5:    c    f
#> 6:    c    f

Created on 2019-05-21 by the reprex package (v0.2.1)

Testing Spring's @RequestBody using Spring MockMVC

the following works for me,

  mockMvc.perform(
            MockMvcRequestBuilders.post("/api/test/url")
                    .contentType(MediaType.APPLICATION_JSON)
                    .content(asJsonString(createItemForm)))
            .andExpect(status().isCreated());

  public static String asJsonString(final Object obj) {
    try {
        return new ObjectMapper().writeValueAsString(obj);
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

Angular 6 Material mat-select change method removed

For:

1) mat-select (selectionChange)="myFunction()" works in angular as:

sample.component.html

 <mat-select placeholder="Select your option" [(ngModel)]="option" name="action" 
      (selectionChange)="onChange()">
     <mat-option *ngFor="let option of actions" [value]="option">
       {{option}}
     </mat-option>
 </mat-select>

sample.component.ts

actions=['A','B','C'];
onChange() {
  //Do something
}

2) Simple html select (change)="myFunction()" works in angular as:

sample.component.html

<select (change)="onChange()" [(ngModel)]="regObj.status">
    <option>A</option>
    <option>B</option>
    <option>C</option>
</select>

sample.component.ts

onChange() {
  //Do something
}

How to decode viewstate

This is somewhat "native" .NET way of converting ViewState from string into StateBag Code is below:

public static StateBag LoadViewState(string viewState)
    {
        System.Web.UI.Page converterPage = new System.Web.UI.Page();
        HiddenFieldPageStatePersister persister = new HiddenFieldPageStatePersister(new Page());
        Type utilClass = typeof(System.Web.UI.BaseParser).Assembly.GetType("System.Web.UI.Util");
        if (utilClass != null && persister != null)
        {
            MethodInfo method = utilClass.GetMethod("DeserializeWithAssert", BindingFlags.NonPublic | BindingFlags.Static);
            if (method != null)
            {
                PropertyInfo formatterProperty = persister.GetType().GetProperty("StateFormatter", BindingFlags.NonPublic | BindingFlags.Instance);
                if (formatterProperty != null)
                {
                    IStateFormatter formatter = (IStateFormatter)formatterProperty.GetValue(persister, null);
                    if (formatter != null)
                    {
                        FieldInfo pageField = formatter.GetType().GetField("_page", BindingFlags.NonPublic | BindingFlags.Instance);
                        if (pageField != null)
                        {
                            pageField.SetValue(formatter, null);
                            try
                            {
                                Pair pair = (Pair)method.Invoke(null, new object[] { formatter, viewState });
                                if (pair != null)
                                {
                                    MethodInfo loadViewState = converterPage.GetType().GetMethod("LoadViewStateRecursive", BindingFlags.Instance | BindingFlags.NonPublic);
                                    if (loadViewState != null)
                                    {
                                        FieldInfo postback = converterPage.GetType().GetField("_isCrossPagePostBack", BindingFlags.NonPublic | BindingFlags.Instance);
                                        if (postback != null)
                                        {
                                            postback.SetValue(converterPage, true);
                                        }
                                        FieldInfo namevalue = converterPage.GetType().GetField("_requestValueCollection", BindingFlags.NonPublic | BindingFlags.Instance);
                                        if (namevalue != null)
                                        {
                                            namevalue.SetValue(converterPage, new NameValueCollection());
                                        }
                                        loadViewState.Invoke(converterPage, new object[] { ((Pair)((Pair)pair.First).Second) });
                                        FieldInfo viewStateField = typeof(Control).GetField("_viewState", BindingFlags.NonPublic | BindingFlags.Instance);
                                        if (viewStateField != null)
                                        {
                                            return (StateBag)viewStateField.GetValue(converterPage);
                                        }
                                    }
                                }
                            }
                            catch (Exception ex)
                            {
                                if (ex != null)
                                {

                                }
                            }
                        }
                    }
                }
            }
        }
        return null;
    }

Is it possible to access to google translate api for free?

Yes, you can use GT for free. See the post with explanation. And look at repo on GitHub.

UPD 19.03.2019 Here is a version for browser on GitHub.

fatal: Unable to create temporary file '/home/username/git/myrepo.git/./objects/pack/tmp_pack_XXXXXX': Permission denied

It sounds like you have file in the git repo owned by root. Since you're ssh'ing in as 'username' to do the push, the files must be writable by username. The easiest thing is probably to create the repo as the user, and use the same user to do your pushes. Another option is to create a group, make everything writable by the group, and make your user a member of that group.

What HTTP traffic monitor would you recommend for Windows?

Fiddler is great when you are only interested in the http(s) side of the communications. It is also very useful when you are trying to inspect inside a https stream.

Why have header files and .cpp files?

It's the preprocessor way of declaring interfaces. You put the interface (method declarations) into the header file, and the implementation into the cpp. Applications using your library only need to know the interface, which they can access through #include.

PHPMailer character encoding issues

To avoid problems of character encoding in sending emails using the class PHPMailer we can configure it to send it with UTF-8 character encoding using the "CharSet" parameter, as we can see in the following Php code:

$mail = new PHPMailer();
$mail->From = '[email protected]';
$mail->FromName = 'Mi nombre';
$mail->AddAddress('[email protected]');
$mail->Subject = 'Prueba';
$mail->Body = '';
$mail->IsHTML(true);


// Active condition utf-8
$mail->CharSet = 'UTF-8';


// Send mail
$mail->Send();

What is the difference between DBMS and RDBMS?

A DBMS is used for storage of data in files. In DBMS relationships can be established between two files. Data is stored in flat files with metadata whereas RDBMS stores the data in tabular form with additional condition of data that enforces relationships among the tables. Unlike RDBMS, DBMS does not support client server architecture. RDBMS imposes integrity constraints and also follows normalization which is not supported in DBMS.

Update Multiple Rows in Entity Framework from a list of ids

I think you are looking for below method:

var idList=new int[]{1, 2, 3, 4};
using (var db=new SomeDatabaseContext())
{
    var friends= db.Friends.Where(f=>idList.Contains(f.ID));
    friends.ForEachAsync(a=>a.msgSentBy='1234');
    await db.SaveChangesAsync();
}

This should be the efficient way of handling this.

How to restart remote MySQL server running on Ubuntu linux?

  1. SSH into the machine. Using the proper credentials and ip address, ssh [email protected]. This should provide you with shell access to the Ubuntu server.
  2. Restart the mySQL service. sudo service mysql restart should do the job.

If your mySQL service is named something else like mysqld you may have to change the command accordingly or try this: sudo /etc/init.d/mysql restart

Creating a list/array in excel using VBA to get a list of unique names in a column

You can try my suggestion for a work around in Doug's approach.
But if you want to stick with your logic though, you can try this:

Option Explicit

Sub GetUnique()

Dim rng As Range
Dim myarray, myunique
Dim i As Integer

ReDim myunique(1)

With ThisWorkbook.Sheets("Sheet1")
    Set rng = .Range(.Range("A1"), .Range("A" & .Rows.Count).End(xlUp))
    myarray = Application.Transpose(rng)
    For i = LBound(myarray) To UBound(myarray)
        If IsError(Application.Match(myarray(i), myunique, 0)) Then
            myunique(UBound(myunique)) = myarray(i)
            ReDim Preserve myunique(UBound(myunique) + 1)
        End If
    Next
End With

For i = LBound(myunique) To UBound(myunique)
    Debug.Print myunique(i)
Next

End Sub

This uses array instead of range.
It also uses Match function instead of a nested For Loop.
I didn't have the time to check the time difference though.
So I leave the testing to you.

Is there a PowerShell "string does not contain" cmdlet or syntax?

To exclude the lines that contain any of the strings in $arrayOfStringsNotInterestedIn, you should use:

(Get-Content $FileName) -notmatch [String]::Join('|',$arrayofStringsNotInterestedIn)

The code proposed by Chris only works if $arrayofStringsNotInterestedIn contains the full lines you want to exclude.

How to add anchor tags dynamically to a div in Javascript?

One more variation wrapped up nicely where setAttribute isn't needed.

There are 3 lines that wouldn't be needed if Wetfox could dry off.

var saveAs = function (filename, content) {
    if(filename === undefined) filename = "Unknown.txt";
    if(content === undefined) content = "Empty?!";
    let link = document.createElement('a');
    link.style.display = "none"; // because Firefox sux
    document.body.appendChild(link); // because Firefox sux
    link.href = "data:application/octet-stream," + encodeURIComponent(content);
    link.download = filename;
    link.click();
    document.body.removeChild(link); // because Firefox sux
};

Thanks for the help.

Can Powershell Run Commands in Parallel?

http://gallery.technet.microsoft.com/scriptcenter/Invoke-Async-Allows-you-to-83b0c9f0

i created an invoke-async which allows you do run multiple script blocks/cmdlets/functions at the same time. this is great for small jobs (subnet scan or wmi query against 100's of machines) because the overhead for creating a runspace vs the startup time of start-job is pretty drastic. It can be used like so.

with scriptblock,

$sb = [scriptblock] {param($system) gwmi win32_operatingsystem -ComputerName $system | select csname,caption} 

$servers = Get-Content servers.txt 

$rtn = Invoke-Async -Set $server -SetParam system  -ScriptBlock $sb

just cmdlet/function

$servers = Get-Content servers.txt 

$rtn = Invoke-Async -Set $servers -SetParam computername -Params @{count=1} -Cmdlet Test-Connection -ThreadCount 50

Converting float to char*

char array[10];
sprintf(array, "%f", 3.123);

sprintf: (from MSDN)

How can I change the class of an element with jQuery>

Use jQuery's

$(this).addClass('showhideExtra_up_hover');

and

$(this).addClass('showhideExtra_down_hover');

Does height and width not apply to span?

As per comment from @Paul, If display: block is specified, span stops to be an inline element and an element after it appears on next line.

I came here to find solution to my span height problem and I got a solution of my own

Adding overflow:hidden; and keeing it inline will solve the problem just tested in IE8 Quirks mode

Convert byte slice to io.Reader

r := strings(byteData)

This also works to turn []byte into io.Reader

Difference between multitasking, multithreading and multiprocessing?

Both multiprogramming and multitasking solve different problems, though they use similar method of switching between the processes.

Multiprogramming : In the early days, it was seen that at times certain processes where using peripherals (e.g.: I/O). In such cases, the CPU remained idle. To use the CPU more efficiently, it was prudent to load multiple processes in the memory. This way, if a certain process were to use the peripheral, certain other process would use the CPU. This was multiprogramming in action.

Multitasking : To the end user, multiple processes had to appear running at the same time. This was mocked by switching between different processes and by making them run on the CPU simultaneously. This was the idea behind multitasking.

Formatting a float to 2 decimal places

string outString= number.ToString("####0.00");

Class JavaLaunchHelper is implemented in both ... libinstrument.dylib. One of the two will be used. Which one is undefined

?? For JetBrains IntelliJ IDEA: Go to Help -> Edit Custom Properties.... Create the file if it asks you to create it. To disable the error message paste the following to the file you created:

idea_rt
idea.no.launcher=true

This will take effect on the restart of the IntelliJ.

A terminal command for a rooted Android to remount /System as read/write

You don't need to pass both arguments when performing a remount. You can simply pass the mount point (here /system). And /system is universal amongst Android devices.

How to remove item from array by value?

Removing all matching elements from the array (rather than just the first as seems to be the most common answer here):

while ($.inArray(item, array) > -1) {
    array.splice( $.inArray(item, array), 1 );
}

I used jQuery for the heavy lifting, but you get the idea if you want to go native.

How to copy static files to build directory with Webpack?

lets say all your static assets are in a folder "static" at the root level and you want copy them to the build folder maintaining the structure of subfolder, then in your entry file) just put

//index.js or index.jsx

require.context("!!file?name=[path][name].[ext]&context=./static!../static/", true, /^\.\/.*\.*/);

How to fix: fatal error: openssl/opensslv.h: No such file or directory in RedHat 7

On CYGwin, you can install this as a typical package in the first screen. Look for

libssl-devel

Selected tab's color in Bottom Navigation View

It's too late to answer but might be helpful for someone. I was doing a very silly mistake, I was using a selector file named as bottom_color_nav.xml for Select and unselect color change but still it was not reflecting any color change in BottomNavigationView.

Then I realize, I was returning false in onNavigationItemSelected method. It will work fine if you'll return true in this method.

Better way to find control in ASP.NET

Recursively find all controls matching the specified predicate (do not include root Control):

    public static IEnumerable<Control> FindControlsRecursive(this Control control, Func<Control, bool> predicate)
    {
        var results = new List<Control>();

        foreach (Control child in control.Controls)
        {
            if (predicate(child))
            {
                results.Add(child);
            }
            results.AddRange(child.FindControlsRecursive(predicate));
        }

        return results;
    }

Usage:

myControl.FindControlsRecursive(c => c.ID == "findThisID");

Is there a way to instantiate a class by name in Java?

Two ways:

Method 1 - only for classes having a no-arg constructor

If your class has a no-arg constructor, you can get a Class object using Class.forName() and use the newInstance() method to create an instance (though beware that this method is often considered evil because it can defeat Java's checked exceptions).

For example:

Class<?> clazz = Class.forName("java.util.Date");
Object date = clazz.newInstance();

Method 2

An alternative safer approach which also works if the class doesn't have any no-arg constructors is to query your class object to get its Constructor object and call a newInstance() method on this object:

Class<?> clazz = Class.forName("com.foo.MyClass");
Constructor<?> constructor = clazz.getConstructor(String.class, Integer.class);
Object instance = constructor.newInstance("stringparam", 42);

Both methods are known as reflection. You will typically have to catch the various exceptions which can occur, including things like:

  • the JVM can't find or can't load your class
  • the class you're trying to instantiate doesn't have the right sort of constructors
  • the constructor itself threw an exception
  • the constructor you're trying to invoke isn't public
  • a security manager has been installed and is preventing reflection from occurring

curl error 18 - transfer closed with outstanding read data remaining

I had the same problem, but managed to fix it by suppressing the 'Expect: 100-continue' header that cURL usually sends (the following is PHP code, but should work similarly with other cURL APIs):

curl_setopt($curl, CURLOPT_HTTPHEADER, array('Expect:'));

By the way, I am sending calls to the HTTP server that is included in the JDK 6 REST stuff, which has all kinds of problems. In this case, it first sends a 100 response, and then with some requests doesn't send the subsequent 200 response correctly.

Why shouldn't `&apos;` be used to escape single quotes?

&quot; is on the official list of valid HTML 4 entities, but &apos; is not.

From C.16. The Named Character Reference ':

The named character reference &apos; (the apostrophe, U+0027) was introduced in XML 1.0 but does not appear in HTML. Authors should therefore use &#39; instead of &apos; to work as expected in HTML 4 user agents.

Is there any kind of hash code function in JavaScript?

My solution introduces a static function for the global Object object.

(function() {
    var lastStorageId = 0;

    this.Object.hash = function(object) {
        var hash = object.__id;

        if (!hash)
             hash = object.__id = lastStorageId++;

        return '#' + hash;
    };
}());

I think this is more convenient with other object manipulating functions in JavaScript.

Disable Pinch Zoom on Mobile Web

Unfortunately, the offered solution doesn't work in Safari 10+, since Apple has decided to ignore user-scalable=no. This thread has more details and some JS hacks: disable viewport zooming iOS 10+ safari?

Angularjs error Unknown provider

bmleite has the correct answer about including the module.

If that is correct in your situation, you should also ensure that you are not redefining the modules in multiple files.

Remember:

angular.module('ModuleName', [])   // creates a module.

angular.module('ModuleName')       // gets you a pre-existing module.

So if you are extending a existing module, remember not to overwrite when trying to fetch it.

What is newline character -- '\n'

NewLine (\n) is 10 (0xA) and CarriageReturn (\r) is 13 (0xD).

Different operating systems picked different end of line representations for files. Windows uses CRLF (\r\n). Unix uses LF (\n). Older Mac OS versions use CR (\r), but OS X switched to the Unix character.

Here is a relatively useful FAQ.

How to use onResume()?

The best way to understand would be to have all the LifeCycle methods overridden in your activity and placing a breakpoint(if checking in emulator) or a Log in each one of them. You'll get to know which one gets called when.

Just as an spoiler, onCreate() gets called first, then if you paused the activity by either going to home screen or by launching another activity, onPause() gets called. If the OS destroys the activity in the meantime, onDestroy() gets called. If you resume the app and the app already got destroyed, onCreate() will get called, or else onResume() will get called.

Edit: I forgot about onStop(), it gets called before onDestroy().

Do the exercise I mentioned and you'll be having a better understanding.

How do I escape double quotes in attributes in an XML String in T-SQL?

Wouldn't that be &quot; in xml? i.e.

"hi &quot;mom&quot; lol" 

**edit: ** tested; works fine:

declare @xml xml

 set @xml = '<transaction><item value="hi &quot;mom&quot; lol" 
    ItemId="106"  ItemType="2"  instanceId="215923801"  dataSetId="1" /></transaction>'

select @xml.value('(//item/@value)[1]','varchar(50)')

Bootstrap: Open Another Modal in Modal

Modals in Modal:

_x000D_
_x000D_
$('.modal-child').on('show.bs.modal', function () {_x000D_
    var modalParent = $(this).attr('data-modal-parent');_x000D_
    $(modalParent).css('opacity', 0);_x000D_
});_x000D_
 _x000D_
$('.modal-child').on('hidden.bs.modal', function () {_x000D_
    var modalParent = $(this).attr('data-modal-parent');_x000D_
    $(modalParent).css('opacity', 1);_x000D_
});
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet"/>_x000D_
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>_x000D_
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>_x000D_
_x000D_
<a href="#myModal" role="button" class="btn btn-primary" data-toggle="modal">Modals in Modal</a>_x000D_
_x000D_
_x000D_
<div id="myModal" class="modal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">_x000D_
    <div class="modal-dialog">_x000D_
        <!-- Modal content-->_x000D_
        <div class="modal-content">_x000D_
            <div class="modal-header">_x000D_
             _x000D_
                <button type="button" class="close" data-dismiss="modal">&times;</button>_x000D_
                <h4 class="modal-title">Modal Header</h4>_x000D_
            </div>_x000D_
            <div class="modal-body">_x000D_
                <a href="#myModal1" role="button" class="btn btn-primary" data-toggle="modal">Launch other modal 1</a>_x000D_
                <a href="#myModal2" role="button" class="btn btn-primary" data-toggle="modal">Launch other modal 2</a>_x000D_
            </div>_x000D_
_x000D_
        </div>_x000D_
    </div>_x000D_
</div>_x000D_
_x000D_
<div id="myModal1" class="modal modal-child" data-backdrop-limit="1" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true" data-modal-parent="#myModal">_x000D_
    <div class="modal-dialog">_x000D_
        <!-- Modal content-->_x000D_
        <div class="modal-content">_x000D_
            <div class="modal-header">_x000D_
                <button type="button" class="close" data-dismiss="modal">&times;</button>_x000D_
                <h4 class="modal-title">Modal Header 1</h4>_x000D_
            </div>_x000D_
            <div class="modal-body">_x000D_
                <p>Two modal body…1</p>_x000D_
            </div>_x000D_
            <div class="modal-footer">_x000D_
                <button class="btn btn-default" data-dismiss="modal" data-dismiss="modal" aria-hidden="true">Cancel</button>_x000D_
            </div>_x000D_
_x000D_
        </div>_x000D_
    </div>_x000D_
</div>_x000D_
_x000D_
<div id="myModal2" class="modal modal-child" data-backdrop-limit="1" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true" data-modal-parent="#myModal">_x000D_
    <div class="modal-dialog">_x000D_
        <!-- Modal content-->_x000D_
        <div class="modal-content">_x000D_
            <div class="modal-header">_x000D_
                _x000D_
                <button type="button" class="close" data-dismiss="modal">&times;</button>_x000D_
                <h4 class="modal-title">Modal Header 2</h4>_x000D_
            </div>_x000D_
            <div class="modal-body">_x000D_
                <p>Modal body…2</p>_x000D_
            </div>_x000D_
            <div class="modal-footer">_x000D_
                <button class="btn btn-default" data-dismiss="modal" data-dismiss="modal" aria-hidden="true">Cancel</button>_x000D_
            </div>_x000D_
_x000D_
        </div>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Showing all errors and warnings

Set these on php.ini:

;display_startup_errors = On
display_startup_errors=off
display_errors =on
html_errors= on

From your PHP page, use a suitable filter for error reporting.

error_reporting(E_ALL);

Filers can be made according to requirements.

E_ALL
E_ALL | E_STRICT

Using Java to pull data from a webpage?

Since Java 11 the most convenient way it to use java.net.http.HttpClient from the standard library.

Example:

HttpRequest request = HttpRequest.newBuilder(new URI(
    "https://stackoverflow.com/questions/6159118/using-java-to-pull-data-from-a-webpage"))
  .timeout(Duration.of(10, SECONDS))
  .GET()
  .build();

HttpResponse<String> response = HttpClient.newHttpClient()
  .send(request, BodyHandlers.ofString());

if (response.statusCode() != 200) {
  throw new RuntimeException(
    "Invalid response: " + response.statusCode() + ", request: " + response);
}

System.out.println(response.body());

What is the difference between class and instance methods?

In Objective-C all methods start with either a "-" or "+" character. Example:

@interface MyClass : NSObject
// instance method
- (void) instanceMethod;

+ (void) classMethod;
@end

The "+" and "-" characters specify whether a method is a class method or an instance method respectively.

The difference would be clear if we call these methods. Here the methods are declared in MyClass.

instance method require an instance of the class:

MyClass* myClass = [[MyClass alloc] init];
[myClass instanceMethod];

Inside MyClass other methods can call instance methods of MyClass using self:

-(void) someMethod
{
    [self instanceMethod];
}

But, class methods must be called on the class itself:

[MyClass classMethod];

Or:

MyClass* myClass = [[MyClass alloc] init];
[myClass class] classMethod];

This won't work:

// Error
[myClass classMethod];
// Error
[self classMethod];

twitter bootstrap text-center when in xs mode

Use bs3-upgrade library for spacings and text aligment...

https://github.com/studija/bs3-upgrade

col-xs-text-center col-sm-text-left

col-xs-text-center col-sm-text-right

<div class="container">
    <div class="row">
        <div class="col-xs-12 col-sm-6 col-xs-text-center col-sm-text-left">
            <p>
                &copy; 2015 example.com. All rights reserved.
            </p>
        </div>
        <div class="col-xs-12 col-sm-6 col-xs-text-center col-sm-text-right">
            <p>
                <a href="#"><i class="fa fa-facebook"></i></a> 
                <a href="#"><i class="fa fa-twitter"></i></a> 
                <a href="#"><i class="fa fa-google-plus"></i></a>
            </p>
        </div>
    </div>
</div>

Why is Event.target not Element in Typescript?

It doesn't inherit from Element because not all event targets are elements.

From MDN:

Element, document, and window are the most common event targets, but other objects can be event targets too, for example XMLHttpRequest, AudioNode, AudioContext, and others.

Even the KeyboardEvent you're trying to use can occur on a DOM element or on the window object (and theoretically on other things), so right there it wouldn't make sense for evt.target to be defined as an Element.

If it is an event on a DOM element, then I would say that you can safely assume evt.target. is an Element. I don't think this is an matter of cross-browser behavior. Merely that EventTarget is a more abstract interface than Element.

Further reading: https://typescript.codeplex.com/discussions/432211

Can you find all classes in a package using reflection?

The most robust mechanism for listing all classes in a given package is currently ClassGraph, because it handles the widest possible array of classpath specification mechanisms, including the new JPMS module system. (I am the author.)

List<String> classNames = new ArrayList<>();
try (ScanResult scanResult = new ClassGraph().acceptPackages("my.package")
        .enableClassInfo().scan()) {
    classNames.addAll(scanResult.getAllClasses().getNames());
}

Understanding events and event handlers in C#

I recently made an example of how to use events in c#, and posted it on my blog. I tried to make it as clear as possible, with a very simple example. In case it might help anyone, here it is: http://www.konsfik.com/using-events-in-csharp/

It includes description and source code (with lots of comments), and it mainly focuses on a proper (template - like) usage of events and event handlers.

Some key points are:

  • Events are like "sub - types of delegates", only more constrained (in a good way). In fact an event's declaration always includes a delegate (EventHandlers are a type of delegate).

  • Event Handlers are specific types of delegates (you may think of them as a template), which force the user to create events which have a specific "signature". The signature is of the format: (object sender, EventArgs eventarguments).

  • You may create your own sub-class of EventArgs, in order to include any type of information the event needs to convey. It is not necessary to use EventHandlers when using events. You may completely skip them and use your own kind of delegate in their place.

  • One key difference between using events and delegates, is that events can only be invoked from within the class that they were declared in, even though they may be declared as public. This is a very important distinction, because it allows your events to be exposed so that they are "connected" to external methods, while at the same time they are protected from "external misuse".

Open web in new tab Selenium + Python

The other solutions do not work for chrome driver v83.

Instead, it works as follows, suppose there is only 1 opening tab:

driver.execute_script("window.open('');")
driver.switch_to.window(driver.window_handles[1])
driver.get("https://www.example.com")

If there are already more than 1 opening tabs, you should first get the index of the last newly-created tab and switch to the tab before calling the url (Credit to tylerl) :

driver.execute_script("window.open('');")
driver.switch_to.window(len(driver.window_handles)-1)
driver.get("https://www.example.com")

Send json post using php

Without using any external dependency or library:

$options = array(
  'http' => array(
    'method'  => 'POST',
    'content' => json_encode( $data ),
    'header'=>  "Content-Type: application/json\r\n" .
                "Accept: application/json\r\n"
    )
);

$context  = stream_context_create( $options );
$result = file_get_contents( $url, false, $context );
$response = json_decode( $result );

$response is an object. Properties can be accessed as usual, e.g. $response->...

where $data is the array contaning your data:

$data = array(
  'userID'      => 'a7664093-502e-4d2b-bf30-25a2b26d6021',
  'itemKind'    => 0,
  'value'       => 1,
  'description' => 'Boa saudaÁ„o.',
  'itemID'      => '03e76d0a-8bab-11e0-8250-000c29b481aa'
);

Warning: this won't work if the allow_url_fopen setting is set to Off in the php.ini.

If you're developing for WordPress, consider using the provided APIs: https://developer.wordpress.org/plugins/http-api/

How do I delete everything below row X in VBA/Excel?

Any Reference to 'Row' should use 'long' not 'integer' else it will overflow if the spreadsheet has a lot of data.

How do I detect what .NET Framework versions and service packs are installed?

The Framework 4 beta installs to a differing registry key.

using System;
using System.Collections.ObjectModel;
using Microsoft.Win32;

class Program
{
    static void Main(string[] args)
    {
        foreach(Version ver in InstalledDotNetVersions())
            Console.WriteLine(ver);

        Console.ReadKey();
    }


    public static Collection<Version> InstalledDotNetVersions()
    {
        Collection<Version> versions = new Collection<Version>();
        RegistryKey NDPKey = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP");
        if (NDPKey != null)
        {
            string[] subkeys = NDPKey.GetSubKeyNames();
            foreach (string subkey in subkeys)
            {
                GetDotNetVersion(NDPKey.OpenSubKey(subkey), subkey, versions);
                GetDotNetVersion(NDPKey.OpenSubKey(subkey).OpenSubKey("Client"), subkey, versions);
                GetDotNetVersion(NDPKey.OpenSubKey(subkey).OpenSubKey("Full"), subkey, versions);
            }
        }
        return versions;
    }

    private static void GetDotNetVersion(RegistryKey parentKey, string subVersionName, Collection<Version> versions)
    {
        if (parentKey != null)
        {
            string installed = Convert.ToString(parentKey.GetValue("Install"));
            if (installed == "1")
            {
                string version = Convert.ToString(parentKey.GetValue("Version"));
                if (string.IsNullOrEmpty(version))
                {
                    if (subVersionName.StartsWith("v"))
                        version = subVersionName.Substring(1);
                    else
                        version = subVersionName;
                }

                Version ver = new Version(version);

                if (!versions.Contains(ver))
                    versions.Add(ver);
            }
        }
    }
}

JSON - Iterate through JSONArray

JsonArray jsonArray;
Iterator<JsonElement> it = jsonArray.iterator();
while(it.hasNext()){
    System.out.println(it.next());
}

Add one year in current date PYTHON

AGSM's answer shows a convenient way of solving this problem using the python-dateutil package. But what if you don't want to install that package? You could solve the problem in vanilla Python like this:

from datetime import date

def add_years(d, years):
    """Return a date that's `years` years after the date (or datetime)
    object `d`. Return the same calendar date (month and day) in the
    destination year, if it exists, otherwise use the following day
    (thus changing February 29 to March 1).

    """
    try:
        return d.replace(year = d.year + years)
    except ValueError:
        return d + (date(d.year + years, 1, 1) - date(d.year, 1, 1))

If you want the other possibility (changing February 29 to February 28) then the last line should be changed to:

        return d + (date(d.year + years, 3, 1) - date(d.year, 3, 1))

How to stop PHP code execution?

or try

trigger_error('Die', E_ERROR);

HTTP Error 500.22 - Internal Server Error (An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.)

In your web.config, make sure these keys exist:

<configuration>
    <system.webServer>
        <validation validateIntegratedModeConfiguration="false"/>
    </system.webServer>
</configuration>

In Angular, I need to search objects in an array

Saw this thread but I wanted to search for IDs that did not match my search. Code to do that:

found = $filter('filter')($scope.fish, {id: '!fish_id'}, false);

CSS: Set Div height to 100% - Pixels

_x000D_
_x000D_
div{_x000D_
  height:100vh;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

How to make html <select> element look like "disabled", but pass values?

You can keep it disabled as desired, and then remove the disabled attribute before the form is submitted.

$('#myForm').submit(function() {
    $('select').removeAttr('disabled');
});

Note that if you rely on this method, you'll want to disable it programmatically as well, because if JS is disabled or not supported, you'll be stuck with the disabled select.

$(document).ready(function() {
    $('select').attr('disabled', 'disabled');
});

Android: How can I pass parameters to AsyncTask's onPreExecute()?

You can either pass the parameter in the task constructor or when you call execute:

AsyncTask<Object, Void, MyTaskResult>

The first parameter (Object) is passed in doInBackground. The third parameter (MyTaskResult) is returned by doInBackground. You can change them to the types you want. The three dots mean that zero or more objects (or an array of them) may be passed as the argument(s).

public class MyActivity extends AppCompatActivity {

    TextView textView1;
    TextView textView2;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);    
        textView1 = (TextView) findViewById(R.id.textView1);
        textView2 = (TextView) findViewById(R.id.textView2);

        String input1 = "test";
        boolean input2 = true;
        int input3 = 100;
        long input4 = 100000000;

        new MyTask(input3, input4).execute(input1, input2);
    }

    private class MyTaskResult {
        String text1;
        String text2;
    }

    private class MyTask extends AsyncTask<Object, Void, MyTaskResult> {
        private String val1;
        private boolean val2;
        private int val3;
        private long val4;


        public MyTask(int in3, long in4) {
            this.val3 = in3;
            this.val4 = in4;

            // Do something ...
        }

        protected void onPreExecute() {
            // Do something ...
        }

        @Override
        protected MyTaskResult doInBackground(Object... params) {
            MyTaskResult res = new MyTaskResult();
            val1 = (String) params[0];
            val2 = (boolean) params[1];

            //Do some lengthy operation    
            res.text1 = RunProc1(val1);
            res.text2 = RunProc2(val2);

            return res;
        }

        @Override
        protected void onPostExecute(MyTaskResult res) {
            textView1.setText(res.text1);
            textView2.setText(res.text2);

        }
    }

}

default value for struct member in C

You can use some function to initialize struct as follows,

typedef struct
{
    int flag;
} MyStruct;

MyStruct GetMyStruct(int value)
{
    MyStruct My = {0};
    My.flag = value;
    return My;
}

void main (void)
{
    MyStruct temp;
    temp = GetMyStruct(3);
    printf("%d\n", temp.flag);
}

EDIT:

typedef struct
{
    int flag;
} MyStruct;

MyStruct MyData[20];

MyStruct GetMyStruct(int value)
{
    MyStruct My = {0};
    My.flag = value;
    return My;
}

void main (void)
{
    int i;
    for (i = 0; i < 20; i ++)
        MyData[i] = GetMyStruct(3);

    for (i = 0; i < 20; i ++)
        printf("%d\n", MyData[i].flag);
}

Remove Item from ArrayList

 public void DeleteUserIMP(UserIMP useriamp) {
       synchronized (ListUserIMP) {
            if (ListUserIMP.isEmpty()) {
            System.out.println("user is empty");
        }  else {
            Iterator<UserIMP> it = ListUserIMP.iterator();
            while (it.hasNext()) {
                UserIMP user = it.next();
                if (useriamp.getMoblieNumber().equals(user.getMoblieNumber())) {
                    it.remove();
                    System.out.println("remove it");
                }
            }
            // ListUserIMP.remove(useriamp);

            System.out.println(" this user removed");
        }
        Constants.RESULT_FOR_REGISTRATION = Constants.MESSAGE_OK;
        // System.out.println("This user Deleted " + Constants.MESSAGE_OK);

    }
}

Set SSH connection timeout

The ConnectTimeout option allows you to tell your ssh client how long you're willing to wait for a connection before returning an error. By setting ConnectTimeout to 1, you're effectively saying "try for at most 1 second and then fail if you haven't connected yet".

The problem is that when you connect by name, the DNS lookup can take several seconds. Connecting by IP address is much faster, and may actually work in one second or less. What sinelaw is experiencing is that every attempt to connect by DNS name is failing to occur within one second. The default setting of ConnectTimeout defers to the linux kernel connect timeout, which is usually pretty long.

Show/hide image with JavaScript

If you already have a JavaScript function called showImage defined to show the image, you can link as such:

<a href="javascript:showImage()">show image</a>

If you need help defining the function, I would try:

function showImage() {
    var img = document.getElementById('myImageId');
    img.style.visibility = 'visible';
}

Or, better yet,

function setImageVisible(id, visible) {
    var img = document.getElementById(id);
    img.style.visibility = (visible ? 'visible' : 'hidden');
}

Then, your links would be:

<a href="javascript:setImageVisible('myImageId', true)">show image</a>
<a href="javascript:setImageVisible('myImageId', false)">hide image</a>

Text File Parsing in Java

Have a look at these pages. They contain many open source CSV parsers. JSaPar is one of them.

Variable is accessed within inner class. Needs to be declared final

If you don't want to make it final, you can always just make it a global variable.

How to change the application launcher icon on Flutter?

The one marked as correct answer, is not enough, you need one more step, type this command in the terminal in order to create the icons:

flutter pub run flutter_launcher_icons:main

Add new item in existing array in c#.net

Using LINQ:

arr = (arr ?? Enumerable.Empty<string>()).Concat(new[] { newitem }).ToArray();

I like using this as it is a one-liner and very convenient to embed in a switch statement, a simple if-statement, or pass as argument.

EDIT:

Some people don't like new[] { newitem } because it creates a small, one-item, temporary array. Here is a version using Enumerable.Repeat that does not require creating any object (at least not on the surface -- .NET iterators probably create a bunch of state machine objects under the table).

arr = (arr ?? Enumerable.Empty<string>()).Concat(Enumerable.Repeat(newitem,1)).ToArray();

And if you are sure that the array is never null to start with, you can simplify it to:

arr.Concat(Enumerable.Repeat(newitem,1)).ToArray();

Notice that if you want to add items to a an ordered collection, List is probably the data structure you want, not an array to start with.

Reset all the items in a form

If you have some panels or groupboxes reset fields should be recursive.

public class Utilities
{
    public static void ResetAllControls(Control form)
    {
        foreach (Control control in form.Controls)
        {
            RecursiveResetForm(control);
        }
    }

    private void RecursiveResetForm(Control control)
    {            
        if (control.HasChildren)
        {
            foreach (Control subControl in control.Controls)
            {
                RecursiveResetForm(subControl);
            }
        }
        switch (control.GetType().Name)
        {
            case "TextBox":
                TextBox textBox = (TextBox)control;
                textBox.Text = null;
                break;

            case "ComboBox":
                ComboBox comboBox = (ComboBox)control;
                if (comboBox.Items.Count > 0)
                    comboBox.SelectedIndex = 0;
                break;

            case "CheckBox":
                CheckBox checkBox = (CheckBox)control;
                checkBox.Checked = false;
                break;

            case "ListBox":
                ListBox listBox = (ListBox)control;
                listBox.ClearSelected();
                break;

            case "NumericUpDown":
                NumericUpDown numericUpDown = (NumericUpDown)control;
                numericUpDown.Value = 0;
                break;
        }
    }        
}

How do I purge a linux mail box with huge number of emails?

If you're using cyrus/sasl/imap on your mailserver, then one fast and efficient way to purge everything in a mailbox that is older then number of days specified is to use cyrus/imap ipurge command. For example, here is an example removing everything (be carefull!!), older then 30 days from user vleo. Notice, that you must be logged in as cyrus (imap mail administrator) user:

[cyrus@mailserver ~]$ /usr/lib/cyrus-imapd/ipurge -f -d 30 user.vleo Working on user.vleo... total messages 4 total bytes 113183 Deleted messages 0 Deleted bytes 0 Remaining messages 4 Remaining bytes 113183

"UserWarning: Matplotlib is currently using agg, which is a non-GUI backend, so cannot show the figure." when plotting figure with pyplot on Pycharm

If you use Arch Linux (distributions like Manjaro or Antegros) simply type:

sudo pacman -S tk

And all will work perfectly!

How to default to other directory instead of home directory

My Git Bash shortcut on Windows complained when I put the cd to my work directory into ~/.bashrc

WARNING: Found ~/.bashrc but no ~/.bash_profile, ~/.bash_login or ~/.profile.

This looks like an incorrect setup.
A ~/.bash_profile that loads ~/.bashrc will be created for you.

So git created this .bash_profile:

$ cat ~/.bash_profile
# generated by Git for Windows
test -f ~/.profile && . ~/.profile
test -f ~/.bashrc && . ~/.bashrc

Which does the job.

Alternatively, you can just remove the .bashrc again and put the cd command into .bash_profile:

$ rm ~/.bashrc
$ echo "cd Source/Repos" >~/.bash_profile

$ cat ~/.bash_profile
cd Source/Repos

Once this is done you can close the Window and re-open it using your desktop shortcut and the prompt will tell you that your location is now where you wanted it - looks like this is my case:

Administrator@raptor1 MINGW64 ~/Source/Repos
$

Query comparing dates in SQL

Try like this

select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
where 
created_date <= '2013-12-04'

Font is not available to the JVM with Jasper Reports

Copy your Fonts on the following directory JDK_HOME\jre\lib\fonts

Center the nav in Twitter Bootstrap

I prefer this :

<nav class="navbar">
  <div class="hidden-xs hidden-sm" style="position: absolute;left: 50%;margin-left:-56px;width:112px" id="centered-div">
    <!-- this element is on the center of the nav, visible only on -md and -lg -->
    <a></a>
  </div>

  <div class="container-fluid">
    <!-- ...things with your navbar... -->
      <div class="visible-xs visible-sm">
        <!-- this element will be hidden on -md and -lg -->
      </div>
    <!-- ...things with your navbar... -->
  </div>
</nav>

The element is perfectly centered, and will be hidden on some screen sizes (there was no place left on -xs and -sm for me for example). I get the idea from Twitter's actual navbar

IIs Error: Application Codebehind=“Global.asax.cs” Inherits=“nadeem.MvcApplication”

In My case the issue was fixed by changing the solution platform from AnyCPU to x86.

Youtube - How to force 480p video quality in embed link / <iframe>

You can use the fmt= parameter and fill the value based on the following table :

http://en.wikipedia.org/wiki/YouTube#Quality_and_codecs

Ex : your URL would become :

http://www.youtube.com/embed/FqRgAs0SOpU?fmt=35

How do I print colored output to the terminal in Python?

I suggest sty. It's similar to colorama, but less verbose and it supports 8bit and 24bit colors. You can also extend the color register with your own colors.

Examples:

from sty import fg, bg, ef, rs

foo = fg.red + 'This is red text!' + fg.rs
bar = bg.blue + 'This has a blue background!' + bg.rs
baz = ef.italic + 'This is italic text' + rs.italic
qux = fg(201) + 'This is pink text using 8bit colors' + fg.rs
qui = fg(255, 10, 10) + 'This is red text using 24bit colors.' + fg.rs

# Add custom colors:

from sty import Style, RgbFg

fg.orange = Style(RgbFg(255, 150, 50))

buf = fg.orange + 'Yay, Im orange.' + fg.rs

print(foo, bar, baz, qux, qui, buf, sep='\n')

enter image description here

Demo:

enter image description here

I just assigned a variable, but echo $variable shows something else

You may want to know why this is happening. Together with the great explanation by that other guy, find a reference of Why does my shell script choke on whitespace or other special characters? written by Gilles in Unix & Linux:

Why do I need to write "$foo"? What happens without the quotes?

$foo does not mean “take the value of the variable foo”. It means something much more complex:

  • First, take the value of the variable.
  • Field splitting: treat that value as a whitespace-separated list of fields, and build the resulting list. For example, if the variable contains foo * bar ? then the result of this step is the 3-element list foo, *, bar.
  • Filename generation: treat each field as a glob, i.e. as a wildcard pattern, and replace it by the list of file names that match this pattern. If the pattern doesn't match any files, it is left unmodified. In our example, this results in the list containing foo, following by the list of files in the current directory, and finally bar. If the current directory is empty, the result is foo, *, bar.

Note that the result is a list of strings. There are two contexts in shell syntax: list context and string context. Field splitting and filename generation only happen in list context, but that's most of the time. Double quotes delimit a string context: the whole double-quoted string is a single string, not to be split. (Exception: "$@" to expand to the list of positional parameters, e.g. "$@" is equivalent to "$1" "$2" "$3" if there are three positional parameters. See What is the difference between $* and $@?)

The same happens to command substitution with $(foo) or with `foo`. On a side note, don't use `foo`: its quoting rules are weird and non-portable, and all modern shells support $(foo) which is absolutely equivalent except for having intuitive quoting rules.

The output of arithmetic substitution also undergoes the same expansions, but that isn't normally a concern as it only contains non-expandable characters (assuming IFS doesn't contain digits or -).

See When is double-quoting necessary? for more details about the cases when you can leave out the quotes.

Unless you mean for all this rigmarole to happen, just remember to always use double quotes around variable and command substitutions. Do take care: leaving out the quotes can lead not just to errors but to security holes.

You need to use a Theme.AppCompat theme (or descendant) with this activity

I had the same problem, but it solved when i put this on manifest: android:theme="@style/Theme.AppCompat.

    <application
        android:allowBackup="true"
        android:icon="@drawable/icon"
        android:label="@string/app_name_test"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat">

        ...    

    </application>

How can I edit a view using phpMyAdmin 3.2.4?

To expand one what CheeseConQueso is saying, here are the entire steps to update a view using PHPMyAdmin:

  1. Run the following query: SHOW CREATE VIEW your_view_name
  2. Expand the options and choose Full Texts
  3. Press Go
  4. Copy entire contents of the Create View column.
  5. Make changes to the query in the editor of your choice
  6. Run the query directly (without the CREATE VIEW... syntax) to make sure it runs as you expect it to.
  7. Once you're satisfied, click on your view in the list on the left to browse its data and then scroll all the way to the bottom where you'll see a CREATE VIEW link. Click that.
  8. Place a check in the OR REPLACE field.
  9. In the VIEW name put the name of the view you are going to update.
  10. In the AS field put the contents of the query that you ran while testing (without the CREATE VIEW... syntax).
  11. Press Go

I hope that helps somebody. Special thanks to CheesConQueso for his/her insightful answer.

What is the use of "assert"?

format : assert Expression[,arguments] When assert encounters a statement,Python evaluates the expression.If the statement is not true,an exception is raised(assertionError). If the assertion fails, Python uses ArgumentExpression as the argument for the AssertionError. AssertionError exceptions can be caught and handled like any other exception using the try-except statement, but if not handled, they will terminate the program and produce a traceback. Example:

def KelvinToFahrenheit(Temperature):    
    assert (Temperature >= 0),"Colder than absolute zero!"    
    return ((Temperature-273)*1.8)+32    
print KelvinToFahrenheit(273)    
print int(KelvinToFahrenheit(505.78))    
print KelvinToFahrenheit(-5)    

When the above code is executed, it produces the following result:

32.0
451
Traceback (most recent call last):    
  File "test.py", line 9, in <module>    
    print KelvinToFahrenheit(-5)    
  File "test.py", line 4, in KelvinToFahrenheit    
    assert (Temperature >= 0),"Colder than absolute zero!"    
AssertionError: Colder than absolute zero!    

Most common C# bitwise operations on enums

For the best performance and zero garbage, use this:

using System;
using T = MyNamespace.MyFlags;

namespace MyNamespace
{
    [Flags]
    public enum MyFlags
    {
        None = 0,
        Flag1 = 1,
        Flag2 = 2
    }

    static class MyFlagsEx
    {
        public static bool Has(this T type, T value)
        {
            return (type & value) == value;
        }

        public static bool Is(this T type, T value)
        {
            return type == value;
        }

        public static T Add(this T type, T value)
        {
            return type | value;
        }

        public static T Remove(this T type, T value)
        {
            return type & ~value;
        }
    }
}

How to execute a raw update sql with dynamic binding in rails

ActiveRecord::Base.connection has a quote method that takes a string value (and optionally the column object). So you can say this:

ActiveRecord::Base.connection.execute(<<-EOQ)
  UPDATE  foo
  SET     bar = #{ActiveRecord::Base.connection.quote(baz)}
EOQ

Note if you're in a Rails migration or an ActiveRecord object you can shorten that to:

connection.execute(<<-EOQ)
  UPDATE  foo
  SET     bar = #{connection.quote(baz)}
EOQ

UPDATE: As @kolen points out, you should use exec_update instead. This will handle the quoting for you and also avoid leaking memory. The signature works a bit differently though:

connection.exec_update(<<-EOQ, "SQL", [[nil, baz]])
  UPDATE  foo
  SET     bar = $1
EOQ

Here the last param is a array of tuples representing bind parameters. In each tuple, the first entry is the column type and the second is the value. You can give nil for the column type and Rails will usually do the right thing though.

There are also exec_query, exec_insert, and exec_delete, depending on what you need.

Using Java to find substring of a bigger string using Regular Expression

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public static String get_match(String s, String p) {
    // returns first match of p in s for first group in regular expression 
    Matcher m = Pattern.compile(p).matcher(s);
    return m.find() ? m.group(1) : "";
}

get_match("FOO[BAR]", "\\[(.*?)\\]")  // returns "BAR"

public static List<String> get_matches(String s, String p) {
    // returns all matches of p in s for first group in regular expression 
    List<String> matches = new ArrayList<String>();
    Matcher m = Pattern.compile(p).matcher(s);
    while(m.find()) {
        matches.add(m.group(1));
    }
    return matches;
}

get_matches("FOO[BAR] FOO[CAT]", "\\[(.*?)\\]")) // returns [BAR, CAT]

Detect if the device is iPhone X

For a quick fix, I like this:

let var:CGFloat = (UIDevice.current.userInterfaceIdiom == .phone && UIScreen.main.nativeBounds.height == 2436) ? <iPhoneX> : <AllOthers>

How can I remove the first line of a text file using bash/sed script?

As Pax said, you probably aren't going to get any faster than this. The reason is that there are almost no filesystems that support truncating from the beginning of the file so this is going to be an O(n) operation where n is the size of the file. What you can do much faster though is overwrite the first line with the same number of bytes (maybe with spaces or a comment) which might work for you depending on exactly what you are trying to do (what is that by the way?).

How do I fix MSB3073 error in my post-build event?

I've found the issue happens when you have multiple projects building in parallel and one or more of the projects are attempting to copy the same files, creating race conditions that will result in occasional errors. So how to solve it?

There's a lot of options, as above just changing things around could solve the issue for some people. More robust solutions would be...

  • Restrict the files being copied i.e. instead of xcopy $(TargetDir)*.*"... instead do xcopy "$(TargetDir)$(TargetName).*"...

  • Catch the error and retry i.e:

    :loop
    xcopy /Y /R /S /J /Q  "$(TargetDir)$(TargetName).*" "somewhere"
    if ErrorLevel 1 goto loop
  • Use robocopy instead of xcopy

  • You probably won't want to do this as it will increase your build times, but you could reduce the maximum number of parallel project builds to 1 ...

enter image description here

Postgres FOR LOOP

I just ran into this question and, while it is old, I figured I'd add an answer for the archives. The OP asked about for loops, but their goal was to gather a random sample of rows from the table. For that task, Postgres 9.5+ offers the TABLESAMPLE clause on WHERE. Here's a good rundown:

https://www.2ndquadrant.com/en/blog/tablesample-in-postgresql-9-5-2/

I tend to use Bernoulli as it's row-based rather than page-based, but the original question is about a specific row count. For that, there's a built-in extension:

https://www.postgresql.org/docs/current/tsm-system-rows.html

CREATE EXTENSION tsm_system_rows;

Then you can grab whatever number of rows you want:

select * from playtime tablesample system_rows (15);

How to use boolean 'and' in Python

You can also test them as a couple.

if (i,ii)==(5,10):
    print "i is 5 and ii is 10"

possible EventEmitter memory leak detected

I was having this till today when I start grunt watch. Finally solved by

watch: {
  options: {
    maxListeners: 99,
    livereload: true
  },
}

The annoying message is gone.

printf() prints whole array

But still, the memory address for each letter in this address is different.

Memory address is different but as its array of characters they are sequential. When you pass address of first element and use %s, printf will print all characters starting from given address until it finds '\0'.

Get class name of object as string in Swift

Sometimes the other solutions will give a non useful name depending on what object you are trying to look at. In that case you can get the class name as a string using the following.

String(cString: object_getClassName(Any!))

? click the function in xcode to see some related methods that are fairly useful. or check here https://developer.apple.com/reference/objectivec/objective_c_functions

How to create a directory and give permission in single command

You could write a simple shell script, for example:

#!/bin/bash
mkdir "$1"
chmod 777 "$1"

Once saved, and the executable flag enabled, you could run it instead of mkdir and chmod:

./scriptname path/foldername

However, alex's answer is much better because it spawns one process instead of three. I didn't know about the -m option.

The module was expected to contain an assembly manifest

First try to open the file with a decompiler such as ILSpy, your dll might be corrupt. I had this error on an online web site, when I downloaded the dll and tried to open it, it was corrupt, probably some error occurred while uploading it via ftp.

Execute and get the output of a shell command in node.js

This is the method I'm using in a project I am currently working on.

var exec = require('child_process').exec;
function execute(command, callback){
    exec(command, function(error, stdout, stderr){ callback(stdout); });
};

Example of retrieving a git user:

module.exports.getGitUser = function(callback){
    execute("git config --global user.name", function(name){
        execute("git config --global user.email", function(email){
            callback({ name: name.replace("\n", ""), email: email.replace("\n", "") });
        });
    });
};

Selenium Error - The HTTP request to the remote WebDriver timed out after 60 seconds

In my case the issue was with SendKeys() and Remote Desktop. Posting the workaround I have so far:

I had a Selenium test which would fail when run as part of a Jenkins job on a node hosted in vSphere and administered through RDP. After some troubleshooting it turned out it succeeds if Remote Desktop is connected and focused but fails with the exception if Remote Desktop is disconnected or even minimized.

As a workaround, I logged through vSphere Console instead of RDP and then even after closing vSphere the test didn't fail anymore. This is a workaround but I would have to be careful never to login through RDP and always to administer only through vSphere Console.

How to break lines at a specific character in Notepad++?

Let's assume ], is the character where we wanted to break at

  1. Open notePad++
  2. Open Find window Ctrl+F
  3. Switch to Replace Tab
  4. Choose Search Mode to Extended
  5. Type ], in Find What field
  6. Type \nin Replace with field
  7. Hit Replace All
  8. Boom

laravel 5.3 new Auth::routes()

Auth routes for Laravel 5.3 instead Auth::routes(). I hope it helps...

Route::group(['middleware' => ['web']], function() {

// Login Routes...
    Route::get('login', ['as' => 'login', 'uses' => 'Auth\LoginController@showLoginForm']);
    Route::post('login', ['as' => 'login.post', 'uses' => 'Auth\LoginController@login']);
    Route::post('logout', ['as' => 'logout', 'uses' => 'Auth\LoginController@logout']);

// Registration Routes...
    Route::get('register', ['as' => 'register', 'uses' => 'Auth\RegisterController@showRegistrationForm']);
    Route::post('register', ['as' => 'register.post', 'uses' => 'Auth\RegisterController@register']);

// Password Reset Routes...
    Route::get('password/reset', ['as' => 'password.reset', 'uses' => 'Auth\ForgotPasswordController@showLinkRequestForm']);
    Route::post('password/email', ['as' => 'password.email', 'uses' => 'Auth\ForgotPasswordController@sendResetLinkEmail']);
    Route::get('password/reset/{token}', ['as' => 'password.reset.token', 'uses' => 'Auth\ResetPasswordController@showResetForm']);
    Route::post('password/reset', ['as' => 'password.reset.post', 'uses' => 'Auth\ResetPasswordController@reset']);
});

So if you change some names of these routes, remember to also change in views the actions of the posts!

Generate random 5 characters string

Here are my random 5 cents ...

$random=function($a, $b) {
    return(
        substr(str_shuffle(('\\`)/|@'.
        password_hash(mt_rand(0,999999),
        PASSWORD_DEFAULT).'!*^&~(')),
        $a, $b)
    );
};

echo($random(0,5));

PHP's new password_hash() (* >= PHP 5.5) function is doing the job for generation of decently long set of uppercase and lowercase characters and numbers.

Two concat. strings before and after password_hash within $random function are suitable for change.

Paramteres for $random() *($a,$b) are actually substr() parameters. :)

NOTE: this doesn't need to be a function, it can be normal variable as well .. as one nasty singleliner, like this:

$random=(substr(str_shuffle(('\\`)/|@'.password_hash(mt_rand(0,999999), PASSWORD_DEFAULT).'!*^&~(')), 0, 5));

echo($random);

Android: How can I print a variable on eclipse console?

By the way, in case you dont know what is the exact location of your JSONObject inside your JSONArray i suggest using the following code: (I assumed that "jsonArray" is your main variable with all the data, and i'm searching the exact object inside the array with equals function)

    JSONArray list = new JSONArray(); 
    if (jsonArray != null){
        int len = jsonArray.length();
        for (int i=0;i<len;i++)
        { 
            boolean flag;
            try {
                flag = jsonArray.get(i).toString().equals(obj.toString());
                //Excluding the item at position
                if (!flag) 
                {
                    list.put(jsonArray.get(i));
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }  
        } 
    }
    jsonArray = list;

Get array of object's keys

In case you're here looking for something to list the keys of an n-depth nested object as a flat array:

_x000D_
_x000D_
const getObjectKeys = (obj, prefix = '') => {_x000D_
  return Object.entries(obj).reduce((collector, [key, val]) => {_x000D_
    const newKeys = [ ...collector, prefix ? `${prefix}.${key}` : key ]_x000D_
    if (Object.prototype.toString.call(val) === '[object Object]') {_x000D_
      const newPrefix = prefix ? `${prefix}.${key}` : key_x000D_
      const otherKeys = getObjectKeys(val, newPrefix)_x000D_
      return [ ...newKeys, ...otherKeys ]_x000D_
    }_x000D_
    return newKeys_x000D_
  }, [])_x000D_
}_x000D_
_x000D_
console.log(getObjectKeys({a: 1, b: 2, c: { d: 3, e: { f: 4 }}}))
_x000D_
_x000D_
_x000D_

How do I increase the contrast of an image in Python OpenCV

Best explanation for X = aY + b (in fact it f(x) = ax + b)) is provided at https://math.stackexchange.com/a/906280/357701

A Simpler one by just adjusting lightness/luma/brightness for contrast as is below:

import cv2

img = cv2.imread('test.jpg')
cv2.imshow('test', img)
cv2.waitKey(1000)
imghsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)


imghsv[:,:,2] = [[max(pixel - 25, 0) if pixel < 190 else min(pixel + 25, 255) for pixel in row] for row in imghsv[:,:,2]]
cv2.imshow('contrast', cv2.cvtColor(imghsv, cv2.COLOR_HSV2BGR))
cv2.waitKey(1000)
raw_input()

What is Android's file system?

Similar to Linux:

  • /boot

  • /system

  • /recovery

  • /data

  • /cache

  • /misc

ASP.NET MVC controller actions that return JSON or partial html

Another nice way to deal with JSON data is using the JQuery getJSON function. You can call the

public ActionResult SomeActionMethod(int id) 
{ 
    return Json(new {foo="bar", baz="Blech"});
}

Method from the jquery getJSON method by simply...

$.getJSON("../SomeActionMethod", { id: someId },
    function(data) {
        alert(data.foo);
        alert(data.baz);
    }
);

WARNING: Exception encountered during context initialization - cancelling refresh attempt

This was my stupidity, but a stupidity that was not easy to identify :).

Problem:

  1. My code is compiled on Jdk 1.8.
  2. My eclipse, had JDK 1.8 as the compiler.
  3. My tomcat in eclipse was using Java 1.7 for its container, hence it was not able to understand the .class files which were compiled using 1.8.
  4. To avoid the problem, ensure in your eclipse, double click on your server -> Open Launch configuration -> Classpath -> JRE System Library -> Give the JDK/JRE of the compiled version of java class, in my case, it had to be JDK 1.8
    1. Post this, clean the server, build and redeploy, start the tomcat.

If you are deploying manually into your server, ensure your JAVA_HOME, JDK_HOME points to the correct JDK which you used to compile the project and build the war.

If you do not like to change JAVA_HOME, JDK_HOME, you can always change the JAVA_HOME and JDK_HOME in catalina.bat(for tomcat server) and that'll enable your life to be easy!

Elasticsearch query to return all records

elasticsearch(ES) supports both a GET or a POST request for getting the data from the ES cluster index.

When we do a GET:

http://localhost:9200/[your index name]/_search?size=[no of records you want]&q=*:*

When we do a POST:

http://localhost:9200/[your_index_name]/_search
{
  "size": [your value] //default 10
  "from": [your start index] //default 0
  "query":
   {
    "match_all": {}
   }
}   

I would suggest to use a UI plugin with elasticsearch http://mobz.github.io/elasticsearch-head/ This will help you get a better feeling of the indices you create and also test your indices.

Javascript: How to check if a string is empty?

if (value == "") {
  // it is empty
}

How to redirect to another page using AngularJS?

I used the below code to redirect to new page

$window.location.href = '/foldername/page.html';

and injected $window object in my controller function.

Find TODO tags in Eclipse

In adition to the other answers mentioning the Tasks view:

It is also possible to filter the Tasks that are listed to only show the TODOs that contain the text // TODO Auto-generated method stub.

To achieve this you can click on the Filters... button in the top right of the Tasks View and define custom filters like this:

enter image description here

This way it's a bit easier and faster to find only some of the TODOs in the project in the Tasks View, and you don't have to search for the text in all files using the eclipse search tool (which can take quite some time).

how to install apk application from my pc to my mobile android

1.question answer-In your mobile having Developer Option in settings and enable that one. after In android studio project source file in bin--> apk file .just copy the apk file and paste in mobile memory in ur pc.. after all finished .you click that apk file in your mobile is automatically installed.

2.question answer-Your mobile is Samsung are just add Samsung Kies software in your pc..its helps to android code run in your mobile ...

Load CSV data into MySQL in Python

If you do not have the pandas and sqlalchemy libraries, import using pip

pip install pandas
pip install sqlalchemy

We can use pandas and sqlalchemy to directly insert into the database

import csv
import pandas as pd
from sqlalchemy import create_engine, types

engine = create_engine('mysql://root:*Enter password here*@localhost/*Enter Databse name here*') # enter your password and database names here

df = pd.read_csv("Excel_file_name.csv",sep=',',quotechar='\'',encoding='utf8') # Replace Excel_file_name with your excel sheet name
df.to_sql('Table_name',con=engine,index=False,if_exists='append') # Replace Table_name with your sql table name

convert date string to mysql datetime field

$time = strtotime($oldtime);

Then use date() to put it into the correct format.

How to create a release signed apk file using Gradle?

You can request passwords from the command line:

...

signingConfigs {
  if (gradle.startParameter.taskNames.any {it.contains('Release') }) {
    release {
      storeFile file("your.keystore")
      storePassword new String(System.console().readPassword("\n\$ Enter keystore password: "))
      keyAlias "key-alias"
      keyPassword new String(System.console().readPassword("\n\$ Enter keys password: "))
    } 
  } else {
    //Here be dragons: unreachable else-branch forces Gradle to create
    //install...Release tasks.
    release {
      keyAlias 'dummy'
      keyPassword 'dummy'
      storeFile file('dummy')
      storePassword 'dummy'
    } 
  }
}

...

buildTypes {
  release {

    ...

    signingConfig signingConfigs.release
  }

  ...
}

...

The if-then-else block prevents requests for passwords when you're building a release. Although the else branch is unreachable, it tricks Gradle into creating an install...Release task.

Backstory. As noted by https://stackoverflow.com/a/19130098/3664487, "Gradle scripts can prompt for user input using the System.console().readLine method." Unfortunately, Gradle will always request a password, even when you're building a debug release (cf. How to create a release signed apk file using Gradle?). Fortunately, this can be overcome, as I have shown above.

Check if a property exists in a class

I got this error: "Type does not contain a definition for GetProperty" when tying the accepted answer.

This is what i ended up with:

using System.Reflection;

if (productModel.GetType().GetTypeInfo().GetDeclaredProperty(propertyName) != null)
{

}

How to install wget in macOS?

I update mac to Sierra , 10.12.3

My wget stop working.

When I tried to install by typing

brew install wget --with-libressl

I got the following warning

Warning: wget-1.19.1 already installed, it's just not linked.

Then tried to unsintall by typing

brew uninstall wget --with-libressl

Then I reinstalled by typing

brew install wget --with-libressl

Finally I got it worked.Thank God!

Random strings in Python

try importing the below package from random import*

@HostBinding and @HostListener: what do they do and what are they for?

// begginers
@Component({
  selector: 'custom-comp',
  template: ` <div class="my-class" (click)="onClick()">CLICK ME</div> `,
})
export class CustomComp {
  onClick = () => console.log('click event');
}

// pros
@Component({
  selector: 'custom-comp',
  template: ` CLICK ME `,
})
export class CustomComp {
  @HostBinding('class') class = 'my-class';
  @HostListener('click') onClick = () => console.log('click event');
}

// experts
@Component({
  selector: 'custom-comp',
  template: ` CLICK ME `,
  host: {
    class: 'my-class',
    '(click)': 'onClick()',
  },
})
export class CustomComp {}

------------------------------------------------
The 1st way will result in:
<custom-comp>
   <div class="my-class" (click)="onClick()">
      CLICK ME
   <div>
</custom-comp>

The last 2 ways will result in:
<custom-comp class="my-class" (click)="onClick()">
   CLICK ME
</custom-comp>

How to Lock the data in a cell in excel using vba

Sub LockCells()

Range("A1:A1").Select

Selection.Locked = True

Selection.FormulaHidden = False

ActiveSheet.Protect DrawingObjects:=False, Contents:=True, Scenarios:= False, AllowFormattingCells:=True, AllowFormattingColumns:=True, AllowFormattingRows:=True, AllowInsertingColumns:=True, AllowInsertingRows:=True, AllowInsertingHyperlinks:=True, AllowDeletingColumns:=True, AllowDeletingRows:=True, AllowSorting:=True, AllowFiltering:=True, AllowUsingPivotTables:=True

End Sub

'Use of Unresolved Identifier' in Swift

Your NewClass inherits from UIViewController. You declared signedIn in ViewController. If you want NewClass to be able to identify that variable it will have to be declared in a class that your NewClass inherits from.

Using Address Instead Of Longitude And Latitude With Google Maps API

See this example, initializes the map to "San Diego, CA".

Uses the Google Maps Javascript API v3 Geocoder to translate the address into coordinates that can be displayed on the map.

<html>
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no"/>
<meta http-equiv="content-type" content="text/html; charset=UTF-8"/>
<title>Google Maps JavaScript API v3 Example: Geocoding Simple</title>
<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
  var geocoder;
  var map;
  var address ="San Diego, CA";
  function initialize() {
    geocoder = new google.maps.Geocoder();
    var latlng = new google.maps.LatLng(-34.397, 150.644);
    var myOptions = {
      zoom: 8,
      center: latlng,
    mapTypeControl: true,
    mapTypeControlOptions: {style: google.maps.MapTypeControlStyle.DROPDOWN_MENU},
    navigationControl: true,
      mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
    if (geocoder) {
      geocoder.geocode( { 'address': address}, function(results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
          if (status != google.maps.GeocoderStatus.ZERO_RESULTS) {
          map.setCenter(results[0].geometry.location);

            var infowindow = new google.maps.InfoWindow(
                { content: '<b>'+address+'</b>',
                  size: new google.maps.Size(150,50)
                });
    
            var marker = new google.maps.Marker({
                position: results[0].geometry.location,
                map: map, 
                title:address
            }); 
            google.maps.event.addListener(marker, 'click', function() {
                infowindow.open(map,marker);
            });

          } else {
            alert("No results found");
          }
        } else {
          alert("Geocode was not successful for the following reason: " + status);
        }
      });
    }
  }
</script>
</head>
<body style="margin:0px; padding:0px;" onload="initialize()">
 <div id="map_canvas" style="width:100%; height:100%">
</body>
</html>

working code snippet:

_x000D_
_x000D_
var geocoder;
var map;
var address = "San Diego, CA";

function initialize() {
  geocoder = new google.maps.Geocoder();
  var latlng = new google.maps.LatLng(-34.397, 150.644);
  var myOptions = {
    zoom: 8,
    center: latlng,
    mapTypeControl: true,
    mapTypeControlOptions: {
      style: google.maps.MapTypeControlStyle.DROPDOWN_MENU
    },
    navigationControl: true,
    mapTypeId: google.maps.MapTypeId.ROADMAP
  };
  map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);
  if (geocoder) {
    geocoder.geocode({
      'address': address
    }, function(results, status) {
      if (status == google.maps.GeocoderStatus.OK) {
        if (status != google.maps.GeocoderStatus.ZERO_RESULTS) {
          map.setCenter(results[0].geometry.location);

          var infowindow = new google.maps.InfoWindow({
            content: '<b>' + address + '</b>',
            size: new google.maps.Size(150, 50)
          });

          var marker = new google.maps.Marker({
            position: results[0].geometry.location,
            map: map,
            title: address
          });
          google.maps.event.addListener(marker, 'click', function() {
            infowindow.open(map, marker);
          });

        } else {
          alert("No results found");
        }
      } else {
        alert("Geocode was not successful for the following reason: " + status);
      }
    });
  }
}
google.maps.event.addDomListener(window, 'load', initialize);
_x000D_
html,
body,
#map_canvas {
  height: 100%;
  width: 100%;
}
_x000D_
<script type="text/javascript" src="https://maps.google.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script>
<div id="map_canvas" ></div>
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C# Validating input for textbox on winforms

Description

There are many ways to validate your TextBox. You can do this on every keystroke, at a later time, or on the Validating event.

The Validating event gets fired if your TextBox looses focus. When the user clicks on a other Control, for example. If your set e.Cancel = true the TextBox doesn't lose the focus.

MSDN - Control.Validating Event When you change the focus by using the keyboard (TAB, SHIFT+TAB, and so on), by calling the Select or SelectNextControl methods, or by setting the ContainerControl.ActiveControl property to the current form, focus events occur in the following order

Enter

GotFocus

Leave

Validating

Validated

LostFocus

When you change the focus by using the mouse or by calling the Focus method, focus events occur in the following order:

Enter

GotFocus

LostFocus

Leave

Validating

Validated

Sample Validating Event

private void textBox1_Validating(object sender, CancelEventArgs e)
{
    if (textBox1.Text != "something")
        e.Cancel = true;
}

Update

You can use the ErrorProvider to visualize that your TextBox is not valid. Check out Using Error Provider Control in Windows Forms and C#

More Information

Why do you need to invoke an anonymous function on the same line?

There is one more property JavaScript function has. If you want to call same anonymous function recursively.

(function forInternalOnly(){

  //you can use forInternalOnly to call this anonymous function
  /// forInternalOnly can be used inside function only, like
  var result = forInternalOnly();
})();

//this will not work
forInternalOnly();// no such a method exist

What is special about /dev/tty?

The 'c' means it's a character special file.

Converting strings to floats in a DataFrame

NOTE: pd.convert_objects has now been deprecated. You should use pd.Series.astype(float) or pd.to_numeric as described in other answers.

This is available in 0.11. Forces conversion (or set's to nan) This will work even when astype will fail; its also series by series so it won't convert say a complete string column

In [10]: df = DataFrame(dict(A = Series(['1.0','1']), B = Series(['1.0','foo'])))

In [11]: df
Out[11]: 
     A    B
0  1.0  1.0
1    1  foo

In [12]: df.dtypes
Out[12]: 
A    object
B    object
dtype: object

In [13]: df.convert_objects(convert_numeric=True)
Out[13]: 
   A   B
0  1   1
1  1 NaN

In [14]: df.convert_objects(convert_numeric=True).dtypes
Out[14]: 
A    float64
B    float64
dtype: object

Updating address bar with new URL without hash or reloading the page

Changing only what's after hash - old browsers

document.location.hash = 'lookAtMeNow';

Changing full URL. Chrome, Firefox, IE10+

history.pushState('data to be passed', 'Title of the page', '/test');

The above will add a new entry to the history so you can press Back button to go to the previous state. To change the URL in place without adding a new entry to history use

history.replaceState('data to be passed', 'Title of the page', '/test');

Try running these in the console now!

How to store JSON object in SQLite database

Convert JSONObject into String and save as TEXT/ VARCHAR. While retrieving the same column convert the String into JSONObject.

For example

Write into DB

String stringToBeInserted = jsonObject.toString();
//and insert this string into DB

Read from DB

String json = Read_column_value_logic_here
JSONObject jsonObject = new JSONObject(json);

How to convert a string with Unicode encoding to a string of letters

Just wanted to contribute my version, using regex:

private static final String UNICODE_REGEX = "\\\\u([0-9a-f]{4})";
private static final Pattern UNICODE_PATTERN = Pattern.compile(UNICODE_REGEX);
...
String message = "\u0048\u0065\u006C\u006C\u006F World";
Matcher matcher = UNICODE_PATTERN.matcher(message);
StringBuffer decodedMessage = new StringBuffer();
while (matcher.find()) {
  matcher.appendReplacement(
      decodedMessage, String.valueOf((char) Integer.parseInt(matcher.group(1), 16)));
}
matcher.appendTail(decodedMessage);
System.out.println(decodedMessage.toString());

How can I make the computer beep in C#?

In .Net 2.0, you can use Console.Beep().

// Default beep
Console.Beep();

You can also specify the frequency and length of the beep in milliseconds.

// Beep at 5000 Hz for 1 second
Console.Beep(5000, 1000);

For more information refer http://msdn.microsoft.com/en-us/library/8hftfeyw%28v=vs.110%29.aspx

bootstrap popover not showing on top of all elements

  $('[data-toggle="popover"]').popover({
        placement: 'top',
        boundary: 'viewport',
        trigger: 'hover',
        html: true,
        content: function () {
            let content = $(this).attr("data-popover-content");
            return $(content).html();
        }
    });,



`placement`: 'top',
`boundary`: 'viewport'
both needed

Cannot bulk load. Operating system error code 5 (Access is denied.)

I don't think reinstalling SQL Server is going to fix this, it's just going to kill some time.

  1. Confirm that your user account has read privileges to the folder in question.
  2. Use a tool like Process Monitor to see what user is actually trying to access the file.
  3. My guess is that it is not Michael-PC\Michael that is trying to access the file, but rather the SQL Server service account. If this is the case, then you have at least three options (but probably others):

    a. Set the SQL Server service to run as you.
    b. Grant the SQL Server service account explicit access to that folder.
    c. Put the files somewhere more logical where SQL Server has access, or can be made to have access (e.g. C:\bulk\).

I suggest these things assuming that this is a contained, local workstation. There are definitely more serious security concerns around local filesystem access from SQL Server when we're talking about a production machine, of course this can still be largely mitigated by using c. above - and only giving the service account access to the folders you want it to be able to touch.

Is there an upside down caret character?

There's always a lowercase "v". But seriously, aside from Unicode, all I can find would be &darr, which looks like ↓.

How to add a downloaded .box file to Vagrant?

F:\PuppetLab\src\boxes>vagrant box add precise32 file:///F:/PuppetLab/src/boxes/precise32.box
==> box: Adding box 'precise32' (v0) for provider:
    box: Downloading: file:///F:/PuppetLab/src/boxes/precise32.box
    box: Progress: 100% (Rate: 1200k/s, Estimated time remaining: --:--:--)
==> box: Successfully added box 'precise32' (v0) for 'virtualbox'!

Spring default behavior for lazy-init

The default behaviour is false:

By default, ApplicationContext implementations eagerly create and configure all singleton beans as part of the initialization process. Generally, this pre-instantiation is desirable, because errors in the configuration or surrounding environment are discovered immediately, as opposed to hours or even days later. When this behavior is not desirable, you can prevent pre-instantiation of a singleton bean by marking the bean definition as lazy-initialized. A lazy-initialized bean tells the IoC container to create a bean instance when it is first requested, rather than at startup.

I suggest reading up

POST data to a URL in PHP

If you're looking to post data to a URL from PHP code itself (without using an html form) it can be done with curl. It will look like this:

$url = 'http://www.someurl.com';
$myvars = 'myvar1=' . $myvar1 . '&myvar2=' . $myvar2;

$ch = curl_init( $url );
curl_setopt( $ch, CURLOPT_POST, 1);
curl_setopt( $ch, CURLOPT_POSTFIELDS, $myvars);
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt( $ch, CURLOPT_HEADER, 0);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1);

$response = curl_exec( $ch );

This will send the post variables to the specified url, and what the page returns will be in $response.

How do I script a "yes" response for installing programs?

You just need to put -y with the install command.

For example: yum install <package_to_install> -y

Correct file permissions for WordPress

Based on all the reading and agonizing on my own sites and after having been hacked I have come up with the above list that includes permissions for a security plugin for Wordpress called Wordfence. (Not affiliated with it)

In our example, the wordpress document root is /var/www/html/example.com/public_html

Open up the permissions so that www-data can write to the document root as follows:

cd /var/www/html/example.com
sudo chown -R www-data:www-data public_html/

Now from the dashboard in your site, as an admin you can perform updates.

Secure Site after Updates are finished by following these steps:

sudo chown -R wp-user:wp-user public_html/

The above command changes permissions of everything in the wordpress install to the wordpress FTP user.

cd public_html/wp-content
sudo chown -R www-data:wp-user wflogs
sudo chown -R www-data:wp-user uploads

The above command ensures that the security plugin Wordfence has access to its logs. The uploads directory is also writeable by www-data.

cd plugins
sudo chown -R www-data:wp-user wordfence/

The above command also ensures that the security plugin has required read write access for its proper function.

Directory and Files Permissions

# Set all directories permissions to 755
find . -type d -exec chmod 755 {} \;

# Set all files permissions to 644
find . -type f -exec chmod 644 {} \;

Set the permissions for wp-config.php to 640 so that only wp-user can read this file and no one else. Permissions of 440 didn't work for me with above file ownership.

sudo chmod 640 wp-config.php

Wordpress automatic updates using SSH were working with fine with PHP5 but broke with PHP7.0 due to problems with php7.0-ssh2 bundeld with Ubuntu 16.04 and I couldn't find how to install the right version and make it work. Fortunately a very reliable plugin called ssh-sftp-updater-support (free) makes automatic updates using SFTP possible without need for libssh2. So the above permissions never have to be loosened except in rare cases as needed.

java.util.MissingResourceException: Can't find bundle for base name 'property_file name', locale en_US

I'd like to share my experience of using Ant in building projects, *.properties files should be copied explicitly. This is because Ant will not compile *.properties files into the build working directory by default (javac just ignore *.properties). For example:

<target name="compile" depends="init">
    <javac destdir="${dst}" srcdir="${src}" debug="on" encoding="utf-8" includeantruntime="false">
        <include name="com/example/**" />
        <classpath refid="libs" />
    </javac>
    <copy todir="${dst}">
        <fileset dir="${src}" includes="**/*.properties" />
    </copy>
</target>

<target name="jars" depends="compile">
    <jar jarfile="${app_jar}" basedir="${dst}" includes="com/example/**/*.*" />
</target>

Please notice that 'copy' section under the 'compile' target, it will replicate *.properties files into the build working directory. Without the 'copy' section the jar file will not contain the properties files, then you may encounter the java.util.MissingResourceException.

Find the paths between two given nodes?

What you're trying to do is essentially to find a path between two vertices in a (directed?) graph check out Dijkstra's algorithm if you need shortest path or write a simple recursive function if you need whatever paths exist.

How to use LocalBroadcastManager?

we can also use interface for same as broadcastManger here i am sharing the testd code for broadcastManager but by interface.

first make an interface like:

public interface MyInterface {
     void GetName(String name);
}

2-this is the first class that need implementation

public class First implements MyInterface{

    MyInterface interfc;    
    public static void main(String[] args) {
      First f=new First();      
      Second s=new Second();
      f.initIterface(s);
      f.GetName("Paddy");
  }
  private void initIterface(MyInterface interfc){
    this.interfc=interfc;
  }
  public void GetName(String name) {
    System.out.println("first "+name);
    interfc.GetName(name);  
  }
}

3-here is the the second class that implement the same interface whose method call automatically

public class Second implements MyInterface{
   public void GetName(String name) {
     System.out.println("Second"+name);
   }
}

so by this approach we can use the interface functioning same as broadcastManager.

When does a cookie with expiration time 'At end of session' expire?

Just to correct mingos' answer:

If you set the expiration time to 0, the cookie won't be created at all. I've tested this on Google Chrome at least, and when set to 0 that was the result. The cookie, I guess, expires immediately after creation.

To set a cookie so it expires at the end of the browsing session, simply OMIT the expiration parameter altogether.

Example:

Instead of:

document.cookie = "cookie_name=cookie_value; 0; path=/";

Just write:

document.cookie = "cookie_name=cookie_value; path=/";

JPA Criteria API - How to add JOIN clause (as general sentence as possible)

Warning! There's a numbers of errors on the Sun JPA 2 example and the resulting pasted content in Pascal's answer. Please consult this post.

This post and the Sun Java EE 6 JPA 2 example really held back my comprehension of JPA 2. After plowing through the Hibernate and OpenJPA manuals and thinking that I had a good understanding of JPA 2, I still got confused afterwards when returning to this post.

Get the real width and height of an image with JavaScript? (in Safari/Chrome)

You can programmatically get the image and check the dimensions using Javascript without having to mess with the DOM at all.

var img = new Image();
img.onload = function() {
  console.log(this.width + 'x' + this.height);
}
img.src = 'http://www.google.com/intl/en_ALL/images/logo.gif';

Convert to/from DateTime and Time in Ruby

require 'time'
require 'date'

t = Time.now
d = DateTime.now

dd = DateTime.parse(t.to_s)
tt = Time.parse(d.to_s)

Mix Razor and Javascript code

Never ever mix more languages.

<script type="text/javascript">
    var data = @Json.Encode(Model); // !!!! export data !!!!

    for(var prop in data){
      console.log( prop + " "+ data[prop]);
    }

In case of problem you can also try

@Html.Raw(Json.Encode(Model));

Adding Http Headers to HttpClient

To set custom headers ON A REQUEST, build a request with the custom header before passing it to httpclient to send to http server. eg:

HttpClient client = HttpClients.custom().build();
HttpUriRequest request = RequestBuilder.get()
  .setUri(someURL)
  .setHeader(HttpHeaders.CONTENT_TYPE, "application/json")
  .build();
client.execute(request);

Default header is SET ON HTTPCLIENT to send on every request to the server.

What exactly does the "u" do? "git push -u origin master" vs "git push origin master"

In more simple terms:

Technically, the -u flag adds a tracking reference to the upstream server you are pushing to.

What is important here is that this lets you do a git pull without supplying any more arguments. For example, once you do a git push -u origin master, you can later call git pull and git will know that you actually meant git pull origin master.

Otherwise, you'd have to type in the whole command.

Android: converting String to int

// Convert String to Integer

// String s = "fred";  // use this if you want to test the exception below


String s = "100"; 
try
{
  // the String to int conversion happens here
  int i = Integer.parseInt(s.trim());

  // print out the value after the conversion
  System.out.println("int i = " + i);
}
catch (NumberFormatException nfe)
{
  System.out.println("NumberFormatException: " + nfe.getMessage());
}

how to split the ng-repeat data with three columns using bootstrap

I fix without .row

<div class="col col-33 left" ng-repeat="photo in photos">
   Content here...
</div>

and css

.left {
  float: left;
}

Return JSON response from Flask view

jsonify serializes the data you pass it to JSON. If you want to serialize the data yourself, do what jsonify does by building a response with status=200 and mimetype='application/json'.

from flask import json

@app.route('/summary')
def summary():
    data = make_summary()
    response = app.response_class(
        response=json.dumps(data),
        status=200,
        mimetype='application/json'
    )
    return response

Draw horizontal rule in React Native

Maybe you should try using react-native-hr something like this:

<Hr lineColor='#b3b3b3'/>

documentation: https://www.npmjs.com/package/react-native-hr

How to check if command line tools is installed

Yosemite

Below are a few extra steps on a fresh Mac that some people might need. This adds a little to @jnovack's excellent answer.

Update: A few other notes when setting this up:

Make sure your admin user has a password. A blank password won't work when trying to enable a root user.

System Preferences > Users and Groups > (select user) > Change password

Then to enable root, run dsenableroot in a terminal:

$ dsenableroot
username = mac_admin_user
user password:
root password:
verify root password:

dsenableroot:: ***Successfully enabled root user.

Type in the admin user's password, then the new enabled root password twice.

Next type:

sudo gcc

or

sudo make

It will respond with something like the following:

WARNING: Improper use of the sudo command could lead to data loss
or the deletion of important system files. Please double-check your
typing when using sudo. Type "man sudo" for more information.

To proceed, enter your password, or type Ctrl-C to abort.

Password:


You have not agreed to the Xcode license agreements. You must agree to 
both license agreements below in order to use Xcode.

Press enter when it prompts to show you the license agreement.

Hit the Enter key to view the license agreements at 
'/Applications/Xcode.app/Contents/Resources/English.lproj/License.rtf'

IMPORTANT: BY USING THIS SOFTWARE, YOU ARE AGREEING TO BE BOUND BY THE 
FOLLOWING APPLE TERMS:

//...

Press q to exit the license agreement view.

By typing 'agree' you are agreeing to the terms of the software license 
agreements. Type 'print' to print them or anything else to cancel, 
[agree, print, cancel]

Type agree. And then it will end with:

clang: error: no input files 

Which basically means that you didn't give make or gcc any input files.

Here is what the check looked like:

$ xcode-select -p
/Applications/Xcode.app/Contents/Developer

Mavericks

With Mavericks, it is a little different now.

When the tools were NOT found, this is what the command pkgutil command returned:

$ pkgutil --pkg-info=com.apple.pkg.CLTools_Executables
No receipt for 'com.apple.pkg.CLTools_Executables' found at '/'.

To install the command line tools, this works nicely from the Terminal, with a nice gui and everything.

$ xcode-select --install

http://macops.ca/installing-command-line-tools-automatically-on-mavericks/

When they were found, this is what the pkgutil command returned:

$ pkgutil --pkg-info=com.apple.pkg.CLTools_Executables
package-id: com.apple.pkg.CLTools_Executables
version: 5.0.1.0.1.1382131676
volume: /
location: /
install-time: 1384149984
groups: com.apple.FindSystemFiles.pkg-group com.apple.DevToolsBoth.pkg-group com.apple.DevToolsNonRelocatableShared.pkg-group 

This command returned the same before and after the install.

$ pkgutil --pkg-info=com.apple.pkg.DeveloperToolsCLI
No receipt for 'com.apple.pkg.DeveloperToolsCLI' found at '/'.

Also I had the component for the CLT selected and installed in xcode's downloads section before, but it seems like it didn't make it to the terminal...

Hope that helps.

DateTime2 vs DateTime in SQL Server

I just stumbled across one more advantage for DATETIME2: it avoids a bug in the Python adodbapi module, which blows up if a standard library datetime value is passed which has non-zero microseconds for a DATETIME column but works fine if the column is defined as DATETIME2.

How to access global js variable in AngularJS directive

I created a working CodePen example demonstrating how to do this the correct way in AngularJS. The Angular $window service should be used to access any global objects since directly accessing window makes testing more difficult.

HTML:

<section ng-app="myapp" ng-controller="MainCtrl">
  Value of global variable read by AngularJS: {{variable1}}
</section>

JavaScript:

// global variable outside angular
var variable1 = true;

var app = angular.module('myapp', []);

app.controller('MainCtrl', ['$scope', '$window', function($scope, $window) {
  $scope.variable1 = $window.variable1;
}]);

Count number of times value appears in particular column in MySQL

select name, count(*) from table group by name;

i think should do it

Git merge develop into feature branch outputs "Already up-to-date" while it's not

Initially my repo said "Already up to date."

MINGW64 (feature/Issue_123) 
$ git merge develop

Output:

Already up to date.

But the code is not up to date & it is showing some differences in some files.

MINGW64 (feature/Issue_123)
$ git diff develop

Output:

diff --git 
a/src/main/database/sql/additional/pkg_etl.sql 
b/src/main/database/sql/additional/pkg_etl.sql
index ba2a257..1c219bb 100644
--- a/src/main/database/sql/additional/pkg_etl.sql
+++ b/src/main/database/sql/additional/pkg_etl.sql

However, merging fixes it.

MINGW64 (feature/Issue_123)
$ git merge origin/develop

Output:

Updating c7c0ac9..09959e3
Fast-forward
3 files changed, 157 insertions(+), 92 deletions(-)

Again I have confirmed this by using diff command.

MINGW64 (feature/Issue_123)
$ git diff develop

No differences in the code now!

Comparing Arrays of Objects in JavaScript

There`s my solution. It will compare arrays which also have objects and arrays. Elements can be stay in any positions. Example:

const array1 = [{a: 1}, {b: 2}, { c: 0, d: { e: 1, f: 2, } }, [1,2,3,54]];
const array2 = [{a: 1}, {b: 2}, { c: 0, d: { e: 1, f: 2, } }, [1,2,3,54]];

const arraysCompare = (a1, a2) => {
  if (a1.length !== a2.length) return false;
  const objectIteration = (object) => {
    const result = [];
    const objectReduce = (obj) => {
      for (let i in obj) {
        if (typeof obj[i] !== 'object') {
          result.push(`${i}${obj[i]}`);
        } else {
          objectReduce(obj[i]);
        }
      }
    };
    objectReduce(object);
    return result;
  };
  const reduceArray1 = a1.map(item => {
    if (typeof item !== 'object') return item;
    return objectIteration(item).join('');
  });
  const reduceArray2 = a2.map(item => {
    if (typeof item !== 'object') return item;
    return objectIteration(item).join('');
  });
  const compare =  reduceArray1.map(item => reduceArray2.includes(item));
  return compare.reduce((acc, item) => acc + Number(item)) === a1.length;
};

console.log(arraysCompare(array1, array2));

SQL: Combine Select count(*) from multiple tables

SELECT 
(select count(*) from foo1 where ID = '00123244552000258')
+
(select count(*) from foo2 where ID = '00123244552000258')
+
(select count(*) from foo3 where ID = '00123244552000258')

This is an easy way.

How to use \n new line in VB msgbox() ...?

Module MyHelpers
    <Extension()>
    Public Function UnEscape(ByVal aString As String) As String

       Return Regex.Unescape(aString)

    End Function
End Module

Usage:

console.writeline("Ciao!\n".unEscape)