Programs & Examples On #Parallel port

A now-obsolete bidirectional DB25-based I/O port.

PL/SQL block problem: No data found error

Might be worth checking online for the errata section for your book.

There's an example of handling this exception here http://www.dba-oracle.com/sf_ora_01403_no_data_found.htm

Make file echo displaying "$PATH" string

In the manual for GNU make, they talk about this specific example when describing the value function:

The value function provides a way for you to use the value of a variable without having it expanded. Please note that this does not undo expansions which have already occurred; for example if you create a simply expanded variable its value is expanded during the definition; in that case the value function will return the same result as using the variable directly.

The syntax of the value function is:

 $(value variable)

Note that variable is the name of a variable; not a reference to that variable. Therefore you would not normally use a ‘$’ or parentheses when writing it. (You can, however, use a variable reference in the name if you want the name not to be a constant.)

The result of this function is a string containing the value of variable, without any expansion occurring. For example, in this makefile:

 FOO = $PATH

 all:
         @echo $(FOO)
         @echo $(value FOO)

The first output line would be ATH, since the “$P” would be expanded as a make variable, while the second output line would be the current value of your $PATH environment variable, since the value function avoided the expansion.

Check if input value is empty and display an alert

Check empty input with removing space(if user enter space) from input using trim

$(document).ready(function(){     
       $('#button').click(function(){
            if($.trim($('#fname').val()) == '')
           {
               $('#fname').css("border-color", "red");
               alert("Empty"); 
           }
     });
});

Java getHours(), getMinutes() and getSeconds()

Java 8

    System.out.println(LocalDateTime.now().getHour());       // 7
    System.out.println(LocalDateTime.now().getMinute());     // 45
    System.out.println(LocalDateTime.now().getSecond());     // 32

Calendar

System.out.println(Calendar.getInstance().get(Calendar.HOUR_OF_DAY));  // 7 
System.out.println(Calendar.getInstance().get(Calendar.MINUTE));       // 45
System.out.println(Calendar.getInstance().get(Calendar.SECOND));       // 32

Joda Time

    System.out.println(new DateTime().getHourOfDay());      // 7
    System.out.println(new DateTime().getMinuteOfHour());   // 45
    System.out.println(new DateTime().getSecondOfMinute()); // 32

Formatted

Java 8

    // 07:48:55.056
    System.out.println(ZonedDateTime.now().format(DateTimeFormatter.ISO_LOCAL_TIME));
    // 7:48:55
    System.out.println(LocalTime.now().getHour() + ":" + LocalTime.now().getMinute() + ":" + LocalTime.now().getSecond());

    // 07:48:55
    System.out.println(new SimpleDateFormat("HH:mm:ss").format(Calendar.getInstance().getTime()));

    // 074855
    System.out.println(new SimpleDateFormat("HHmmss").format(Calendar.getInstance().getTime()));

    // 07:48:55 
    System.out.println(new Date().toString().substring(11, 20));

The maximum value for an int type in Go

MaxInt8   = 1<<7 - 1
MinInt8   = -1 << 7
MaxInt16  = 1<<15 - 1
MinInt16  = -1 << 15
MaxInt32  = 1<<31 - 1
MinInt32  = -1 << 31
MaxInt64  = 1<<63 - 1
MinInt64  = -1 << 63
MaxUint8  = 1<<8 - 1
MaxUint16 = 1<<16 - 1
MaxUint32 = 1<<32 - 1
MaxUint64 = 1<<64 - 1

git with development, staging and production branches

Actually what made this so confusing is that the Beanstalk people stand behind their very non-standard use of Staging (it comes before development in their diagram, and it's not a mistake!

https://twitter.com/Beanstalkapp/status/306129447885631488

Why docker container exits immediately

A docker container exits when its main process finishes.

In this case it will exit when your start-all.sh script ends. I don't know enough about hadoop to tell you how to do it in this case, but you need to either leave something running in the foreground or use a process manager such as runit or supervisord to run the processes.

I think you must be mistaken about it working if you don't specify -d; it should have exactly the same effect. I suspect you launched it with a slightly different command or using -it which will change things.

A simple solution may be to add something like:

while true; do sleep 1000; done

to the end of the script. I don't like this however, as the script should really be monitoring the processes it kicked off.

(I should say I stole that code from https://github.com/sequenceiq/hadoop-docker/blob/master/bootstrap.sh)

What is simplest way to read a file into String?

Don't write your own util class to do this - I would recommend using Guava, which is full of all kinds of goodness. In this case you'd want either the Files class (if you're really just reading a file) or CharStreams for more general purpose reading. It has methods to read the data into a list of strings (readLines) or totally (toString).

It has similar useful methods for binary data too. And then there's the rest of the library...

I agree it's annoying that there's nothing similar in the standard libraries. Heck, just being able to supply a CharSet to a FileReader would make life a little simpler...

Check if application is on its first run

This might help you

public class FirstActivity extends Activity {

    SharedPreferences sharedPreferences = null;
    Editor editor;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_login);

        sharedPreferences = getSharedPreferences("com.myAppName", MODE_PRIVATE);
    }

    @Override
    protected void onResume() {
        super.onResume();

        if (sharedPreferences.getBoolean("firstRun", true)) {
         //You can perform anything over here. This will call only first time
                 editor = sharedPreferences.edit();
                 editor.putBoolean("firstRun", false)
                 editor.commit();

        }
    }
}

List of Java processes

This will return all the running java processes in linux environment. Then you can kill the process using the process ID.

ps -e|grep java

Adding Table rows Dynamically in Android

You shouldn't be using an item defined in the Layout XML in order to create more instances of it. You should either create it in a separate XML and inflate it or create the TableRow programmaticaly. If creating them programmaticaly, should be something like this:

    public void init(){
    TableLayout ll = (TableLayout) findViewById(R.id.displayLinear);


    for (int i = 0; i <2; i++) {

        TableRow row= new TableRow(this);
        TableRow.LayoutParams lp = new TableRow.LayoutParams(TableRow.LayoutParams.WRAP_CONTENT);
        row.setLayoutParams(lp);
        checkBox = new CheckBox(this);
        tv = new TextView(this);
        addBtn = new ImageButton(this);
        addBtn.setImageResource(R.drawable.add);
        minusBtn = new ImageButton(this);
        minusBtn.setImageResource(R.drawable.minus);
        qty = new TextView(this);
        checkBox.setText("hello");
        qty.setText("10");
        row.addView(checkBox);
        row.addView(minusBtn);
        row.addView(qty);
        row.addView(addBtn);
        ll.addView(row,i);
    }
}

How to build jars from IntelliJ properly?

Here is the official answer of IntelliJ IDEA 2018.3 Help. I tried and It worked.

To build a JAR file from a module;

  1. On the main menu, choose Build | Build Artifact.

  2. From the drop-down list, select the desired artifact of the type JAR. The list shows all the artifacts configured for the current project. To have all the configured artifacts built, choose the Build all artifacts option.

"Logging out" of phpMyAdmin?

The presence of the logout button depends on whether you are required to login or not, in the first place. This is tweakable in PHPMyAdmin config files.

Yet, I don't think that would change anything concerning your error message. You would need to fix the configuration for the message to go away.

Edit: this is the kind of solution you should be searching for. And here are plenty of others for you to explore ^^

How to export JavaScript array info to csv (on client side)?

This is a modified answer based on the accepted answer wherein the data would be coming from JSON.

            JSON Data Ouptut:
             0 :{emails: "SAMPLE Co., [email protected]"}, 1:{emails: "Another CO. , [email protected]"}


            JS:
            $.getJSON('yourlink_goes_here', { if_you_have_parameters}, function(data) {
            var csvContent = "data:text/csv;charset=utf-8,";
            var dataString = '';
             $.each(data, function(k, v) {
                dataString += v.emails + "\n";
             });

            csvContent += dataString;

            var encodedUri = encodeURI(csvContent);
            var link = document.createElement("a");
            link.setAttribute("href", encodedUri);
            link.setAttribute("download", "your_filename.csv");
            document.body.appendChild(link); // Required for FF

            link.click();
        });

A python class that acts like dict

Here is an alternative solution:

class AttrDict(dict):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.__dict__ = self

a = AttrDict()
a.a = 1
a.b = 2

How to secure the ASP.NET_SessionId cookie?

Found that setting the secure property in Session_Start is sufficient, as recommended in MSDN blog "Securing Session ID: ASP/ASP.NET" with some augmentation.

    protected void Session_Start(Object sender, EventArgs e)
    {
        SessionStateSection sessionState = 
 (SessionStateSection)ConfigurationManager.GetSection("system.web/sessionState");
        string sidCookieName = sessionState.CookieName;

        if (Request.Cookies[sidCookieName] != null)
        {
            HttpCookie sidCookie = Response.Cookies[sidCookieName];
            sidCookie.Value = Session.SessionID;
            sidCookie.HttpOnly = true;
            sidCookie.Secure = true;
            sidCookie.Path = "/";
        }
    }

getResourceAsStream() vs FileInputStream

classname.getResourceAsStream() loads a file via the classloader of classname. If the class came from a jar file, that is where the resource will be loaded from.

FileInputStream is used to read a file from the filesystem.

Best way to format if statement with multiple conditions

The first example is more "easy to read".

Actually, in my opinion you should only use the second one whenever you have to add some "else logic", but for a simple Conditional, use the first flavor. If you are worried about the long of the condition you always can use the next syntax:

if(ConditionOneThatIsTooLongAndProbablyWillUseAlmostOneLine
                 && ConditionTwoThatIsLongAsWell
                 && ConditionThreeThatAlsoIsLong) { 
     //Code to execute 
}

Good Luck!

HTTP Error 403.14 - Forbidden The Web server is configured to not list the contents

Check this also:

This problem occurs because the Web site does not have the Directory Browsing feature enabled, and the default document is not configured. To resolve this problem, use one of the following methods:

  • Method 1: Enable the Directory Browsing feature in IIS (Recommended)
  • Method 2: Add a default document Method
  • Method 3: Enable the Directory Browsing feature in IIS Express

LINK : https://support.microsoft.com/en-us/kb/942062

In Python, how to check if a string only contains certain characters?

Simpler approach? A little more Pythonic?

>>> ok = "0123456789abcdef"
>>> all(c in ok for c in "123456abc")
True
>>> all(c in ok for c in "hello world")
False

It certainly isn't the most efficient, but it's sure readable.

How can I set size of a button?

GridLayout is often not the best choice for buttons, although it might be for your application. A good reference is the tutorial on using Layout Managers. If you look at the GridLayout example, you'll see the buttons look a little silly -- way too big.

A better idea might be to use a FlowLayout for your buttons, or if you know exactly what you want, perhaps a GroupLayout. (Sun/Oracle recommend that GroupLayout or GridBag layout are better than GridLayout when hand-coding.)

Guid is all 0's (zeros)?

Use the static method Guid.NewGuid() instead of calling the default constructor.

var responseObject = proxy.CallService(new RequestObject
{
    Data = "misc. data",
    Guid = Guid.NewGuid()
});

python ignore certificate validation urllib2

urllib2 does not verify server certificate by default. Check this documentation.

Edit: As pointed out in below comment, this is not true anymore for newer versions (seems like >= 2.7.9) of Python. Refer the below ANSWER

how to emulate "insert ignore" and "on duplicate key update" (sql merge) with postgresql?

Edit: in case you missed warren's answer, PG9.5 now has this natively; time to upgrade!


Building on Bill Karwin's answer, to spell out what a rule based approach would look like (transferring from another schema in the same DB, and with a multi-column primary key):

CREATE RULE "my_table_on_duplicate_ignore" AS ON INSERT TO "my_table"
  WHERE EXISTS(SELECT 1 FROM my_table 
                WHERE (pk_col_1, pk_col_2)=(NEW.pk_col_1, NEW.pk_col_2))
  DO INSTEAD NOTHING;
INSERT INTO my_table SELECT * FROM another_schema.my_table WHERE some_cond;
DROP RULE "my_table_on_duplicate_ignore" ON "my_table";

Note: The rule applies to all INSERT operations until the rule is dropped, so not quite ad hoc.

How to get the current time in Python

>>> import datetime, time
>>> time = time.strftime("%H:%M:%S:%MS", time.localtime())
>>> print time
'00:21:38:20S'

How do I make the return type of a method generic?

There are many ways of doing this(listed by priority, specific to the OP's problem)

  1. Option 1: Straight approach - Create multiple functions for each type you expect rather than having one generic function.

    public static bool ConfigSettingInt(string settingName)
    {  
         return Convert.ToBoolean(ConfigurationManager.AppSettings[settingName]);
    }
    
  2. Option 2: When you don't want to use fancy methods of conversion - Cast the value to object and then to generic type.

    public static T ConfigSetting<T>(string settingName)
    {  
         return (T)(object)ConfigurationManager.AppSettings[settingName];
    }
    

    Note - This will throw an error if the cast is not valid(your case). I would not recommend doing this if you are not sure about the type casting, rather go for option 3.

  3. Option 3: Generic with type safety - Create a generic function to handle type conversion.

    public static T ConvertValue<T,U>(U value) where U : IConvertible
    {
        return (T)Convert.ChangeType(value, typeof(T));
    } 
    

    Note - T is the expected type, note the where constraint here(type of U must be IConvertible to save us from the errors)

How to use Boost in Visual Studio 2010

A small addition to KTC's very informative main answer:

If you are using the free Visual Studio c++ 2010 Express, and managed to get that one to compile 64-bits binaries, and now want to use that to use a 64-bits version of the Boost libaries, you may end up with 32-bits libraries (your mileage may vary of course, but on my machine this is the sad case).

I could fix this using the following: inbetween the steps described above as

  1. Start a 32-bit MSVC command prompt and change to the directory where Boost was unzipped.
  2. Run: bootstrap

I inserted a call to 'setenv' to set the environment. For a release build, the above steps become:

  1. Start a 32-bit MSVC command prompt and change to the directory where Boost was unzipped.
  2. Run: "C:\Program Files\Microsoft SDKs\Windows\v7.1\Bin\setenv.cmd" /Release /x64
  3. Run: bootstrap

I found this info here: http://boost.2283326.n4.nabble.com/64-bit-with-VS-Express-again-td3044258.html

How do I view 'git diff' output with my preferred diff tool/ viewer?

Since Git1.6.3, you can use the git difftool script: see my answer below.


May be this article will help you. Here are the best parts:

There are two different ways to specify an external diff tool.

The first is the method you used, by setting the GIT_EXTERNAL_DIFF variable. However, the variable is supposed to point to the full path of the executable. Moreover, the executable specified by GIT_EXTERNAL_DIFF will be called with a fixed set of 7 arguments:

path old-file old-hex old-mode new-file new-hex new-mode

As most diff tools will require a different order (and only some) of the arguments, you will most likely have to specify a wrapper script instead, which in turn calls the real diff tool.

The second method, which I prefer, is to configure the external diff tool via "git config". Here is what I did:

1) Create a wrapper script "git-diff-wrapper.sh" which contains something like

-->8-(snip)--
#!/bin/sh

# diff is called by git with 7 parameters:
# path old-file old-hex old-mode new-file new-hex new-mode

"<path_to_diff_executable>" "$2" "$5" | cat
--8<-(snap)--

As you can see, only the second ("old-file") and fifth ("new-file") arguments will be passed to the diff tool.

2) Type

$ git config --global diff.external <path_to_wrapper_script>

at the command prompt, replacing with the path to "git-diff-wrapper.sh", so your ~/.gitconfig contains

-->8-(snip)--
[diff]
    external = <path_to_wrapper_script>
--8<-(snap)--

Be sure to use the correct syntax to specify the paths to the wrapper script and diff tool, i.e. use forward slashed instead of backslashes. In my case, I have

[diff]
    external = \"c:/Documents and Settings/sschuber/git-diff-wrapper.sh\"

in .gitconfig and

"d:/Program Files/Beyond Compare 3/BCompare.exe" "$2" "$5" | cat

in the wrapper script. Mind the trailing "cat"!

(I suppose the '| cat' is needed only for some programs which may not return a proper or consistent return status. You might want to try without the trailing cat if your diff tool has explicit return status)

(Diomidis Spinellis adds in the comments:

The cat command is required, because diff(1), by default exits with an error code if the files differ.
Git expects the external diff program to exit with an error code only if an actual error occurred, e.g. if it run out of memory.
By piping the output of git to cat the non-zero error code is masked.
More efficiently, the program could just run exit with and argument of 0.)


That (the article quoted above) is the theory for external tool defined through config file (not through environment variable).
In practice (still for config file definition of external tool), you can refer to:

How do I download code using SVN/Tortoise from Google Code?

Create a folder where you want to keep the code, and right click on it. Choose SVN Checkout... and type http://wittytwitter.googlecode.com/svn/trunk into the URL of repository field.

You can also run

svn checkout http://wittytwitter.googlecode.com/svn/trunk

from the command line in the folder you want to keep it (svn.exe has to be in your path, of course).

Button that refreshes the page on click

If you are looking for a form reset:

<input type="reset" value="Reset Form Values"/>

or to reset other aspects of the form not handled by the browser

<input type="reset" onclick="doFormReset();" value="Reset Form Values"/>

Using jQuery

function doFormReset(){
    $(".invalid").removeClass("invalid");
}

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

From what I've found online, this is a bug introduced in JDK 1.7.0_45. It appears to also be present in JDK 1.7.0_60. A bug report on Oracle's website states that, while there was a fix, it was removed before the JDK was released. I do not know why the fix was removed, but it confirms what we've already suspected -- the JDK is still broken.

The bug report claims that the error is benign and should not cause any run-time problems, though one of the comments disagrees with that. In my own experience, I have been able to work without any problems using JDK 1.7.0_60 despite seeing the message.

If this issue is causing serious problems, here are a few things I would suggest:

  • Revert back to JDK 1.7.0_25 until a fix is added to the JDK.

  • Keep an eye on the bug report so that you are aware of any work being done on this issue. Maybe even add your own comment so Oracle is aware of the severity of the issue.

  • Try the JDK early releases as they come out. One of them might fix your problem.

Instructions for installing the JDK on Mac OS X are available at JDK 7 Installation for Mac OS X. It also contains instructions for removing the JDK.

Parsing JSON in Java without knowing JSON format

Would you be satisfied with a Map from Jackson?

ObjectMapper objectMapper = new ObjectMapper();
Map<String, Object> map = objectMapper.readValue(jsonString, new TypeReference<HashMap<String,Object>>(){});

Or maybe a JsonNode?

JsonNode jsonNode = objectMapper.readTree(String jsonString) 

How can I subset rows in a data frame in R based on a vector of values?

If you really just want to subset each data frame by an index that exists in both data frames, you can do this with the 'match' function, like so:

data_A[match(data_B$index, data_A$index, nomatch=0),]
data_B[match(data_A$index, data_B$index, nomatch=0),]

This is, though, the same as:

data_A[data_A$index %in% data_B$index,]
data_B[data_B$index %in% data_A$index,]

Here is a demo:

# Set seed for reproducibility.
set.seed(1)

# Create two sample data sets.
data_A <- data.frame(index=sample(1:200, 90, rep=FALSE), value=runif(90))
data_B <- data.frame(index=sample(1:200, 120, rep=FALSE), value=runif(120))

# Subset data of each data frame by the index in the other.
t_A <- data_A[match(data_B$index, data_A$index, nomatch=0),]
t_B <- data_B[match(data_A$index, data_B$index, nomatch=0),]

# Make sure they match.
data.frame(t_A[order(t_A$index),], t_B[order(t_B$index),])[1:20,]

#    index     value index.1    value.1
# 27     3 0.7155661       3 0.65887761
# 10    12 0.6049333      12 0.14362694
# 88    14 0.7410786      14 0.42021589
# 56    15 0.4525708      15 0.78101754
# 38    18 0.2075451      18 0.70277874
# 24    23 0.4314737      23 0.78218212
# 34    32 0.1734423      32 0.85508236
# 22    38 0.7317925      38 0.56426384
# 84    39 0.3913593      39 0.09485786
# 5     40 0.7789147      40 0.31248966
# 74    43 0.7799849      43 0.10910096
# 71    45 0.2847905      45 0.26787813
# 57    46 0.1751268      46 0.17719454
# 25    48 0.1482116      48 0.99607737
# 81    53 0.6304141      53 0.26721208
# 60    58 0.8645449      58 0.96920881
# 30    59 0.6401010      59 0.67371223
# 75    61 0.8806190      61 0.69882454
# 63    64 0.3287773      64 0.36918946
# 19    70 0.9240745      70 0.11350771

RecyclerView - How to smooth scroll to top of item on a certain position?

This is an extension function I wrote in Kotlin to use with the RecyclerView (based on @Paul Woitaschek answer):

fun RecyclerView.smoothSnapToPosition(position: Int, snapMode: Int = LinearSmoothScroller.SNAP_TO_START) {
  val smoothScroller = object : LinearSmoothScroller(this.context) {
    override fun getVerticalSnapPreference(): Int = snapMode
    override fun getHorizontalSnapPreference(): Int = snapMode
  }
  smoothScroller.targetPosition = position
  layoutManager?.startSmoothScroll(smoothScroller)
}

Use it like this:

myRecyclerView.smoothSnapToPosition(itemPosition)

Uppercase first letter of variable

Use the .replace[MDN] function to replace the lowercase letters that begin a word with the capital letter.

_x000D_
_x000D_
var str = "hello world";_x000D_
str = str.toLowerCase().replace(/\b[a-z]/g, function(letter) {_x000D_
    return letter.toUpperCase();_x000D_
});_x000D_
alert(str); //Displays "Hello World"
_x000D_
_x000D_
_x000D_


Edit: If you are dealing with word characters other than just a-z, then the following (more complicated) regular expression might better suit your purposes.

_x000D_
_x000D_
var str = "???? ????????? björn über ñaque a?fa";_x000D_
str = str.toLowerCase().replace(/^[\u00C0-\u1FFF\u2C00-\uD7FF\w]|\s[\u00C0-\u1FFF\u2C00-\uD7FF\w]/g, function(letter) {_x000D_
    return letter.toUpperCase();_x000D_
});_x000D_
alert(str); //Displays "???? ????????? Björn Über Ñaque ??fa"
_x000D_
_x000D_
_x000D_

Crystal Reports for VS2012 - VS2013 - VS2015 - VS2017 - VS2019

"SP25 work on Visual Studio 2019" is an exaggeration. It is extremely unreliable and should be avoided at all costs. I currently have to maintain a second development environment with V2015 for report development.

How can I parse a YAML file from a Linux shell script?

It's possible to pass a small script to some interpreters, like Python. An easy way to do so using Ruby and its YAML library is the following:

$ RUBY_SCRIPT="data = YAML::load(STDIN.read); puts data['a']; puts data['b']"
$ echo -e '---\na: 1234\nb: 4321' | ruby -ryaml -e "$RUBY_SCRIPT"
1234
4321

, wheredata is a hash (or array) with the values from yaml.

As a bonus, it'll parse Jekyll's front matter just fine.

ruby -ryaml -e "puts YAML::load(open(ARGV.first).read)['tags']" example.md

Remove .php extension with .htaccess

Try this
The following code will definitely work

RewriteEngine on
RewriteCond %{THE_REQUEST} /([^.]+)\.php [NC]
RewriteRule ^ /%1 [NC,L,R]

RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^ %{REQUEST_URI}.php [NC,L]

How to store(bitmap image) and retrieve image from sqlite database in android?

If you are working with Android's MediaStore database, here is how to store an image and then display it after it is saved.

on button click write this

 Intent in = new Intent(Intent.ACTION_PICK,
                    android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            in.putExtra("crop", "true");
            in.putExtra("outputX", 100);
            in.putExtra("outputY", 100);
            in.putExtra("scale", true);
            in.putExtra("return-data", true);

            startActivityForResult(in, 1);

then do this in your activity

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == 1 && resultCode == RESULT_OK && data != null) {

            Bitmap bmp = (Bitmap) data.getExtras().get("data");

            img.setImageBitmap(bmp);
            btnadd.requestFocus();

            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            bmp.compress(Bitmap.CompressFormat.JPEG, 100, baos);
            byte[] b = baos.toByteArray();
            String encodedImageString = Base64.encodeToString(b, Base64.DEFAULT);

            byte[] bytarray = Base64.decode(encodedImageString, Base64.DEFAULT);
            Bitmap bmimage = BitmapFactory.decodeByteArray(bytarray, 0,
                    bytarray.length);

        }

    }

View a specific Git commit

git show <revhash>

Documentation here. Or if that doesn't work, try Google Code's GIT Documentation

Transition of background-color

As far as I know, transitions currently work in Safari, Chrome, Firefox, Opera and Internet Explorer 10+.

This should produce a fade effect for you in these browsers:

_x000D_
_x000D_
a {_x000D_
    background-color: #FF0;_x000D_
}_x000D_
_x000D_
a:hover {_x000D_
    background-color: #AD310B;_x000D_
    -webkit-transition: background-color 1000ms linear;_x000D_
    -ms-transition: background-color 1000ms linear;_x000D_
    transition: background-color 1000ms linear;_x000D_
}
_x000D_
<a>Navigation Link</a>
_x000D_
_x000D_
_x000D_

Note: As pointed out by Gerald in the comments, if you put the transition on the a, instead of on a:hover it will fade back to the original color when your mouse moves away from the link.

This might come in handy, too: CSS Fundamentals: CSS 3 Transitions

Difference between abstraction and encapsulation?

One thing, perhaps a fundamental thing that other answers forget to mention is that, encapsulation IS abstraction. Therefore, it is not accurate to contrast the two and look for differences, but rather to look at encapsulation as a form of abstraction.

Request string without GET arguments

$uri_parts = explode('?', $_SERVER['REQUEST_URI'], 2);
$request_uri = $uri_parts[0];
echo $request_uri;

@font-face not working

Double period (..) means you go up one folder and then look for the folder behind the slash. For example:

If your index.html is in the folder html/files and the fonts are in html/fonts, the .. is fine (because you have to go back one folder to go to /fonts). Is your index.html in html and your fonts in html/fonts, then you should use only one period.

Another problem could be that your browser might not support .eot font-files.

Without seeing more of your code (and maybe a link to a live version of your website), I can't really help you further.

Edit: Forget the .eot part, I missed the .ttf file in your css.

Try the following:

@font-face { 
font-family: Gotham;
src: url(../fonts/gothammedium.eot);
src: url(../fonts/Gotham-Medium.ttf); 
}

What's the function like sum() but for multiplication? product()?

Actually, Guido vetoed the idea: http://bugs.python.org/issue1093

But, as noted in that issue, you can make one pretty easily:

from functools import reduce # Valid in Python 2.6+, required in Python 3
import operator

reduce(operator.mul, (3, 4, 5), 1)

getting " (1) no such column: _id10 " error

I think you missed a equal sign at:

Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + "" + l, null, null, null, null);  

Change to:

Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + " = " + l, null, null, null, null); 

count files in specific folder and display the number into 1 cel

Try below code :

Assign the path of the folder to variable FolderPath before running the below code.

Sub sample()

    Dim FolderPath As String, path As String, count As Integer
    FolderPath = "C:\Documents and Settings\Santosh\Desktop"

    path = FolderPath & "\*.xls"

    Filename = Dir(path)

    Do While Filename <> ""
       count = count + 1
        Filename = Dir()
    Loop

    Range("Q8").Value = count
    'MsgBox count & " : files found in folder"
End Sub

Find substring in the string in TWIG

Just searched for the docs, and found this:

Containment Operator: The in operator performs containment test. It returns true if the left operand is contained in the right:

{# returns true #}

{{ 1 in [1, 2, 3] }}

{{ 'cd' in 'abcde' }}

How do I dynamically set HTML5 data- attributes using react?

Note - if you want to pass a data attribute to a React Component, you need to handle them a little differently than other props.

2 options

Don't use camel case

<Option data-img-src='value' ... />

And then in the component, because of the dashes, you need to refer to the prop in quotes.

// @flow
class Option extends React.Component {

  props: {
    'data-img-src': string
  }

And when you refer to it later, you don't use the dot syntax

  render () {
    return (
      <option data-img-src={this.props['data-img-src']} >...</option>
    )
  }
}

Or use camel case

<Option dataImgSrc='value' ... />

And then in the component, you need to convert.

// @flow
class Option extends React.Component {

  props: {
    dataImgSrc: string
  }

And when you refer to it later, you don't use the dot syntax

  render () {
    return (
      <option data-img-src={this.props.dataImgSrc} >...</option>
    )
  }
}

Mainly just realize data- attributes and aria- attributes are treated specially. You are allowed to use hyphens in the attribute name in those two cases.

org.springframework.beans.factory.BeanCreationException: Error creating bean with name

According to the stack trace, your issue is that your app cannot find org.apache.commons.dbcp.BasicDataSource, as per this line:

java.lang.ClassNotFoundException: org.apache.commons.dbcp.BasicDataSource

I see that you have commons-dbcp in your list of jars, but for whatever reason, your app is not finding the BasicDataSource class in it.

How to set a transparent background of JPanel?

Calling setOpaque(false) on the upper JPanel should work.

From your comment, it sounds like Swing painting may be broken somewhere -

First - you probably wanted to override paintComponent() rather than paint() in whatever component you have paint() overridden in.

Second - when you do override paintComponent(), you'll first want to call super.paintComponent() first to do all the default Swing painting stuff (of which honoring setOpaque() is one).

Example -

import java.awt.Color;
import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;


public class TwoPanels {
    public static void main(String[] args) {

        JPanel p = new JPanel();
        // setting layout to null so we can make panels overlap
        p.setLayout(null);

        CirclePanel topPanel = new CirclePanel();
        // drawing should be in blue
        topPanel.setForeground(Color.blue);
        // background should be black, except it's not opaque, so 
        // background will not be drawn
        topPanel.setBackground(Color.black);
        // set opaque to false - background not drawn
        topPanel.setOpaque(false);
        topPanel.setBounds(50, 50, 100, 100);
        // add topPanel - components paint in order added, 
        // so add topPanel first
        p.add(topPanel);

        CirclePanel bottomPanel = new CirclePanel();
        // drawing in green
        bottomPanel.setForeground(Color.green);
        // background in cyan
        bottomPanel.setBackground(Color.cyan);
        // and it will show this time, because opaque is true
        bottomPanel.setOpaque(true);
        bottomPanel.setBounds(30, 30, 100, 100);
        // add bottomPanel last...
        p.add(bottomPanel);

        // frame handling code...
        JFrame f = new JFrame("Two Panels");
        f.setContentPane(p);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setSize(300, 300);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    // Panel with a circle drawn on it.
    private static class CirclePanel extends JPanel {

        // This is Swing, so override paint*Component* - not paint
        protected void paintComponent(Graphics g) {
            // call super.paintComponent to get default Swing 
            // painting behavior (opaque honored, etc.)
            super.paintComponent(g);
            int x = 10;
            int y = 10;
            int width = getWidth() - 20;
            int height = getHeight() - 20;
            g.drawArc(x, y, width, height, 0, 360);
        }
    }
}

Dump a mysql database to a plaintext (CSV) backup from the command line

If you want to dump the entire db as csv

#!/bin/bash

host=hostname
uname=username
pass=password

port=portnr
db=db_name
s3_url=s3://bxb2-anl-analyzed-pue2/bxb_ump/db_dump/



DATE=`date +%Y%m%d`
rm -rf $DATE

echo 'show tables' | mysql -B -h${host} -u${uname} -p${pass} -P${port} ${db} > tables.txt
awk 'NR>1' tables.txt > tables_new.txt

while IFS= read -r line
do
  mkdir -p $DATE/$line
  echo "select * from $line" | mysql -B -h"${host}" -u"${uname}" -p"${pass}" -P"${port}" "${db}" > $DATE/$line/dump.tsv
done < tables_new.txt

touch $DATE/$DATE.fin


rm -rf tables_new.txt tables.txt

Set proxy through windows command line including login parameters

If you are using Microsoft windows environment then you can set a variable named HTTP_PROXY, FTP_PROXY, or HTTPS_PROXY depending on the requirement.

I have used following settings for allowing my commands at windows command prompt to use the browser proxy to access internet.

set HTTP_PROXY=http://proxy_userid:proxy_password@proxy_ip:proxy_port

The parameters on right must be replaced with actual values.

Once the variable HTTP_PROXY is set, all our subsequent commands executed at windows command prompt will be able to access internet through the proxy along with the authentication provided.

Additionally if you want to use ftp and https as well to use the same proxy then you may like to the following environment variables as well.

set FTP_PROXY=%HTTP_PROXY%

set HTTPS_PROXY=%HTTP_PROXY%

c# Best Method to create a log file

I would recommend log4net.

You would need multiple log files. So multiple file appenders. Plus you can create the file appenders dynamically.

Sample Code:

using log4net;
using log4net.Appender;
using log4net.Layout;
using log4net.Repository.Hierarchy;

// Set the level for a named logger
public static void SetLevel(string loggerName, string levelName)
{
    ILog log = LogManager.GetLogger(loggerName);
    Logger l = (Logger)log.Logger;

    l.Level = l.Hierarchy.LevelMap[levelName];
    }

// Add an appender to a logger
public static void AddAppender(string loggerName, IAppender appender)
{
    ILog log = LogManager.GetLogger(loggerName);
    Logger l = (Logger)log.Logger;

    l.AddAppender(appender);
}

// Create a new file appender
public static IAppender CreateFileAppender(string name, string fileName)
{
    FileAppender appender = new
        FileAppender();
    appender.Name = name;
    appender.File = fileName;
    appender.AppendToFile = true;

    PatternLayout layout = new PatternLayout();
    layout.ConversionPattern = "%d [%t] %-5p %c [%x] - %m%n";
    layout.ActivateOptions();

    appender.Layout = layout;
    appender.ActivateOptions();

    return appender;
}

// In order to set the level for a logger and add an appender reference you
// can then use the following calls:
SetLevel("Log4net.MainForm", "ALL");
AddAppender("Log4net.MainForm", CreateFileAppender("appenderName", "fileName.log"));

// repeat as desired

Sources/Good links:

Log4Net: Programmatically specify multiple loggers (with multiple file appenders)

Adding appenders programmatically

How to configure log4net programmatically from scratch (no config)

Plus the log4net also allows to write into event log as well. Everything is configuration based, and the configuration can be loaded dynamically from xml at runtime as well.

Edit 2:

One way to switch log files on the fly: Log4Net configuration file supports environment variables:

Environment.SetEnvironmentVariable("log4netFileName", "MyApp.log");

and in the log4net config:

<param name="File" value="${log4netFileName}".log/>

Import functions from another js file. Javascript

You can try as follows:

//------ js/functions.js ------
export function square(x) {
    return x * x;
}
export function diag(x, y) {
    return sqrt(square(x) + square(y));
}

//------ js/main.js ------
import { square, diag } from './functions.js';
console.log(square(11)); // 121
console.log(diag(4, 3)); // 5

You can also import completely:

//------ js/main.js ------
import * as lib from './functions.js';
console.log(lib.square(11)); // 121
console.log(lib.diag(4, 3)); // 5

Normally we use ./fileName.js for importing own js file/module and fileName.js is used for importing package/library module

When you will include the main.js file to your webpage you must set the type="module" attribute as follows:

<script type="module" src="js/main.js"></script>

For more details please check ES6 modules

Error: Argument is not a function, got undefined

If you are in a submodule, don't forget to declare the module in main app. ie :

<scrip>
angular.module('mainApp', ['subModule1', 'subModule2']);

angular.module('subModule1')
   .controller('MyController', ['$scope', function($scope) {
      $scope.moduleName = 'subModule1';
   }]);
</script>
...
<div ng-app="mainApp">
   <div ng-controller="MyController">
   <span ng-bind="moduleName"></span>
</div>

If you don't declare subModule1 in mainApp, you will got a "[ng:areq] Argument "MyController" is not a function, got undefined.

Looking to understand the iOS UIViewController lifecycle

There's a lot of outdated and incomplete information here. For iOS 6 and newer only:

  1. loadView[a]
  2. viewDidLoad[a]
  3. viewWillAppear
  4. viewWillLayoutSubviews is the first time bounds are finalized
  5. viewDidLayoutSubviews
  6. viewDidAppear
  7. * viewWillLayoutSubviews[b]
  8. * viewDidLayoutSubviews[b]

Footnotes:

(a) - If you manually nil out your view during didReceiveMemoryWarning, loadView and viewDidLoad will be called again. That is, by default loadView and viewDidLoad only gets called once per view controller instance.

(b) May be called an additional 0 or more times.

Adding HTML entities using CSS content

I know this is an pretty old post, but if spacing is all your after, why not simply:

.breadcrumbs a::before {
    content: '>';
    margin-left: 8px;
    margin-right: 8px;
}

I have used this method before. It wraps perfectly fine to other lines with ">" by its side in my testing.

How to run Maven from another directory (without cd to project dir)?

For me, works this way: mvn -f /path/to/pom.xml [goals]

Why isn't ProjectName-Prefix.pch created automatically in Xcode 6?

If you decide to add a .pch file manually and you want to use Objective-C just like before xCode 6 you will also have to import UIKit and Foundation frameworks in the .pch file. Otherwise you will have to import these frameworks manually in each header file. You can add the following code anyway as it tests for the language used:

#ifdef __OBJC__
    #import <UIKit/UIKit.h>
    #import <Foundation/Foundation.h>
#endif

unique() for more than one variable

This dplyr method works nicely when piping.

For selected columns:

library(dplyr)
iris %>% 
  select(Sepal.Width, Species) %>% 
  t %>% c %>% unique

 [1] "3.5"        "setosa"     "3.0"        "3.2"        "3.1"       
 [6] "3.6"        "3.9"        "3.4"        "2.9"        "3.7"       
[11] "4.0"        "4.4"        "3.8"        "3.3"        "4.1"       
[16] "4.2"        "2.3"        "versicolor" "2.8"        "2.4"       
[21] "2.7"        "2.0"        "2.2"        "2.5"        "2.6"       
[26] "virginica" 

Or for the whole dataframe:

iris %>% t %>% c %>% unique 

 [1] "5.1"        "3.5"        "1.4"        "0.2"        "setosa"     "4.9"       
 [7] "3.0"        "4.7"        "3.2"        "1.3"        "4.6"        "3.1"       
[13] "1.5"        "5.0"        "3.6"        "5.4"        "3.9"        "1.7"       
[19] "0.4"        "3.4"        "0.3"        "4.4"        "2.9"        "0.1"       
[25] "3.7"        "4.8"        "1.6"        "4.3"        "1.1"        "5.8"       
[31] "4.0"        "1.2"        "5.7"        "3.8"        "1.0"        "3.3"       
[37] "0.5"        "1.9"        "5.2"        "4.1"        "5.5"        "4.2"       
[43] "4.5"        "2.3"        "0.6"        "5.3"        "7.0"        "versicolor"
[49] "6.4"        "6.9"        "6.5"        "2.8"        "6.3"        "2.4"       
[55] "6.6"        "2.7"        "2.0"        "5.9"        "6.0"        "2.2"       
[61] "6.1"        "5.6"        "6.7"        "6.2"        "2.5"        "1.8"       
[67] "6.8"        "2.6"        "virginica"  "7.1"        "2.1"        "7.6"       
[73] "7.3"        "7.2"        "7.7"        "7.4"        "7.9" 

SQL Server replace, remove all after certain character

For the times when some fields have a ";" and some do not you can also add a semi-colon to the field and use the same method described.

SET MyText = LEFT(MyText+';', CHARINDEX(';',MyText+';')-1)

how to check if a datareader is null or empty

Try this simpler equivalent syntax:

ltlAdditional.Text = (myReader["Additional"] == DBNull.Value) ? "is null" : "contains data";

Angular 2 - How to navigate to another route using this.router.parent.navigate('/about')?

import { Router } from '@angular/router';
//in your constructor
constructor(public router: Router){}

//navigation 
link.this.router.navigateByUrl('/home');

Curl to return http status code along with the response

My way to achieve this:

To get both (header and body), I usually perform a curl -D- <url> as in:

$ curl -D- http://localhost:1234/foo
HTTP/1.1 200 OK
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: application/json
Date: Wed, 29 Jul 2020 20:59:21 GMT

{"data":["out.csv"]}

This will dump headers (-D) to stdout (-) (Look for --dump-header in man curl).

IMHO also very handy in this context:

I often use jq to get that json data (eg from some rest APIs) formatted. But as jq doesn't expect a HTTP header, the trick is to print headers to stderr using -D/dev/stderr. Note that this time we also use -sS (--silent, --show-errors) to suppress the progress meter (because we write to a pipe).

$ curl -sSD/dev/stderr http://localhost:1231/foo | jq .
HTTP/1.1 200 OK
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: application/json
Date: Wed, 29 Jul 2020 21:08:22 GMT

{
  "data": [
    "out.csv"
  ]
}

I guess this also can be handy if you'd like to print headers (for quick inspection) to console but redirect body to a file (eg when its some kind of binary to not mess up your terminal):

$ curl -sSD/dev/stderr http://localhost:1231 > /dev/null
HTTP/1.1 200 OK
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: application/json
Date: Wed, 29 Jul 2020 21:20:02 GMT

Be aware: This is NOT the same as curl -I <url>! As -I will perform a HEAD request and not a GET request (Look for --head in man curl. Yes: For most HTTP servers this will yield same result. But I know a lot of business applications which don't implement HEAD request at all ;-P

Find files with size in Unix

Find can be used to print out the file-size in bytes with %s as a printf. %h/%f prints the directory prefix and filename respectively. \n forces a newline.

Example

find . -size +10000k -printf "%h/%f,%s\n"

Output

./DOTT/extract/DOTT/TENTACLE.001,11358470
./DOTT/Day Of The Tentacle.nrg,297308316
./DOTT/foo.iso,297001116

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

If the text contains \r\n that need to be converted into new lines use the 'Extended' or 'Regular expression' modes and escape the backslash character in 'Find what':

Find what: \\r\\n

Replace with: \r\n

Non-recursive depth first search algorithm

PreOrderTraversal is same as DFS in binary tree. You can do the same recursion 
taking care of Stack as below.

    public void IterativePreOrder(Tree root)
            {
                if (root == null)
                    return;
                Stack s<Tree> = new Stack<Tree>();
                s.Push(root);
                while (s.Count != 0)
                {
                    Tree b = s.Pop();
                    Console.Write(b.Data + " ");
                    if (b.Right != null)
                        s.Push(b.Right);
                    if (b.Left != null)
                        s.Push(b.Left);

                }
            }

The general logic is, push a node(starting from root) into the Stack, Pop() it and Print() value. Then if it has children( left and right) push them into the stack - push Right first so that you will visit Left child first(after visiting node itself). When stack is empty() you will have visited all nodes in Pre-Order.

How can I check whether a radio button is selected with JavaScript?

A vanilla JavaScript way

var radios = document.getElementsByTagName('input');
var value;
for (var i = 0; i < radios.length; i++) {
    if (radios[i].type === 'radio' && radios[i].checked) {
        // get value, set checked flag or do whatever you need to
        value = radios[i].value;       
    }
}

How to set a cell to NaN in a pandas dataframe

just use replace:

In [106]:
df.replace('N/A',np.NaN)

Out[106]:
    x    y
0  10   12
1  50   11
2  18  NaN
3  32   13
4  47   15
5  20  NaN

What you're trying is called chain indexing: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy

You can use loc to ensure you operate on the original dF:

In [108]:
df.loc[df['y'] == 'N/A','y'] = np.nan
df

Out[108]:
    x    y
0  10   12
1  50   11
2  18  NaN
3  32   13
4  47   15
5  20  NaN

What algorithms compute directions from point A to point B on a map?

Maps never take into consideration the whole map. My guess is:- 1. According to your location, they load a place and the landmarks on that place. 2. When you search the destination, thats when they load the other part of the map and make a graph out of two places and then apply the shortest path algorithms.

Also, there is an important technique Dynamic programming which i suspect is used in the calculation of shortest paths. You can refer to that as well.

Difference between "or" and || in Ruby?

or is NOT the same as ||. Use only || operator instead of the or operator.

Here are some reasons. The:

  • or operator has a lower precedence than ||.
  • or has a lower precedence than the = assignment operator.
  • and and or have the same precedence, while && has a higher precedence than ||.

Table Naming Dilemma: Singular vs. Plural Names

If you use certain frameworks like Zend Framework (PHP) it is only wise to use plural for table classes and singular for row classes.

So say you create a table object $users = new Users() and have declared the row class to be User you will be able to call new User() as well.

Now if you use singular for table names you would have to do something like new UserTable() with the row being new UserRow(). This looks more clumsy to me than just having an object Users() for the table and User() objects for the rows.

wordpress contactform7 textarea cols and rows change in smaller screens

In the documentaion http://contactform7.com/text-fields/#textarea

[textarea* message id:contact-message 10x2 placeholder "Your Message"]

The above will generate a textarea with cols="10" and rows="2"

<textarea name="message" cols="10" rows="2" class="wpcf7-form-control wpcf7-textarea wpcf7-validates-as-required" id="contact-message" aria-required="true" aria-invalid="false" placeholder="Your Message"></textarea>

How do I iterate through lines in an external file with shell?

cat names.txt|while read line; do
    echo "$line";
done

PHP: Count a stdClass object

The problem is that count is intended to count the indexes in an array, not the properties on an object, (unless it's a custom object that implements the Countable interface). Try casting the object, like below, as an array and seeing if that helps.

$total = count((array)$obj);

Simply casting an object as an array won't always work but being a simple stdClass object it should get the job done here.

SMTP error 554

SMTP error 554 is one of the more vague error codes, but is typically caused by the receiving server seeing something in the From or To headers that it doesn't like. This can be caused by a spam trap identifying your machine as a relay, or as a machine not trusted to send mail from your domain.

We ran into this problem recently when adding a new server to our array, and we fixed it by making sure that we had the correct reverse DNS lookup set up.

SQL: parse the first, middle and last name from a fullname field

Based on @hajili's contribution (which is a creative use of the parsename function, intended to parse the name of an object that is period-separated), I modified it so it can handle cases where the data doesn't containt a middle name or when the name is "John and Jane Doe". It's not 100% perfect but it's compact and might do the trick depending on the business case.

SELECT NAME,
CASE WHEN parsename(replace(NAME, ' ', '.'), 4) IS NOT NULL THEN 
   parsename(replace(NAME, ' ', '.'), 4) ELSE
    CASE WHEN parsename(replace(NAME, ' ', '.'), 3) IS NOT NULL THEN 
    parsename(replace(NAME, ' ', '.'), 3) ELSE
   parsename(replace(NAME, ' ', '.'), 2) end END as FirstName
   ,
CASE WHEN parsename(replace(NAME, ' ', '.'), 3) IS NOT NULL THEN 
   parsename(replace(NAME, ' ', '.'), 2) ELSE NULL END as MiddleName,
   parsename(replace(NAME, ' ', '.'), 1) as LastName
from  {@YourTableName}

Check if starting characters of a string are alphabetical in T-SQL

You don't need to use regex, LIKE is sufficient:

WHERE my_field LIKE '[a-zA-Z][a-zA-Z]%'

Assuming that by "alphabetical" you mean only latin characters, not anything classified as alphabetical in Unicode.

Note - if your collation is case sensitive, it's important to specify the range as [a-zA-Z]. [a-z] may exclude A or Z. [A-Z] may exclude a or z.

Serialize form data to JSON

Well, here's a handy plugin for it: https://github.com/macek/jquery-serialize-object

The issue for it is:

Moving ahead, on top of core serialization, .serializeObject will support correct serializaton for boolean and number values, resulting valid types for both cases.

Look forward to these in >= 2.1.0

Detect change to ngModel on a select tag (Angular 2)

I have stumbled across this question and I will submit my answer that I used and worked pretty well. I had a search box that filtered and array of objects and on my search box I used the (ngModelChange)="onChange($event)"

in my .html

<input type="text" [(ngModel)]="searchText" (ngModelChange)="reSearch(newValue)" placeholder="Search">

then in my component.ts

reSearch(newValue: string) {
    //this.searchText would equal the new value
    //handle my filtering with the new value
}

What's the purpose of META-INF?

From the official JAR File Specification (link goes to the Java 7 version, but the text hasn't changed since at least v1.3):

The META-INF directory

The following files/directories in the META-INF directory are recognized and interpreted by the Java 2 Platform to configure applications, extensions, class loaders and services:

  • MANIFEST.MF

The manifest file that is used to define extension and package related data.

  • INDEX.LIST

This file is generated by the new "-i" option of the jar tool, which contains location information for packages defined in an application or extension. It is part of the JarIndex implementation and used by class loaders to speed up their class loading process.

  • x.SF

The signature file for the JAR file. 'x' stands for the base file name.

  • x.DSA

The signature block file associated with the signature file with the same base file name. This file stores the digital signature of the corresponding signature file.

  • services/

This directory stores all the service provider configuration files.

Convert InputStream to JSONObject

Make use of Jackson JSON Parser

ObjectMapper mapper = new ObjectMapper();
Map<String,Object> map = mapper.readValue(inputStreamObject,Map.class);

If you want specifically a JSONObject then you can convert the map

JSONObject json = new JSONObject(map);

Refer this for the usage of JSONObject constructor http://stleary.github.io/JSON-java/index.html

Folder structure for a Node.js project

This is indirect answer, on the folder structure itself, very related.

A few years ago I had same question, took a folder structure but had to do a lot directory moving later on, because the folder was meant for a different purpose than that I have read on internet, that is, what a particular folder does has different meanings for different people on some folders.

Now, having done multiple projects, in addition to explanation in all other answers, on the folder structure itself, I would strongly suggest to follow the structure of Node.js itself, which can be seen at: https://github.com/nodejs/node. It has great detail on all, say linters and others, what file and folder structure they have and where. Some folders have a README that explains what is in that folder.

Starting in above structure is good because some day a new requirement comes in and but you will have a scope to improve as it is already followed by Node.js itself which is maintained over many years now.

Hope this helps.

Where are the Properties.Settings.Default stored?

if you use Windows 10, this is the directory:

C:\Users<UserName>\AppData\Local\

+

<ProjectName.exe_Url_somedata>\1.0.0.0<filename.config>

Select multiple columns in data.table by their numeric indices

If you want to use column names to select the columns, simply use .(), which is an alias for list():

library(data.table)
dt <- data.table(a = 1:2, b = 2:3, c = 3:4)
dt[ , .(b, c)] # select the columns b and c
# Result:
#    b c
# 1: 2 3
# 2: 3 4

How do I tell Maven to use the latest version of a dependency?

Unlike others I think there are many reasons why you might always want the latest version. Particularly if you are doing continuous deployment (we sometimes have like 5 releases in a day) and don't want to do a multi-module project.

What I do is make Hudson/Jenkins do the following for every build:

mvn clean versions:use-latest-versions scm:checkin deploy -Dmessage="update versions" -DperformRelease=true

That is I use the versions plugin and scm plugin to update the dependencies and then check it in to source control. Yes I let my CI do SCM checkins (which you have to do anyway for the maven release plugin).

You'll want to setup the versions plugin to only update what you want:

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>versions-maven-plugin</artifactId>
    <version>1.2</version>
    <configuration>
        <includesList>com.snaphop</includesList>
        <generateBackupPoms>false</generateBackupPoms>
        <allowSnapshots>true</allowSnapshots>
    </configuration>
</plugin>

I use the release plugin to do the release which takes care of -SNAPSHOT and validates that there is a release version of -SNAPSHOT (which is important).

If you do what I do you will get the latest version for all snapshot builds and the latest release version for release builds. Your builds will also be reproducible.

Update

I noticed some comments asking some specifics of this workflow. I will say we don't use this method anymore and the big reason why is the maven versions plugin is buggy and in general is inherently flawed.

It is flawed because to run the versions plugin to adjust versions all the existing versions need to exist for the pom to run correctly. That is the versions plugin cannot update to the latest version of anything if it can't find the version referenced in the pom. This is actually rather annoying as we often cleanup old versions for disk space reasons.

Really you need a separate tool from maven to adjust the versions (so you don't depend on the pom file to run correctly). I have written such a tool in the the lowly language that is Bash. The script will update the versions like the version plugin and check the pom back into source control. It also runs like 100x faster than the mvn versions plugin. Unfortunately it isn't written in a manner for public usage but if people are interested I could make it so and put it in a gist or github.

Going back to workflow as some comments asked about that this is what we do:

  1. We have 20 or so projects in their own repositories with their own jenkins jobs
  2. When we release the maven release plugin is used. The workflow of that is covered in the plugin's documentation. The maven release plugin sort of sucks (and I'm being kind) but it does work. One day we plan on replacing this method with something more optimal.
  3. When one of the projects gets released jenkins then runs a special job we will call the update all versions job (how jenkins knows its a release is a complicated manner in part because the maven jenkins release plugin is pretty crappy as well).
  4. The update all versions job knows about all the 20 projects. It is actually an aggregator pom to be specific with all the projects in the modules section in dependency order. Jenkins runs our magic groovy/bash foo that will pull all the projects update the versions to the latest and then checkin the poms (again done in dependency order based on the modules section).
  5. For each project if the pom has changed (because of a version change in some dependency) it is checked in and then we immediately ping jenkins to run the corresponding job for that project (this is to preserve build dependency order otherwise you are at the mercy of the SCM Poll scheduler).

At this point I'm of the opinion it is a good thing to have the release and auto version a separate tool from your general build anyway.

Now you might think maven sort of sucks because of the problems listed above but this actually would be fairly difficult with a build tool that does not have a declarative easy to parse extendable syntax (aka XML).

In fact we add custom XML attributes through namespaces to help hint bash/groovy scripts (e.g. don't update this version).

Deserialize JSON with C#

Newtonsoft.JSON is a good solution for these kind of situations. Also Newtonsof.JSON is faster than others, such as JavaScriptSerializer, DataContractJsonSerializer.

In this sample, you can the following:

var jsonData = JObject.Parse("your JSON data here");

Then you can cast jsonData to JArray, and you can use a for loop to get data at each iteration.

Also, I want to add something:

for (int i = 0; (JArray)jsonData["data"].Count; i++)
{
    var data = jsonData[i - 1];
}

Working with dynamic object and using Newtonsoft serialize is a good choice.

C# Dictionary get item by index

If you need to extract an element key based on index, this function can be used:

public string getCard(int random)
{
    return Karta._dict.ElementAt(random).Key;
}

If you need to extract the Key where the element value is equal to the integer generated randomly, you can used the following function:

public string getCard(int random)
{
    return Karta._dict.FirstOrDefault(x => x.Value == random).Key;
}

Side Note: The first element of the dictionary is The Key and the second is the Value

How do I alias commands in git?

Another possibility for windows would be to have a directory filled with .bat files that have your shortcuts in them. The name of the file is the shortcut to be used. Simply add the directory to your PATH environment variable and you have all the shortcuts to your disposal in the cmd window.

For example (gc.bat):

git commit -m %1

Then you can execute the following command in the console:

gc "changed stuff"

The reason I'm adding this as an answer is because when using this you aren't limited to git ... only commands.

How do I determine if a port is open on a Windows server?

I did like that:

netstat -an | find "8080" 

from telnet

telnet 192.168.100.132 8080

And just make sure that the firewall is off on that machine.

When should I use a table variable vs temporary table in sql server?

Use a table variable if for a very small quantity of data (thousands of bytes)

Use a temporary table for a lot of data

Another way to think about it: if you think you might benefit from an index, automated statistics, or any SQL optimizer goodness, then your data set is probably too large for a table variable.

In my example, I just wanted to put about 20 rows into a format and modify them as a group, before using them to UPDATE / INSERT a permanent table. So a table variable is perfect.

But I am also running SQL to back-fill thousands of rows at a time, and I can definitely say that the temporary tables perform much better than table variables.

This is not unlike how CTE's are a concern for a similar size reason - if the data in the CTE is very small, I find a CTE performs as good as or better than what the optimizer comes up with, but if it is quite large then it hurts you bad.

My understanding is mostly based on http://www.developerfusion.com/article/84397/table-variables-v-temporary-tables-in-sql-server/, which has a lot more detail.

How to restart a node.js server

Using "kill -9 [PID]" or "killall -9 node" worked for me where "kill -2 [PID]" did not work.

How to find and replace with regex in excel

If you want a formula to do it then:

=IF(ISNUMBER(SEARCH("*texts are *",A1)),LEFT(A1,FIND("texts are ",A1) + 9) & "WORD",A1)

This will do it. Change `"WORD" To the word you want.

Java converting int to hex and back again

Hehe, curious. I think this is an "intentianal bug", so to speak.

The underlying reason is how the Integer class is written. Basically, parseInt is "optimized" for positive numbers. When it parses the string, it builds the result cumulatively, but negated. Then it flips the sign of the end-result.

Example:

66 = 0x42

parsed like:

4*(-1) = -4
-4 * 16 = -64 (hex 4 parsed)

-64 - 2 = -66 (hex 2 parsed)

return -66 * (-1) = 66

Now, let's look at your example FFFF8000

16*(-1) = -16 (first F parsed)
-16*16 = -256 

-256 - 16 = -272 (second F parsed)
-272 * 16 = -4352 

-4352 - 16 = -4368 (third F parsed)
-4352 * 16 = -69888

-69888 - 16 = -69904 (forth F parsed)
-69904 * 16 = -1118464 

-1118464 - 8 = -1118472 (8 parsed)
-1118464 * 16 = -17895552 

-17895552 - 0 = -17895552 (first 0 parsed)
Here it blows up since -17895552 < -Integer.MAX_VALUE / 16 (-134217728). 
Attempting to execute the next logical step in the chain (-17895552 * 16)
would cause an integer overflow error.

Edit (addition): in order for the parseInt() to work "consistently" for -Integer.MAX_VALUE <= n <= Integer.MAX_VALUE, they would have had to implement logic to "rotate" when reaching -Integer.MAX_VALUE in the cumulative result, starting over at the max-end of the integer range and continuing downwards from there. Why they did not do this, one would have to ask Josh Bloch or whoever implemented it in the first place. It might just be an optimization.

However,

Hex=Integer.toHexString(Integer.MAX_VALUE);
System.out.println(Hex);
System.out.println(Integer.parseInt(Hex.toUpperCase(), 16));

works just fine, for just this reason. In the sourcee for Integer you can find this comment.

// Accumulating negatively avoids surprises near MAX_VALUE

Why is setTimeout(fn, 0) sometimes useful?

Javascript is single threaded application so that don't allow to run function concurrently so to achieve this event loops are use. So exactly what setTimeout(fn, 0) do that its pussed into task quest which is executed when your call stack is empty. I know this explanation is pretty boring, so i recommend you to go through this video this will help you how things work under the hood in browser. Check out this video:- https://www.youtube.com/watch?time_continue=392&v=8aGhZQkoFbQ

How to debug (only) JavaScript in Visual Studio?

First open Visual studio ..select your project in solution explorer..Right click and choose option "browse with" then set IE as default browser.

enter image description here Now open IE ..go to
Tools >> Internet option >> Advance>> uncheck the checkbox having "Disable Script Debugging (Internet Explorer). and then click Apply and OK and you are done ..

Now you can set breakpoints in your JS file and then hit the debug button in VS..

enter image description here

EDIT:- For asp.net web application right click on the page which is your startup page(say default.aspx) and perform the same steps. :)

What does Statement.setFetchSize(nSize) method really do in SQL Server JDBC driver?

In JDBC, the setFetchSize(int) method is very important to performance and memory-management within the JVM as it controls the number of network calls from the JVM to the database and correspondingly the amount of RAM used for ResultSet processing.

Inherently if setFetchSize(10) is being called and the driver is ignoring it, there are probably only two options:

  1. Try a different JDBC driver that will honor the fetch-size hint.
  2. Look at driver-specific properties on the Connection (URL and/or property map when creating the Connection instance).

The RESULT-SET is the number of rows marshalled on the DB in response to the query. The ROW-SET is the chunk of rows that are fetched out of the RESULT-SET per call from the JVM to the DB. The number of these calls and resulting RAM required for processing is dependent on the fetch-size setting.

So if the RESULT-SET has 100 rows and the fetch-size is 10, there will be 10 network calls to retrieve all of the data, using roughly 10*{row-content-size} RAM at any given time.

The default fetch-size is 10, which is rather small. In the case posted, it would appear the driver is ignoring the fetch-size setting, retrieving all data in one call (large RAM requirement, optimum minimal network calls).

What happens underneath ResultSet.next() is that it doesn't actually fetch one row at a time from the RESULT-SET. It fetches that from the (local) ROW-SET and fetches the next ROW-SET (invisibly) from the server as it becomes exhausted on the local client.

All of this depends on the driver as the setting is just a 'hint' but in practice I have found this is how it works for many drivers and databases (verified in many versions of Oracle, DB2 and MySQL).

How do I concatenate two lists in Python?

You can use sets to obtain merged list of unique values

mergedlist = list(set(listone + listtwo))

What does if [ $? -eq 0 ] mean for shell scripts?

It's checking the return value ($?) of grep. In this case it's comparing it to 0 (success).

Usually when you see something like this (checking the return value of grep) it's checking to see whether the particular string was detected. Although the redirect to /dev/null isn't necessary, the same thing can be accomplished using -q.

Remove by _id in MongoDB console

Well, the _id is an object in your example, so you just need to pass an object

'db.test_users.remove({"_id": { "$oid" : "4d513345cc9374271b02ec6c" }})'

This should work

Edit: Added trailing paren to ensure that it compiled.

How do you resize a form to fit its content automatically?

This technique solved my problem:

In parent form:

frmEmployee frm = new frmEmployee();
frm.MdiParent = this;
frm.Dock = DockStyle.Fill;
frm.Show();

In the child form (Load event):

this.WindowState = FormWindowState.Maximized;

How to show uncommitted changes in Git and some Git diffs in detail

I had a situation of git status showing changes, but git diff printing nothing, although there were changes in several lines. However:

$ git diff data.txt > myfile
$ cat myfile
<prints diff>

Git 2.20.1 on raspbian. Other commands like git checkout, git pull are printing to stdout without problems.

Print specific part of webpage

I wrote a tiny JavaScript module called PrintElements for dynamically printing parts of a webpage.

It works by iterating through selected node elements, and for each node, it traverses up the DOM tree until the BODY element. At each level, including the initial one (which is the to-be-printed node’s level), it attaches a marker class (pe-preserve-print) to the current node. Then attaches another marker class (pe-no-print) to all siblings of the current node, but only if there is no pe-preserve-print class on them. As a third act, it also attaches another class to preserved ancestor elements pe-preserve-ancestor.

A dead-simple supplementary print-only css will hide and show respective elements. Some benefits of this approach is that all styles are preserved, it does not open a new window, there is no need to move around a lot of DOM elements, and generally it is non-invasive with your original document.

See the demo, or read the related article for further details.

Output single character in C

Be careful of difference between 'c' and "c"

'c' is a char suitable for formatting with %c

"c" is a char* pointing to a memory block with a length of 2 (with the null terminator).

"Parameter" vs "Argument"

A parameter is the variable which is part of the method’s signature (method declaration). An argument is an expression used when calling the method.

Consider the following code:

void Foo(int i, float f)
{
    // Do things
}

void Bar()
{
    int anInt = 1;
    Foo(anInt, 2.0);
}

Here i and f are the parameters, and anInt and 2.0 are the arguments.

map vs. hash_map in C++

I don't know what gives, but, hash_map takes more than 20 seconds to clear() 150K unsigned integer keys and float values. I am just running and reading someone else's code.

This is how it includes hash_map.

#include "StdAfx.h"
#include <hash_map>

I read this here https://bytes.com/topic/c/answers/570079-perfomance-clear-vs-swap

saying that clear() is order of O(N). That to me, is very strange, but, that's the way it is.

uint8_t vs unsigned char

It documents your intent - you will be storing small numbers, rather than a character.

Also it looks nicer if you're using other typedefs such as uint16_t or int32_t.

java.net.SocketException: Connection reset by peer: socket write error When serving a file

It is possible for the TCP socket to be "closing" and your code to not have yet been notified.

Here is a animation for the life cycle. http://tcp.cs.st-andrews.ac.uk/index.shtml?page=connection_lifecycle

Basically, the connection was closed by the client. You already have throws IOException and SocketException extends IOException. This is working just fine. You just need to properly handle IOException because it is a normal part of the api.

EDIT: The RST packet occurs when a packet is received on a socket which does not exist or was closed. There is no difference to your application. Depending on the implementation the reset state may stick and closed will never officially occur.

Return None if Dictionary key is not available

You should use the get() method from the dict class

d = {}
r = d.get('missing_key', None)

This will result in r == None. If the key isn't found in the dictionary, the get function returns the second argument.

Convert string to ASCII value python

def stringToNumbers(ord(message)):
    return stringToNumbers
    stringToNumbers.append = (ord[0])
    stringToNumbers = ("morocco")

How to use a variable for the database name in T-SQL?

You cannot use a variable in a create table statement. The best thing I can suggest is to write the entire query as a string and exec that.

Try something like this:

declare @query varchar(max);
set @query = 'create database TEST...';

exec (@query);

How do you properly determine the current script directory?

Note: this answer is now a package

$ pip install locate

>>> from locate import this_dir
>>> print(this_dir())
C:/Users/simon

For .py scripts as well as interactive usage:

I frequently use the directory of my scripts (for accessing files stored along side them), but I also frequently run these scripts in an interactive shell for debugging purposes. I define __dirpath__ as:

  • When running or importing a .py file, the file's base directory. This is always the correct path.
  • When running an .ipyn notebook, the current working directory. This is always the correct path, since Jupyter sets the working directory as the .ipynb base directory.
  • When running in a REPL, the current working directory. Hmm, what is the actual "correct path" when the code is detached from a file? Rather, make it your responsibility to change into the "correct path" before invoking the REPL.

Python 3.4 (and above):

from pathlib import Path
__dirpath__ = Path(globals().get("__file__", "./_")).absolute().parent

Python 2 (and above):

import os
__dirpath__ = os.path.dirname(os.path.abspath(globals().get("__file__", "./_")))

Explanation:

  • globals() returns all the global variables as a dictionary.
  • .get("__file__", "./_") returns the value from the key "__file__" if it exists in globals(), otherwise it returns the provided default value "./_".
  • The rest of the code just expands __file__ (or "./_") into an absolute filepath, and then returns the filepath's base directory.

Oracle SQL Developer: Unable to find a JVM

I just installed SQL Developer 4.0.0.13 and the SetJavaHome can now be overridden by a user-specific configuration file (not sure if this is new to 4.0.0.13 or not).

The location of this user-specific configuration file can be seen in the user.conf property under 'Help -> About' on the 'Properties' tab. For example, mine was set to:

C:\Users\username\AppData\Roaming\sqldeveloper\1.0.0.0.0\product.conf

On Windows 7.

The first section of this file is used to set the JDK that SQLDeveloper should use:

#
# By default, the product launcher will search for a JDK to use, and if none
# can be found, it will ask for the location of a JDK and store its location
# in this file. If a particular JDK should be used instead, uncomment the
# line below and set the path to your preferred JDK.
#
SetJavaHome C:\Program Files (x86)\Java\jdk1.7.0_03

This setting overrides the setting in sqldeveloper.conf

Clear icon inside input text

Could I suggest, if you're okay with this being limited to html 5 compliant browsers, simply using:

<input type="search" />

JS Fiddle demo

Admittedly, in Chromium (Ubuntu 11.04), this does require there to be text inside the input element before the clear-text image/functionality will appear.

Reference:

What is copy-on-write?

I shall not repeat the same answer on Copy-on-Write. I think Andrew's answer and Charlie's answer have already made it very clear. I will give you an example from OS world, just to mention how widely this concept is used.

We can use fork() or vfork() to create a new process. vfork follows the concept of copy-on-write. For example, the child process created by vfork will share the data and code segment with the parent process. This speeds up the forking time. It is expected to use vfork if you are performing exec followed by vfork. So vfork will create the child process which will share data and code segment with its parent but when we call exec, it will load up the image of a new executable in the address space of the child process.

Date minus 1 year?

Using the DateTime object...

$time = new DateTime('2099-01-01');
$newtime = $time->modify('-1 year')->format('Y-m-d');

Or using now for today

$time = new DateTime('now');
$newtime = $time->modify('-1 year')->format('Y-m-d');

Where do I put image files, css, js, etc. in Codeigniter?

(I am new to Codeigniter, so I don't know if this is the best advice)

I keep publicly available files in my public folder. It is logical for them to be there, and I don't want to use Codeigniter for something I don't need to use it for.

The directory tree looks likes this:

  • /application/
  • /public/
  • /public/css/
  • /public/img/
  • /public/js/
  • /system/

The only files I keep in /public/ are Codeigniter's index.php, and my .htaccess file:

RewriteEngine On
RewriteBase /

RewriteRule ^css/ - [L]
RewriteRule ^img/ - [L]
RewriteRule ^js/ - [L]

RewriteRule ^index.php(.*)$ - [L]
RewriteRule ^(.*)$ /index.php?/$1 [L]

How to use BOOLEAN type in SELECT statement

You can build a wrapper function like this:

function get_something(name in varchar2,
                   ignore_notfound in varchar2) return varchar2
is
begin
    return get_something (name, (upper(ignore_notfound) = 'TRUE') );
end;

then call:

select get_something('NAME', 'TRUE') from dual;

It's up to you what the valid values of ignore_notfound are in your version, I have assumed 'TRUE' means TRUE and anything else means FALSE.

Pretty git branch graphs

This is my take on this matter:

Screenshot:

Screenshot

Usage:

git hist - Show the history of current branch

git hist --all - Show the graph of all branches (including remotes)

git hist master devel - Show the relationship between two or more branches

git hist --branches - Show all local branches

Add --topo-order to sort commits topologically, instead of by date (default in this alias)

Benefits:

  • Looks just like plain --decorate, so with separate colors for different branch names
  • Adds committer email
  • Adds commit relative and absolute date
  • Sorts commits by date

Setup:

git config --global alias.hist "log --graph --date-order --date=short \
--pretty=format:'%C(auto)%h%d %C(reset)%s %C(bold blue)%ce %C(reset)%C(green)%cr (%cd)'"

jquery get height of iframe content when loaded

this is the correct answer that worked for me

$(document).ready(function () {
        function resizeIframe() {
            if ($('iframe').contents().find('html').height() > 100) {
                $('iframe').height(($('iframe').contents().find('html').height()) + 'px')
            } else {
                setTimeout(function (e) {
                    resizeIframe();
                }, 50);
            }
        }
        resizeIframe();
    });

Using command line arguments in VBscript

If you need direct access:

WScript.Arguments.Item(0)
WScript.Arguments.Item(1)
...

Get list from pandas dataframe column or row?

This returns a numpy array:

arr = df["cluster"].to_numpy()

This returns a numpy array of unique values:

unique_arr = df["cluster"].unique()

You can also use numpy to get the unique values, although there are differences between the two methods:

arr = df["cluster"].to_numpy()
unique_arr = np.unique(arr)

Stack array using pop() and push()

Stack Implementation in Java

  class stack
  {  private int top;
     private int[] element;
      stack()
      {element=new int[10];
      top=-1;
      }
      void push(int item)
      {top++;
      if(top==9)
          System.out.println("Overflow");
      else
              {
               top++;
      element[top]=item;

      }

      void pop()
      {if(top==-1)
          System.out.println("Underflow");
      else  
      top--;
      }
      void display()
      {
          System.out.println("\nTop="+top+"\nElement="+element[top]);
      }

      public static void main(String args[])
      {
        stack s1=new stack();
        s1.push(10);
        s1.display();
        s1.push(20);
        s1.display();
        s1.push(30);
        s1.display();
        s1.pop();
        s1.display();
      }

  }

Output

Top=0 Element=10 Top=1 Element=20 Top=2 Element=30 Top=1 Element=20

How to validate a credit card number

You should really use .test():

if (!re16digit.test(document.myform.CreditCardNumber.value)) {
  alert("Please ... ");
}

You should also look around for implementations of (one or more of) the card number checksum algorithms. They're very simple.

When to use RSpec let()?

let is functional as its essentially a Proc. Also its cached.

One gotcha I found right away with let... In a Spec block that is evaluating a change.

let(:object) {FactoryGirl.create :object}

expect {
  post :destroy, id: review.id
}.to change(Object, :count).by(-1)

You'll need to be sure to call let outside of your expect block. i.e. you're calling FactoryGirl.create in your let block. I usually do this by verifying the object is persisted.

object.persisted?.should eq true

Otherwise when the let block is called the first time a change in the database will actually happen due to the lazy instantiation.

Update

Just adding a note. Be careful playing code golf or in this case rspec golf with this answer.

In this case, I just have to call some method to which the object responds. So I invoke the _.persisted?_ method on the object as its truthy. All I'm trying to do is instantiate the object. You could call empty? or nil? too. The point isn't the test but bringing the object ot life by calling it.

So you can't refactor

object.persisted?.should eq true

to be

object.should be_persisted 

as the object hasn't been instantiated... its lazy. :)

Update 2

leverage the let! syntax for instant object creation, which should avoid this issue altogether. Note though it will defeat a lot of the purpose of the laziness of the non banged let.

Also in some instances you might actually want to leverage the subject syntax instead of let as it may give you additional options.

subject(:object) {FactoryGirl.create :object}

Jackson how to transform JsonNode to ArrayNode without casting?

I would assume at the end of the day you want to consume the data in the ArrayNode by iterating it. For that:

Iterator<JsonNode> iterator = datasets.withArray("datasets").elements();
while (iterator.hasNext()) 
        System.out.print(iterator.next().toString() + " "); 

or if you're into streams and lambda functions:

import com.google.common.collect.Streams;
Streams.stream(datasets.withArray("datasets").elements())
    .forEach( item -> System.out.print(item.toString()) )

Can I pass variable to select statement as column name in SQL Server

You can't use variable names to bind columns or other system objects, you need dynamic sql

DECLARE @value varchar(10)  
SET @value = 'intStep'  
DECLARE @sqlText nvarchar(1000); 

SET @sqlText = N'SELECT ' + @value + ' FROM dbo.tblBatchDetail'
Exec (@sqlText)

Forbidden You don't have permission to access /wp-login.php on this server

Sometimes if you are using some simple login info like this: username: 'admin' and pass: 'admin', the hosting is seeing you as a potential Brute Force Attack through WP login file, and blocks you IP address or that particularly file.

I had that issue with ixwebhosting and just got that info from their support guy. They must unban your IP in this situation. And you must change your WP admin login info to something more secure.

That solved my problem.

How do I display the current value of an Android Preference in the Preference summary?

Thanks for this tip!

I have one preference screen and want to show the value for each list preference as the summary.

This is my way now:

public class Preferences extends PreferenceActivity implements OnSharedPreferenceChangeListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
}

@Override
protected void onResume() {
    super.onResume();

    // Set up initial values for all list preferences
    Map<String, ?> sharedPreferencesMap = getPreferenceScreen().getSharedPreferences().getAll();
    Preference pref;
    ListPreference listPref;
    for (Map.Entry<String, ?> entry : sharedPreferencesMap.entrySet()) {
        pref = findPreference(entry.getKey());
        if (pref instanceof ListPreference) {
            listPref = (ListPreference) pref;
            pref.setSummary(listPref.getEntry());
        }
    }

    // Set up a listener whenever a key changes            
    getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
}

@Override
protected void onPause() {
    super.onPause();

    // Unregister the listener whenever a key changes            
    getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);    
}

public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
    Preference pref = findPreference(key);

    if (pref instanceof ListPreference) {
        ListPreference listPref = (ListPreference) pref;
        pref.setSummary(listPref.getEntry());
    }
}

This works for me, but I'm wondering what is the best solution (performance, stability, scalibility): the one Koem is showing or this one?

Oracle Date TO_CHAR('Month DD, YYYY') has extra spaces in it

Why are there extra spaces between my month and day? Why does't it just put them next to each other?

So your output will be aligned.

If you don't want padding use the format modifier FM:

SELECT TO_CHAR (date_field, 'fmMonth DD, YYYY') 
  FROM ...;

Reference: Format Model Modifiers

SQL Inner-join with 3 tables?

You just need a second inner join that links the ID Number that you have now to the ID Number of the third table. Afterwards, replace the ID Number by the Hall Name and voilá :)

using mailto to send email with an attachment

this is not possible in "mailto" function.

please go with server side coding(C#).make sure open vs in administrative permission.

Microsoft.Office.Interop.Outlook.Application oApp = new Microsoft.Office.Interop.Outlook.Application();
Microsoft.Office.Interop.Outlook.MailItem oMsg = (Microsoft.Office.Interop.Outlook.MailItem)oApp.CreateItem(Microsoft.Office.Interop.Outlook.OlItemType.olMailItem);

oMsg.Subject = "emailSubject";
oMsg.BodyFormat = Microsoft.Office.Interop.Outlook.OlBodyFormat.olFormatHTML;
oMsg.BCC = "emailBcc";
oMsg.To = "emailRecipient";

string body = "emailMessage";

oMsg.HTMLBody = "body";              
oMsg.Attachments.Add(Convert.ToString(@"/my_location_virtual_path/myfile.txt"), Microsoft.Office.Interop.Outlook.OlAttachmentType.olByValue, Type.Missing, Type.Missing);

oMsg.Display(false); //In order to displ

Execute SQLite script

If you are using the windows CMD you can use this command to create a database using sqlite3

C:\sqlite3.exe DBNAME.db ".read DBSCRIPT.sql"

If you haven't a database with that name sqlite3 will create one, and if you already have one, it will run it anyways but with the "TABLENAME already exists" error, I think you can also use this command to change an already existing database (but im not sure)

How is a tag different from a branch in Git? Which should I use, here?

simple:

Tags are expected to always point at the same version of a project, while heads are expected to advance as development progresses.

Git User Manual

How to remove blank lines from a Unix file

sed -i '/^$/d' foo

This tells sed to delete every line matching the regex ^$ i.e. every empty line. The -i flag edits the file in-place, if your sed doesn't support that you can write the output to a temporary file and replace the original:

sed '/^$/d' foo > foo.tmp
mv foo.tmp foo

If you also want to remove lines consisting only of whitespace (not just empty lines) then use:

sed -i '/^[[:space:]]*$/d' foo

Edit: also remove whitespace at the end of lines, because apparently you've decided you need that too:

sed -i '/^[[:space:]]*$/d;s/[[:space:]]*$//' foo

SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax — PHP — PDO

from is a keyword in SQL. You may not used it as a column name without quoting it. In MySQL, things like column names are quoted using backticks, i.e. `from`.

Personally, I wouldn't bother; I'd just rename the column.

PS. as pointed out in the comments, to is another SQL keyword so it needs to be quoted, too. Conveniently, the folks at drupal.org maintain a list of reserved words in SQL.

Open Windows Explorer and select a file

Check out this snippet:

Private Sub openDialog()
    Dim fd As Office.FileDialog

    Set fd = Application.FileDialog(msoFileDialogFilePicker)

   With fd

      .AllowMultiSelect = False

      ' Set the title of the dialog box.
      .Title = "Please select the file."

      ' Clear out the current filters, and add our own.
      .Filters.Clear
      .Filters.Add "Excel 2003", "*.xls"
      .Filters.Add "All Files", "*.*"

      ' Show the dialog box. If the .Show method returns True, the
      ' user picked at least one file. If the .Show method returns
      ' False, the user clicked Cancel.
      If .Show = True Then
        txtFileName = .SelectedItems(1) 'replace txtFileName with your textbox

      End If
   End With
End Sub

I think this is what you are asking for.

WCF gives an unsecured or incorrectly secured fault error

Try changing your security mode to "transport".

You have a mismatch between the security tag and the transport tag.

User GETDATE() to put current date into SQL variable

Just use GetDate() not Select GetDate()

DECLARE @LastChangeDate as date 
SET @LastChangeDate = GETDATE() 

but if it's SQL Server, you can also initialize in same step as declaration...

DECLARE @LastChangeDate date = getDate()

Most efficient conversion of ResultSet to JSON?

public static JSONArray GetJSONDataFromResultSet(ResultSet rs) throws SQLException {
    ResultSetMetaData metaData = rs.getMetaData();
    int count = metaData.getColumnCount();
    String[] columnName = new String[count];
    JSONArray jsonArray = new JSONArray();
    while(rs.next()) {
        JSONObject jsonObject = new JSONObject();
        for (int i = 1; i <= count; i++){
               columnName[i-1] = metaData.getColumnLabel(i);
               jsonObject.put(columnName[i-1], rs.getObject(i));
        }
        jsonArray.put(jsonObject);
    }
    return jsonArray;
}

What is "origin" in Git?

The best answer here:

https://www.git-tower.com/learn/git/glossary/origin

In Git, "origin" is a shorthand name for the remote repository that a project was originally cloned from. More precisely, it is used instead of that original repository's URL - and thereby makes referencing much easier.

Using Switch Statement to Handle Button Clicks

    XML CODE FOR TWO BUTTONS  
     <Button
            android:id="@+id/btn_save"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="SAVE"
            android:onClick="process"
            />
        <Button
            android:id="@+id/btn_show"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="SHOW"
            android:onClick="process"/> 

  Java Code
 <pre> public void process(View view) {
            switch (view.getId()){
                case R.id.btn_save:
                  //add your own code
                    break;
                case R.id.btn_show:
                   //add your own code
                    break;
            }</pre>

How to get the selected row values of DevExpress XtraGrid?

Here is the way that I've followed,

int[] selRows = ((GridView)gridControl1.MainView).GetSelectedRows();
DataRowView selRow = (DataRowView)(((GridView)gridControl1.MainView).GetRow(selRows[0]));
txtName.Text = selRow["name"].ToString();

Also you can iterate through selected rows using the selRows array. Here the code describes how to get data only from first selected row. You can insert these code lines to click event of the grid.

SQL how to make null values come last when sorting ascending

order by -cast([nativeDateModify] as bigint) desc

HSL to RGB color conversion

I got this from Brandon Mathis' HSL Picker source code.

It was originally written in CoffeeScript. I converted it to JavaScript using an online converter, and took out the mechanism to verify the user input was a valid RGB value. This answer worked for my usecase, as the most up-voted answer on this post I found to not produce a valid HSL value.

Note that it returns an hsla value, with a representing opacity/transparency. 0 is completely transparent, and 1 fully opaque.

function rgbToHsl(rgb) {
  var a, add, b, diff, g, h, hue, l, lum, max, min, r, s, sat;
  r = parseFloat(rgb[0]) / 255;
  g = parseFloat(rgb[1]) / 255;
  b = parseFloat(rgb[2]) / 255;
  max = Math.max(r, g, b);
  min = Math.min(r, g, b);
  diff = max - min;
  add = max + min;
  hue = min === max ? 0 : r === max ? ((60 * (g - b) / diff) + 360) % 360 : g === max ? (60 * (b - r) / diff) + 120 : (60 * (r - g) / diff) + 240;
  lum = 0.5 * add;
  sat = lum === 0 ? 0 : lum === 1 ? 1 : lum <= 0.5 ? diff / add : diff / (2 - add);
  h = Math.round(hue);
  s = Math.round(sat * 100);
  l = Math.round(lum * 100);
  a = parseFloat(rgb[3]) || 1;
  return [h, s, l, a];
}

Spring MVC - Why not able to use @RequestBody and @RequestParam together

It happens because of not very straight forward Servlet specification. If you are working with a native HttpServletRequest implementation you cannot get both the URL encode body and the parameters. Spring does some workarounds, which make it even more strange and nontransparent.

In such cases Spring (version 3.2.4) re-renders a body for you using data from the getParameterMap() method. It mixes GET and POST parameters and breaks the parameter order. The class, which is responsible for the chaos is ServletServerHttpRequest. Unfortunately it cannot be replaced, but the class StringHttpMessageConverter can be.

The clean solution is unfortunately not simple:

  1. Replacing StringHttpMessageConverter. Copy/Overwrite the original class adjusting method readInternal().
  2. Wrapping HttpServletRequest overwriting getInputStream(), getReader() and getParameter*() methods.

In the method StringHttpMessageConverter#readInternal following code must be used:

    if (inputMessage instanceof ServletServerHttpRequest) {
        ServletServerHttpRequest oo = (ServletServerHttpRequest)inputMessage;
        input = oo.getServletRequest().getInputStream();
    } else {
        input = inputMessage.getBody();
    }

Then the converter must be registered in the context.

<mvc:annotation-driven>
    <mvc:message-converters register-defaults="true/false">
        <bean class="my-new-converter-class"/>
   </mvc:message-converters>
</mvc:annotation-driven>

The step two is described here: Http Servlet request lose params from POST body after read it once

How to obtain the location of cacerts of the default java installation?

In High Sierra, the cacerts is located at : /Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home/jre/lib/security/cacerts

How to merge lists into a list of tuples?

In Python 2:

>>> list_a = [1, 2, 3, 4]
>>> list_b = [5, 6, 7, 8]
>>> zip(list_a, list_b)
[(1, 5), (2, 6), (3, 7), (4, 8)]

In Python 3:

>>> list_a = [1, 2, 3, 4]
>>> list_b = [5, 6, 7, 8]
>>> list(zip(list_a, list_b))
[(1, 5), (2, 6), (3, 7), (4, 8)]

How do I deal with corrupted Git object files?

For anyone stumbling across the same issue:

I fixed the problem by cloning the repo again at another location. I then copied my whole src dir (without .git dir obviously) from the corrupted repo into the freshly cloned repo. Thus I had all the recent changes and a clean and working repository.

Debugging "Element is not clickable at point" error

I met this because a loading dialog cover on this element. I simplely solve it by add a waiting before working with the this element.

try {
        Thread.sleep((int) (3000));
    } catch (InterruptedException e) {
        //
        e.printStackTrace();
    }

Hope this help!

Convert char to int in C and C++

(This answer addresses the C++ side of things, but the sign extension problem exists in C too.)

Handling all three char types (signed, unsigned, and char) is more delicate than it first appears. Values in the range 0 to SCHAR_MAX (which is 127 for an 8-bit char) are easy:

char c = somevalue;
signed char sc = c;
unsigned char uc = c;
int n = c;

But, when somevalue is outside of that range, only going through unsigned char gives you consistent results for the "same" char values in all three types:

char c = somevalue;
signed char sc = c;
unsigned char uc = c;
// Might not be true: int(c) == int(sc) and int(c) == int(uc).
int nc = (unsigned char)c;
int nsc = (unsigned char)sc;
int nuc = (unsigned char)uc;
// Always true: nc == nsc and nc == nuc.

This is important when using functions from ctype.h, such as isupper or toupper, because of sign extension:

char c = negative_char;  // Assuming CHAR_MIN < 0.
int n = c;
bool b = isupper(n);  // Undefined behavior.

Note the conversion through int is implicit; this has the same UB:

char c = negative_char;
bool b = isupper(c);

To fix this, go through unsigned char, which is easily done by wrapping ctype.h functions through safe_ctype:

template<int (&F)(int)>
int safe_ctype(unsigned char c) { return F(c); }

//...
char c = CHAR_MIN;
bool b = safe_ctype<isupper>(c);  // No UB.

std::string s = "value that may contain negative chars; e.g. user input";
std::transform(s.begin(), s.end(), s.begin(), &safe_ctype<toupper>);
// Must wrap toupper to eliminate UB in this case, you can't cast
// to unsigned char because the function is called inside transform.

This works because any function taking any of the three char types can also take the other two char types. It leads to two functions which can handle any of the types:

int ord(char c) { return (unsigned char)c; }
char chr(int n) {
  assert(0 <= n);  // Or other error-/sanity-checking.
  assert(n <= UCHAR_MAX);
  return (unsigned char)n;
}

// Ord and chr are named to match similar functions in other languages
// and libraries.

ord(c) always gives you a non-negative value – even when passed a negative char or negative signed char – and chr takes any value ord produces and gives back the exact same char.

In practice, I would probably just cast through unsigned char instead of using these, but they do succinctly wrap the cast, provide a convenient place to add error checking for int-to-char, and would be shorter and more clear when you need to use them several times in close proximity.

How to avoid "Permission denied" when using pip with virtualenv

virtualenv permission problems might occur when you create the virtualenv as sudo and then operate without sudo in the virtualenv.

As found out in your question's comment, the solution here is to create the virtualenv without sudo to be able to work (esp. write) in it without sudo.

Checkout one file from Subversion

I wanted to checkout a single file to a directory, which was not part of a working copy.

Let's get the file at the following URL: http://subversion.repository.server/repository/module/directory/myfile

svn co  http://subversion.repository.server/repository/module/directory/myfile /**directoryb**

So I checked out the given directory containing the target file I wanted to get to a dummy directory, (say etcb for the URL ending with /etc).

Then I emptied the file .svn/entries from all files of the target directory I didn't needed, to leave just the file I wanted. In this .svn/entries file, you have a record for each file with its attributes so leave just the record concerning the file you want to get and save.

Now you need just to copy then ''.svn'' to the directory which will be a new "working copy". Then you just need to:

cp .svn /directory
cd /directory
svn update myfile

Now the directory directory is under version control. Do not forget to remove the directory directoryb which was just a ''temporary working copy''.

write() versus writelines() and concatenated strings

Exercise 16 from Zed Shaw's book? You can use escape characters as follows:

paragraph1 = "%s \n %s \n %s \n" % (line1, line2, line3)
target.write(paragraph1)
target.close()

How to get a file directory path from file path?

HERE=$(cd $(dirname $BASH_SOURCE) && pwd)

where you get the full path with new_path=$(dirname ${BASH_SOURCE[0]}). You change current directory with cd new_path and then run pwd to get the full path to the current directory.

How to configure Docker port mapping to use Nginx as an upstream proxy?

@gdbj's answer is a great explanation and the most up to date answer. Here's however a simpler approach.

So if you want to redirect all traffic from nginx listening to 80 to another container exposing 8080, minimum configuration can be as little as:

nginx.conf:

server {
    listen 80;

    location / {
        proxy_pass http://client:8080; # this one here
        proxy_redirect off;
    }

}

docker-compose.yml

version: "2"
services:
  entrypoint:
    image: some-image-with-nginx
    ports:
      - "80:80"
    links:
      - client  # will use this one here

  client:
    image: some-image-with-api
    ports:
      - "8080:8080"

Docker docs

SQL Error: ORA-00913: too many values

For me this works perfect

insert into oehr.employees select * from employees where employee_id=99

I am not sure why you get error. The nature of the error code you have produced is the columns didn't match.

One good approach will be to use the answer @Parodo specified

Typescript interface default values

It is depends on the case and the usage. Generally, in TypeScript there are no default values for interfaces.

If you don't use the default values
You can declare x as:

let x: IX | undefined; // declaration: x = undefined

Then, in your init function you can set real values:

x = {
    a: 'xyz'
    b: 123
    c: new AnotherType()
};

In this way, x can be undefined or defined - undefined represents that the object is uninitialized, without set the default values, if they are unnecessary. This is loggically better than define "garbage".

If you want to partially assign the object:
You can define the type with optional properties like:

interface IX {
    a: string,
    b?: any,
    c?: AnotherType
}

In this case you have to set only a. The other types are marked with ? which mean that they are optional and have undefined as default value.

In any case you can use undefined as a default value, it is just depends on your use case.

Swift: Determine iOS Screen size

In Swift 3.0

let screenSize = UIScreen.main.bounds
let screenWidth = screenSize.width
let screenHeight = screenSize.height

In older swift: Do something like this:

let screenSize: CGRect = UIScreen.mainScreen().bounds

then you can access the width and height like this:

let screenWidth = screenSize.width
let screenHeight = screenSize.height

if you want 75% of your screen's width you can go:

let screenWidth = screenSize.width * 0.75

Swift 4.0

// Screen width.
public var screenWidth: CGFloat {
    return UIScreen.main.bounds.width
}

// Screen height.
public var screenHeight: CGFloat {
    return UIScreen.main.bounds.height
}

In Swift 5.0

let screenSize: CGRect = UIScreen.main.bounds

Redirecting unauthorized controller in ASP.NET MVC

In your Startup.Auth.cs file add this line:

LoginPath = new PathString("/Account/Login"),

Example:

// Enable the application to use a cookie to store information for the signed in user
// and to use a cookie to temporarily store information about a user logging in with a third party login provider
// Configure the sign in cookie
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
    AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
    LoginPath = new PathString("/Account/Login"),
    Provider = new CookieAuthenticationProvider
    {
        // Enables the application to validate the security stamp when the user logs in.
        // This is a security feature which is used when you change a password or add an external login to your account.  
        OnValidateIdentity = SecurityStampValidator.OnValidateIdentity<ApplicationUserManager, ApplicationUser>(
        validateInterval: TimeSpan.FromMinutes(30),
        regenerateIdentity: (manager, user) => user.GenerateUserIdentityAsync(manager))
    }
});

force client disconnect from server with socket.io and nodejs

Add new socket connections to an array and then when you want to close all - loop through them and disconnect. (server side)

var socketlist = [];

   io.sockets.on('connection', function (socket) {
        socketlist.push(socket);  
        //...other code for connection here..
   });


    //close remote sockets
    socketlist.forEach(function(socket) {        
        socket.disconnect();                      
    });    

How can I disable notices and warnings in PHP within the .htaccess file?

Use:

ini_set('display_errors','off');

It is working fine in WordPress' config.php.

Pandas Merge - How to avoid duplicating columns

I use the suffixes option in .merge():

dfNew = df.merge(df2, left_index=True, right_index=True,
                 how='outer', suffixes=('', '_y'))
dfNew.drop(dfNew.filter(regex='_y$').columns.tolist(),axis=1, inplace=True)

Thanks @ijoseph

Show current assembly instruction in GDB

There is a simple solution that consists in using stepi, which in turns moves forward by 1 asm instruction and shows the surrounding asm code.

Convert month int to month name

CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(
    Convert.ToInt32(e.Row.Cells[7].Text.Substring(3,2))).Substring(0,3) 
    + "-" 
    + Convert.ToDateTime(e.Row.Cells[7].Text).ToString("yyyy");

Constructor overload in TypeScript

Regarding constructor overloads one good alternative would be to implement the additional overloads as static factory methods. I think its more readable and simple than checking for all possible argument combinations at the constructor. Here is a simple example:

function calculateAge(birthday): number {
  return new Date().getFullYear() - birthday;
}

class Person {
  static fromData(data: PersonData): Person {
    const { first, last, birthday, gender = 'M' } = data;
    return new this(
      `${last}, ${first}`,
      calculateAge(birthday),
      gender,
    );
  }

  constructor(
    public fullName: string,
    public age: number,
    public gender: 'M' | 'F',
  ) {}

  toString(): string {
    return `Hello, my name is ${this.fullName} and I'm a ${this.age}yo ${this.gender}`;
  }
}

interface PersonData {
  first: string;
  last: string;
  birthday: string;
  gender?: 'M' | 'F';
}


const personA = new Person('Doe, John', 31, 'M');
console.log(personA.toString());
const personB = Person.fromData({
  first: 'Jane',
  last: 'Smith',
  birthday: '1986',
  gender: 'F',
});
console.log(personB.toString());

Method overloading in TypeScript isn't for real, let's say, as it would require too much compiler-generated code and the core team try to avoid that at all costs. Currently the main reason for method overloading to be present on the language is to provide a way to write declarations for libraries with magic arguments in their API. Since you'll need to do all the heavy-lifting by yourself to handle different sets of arguments I don't see much advantage in using overloads instead of separated methods.

What are good grep tools for Windows?

GrepWin Free and open source (GPL)

enter image description hereI've been using grepWin which was written by one of the tortoisesvn guys. Does the job on Windows...

http://stefanstools.sourceforge.net/grepWin.html

How to tell Maven to disregard SSL errors (and trusting all certs)?

An alternative that worked for me is to tell Maven to use http: instead of https: when using Maven Central by adding the following to settings.xml:

<settings>
   .
   .
   .
  <mirrors>
    <mirror>
        <id>central-no-ssl</id>
        <name>Central without ssl</name>
        <url>http://repo.maven.apache.org/maven2</url>
        <mirrorOf>central</mirrorOf>
    </mirror>
  </mirrors>
   .
   .
   .
</settings>

Your mileage may vary of course.

<button> background image

Try changing your CSS to this

button #rock {
    background: url('img/rock.png') no-repeat;
}

...provided that the image is in that place

What is the iPhone 4 user-agent?

Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0 like Mac OS X; en-us) AppleWebKit/532.9 (KHTML, like Gecko) Version/4.0.5 Mobile/8A293 Safari/6531.22.7

How do I get the logfile from an Android device?

I know it's an old question, but I believe still valid even in 2018.

There is an option to Take a bug report hidden in Developer options in every android device.

NOTE: This would dump whole system log

How to enable developer options? see: https://developer.android.com/studio/debug/dev-options

What works for me:

  1. Restart your device (in order to create minimum garbage logs for developer to analyze)
  2. Reproduce your bug
  3. Go to Settings -> Developer options -> Take a bug report
  4. Wait for Android system to collect the logs (watch the progressbar in notification)
  5. Once it completes, tap the notification to share it (you can use gmail or whetever else)

how to read this? open bugreport-1960-01-01-hh-mm-ss.txt

you probably want to look for something like this:

------ SYSTEM LOG (logcat -v threadtime -v printable -d *:v) ------
--------- beginning of crash
06-13 14:37:36.542 19294 19294 E AndroidRuntime: FATAL EXCEPTION: main

or:

------ SYSTEM LOG (logcat -v threadtime -v printable -d *:v) ------
--------- beginning of main

How do I center list items inside a UL element?

I added the div line and it did the trick:

<div style="text-align:center">
<ul>
<li>test</li>
<li>test</li>
<li>test</li>
<li>test</li>
<li>test</li>
</ul>
</div>

Reloading module giving NameError: name 'reload' is not defined

For >= Python3.4:

import importlib
importlib.reload(module)

For <= Python3.3:

import imp
imp.reload(module)

For Python2.x:

Use the in-built reload() function.

reload(module)

How to hide collapsible Bootstrap 4 navbar on click

I am using ANGULAR and since it gave me problems the routerLink just add the data-toggle and target in the li tag.... or use jquery like "ZimSystem"

_x000D_
_x000D_
<div class="collapse navbar-collapse" id="navbarSupportedContent">_x000D_
      <ul class="navbar-nav mr-auto">_x000D_
        <li class="nav-item" data-toggle="collapse" data-target=".navbar-collapse.show">_x000D_
          <a class="nav-link" routerLink="/inicio" routerLinkActive="active" >Inicio</a>_x000D_
        </li>_x000D_
      </ul>_x000D_
</div>
_x000D_
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Git credential helper - update password

None of these answers ended up working for my Git credential issue. Here is what did work if anyone needs it (I'm using Git 1.9 on Windows 8.1).

To update your credentials, go to Control PanelCredential ManagerGeneric Credentials. Find the credentials related to your Git account and edit them to use the updated password.

Reference: How to update your Git credentials on Windows

Note that to use the Windows Credential Manager for Git you need to configure the credential helper like so:

git config --global credential.helper wincred

If you have multiple GitHub accounts that you use for different repositories, then you should configure credentials to use the full repository path (rather than just the domain, which is the default):

git config --global credential.useHttpPath true

How to change the background colour's opacity in CSS

Use RGBA like this: background-color: rgba(255, 0, 0, .5)

Getting number of elements in an iterator in Python

Regarding your original question, the answer is still that there is no way in general to know the length of an iterator in Python.

Given that you question is motivated by an application of the pysam library, I can give a more specific answer: I'm a contributer to PySAM and the definitive answer is that SAM/BAM files do not provide an exact count of aligned reads. Nor is this information easily available from a BAM index file. The best one can do is to estimate the approximate number of alignments by using the location of the file pointer after reading a number of alignments and extrapolating based on the total size of the file. This is enough to implement a progress bar, but not a method of counting alignments in constant time.

#ifdef replacement in the Swift language

There is no Swift preprocessor. (For one thing, arbitrary code substitution breaks type- and memory-safety.)

Swift does include build-time configuration options, though, so you can conditionally include code for certain platforms or build styles or in response to flags you define with -D compiler args. Unlike with C, though, a conditionally compiled section of your code must be syntactically complete. There's a section about this in Using Swift With Cocoa and Objective-C.

For example:

#if os(iOS)
    let color = UIColor.redColor()
#else
    let color = NSColor.redColor()
#endif

Eclipse: How to build an executable jar with external jar?

Try the fat-jar extension. It will include all external jars inside the jar.

How do I remove whitespace from the end of a string in Python?

>>> "    xyz     ".rstrip()
'    xyz'

There is more about rstrip in the documentation.

Android open pdf file

The problem is that there is no app installed to handle opening the PDF. You should use the Intent Chooser, like so:

File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() +"/"+ filename);
Intent target = new Intent(Intent.ACTION_VIEW);
target.setDataAndType(Uri.fromFile(file),"application/pdf");
target.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);

Intent intent = Intent.createChooser(target, "Open File");
try {
    startActivity(intent);
} catch (ActivityNotFoundException e) {
    // Instruct the user to install a PDF reader here, or something
}   

How to get my activity context?

If you need the context of A in B, you need to pass it to B, and you can do that by passing the Activity A as parameter as others suggested. I do not see much the problem of having the many instances of A having their own pointers to B, not sure if that would even be that much of an overhead.

But if that is the problem, a possibility is to keep the pointer to A as a sort of global, avariable of the Application class, as @hasanghaforian suggested. In fact, depending on what do you need the context for, you could even use the context of the Application instead.

I'd suggest reading this article about context to better figure it out what context you need.

Read and overwrite a file in Python

The fileinput module has an inplace mode for writing changes to the file you are processing without using temporary files etc. The module nicely encapsulates the common operation of looping over the lines in a list of files, via an object which transparently keeps track of the file name, line number etc if you should want to inspect them inside the loop.

from fileinput import FileInput
for line in FileInput("file", inplace=1):
    line = line.replace("foobar", "bar")
    print(line)

sqlite3.OperationalError: unable to open database file

in my case, i tried creating the sqlite db in /tmp folder and from all the slashes i missed a single slash

Instead of sqlite:///tmp/mydb.sqlite -> sqlite:////tmp/mydb.sqlite ...

Base64: java.lang.IllegalArgumentException: Illegal character

Your encoded text is [B@6499375d. That is not Base64, something went wrong while encoding. That decoding code looks good.

Use this code to convert the byte[] to a String before adding it to the URL:

String encodedEmailString = new String(encodedEmail, "UTF-8");
// ...
String confirmLink = "Complete your registration by clicking on following"
    + "\n<a href='" + confirmationURL + encodedEmailString + "'>link</a>";

What is the use of join() in Python threading?

"What's the use of using join()?" you say. Really, it's the same answer as "what's the use of closing files, since python and the OS will close my file for me when my program exits?".

It's simply a matter of good programming. You should join() your threads at the point in the code that the thread should not be running anymore, either because you positively have to ensure the thread is not running to interfere with your own code, or that you want to behave correctly in a larger system.

You might say "I don't want my code to delay giving an answer" just because of the additional time that the join() might require. This may be perfectly valid in some scenarios, but you now need to take into account that your code is "leaving cruft around for python and the OS to clean up". If you do this for performance reasons, I strongly encourage you to document that behavior. This is especially true if you're building a library/package that others are expected to utilize.

There's no reason to not join(), other than performance reasons, and I would argue that your code does not need to perform that well.

In Python, how do I convert all of the items in a list to floats?

map(float, mylist) should do it.

(In Python 3, map ceases to return a list object, so if you want a new list and not just something to iterate over, you either need list(map(float, mylist) - or use SilentGhost's answer which arguably is more pythonic.)

Getting PEAR to work on XAMPP (Apache/MySQL stack on Windows)

AS per point 1, your PEAR path is c:\xampplite\php\pear\

However, your path is pointing to \xampplite\php\pear\PEAR

Putting the two one above the other you can clearly see one is too long:

c:\xampplite\php\pear\

\xampplite\php\pear\PEAR

Your include path is set to go one PEAR too deep into the pear tree. The PEAR subfolder of the pear folder includes the PEAR component. You need to adjust your include path up one level.

(you don't need the c: by the way, your path is fine as is, just too deep)

How can I URL encode a string in Excel VBA?

Same as WorksheetFunction.EncodeUrl with UTF-8 support:

Public Function EncodeURL(url As String) As String
  Dim buffer As String, i As Long, c As Long, n As Long
  buffer = String$(Len(url) * 12, "%")

  For i = 1 To Len(url)
    c = AscW(Mid$(url, i, 1)) And 65535

    Select Case c
      Case 48 To 57, 65 To 90, 97 To 122, 45, 46, 95  ' Unescaped 0-9A-Za-z-._ '
        n = n + 1
        Mid$(buffer, n) = ChrW(c)
      Case Is <= 127            ' Escaped UTF-8 1 bytes U+0000 to U+007F '
        n = n + 3
        Mid$(buffer, n - 1) = Right$(Hex$(256 + c), 2)
      Case Is <= 2047           ' Escaped UTF-8 2 bytes U+0080 to U+07FF '
        n = n + 6
        Mid$(buffer, n - 4) = Hex$(192 + (c \ 64))
        Mid$(buffer, n - 1) = Hex$(128 + (c Mod 64))
      Case 55296 To 57343       ' Escaped UTF-8 4 bytes U+010000 to U+10FFFF '
        i = i + 1
        c = 65536 + (c Mod 1024) * 1024 + (AscW(Mid$(url, i, 1)) And 1023)
        n = n + 12
        Mid$(buffer, n - 10) = Hex$(240 + (c \ 262144))
        Mid$(buffer, n - 7) = Hex$(128 + ((c \ 4096) Mod 64))
        Mid$(buffer, n - 4) = Hex$(128 + ((c \ 64) Mod 64))
        Mid$(buffer, n - 1) = Hex$(128 + (c Mod 64))
      Case Else                 ' Escaped UTF-8 3 bytes U+0800 to U+FFFF '
        n = n + 9
        Mid$(buffer, n - 7) = Hex$(224 + (c \ 4096))
        Mid$(buffer, n - 4) = Hex$(128 + ((c \ 64) Mod 64))
        Mid$(buffer, n - 1) = Hex$(128 + (c Mod 64))
    End Select
  Next

  EncodeURL = Left$(buffer, n)
End Function

PHP - Get bool to echo false when false

The %b option of sprintf() will convert a boolean to an integer:

echo sprintf("False will print as %b", false); //False will print as 0
echo sprintf("True will print as %b", true); //True will print as 1

If you're not familiar with it: You can give this function an arbitrary amount of parameters while the first one should be your ouput string spiced with replacement strings like %b or %s for general string replacement.

Each pattern will be replaced by the argument in order:

echo sprintf("<h1>%s</h1><p>%s<br/>%s</p>", "Neat Headline", "First Line in the paragraph", "My last words before this demo is over");

Check input value length

You can add a form onsubmit handler, something like:

<form onsubmit="return validate();">

</form>


<script>function validate() {
 // check if input is bigger than 3
 var value = document.getElementById('titleeee').value;
 if (value.length < 3) {
   return false; // keep form from submitting
 }

 // else form is good let it submit, of course you will 
 // probably want to alert the user WHAT went wrong.

 return true;
}</script>

In HTML5, can the <header> and <footer> tags appear outside of the <body> tag?

If you really want it to look more semantic like having the <body> in the middle you can use the <main> element. With all the recent advances the <body>element is not as semantic as it once was but you just have to think of it as a wrapper in which the view port sees.

<html>
    <head>
    </head>
    <body>
        <header>
        </header>
        <main>
            <section></section>
            <article></article>
        </main>
        <footer>
        </footer>
    <body>
</html>

How do you turn a Mongoose document into a plain object?

In some cases as @JohnnyHK suggested, you would want to get the Object as a Plain Javascript. as described in this Mongoose Documentation there is another alternative to query the data directly as object:

const docs = await Model.find().lean();

In addition if someone might want to conditionally turn to an object,it is also possible as an option argument, see find() docs at the third parameter:

const toObject = true;
const docs = await Model.find({},null,{lean:toObject});

its available on the fonctions: find(), findOne(), findById(), findOneAndUpdate(), and findByIdAndUpdate().

Add Text on Image using PIL

With Pillow, you can also draw on an image using the ImageDraw module. You can draw lines, points, ellipses, rectangles, arcs, bitmaps, chords, pieslices, polygons, shapes and text.

from PIL import Image, ImageDraw
blank_image = Image.new('RGBA', (400, 300), 'white')
img_draw = ImageDraw.Draw(blank_image)
img_draw.rectangle((70, 50, 270, 200), outline='red', fill='blue')
img_draw.text((70, 250), 'Hello World', fill='green')
blank_image.save('drawn_image.jpg')

we create an Image object with the new() method. This returns an Image object with no loaded image. We then add a rectangle and some text to the image before saving it.

C++ code file extension? .cc vs .cpp

Great advice on which to use for the makefile and other tools, considering non-compiler tools while deciding on which extension to use is a great approach to help find an answer that works for you.

I just wanted to add the following to help with some .cc vs .cpp info that I found. The following are extensions broken down by different environments (from the "C++ Primer Plus" book):

Unix uses: .C, .cc, .cxx, .c

GNU C++ uses: .C, .cc, .cxx, .cpp, .c++

Digital Mars uses: .cpp, .cxx

Borland C++ uses: .cpp

Watcom uses: .cpp

Microsoft Visual C++ uses: .cpp, .cxx, .cc

Metrowerks CodeWarrior uses: .cpp, .cp, .cc, .cxx, .c++

The different environments support different extensions. I too was looking to answer this question and found this post. Based on this post I think I might go with .hpp and .cpp for ease of cross-platform/cross-tool recognition.

Datatables: Cannot read property 'mData' of undefined

I had this same problem using DOM data in a Rails view created via the scaffold generator. By default the view omits <th> elements for the last three columns (which contain links to show, hide, and destroy records). I found that if I added in titles for those columns in a <th> element within the <thead> that it fixed the problem.

I can't say if this is the same problem you're having since I can't see your html. If it is not the same problem, you can use the chrome debugger to figure out which column it is erroring out on by clicking on the error in the console (which will take you to the code it is failing on), then adding a conditional breakpoint (at col==undefined). When it stops you can check the variable i to see which column it is currently on which can help you figure out what is different about that column from the others. Hope that helps!

debugging mData error

How to convert int to date in SQL Server 2008

You most likely want to examine the documentation for T-SQL's CAST and CONVERT functions, located in the documentation here: http://msdn.microsoft.com/en-US/library/ms187928(v=SQL.90).aspx

You will then use one of those functions in your T-SQL query to convert the [idate] column from the database into the datetime format of your liking in the output.

Visual Studio 2015 Update 3 Offline Installer (ISO)

You can check Visual Studio Downloads for available Visual Studio Community, Visual Studio Professional, Visual Studio Enterprise and Visual Studio Code download links.


Update!

There is no direct links of Visual Studio 2015 at Visual Studio Downloads anymore. but the below links still works.


OR simply click on direct links below (for .iso/.exe file):


VSCode area:

Flushing footer to bottom of the page, twitter bootstrap

Bootstrap v4+ solution

Here's a solution that doesn't require rethinking the HTML structure or any additional CSS trickery involving padding:

<html style="height:100%;">
  ...
  <body class="d-flex flex-column h-100">
    ...
    <main class="flex-grow-1">...</main>
    <footer>...</footer>
  </body>
  ...
</html>

Note that this solution allows for footers with flexible heights, which particularly comes in handy when designing pages for multiple screen sizes with content wrapping when shrunk.

Why this works

  • style="height:100%;" makes the <html> tag take the whole space of the document.
  • class d-flex sets display:flex to our <body> tag.
  • class flex-column sets flex-direction:column to our <body> tag. Its children (<header>, <main>, <footer> and any other direct child) are now aligned vertically.
  • class h-100 sets height:100% to our <body> tag, meaning it will cover the entire screen vertically.
  • class flex-grow-1 sets flex-grow:1 to our <main>, effectively instructing it to fill any remaining vertical space, thus amounting to the 100% vertical height we set before on our <body> tag.

Working demo here: https://codepen.io/maxencemaire/pen/VwvyRQB

See https://css-tricks.com/snippets/css/a-guide-to-flexbox/ for more information on flexbox.