Programs & Examples On #Cross application

How to start activity in another application?

If both application have the same signature (meaning that both APPS are yours and signed with the same key), you can call your other app activity as follows:

Intent LaunchIntent = getActivity().getPackageManager().getLaunchIntentForPackage(CALC_PACKAGE_NAME);
startActivity(LaunchIntent);

Hope it helps.

How do I execute a file in Cygwin?

When you start in Cygwin you are in the "/home/Administrator" zone, so put your a.exe file there.

Then at the prompt run:

cd a.exe

It will be read in by Cygwin and you will be asked to install it.

Replace multiple characters in one replace call

yourstring = '#Please send_an_information_pack_to_the_following_address:';

replace '#' with '' and replace '_' with a space

var newstring1 = yourstring.split('#').join('');
var newstring2 = newstring1.split('_').join(' ');

newstring2 is your result

Creating hard and soft links using PowerShell

You can call the mklink provided by cmd, from PowerShell to make symbolic links:

cmd /c mklink c:\path\to\symlink c:\target\file

You must pass /d to mklink if the target is a directory.

cmd /c mklink /d c:\path\to\symlink c:\target\directory

For hard links, I suggest something like Sysinternals Junction.

How to reverse apply a stash?

git checkout -f

will remove any non-commit changes.

Convert comma separated string of ints to int array

You should use a foreach loop, like this:

public static IEnumerable<int> StringToIntList(string str) {
    if (String.IsNullOrEmpty(str))
        yield break;

    foreach(var s in str.Split(',')) {
        int num;
        if (int.TryParse(s, out num))
            yield return num;
    }
}

Note that like your original post, this will ignore numbers that couldn't be parsed.

If you want to throw an exception if a number couldn't be parsed, you can do it much more simply using LINQ:

return (str ?? "").Split(',').Select<string, int>(int.Parse);

How to manually send HTTP POST requests from Firefox or Chrome browser?

Check out http-tool for firefox ..

https://addons.mozilla.org/en-US/firefox/addon/http-tool/

Aimed at web developers who need to debug HTTP requests and responses.
Can be extremely useful while developing REST based api.

Features:
* GET
* HEAD
* POST
* PUT
* DELETE

Add header(s) to request.
Add body content to request.

View header(s) in response.
View body content in response.
View status code of response.
View status text of response.

Is there a simple way that I can sort characters in a string in alphabetical order

Yes; copy the string to a char array, sort the char array, then copy that back into a string.

static string SortString(string input)
{
    char[] characters = input.ToArray();
    Array.Sort(characters);
    return new string(characters);
}

Oracle ORA-12154: TNS: Could not resolve service name Error?

We also had the similar issue. What we found out that we had provided multiple aliases for our connection string in tnsnames.ora, something like:

svc01, svc02=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=xxxx)(port=50))(CONNECT_DATA=(SERVER=DEDICATED)(service_name=yyyysvc.world)))

so when creating a connection using ODBC, when we selected the value for TNS service name, the auto populate was showing 'svc01,' (please note the extra comma there). As soon as we removed the comma, it started working for us.

Must declare the scalar variable

Just FYI, I know this is an old post, but depending on the database COLLATION settings you can get this error on a statement like this,

SET @sql = @Sql + ' WHERE RowNum BETWEEN @RowFrom AND @RowTo;';

if for example you typo the S in the

SET @sql = @***S***ql 

sorry to spin off the answers already posted here, but this is an actual instance of the error reported.

Note also that the error will not display the capital S in the message, I am not sure why, but I think it is because the

Set @sql =

is on the left of the equal sign.

Android: adb: Permission Denied

data partition not accessible for non root user, if you want to access it you must root your phone.

adb root not work for all product and depend in phone build type.

in new version on android studio you can explore /data/data path for debuggable apps.

jQuery limit to 2 decimal places

Here is a working example in both Javascript and jQuery:

http://jsfiddle.net/GuLYN/312/

//In jQuery
$("#calculate").click(function() {
    var num = parseFloat($("#textbox").val());
    var new_num = $("#textbox").val(num.toFixed(2));
});


// In javascript
document.getElementById('calculate').onclick = function() {
    var num = parseFloat(document.getElementById('textbox').value);
    var new_num = num.toFixed(2);
    document.getElementById('textbox').value = new_num;
};
?

Electron: jQuery is not defined

Just came across this same problem

npm install jquery --save

<script>window.$ = window.jQuery = require('jquery');</script>

worked for me

col align right

How about this? Bootstrap 4

<div class="row justify-content-end">
    <div class="col-3">
        The content is positioned as if there was
        "col-9" classed div appending this one.
    </div>
</div>

How to change letter spacing in a Textview?

This answer is based on Pedro's answer but adjusted so it also works if text attribute is already set:

package nl.raakict.android.spc.widget;
import android.content.Context;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.ScaleXSpan;
import android.util.AttributeSet;
import android.widget.TextView;


public class LetterSpacingTextView extends TextView {
    private float letterSpacing = LetterSpacing.BIGGEST;
    private CharSequence originalText = "";


    public LetterSpacingTextView(Context context) {
        super(context);
    }

    public LetterSpacingTextView(Context context, AttributeSet attrs){
        super(context, attrs);
        originalText = super.getText();
        applyLetterSpacing();
        this.invalidate();
    }

    public LetterSpacingTextView(Context context, AttributeSet attrs, int defStyle){
        super(context, attrs, defStyle);
    }

    public float getLetterSpacing() {
        return letterSpacing;
    }

    public void setLetterSpacing(float letterSpacing) {
        this.letterSpacing = letterSpacing;
        applyLetterSpacing();
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        originalText = text;
        applyLetterSpacing();
    }

    @Override
    public CharSequence getText() {
        return originalText;
    }

    private void applyLetterSpacing() {
        if (this == null || this.originalText == null) return;
        StringBuilder builder = new StringBuilder();
        for(int i = 0; i < originalText.length(); i++) {
            String c = ""+ originalText.charAt(i);
            builder.append(c.toLowerCase());
            if(i+1 < originalText.length()) {
                builder.append("\u00A0");
            }
        }
        SpannableString finalText = new SpannableString(builder.toString());
        if(builder.toString().length() > 1) {
            for(int i = 1; i < builder.toString().length(); i+=2) {
                finalText.setSpan(new ScaleXSpan((letterSpacing+1)/10), i, i+1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
        }
        super.setText(finalText, BufferType.SPANNABLE);
    }

    public class LetterSpacing {
        public final static float NORMAL = 0;
        public final static float NORMALBIG = (float)0.025;
        public final static float BIG = (float)0.05;
        public final static float BIGGEST = (float)0.2;
    }
}

If you want to use it programatically:

LetterSpacingTextView textView = new LetterSpacingTextView(context);
textView.setSpacing(10); //Or any float. To reset to normal, use 0 or LetterSpacingTextView.Spacing.NORMAL
textView.setText("My text");
//Add the textView in a layout, for instance:
((LinearLayout) findViewById(R.id.myLinearLayout)).addView(textView);

How can I close a Twitter Bootstrap popover with a click from anywhere (else) on the page?

I found this to be a modified solution of pbaron's suggestion above, because his solution activated the popover('hide') on all elements with class 'popup-marker'. However, when you're using popover() for html content instead of the data-content, as I'm doing below, any clicks inside that html popup actually activate the popover('hide'), which promptly closes the window. This method below iterates through each .popup-marker element and discovers first if the parent is related to the .popup-marker's id that was clicked, and if so then does not hide it. All other divs are hidden...

        $(function(){
            $('html').click(function(e) {
                // this is my departure from pbaron's code above
                // $('.popup-marker').popover('hide');
                $('.popup-marker').each(function() {
                    if ($(e.target).parents().children('.popup-marker').attr('id')!=($(this).attr('id'))) {
                        $(this).popover('hide');
                    }
                });
            });

            $('.popup-marker').popover({
                html: true,
                // this is where I'm setting the html for content from a nearby hidden div with id="html-"+clicked_div_id
                content: function() { return $('#html-'+$(this).attr('id')).html(); },
                trigger: 'manual'
            }).click(function(e) {
                $(this).popover('toggle');
                e.stopPropagation();
            });
        });

How do you find the current user in a Windows environment?

Just type whoami in command prompt and you'll get the current username.

Adding an image to a PDF using iTextSharp and scale it properly

You can try something like this:

      Image logo = Image.GetInstance("pathToTheImage")
      logo.ScaleAbsolute(500, 300)

How to open URL in Microsoft Edge from the command line?

All the other solutions work for Microsoft Edge (legacy) and on Windows 10 only. As of 2020, it will be discontinued and replaced by Microsoft Edge (Chromium based).

The solution that works with the new Edge on Windows 7, 8 and 10 is :

start msedge URL

Source :

Constructing pandas DataFrame from values in variables gives "ValueError: If using all scalar values, you must pass an index"

Convert Dictionary to Data Frame

col_dict_df = pd.Series(col_dict).to_frame('new_col').reset_index()

Give new name to Column

col_dict_df.columns = ['col1', 'col2']

intellij incorrectly saying no beans of type found for autowired repository

in my situation my class folder was in wrong address so check if your class is in correct package.

java.sql.SQLException: - ORA-01000: maximum open cursors exceeded

I am adding few more understanding.

  1. Cursor is only about a statement objecct; It is neither resultSet nor the connection object.
  2. But still we have to close the resultset to free some oracle memory. Still if you don't close the resultset that won't be counted for CURSORS.
  3. Closing Statement object will automatically close resultset object too.
  4. Cursor will be created for all the SELECT/INSERT/UPDATE/DELETE statement.
  5. Each ORACLE DB instance can be identified using oracle SID; similarly ORACLE DB can identify each connection using connection SID. Both SID are different.
  6. So ORACLE session is nothing but a jdbc(tcp) connection; which is nothing but one SID.
  7. If we set maximum cursors as 500 then it is only for one JDBC session/connection/SID.
  8. So we can have many JDBC connection with its respective no of cursors (statements).
  9. Once the JVM is terminated all the connections/cursors will be closed, OR JDBCConnection is closed CURSORS with respect to that connection will be closed.

Loggin as sysdba.

In Putty (Oracle login):

  [oracle@db01 ~]$ sqlplus / as sysdba

In SqlPlus:

UserName: sys as sysdba

Set session_cached_cursors value to 0 so that it wont have closed cursors.

 alter session set session_cached_cursors=0
 select * from V$PARAMETER where name='session_cached_cursors'

Select existing OPEN_CURSORS valuse set per connection in DB

 SELECT max(a.value) as highest_open_cur, p.value as max_open_cur FROM v$sesstat a, v$statname b, v$parameter p WHERE a.statistic# = b.statistic# AND b.name = 'opened cursors current' AND p.name= 'open_cursors'  GROUP BY p.value;

Below is the query to find the SID/connections list with open cursor values.

 SELECT a.value, s.username, s.sid, s.serial#
 FROM v$sesstat a, v$statname b, v$session s
 WHERE a.statistic# = b.statistic#  AND s.sid=a.sid 
 AND b.name = 'opened cursors current' AND username = 'SCHEMA_NAME_IN_CAPS'

Use the below query to identify the sql's in the open cursors

 SELECT oc.sql_text, s.sid 
 FROM v$open_cursor oc, v$session s
 WHERE OC.sid = S.sid
 AND s.sid=1604
 AND OC.USER_NAME ='SCHEMA_NAME_IN_CAPS'

Now debug the Code and Enjoy!!! :)

Connecting an input stream to an outputstream

Just because you use a buffer doesn't mean the stream has to fill that buffer. In other words, this should be okay:

public static void copyStream(InputStream input, OutputStream output)
    throws IOException
{
    byte[] buffer = new byte[1024]; // Adjust if you want
    int bytesRead;
    while ((bytesRead = input.read(buffer)) != -1)
    {
        output.write(buffer, 0, bytesRead);
    }
}

That should work fine - basically the read call will block until there's some data available, but it won't wait until it's all available to fill the buffer. (I suppose it could, and I believe FileInputStream usually will fill the buffer, but a stream attached to a socket is more likely to give you the data immediately.)

I think it's worth at least trying this simple solution first.

How to install ADB driver for any android device?

If no other driver package worked for your obscure device go read how to make a truly universal abd and fastboot driver out of Google's USB driver. The trick is to use CompatibleID instead of HardwareID in the driver's INF Models section

How to check if a file exists in Go?

Let's look at few aspects first, both the function provided by os package of golang are not utilities but error checkers, what do I mean by that is they are just a wrapper to handle errors on cross platform.

So basically if os.Stat if this function doesn't give any error that means the file is existing if it does you need to check what kind of error it is, here comes the use of these two function os.IsNotExist and os.IsExist.

This can be understood as the Stat of the file throwing error because it doesn't exists or is it throwing error because it exist and there is some problem with it.

The parameter that these functions take is of type error, although you might be able to pass nil to it but it wouldn't make sense.

This also points to the fact that IsExist is not same as !IsNotExist, they are way two different things.

So now if you want to know if a given file exist in go, I would prefer the best way is:

if _, err := os.Stat(path/to/file); !os.IsNotExist(err){
   //TODO
} 

How to open a file for both reading and writing?

r+ is the canonical mode for reading and writing at the same time. This is not different from using the fopen() system call since file() / open() is just a tiny wrapper around this operating system call.

Android Lint contentDescription warning

Disabling Lint warnings will easily get you into trouble later on. You're better off just specifying contentDescription for all of your ImageViews. If you don't need a description, then just use:

android:contentDescription="@null"

How to check iOS version?

Try the below code:

NSString *versionString = [[UIDevice currentDevice] systemVersion];

How-to turn off all SSL checks for postman for a specific site

enter image description here

This steps are used in spring boot with self signed ssl certificate implementation

if SSL turns off then HTTPS call will be worked as expected.

https://localhost:8443/test/hello

These are the steps we have to follow,

  1. Generate self signed ssl certificate
keytool -genkeypair -alias tomcat -keyalg RSA -keysize 2048 -storetype PKCS12 -keystore keystore.p12 -validity 3650

after key generation has done then copy that file in to the resource foder in your project

  1. add key store properties in applicaiton.properties
server.port: 8443
server.ssl.key-store:classpath:keystore.p12
server.ssl.key-store-password: test123
server.ssl.keyStoreType: PKCS12
server.ssl.keyAlias: tomcat
  1. change your postman ssl verification settings to turn OFF

now verify the url: https://localhost:8443/test/hello

Node.js Best Practice Exception Handling

One instance where using a try-catch might be appropriate is when using a forEach loop. It is synchronous but at the same time you cannot just use a return statement in the inner scope. Instead a try and catch approach can be used to return an Error object in the appropriate scope. Consider:

function processArray() {
    try { 
       [1, 2, 3].forEach(function() { throw new Error('exception'); }); 
    } catch (e) { 
       return e; 
    }
}

It is a combination of the approaches described by @balupton above.

How to show code but hide output in RMarkdown?

For what it's worth.

```{r eval=FALSE}

The document will display the code by default but will prevent the code block from being executed, and thus will also not display any results.

What is the difference between Python and IPython?

ipython is an interactive shell built with python.

From the project website:

IPython provides a rich toolkit to help you make the most out of using Python, with:

  • Powerful Python shells (terminal and Qt-based).
  • A web-based notebook with the same core features but support for code, text, mathematical expressions, inline plots and other rich media.
  • Support for interactive data visualization and use of GUI toolkits.
  • Flexible, embeddable interpreters to load into your own projects.
  • Easy to use, high performance tools for parallel computing.

Note that the first 2 lines tell you it helps you make the most of using Python. Thus, you don't need to alter your code, the IPython shell runs your python code just like the normal python shell does, only with more features.

I recommend reading the IPython tutorial to get a sense of what features you gain when using IPython.

How to get character for a given ascii value

It can also be done in some other manner

byte[] pass_byte = Encoding.ASCII.GetBytes("your input value");

and then print result. by using foreach loop.

Asynchronous Function Call in PHP

I dont have a direct answer, but you might want to look into these things:

check if jquery has been loaded, then load it if false

var f = ()=>{
    if (!window.jQuery) {
        var e = document.createElement('script');
        e.src = "https://code.jquery.com/jquery-3.2.1.min.js";
        e.onload = function () {
            jQuery.noConflict();
            console.log('jQuery ' + jQuery.fn.jquery + ' injected.');
        };
        document.head.appendChild(e);
    } else {
        console.log('jQuery ' + jQuery.fn.jquery + '');
    }
};
f();

Remove columns from DataTable in C#

To remove all columns after the one you want, below code should work. It will remove at index 10 (remember Columns are 0 based), until the Column count is 10 or less.

DataTable dt;
int desiredSize = 10;

while (dt.Columns.Count > desiredSize)
{
   dt.Columns.RemoveAt(desiredSize);
}

Recursively list all files in a directory including files in symlink directories

How about tree? tree -l will follow symlinks.

Disclaimer: I wrote this package.

Can the jQuery UI Datepicker be made to disable Saturdays and Sundays (and holidays)?

These answers were very helpful. Thank you.

My contribution below adds an array where multiple days can return false (we're closed every Tuesday, Wednesday and Thursday). And I bundled the specific dates plus years and the no-weekends functions.

If you want weekends off, add [Saturday], [Sunday] to the closedDays array.

$(document).ready(function(){

    $("#datepicker").datepicker({
        beforeShowDay: nonWorkingDates,
        numberOfMonths: 1,
        minDate: '05/01/09',
        maxDate: '+2M',
        firstDay: 1
    });

    function nonWorkingDates(date){
        var day = date.getDay(), Sunday = 0, Monday = 1, Tuesday = 2, Wednesday = 3, Thursday = 4, Friday = 5, Saturday = 6;
        var closedDates = [[7, 29, 2009], [8, 25, 2010]];
        var closedDays = [[Monday], [Tuesday]];
        for (var i = 0; i < closedDays.length; i++) {
            if (day == closedDays[i][0]) {
                return [false];
            }

        }

        for (i = 0; i < closedDates.length; i++) {
            if (date.getMonth() == closedDates[i][0] - 1 &&
            date.getDate() == closedDates[i][1] &&
            date.getFullYear() == closedDates[i][2]) {
                return [false];
            }
        }

        return [true];
    }




});

'Found the synthetic property @panelState. Please include either "BrowserAnimationsModule" or "NoopAnimationsModule" in your application.'

I ran into similar issues, when I tried to use the BrowserAnimationsModule. Following steps solved my problem:

  1. Delete the node_modules dir
  2. Clear your package cache using npm cache clean
  3. Run one of these two commands listed here to update your existing packages

If you experience a 404 errors like

http://.../node_modules/@angular/platform-browser/bundles/platform-browser.umd.js/animations

add following entries to map in your system.config.js:

'@angular/animations': 'node_modules/@angular/animations/bundles/animations.umd.min.js',
'@angular/animations/browser':'node_modules/@angular/animations/bundles/animations-browser.umd.js',
'@angular/platform-browser/animations': 'node_modules/@angular/platform-browser/bundles/platform-browser-animations.umd.js'

naveedahmed1 provided the solution on this github issue.

How to send json data in the Http request using NSURLRequest

You can try this code for send json string

NSData *jsonData = [NSJSONSerialization dataWithJSONObject:ARRAY_CONTAIN_JSON_STRING options:NSJSONWritin*emphasized text*gPrettyPrinted error:NULL];
NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];
NSString *WS_test = [NSString stringWithFormat:@"www.test.com?xyz.php&param=%@",jsonString];

Reverse engineering from an APK file to a project

Below are some of the tools which you can use to perform reverse engineering from an APK file to source code :

  1. Dex2jar
  2. Java decompiler
  3. Apktool
  4. Apk Analyser

Spring @PropertySource using YAML

Loading custom yml file with multiple profile config in Spring Boot.

1) Add the property bean with SpringBootApplication start up as follows

@SpringBootApplication
@ComponentScan({"com.example.as.*"})
public class TestApplication {

    public static void main(String[] args) {
        SpringApplication.run(TestApplication.class, args);
    }

    @Bean
    @Profile("dev")
    public PropertySourcesPlaceholderConfigurer propertiesStage() {
        return properties("dev");
    }

    @Bean
    @Profile("stage")
    public PropertySourcesPlaceholderConfigurer propertiesDev() {
        return properties("stage");
    }

    @Bean
    @Profile("default")
    public PropertySourcesPlaceholderConfigurer propertiesDefault() {
        return properties("default");

    }
   /**
    * Update custom specific yml file with profile configuration.
    * @param profile
    * @return
    */
    public static PropertySourcesPlaceholderConfigurer properties(String profile) {
       PropertySourcesPlaceholderConfigurer propertyConfig = null;
       YamlPropertiesFactoryBean yaml  = null;

       propertyConfig  = new PropertySourcesPlaceholderConfigurer();
       yaml = new YamlPropertiesFactoryBean();
       yaml.setDocumentMatchers(new SpringProfileDocumentMatcher(profile));// load profile filter.
       yaml.setResources(new ClassPathResource("env_config/test-service-config.yml"));
       propertyConfig.setProperties(yaml.getObject());
       return propertyConfig;
    }
}

2) Config the Java pojo object as follows

@Component
@JsonIgnoreProperties(ignoreUnknown = true)
@JsonInclude(Include.NON_NULL)
@ConfigurationProperties(prefix = "test-service")
public class TestConfig {

    @JsonProperty("id") 
    private  String id;

    @JsonProperty("name")
    private String name;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }   

}

3) Create the custom yml (and place it under resource path as follows, YML File name : test-service-config.yml

Eg Config in the yml file.

test-service: 
    id: default_id
    name: Default application config
---
spring:
  profiles: dev

test-service: 
  id: dev_id
  name: dev application config

--- 
spring:
  profiles: stage

test-service: 
  id: stage_id
  name: stage application config

Generating Fibonacci Sequence

You can get some cache to speedup the algorithm...

var tools = {

    fibonacci : function(n) {
        var cache = {};

        // optional seed cache
        cache[2] = 1;
        cache[3] = 2;
        cache[4] = 3;
        cache[5] = 5;
        cache[6] = 8;

        return execute(n);

        function execute(n) {
            // special cases 0 or 1
            if (n < 2) return n;

            var a = n - 1;
            var b = n - 2;

            if(!cache[a]) cache[a] = execute(a);
            if(!cache[b]) cache[b] = execute(b);

            return cache[a] + cache[b];
        }
    }
};

How to open select file dialog via js?

In HTML only:

<label>
  <input type="file" name="input-name" style="display: none;" />
  <span>Select file</span>
</label>

Edit: I hadn't tested this in Blink, it actually doesn't work with a <button>, but it should work with most other elements–at least in recent browsers.

Check this fiddle with the code above.

Half circle with CSS (border, outline only)

Below is a minimal code to achieve the effect.

This also works responsively since the border-radius is in percentage.

_x000D_
_x000D_
.semi-circle{_x000D_
width: 200px;_x000D_
height: 100px;_x000D_
border-radius: 50% 50% 0 0 / 100% 100% 0 0;_x000D_
border: 10px solid #000;_x000D_
border-bottom: 0;_x000D_
}
_x000D_
<div class="semi-circle"></div>
_x000D_
_x000D_
_x000D_

Constants in Kotlin -- what's a recommended way to create them?

Like val, variables defined with the const keyword are immutable. The difference here is that const is used for variables that are known at compile-time.

Declaring a variable const is much like using the static keyword in Java.

Let's see how to declare a const variable in Kotlin:

const val COMMUNITY_NAME = "wiki"

And the analogous code written in Java would be:

final static String COMMUNITY_NAME = "wiki";

Adding to the answers above -

@JvmField an be used to instruct the Kotlin compiler not to generate getters/setters for this property and expose it as a field.

 @JvmField
 val COMMUNITY_NAME: "Wiki"

Static fields

Kotlin properties declared in a named object or a companion object will have static backing fields either in that named object or in the class containing the companion object.

Usually these fields are private but they can be exposed in one of the following ways:

  • @JvmField annotation;
  • lateinit modifier;
  • const modifier.

More details here - https://kotlinlang.org/docs/reference/java-to-kotlin-interop.html#instance-fields

How to add trendline in python matplotlib dot (scatter) graphs?

as explained here

With help from numpy one can calculate for example a linear fitting.

# plot the data itself
pylab.plot(x,y,'o')

# calc the trendline
z = numpy.polyfit(x, y, 1)
p = numpy.poly1d(z)
pylab.plot(x,p(x),"r--")
# the line equation:
print "y=%.6fx+(%.6f)"%(z[0],z[1])

How can I make git show a list of the files that are being tracked?

If you want to list all the files currently being tracked under the branch master, you could use this command:

git ls-tree -r master --name-only

If you want a list of files that ever existed (i.e. including deleted files):

git log --pretty=format: --name-only --diff-filter=A | sort - | sed '/^$/d'

Unable to begin a distributed transaction

For me, it relate to Firewall setting. Go to your firewall setting, allow DTC Service and it worked.enter image description here

How to deal with SQL column names that look like SQL keywords?

If you ARE using SQL Server, you can just simply wrap the square brackets around the column or table name.

select [select]
from [table]

Align the form to the center in Bootstrap 4

<div class="d-flex justify-content-center align-items-center container ">

    <div class="row ">


        <form action="">
            <div class="form-group">
                <label for="inputUserName" class="control-label">Enter UserName</label>
                <input type="email" class="form-control" id="inputUserName" aria-labelledby="emailnotification">
                <small id="emailnotification" class="form-text text-muted">Enter Valid Email Id</small>
            </div>
            <div class="form-group">
                <label for="inputPassword" class="control-label">Enter Password</label>
                <input type="password" class="form-control" id="inputPassword" aria-labelledby="passwordnotification">

            </div>
        </form>

    </div>

</div>

How can I clear the NuGet package cache using the command line?

dotnet nuget locals all --clear

If you're using .NET Core.

New to unit testing, how to write great tests?

Don't write tests to get full coverage of your code. Write tests that guarantee your requirements. You may discover codepaths that are unnecessary. Conversely, if they are necessary, they are there to fulfill some kind of requirement; find it what it is and test the requirement (not the path).

Keep your tests small: one test per requirement.

Later, when you need to make a change (or write new code), try writing one test first. Just one. Then you'll have taken the first step in test-driven development.

How do I add PHP code/file to HTML(.html) files?

By default you can't use PHP in HTML pages.

To do that, modify your .htacccess file with the following:

AddType application/x-httpd-php .html

What is the difference between Sublime text and Github's Atom

I just got my beta invitation today and tried Atom right away. The GUI feels like Sublime, and yes, there some shortcuts adopted from Sublime.

Besides everything mentioned above, here are some differences I have noticed so far:

  1. Vim mode is not as good as the Vintage mode on Sublime (which is not a fully featured vim either) because the vim package is in an early stage of development. See https://atom.io/packages/vim-mode for detail.

  2. As James mention, Atom is written using web tools, so you have access to the stylesheet of the text editor (styles.less) to do whatever appearance changes you want using CSS. There is also an option to change the startup CoffeeScript.

  3. Again, because Atom is still in the beta stage, Sublime has much more native plugin packages. However, since Atom is written in Node.js, the Atom official site said you can "choose from over 50 thousand in Node's package repository." (Because I am not a Node.js pro, I haven't look into this feature though)

  4. Atom has better Github support out of the box, but Sublime has a several Git packages.

  5. Sublime is a paid application unlimited evaluation period. Atom is free at the beta stage but we don't know whether Github wants to charge it or not.

So the bottom line is Atom is a text editor built with web technology at beta stage. By contrast, Sublime has evolved through many different iterations. Atom is still missing a lot of packages that Sublime supports, so the question is will Atom catch up with Sublime or become some better? Github seems to be confident about the future of this text edit because of its popular underlying technologies, and Atom is probably going to be a good alternative to Sublime in the long run.

What exceptions should be thrown for invalid or unexpected parameters in .NET?

Short answer:
Neither

Longer answer:
using Argument*Exception (except in a library that is a product on its on, such as component library) is a smell. Exceptions are to handle exceptional situation, not bugs, and not user's (i.e. API consumer) shortfalls.

Longest answer:
Throwing exceptions for invalid arguments is rude, unless you write a library.
I prefer using assertions, for two (or more) reasons:

  • Assertions don't need to be tested, while throw assertions do, and test against ArgumentNullException looks ridiculous (try it).
  • Assertions better communicate the intended use of the unit, and is closer to being executable documentation than a class behavior specification.
  • You can change behavior of assertion violation. For example in debug compilation a message box is fine, so that your QA will hit you with it right away (you also get your IDE breaking on the line where it happens), while in unit test you can indicate assertion failure as a test failure.

Here is what handling of null exception looks like (being sarcastic, obviously):

try {
    library.Method(null);
}
catch (ArgumentNullException e) {
    // retry with real argument this time
    library.Method(realArgument);
}

Exceptions shall be used when situation is expected but exceptional (things happen that are outside of consumer's control, such as IO failure). Argument*Exception is an indication of a bug and shall be (my opinion) handled with tests and assisted with Debug.Assert

BTW: In this particular case, you could have used Month type, instead of int. C# falls short when it comes to type safety (Aspect# rulez!) but sometimes you can prevent (or catch at compile time) those bugs all together.

And yes, MicroSoft is wrong about that.

ActiveRecord find and only return selected columns

In Rails 2

l = Location.find(:id => id, :select => "name, website, city", :limit => 1)

...or...

l = Location.find_by_sql(:conditions => ["SELECT name, website, city FROM locations WHERE id = ? LIMIT 1", id])

This reference doc gives you the entire list of options you can use with .find, including how to limit by number, id, or any other arbitrary column/constraint.

In Rails 3 w/ActiveRecord Query Interface

l = Location.where(["id = ?", id]).select("name, website, city").first

Ref: Active Record Query Interface

You can also swap the order of these chained calls, doing .select(...).where(...).first - all these calls do is construct the SQL query and then send it off.

Is there a way to change the spacing between legend items in ggplot2?

A simple fix that I use to add space in horizontal legends, simply add spaces in the labels (see extract below):

  scale_fill_manual(values=c("red","blue","white"),
                    labels=c("Label of category 1          ",
                             "Label of category 2          ",
                             "Label of category 3"))

Which sort algorithm works best on mostly sorted data?

As everyone else said, be careful of naive Quicksort - that can have O(N^2) performance on sorted or nearly sorted data. Nevertheless, with an appropriate algorithm for choice of pivot (either random or median-of-three - see Choosing a Pivot for Quicksort), Quicksort will still work sanely.

In general, the difficulty with choosing algorithms such as insert sort is in deciding when the data is sufficiently out of order that Quicksort really would be quicker.

Find and replace string values in list

An example with for loop (I prefer List Comprehensions).

a, b = '[br]', '<br />'
for i, v in enumerate(words):
    if a in v:
        words[i] = v.replace(a, b)
print(words)
# ['how', 'much', 'is<br/>', 'the', 'fish<br/>', 'no', 'really']

Sending event when AngularJS finished loading

may be i can help you by this example

In the custom fancybox I show contents with interpolated values.

in the service, in the "open" fancybox method, i do

open: function(html, $compile) {
        var el = angular.element(html);
     var compiledEl = $compile(el);
        $.fancybox.open(el); 
      }

the $compile returns compiled data. you can check the compiled data

Android Error - Open Failed ENOENT

Put the text file in the assets directory. If there isnt an assets dir create one in the root of the project. Then you can use Context.getAssets().open("BlockForTest.txt"); to open a stream to this file.

What is the theoretical maximum number of open TCP connections that a modern Linux box can have

If you used a raw socket (SOCK_RAW) and re-implemented TCP in userland, I think the answer is limited in this case only by the number of (local address, source port, destination address, destination port) tuples (~2^64 per local address).

It would of course take a lot of memory to keep the state of all those connections, and I think you would have to set up some iptables rules to keep the kernel TCP stack from getting upset &/or responding on your behalf.

How to run Gulp tasks sequentially one after the other

I generated a node/gulp app using the generator-gulp-webapp Yeoman generator. It handled the "clean conundrum" this way (translating to the original tasks mentioned in the question):

gulp.task('develop', ['clean'], function () {
  gulp.start('coffee');
});

Figuring out whether a number is a Double in Java

Try this:

if (items.elementAt(1) instanceof Double) {
   sum.add( i, items.elementAt(1));
}

How to change Android version and code version number?

You can easily auto increase versionName and versionCode programmatically.

For Android add this to your gradle script and also create a file version.properties with VERSION_CODE=555

android {
        compileSdkVersion 30
        buildToolsVersion "30.0.3"
    
        def versionPropsFile = file('version.properties')
        if (versionPropsFile.canRead()) {
            def Properties versionProps = new Properties()
    
            versionProps.load(new FileInputStream(versionPropsFile))
    
            def code = versionProps['VERSION_CODE'].toInteger() + 1
    
            versionProps['VERSION_CODE'] = code.toString()
            versionProps.store(versionPropsFile.newWriter(), null)
    
    
            defaultConfig {
                applicationId "app.umanusorn.playground"
                minSdkVersion 29
                targetSdkVersion 30
                versionCode code
                versionName code.toString()

Check existence of input argument in a Bash shell script

Try:

 #!/bin/bash
 if [ "$#" -eq  "0" ]
   then
     echo "No arguments supplied"
 else
     echo "Hello world"
 fi

Is java.sql.Timestamp timezone specific?

The answer is that java.sql.Timestamp is a mess and should be avoided. Use java.time.LocalDateTime instead.

So why is it a mess? From the java.sql.Timestamp JavaDoc, a java.sql.Timestamp is a "thin wrapper around java.util.Date that allows the JDBC API to identify this as an SQL TIMESTAMP value". From the java.util.Date JavaDoc, "the Date class is intended to reflect coordinated universal time (UTC)". From the ISO SQL spec a TIMESTAMP WITHOUT TIME ZONE "is a data type that is datetime without time zone". TIMESTAMP is a short name for TIMESTAMP WITHOUT TIME ZONE. So a java.sql.Timestamp "reflects" UTC while SQL TIMESTAMP is "without time zone".

Because java.sql.Timestamp reflects UTC its methods apply conversions. This causes no end of confusion. From the SQL perspective it makes no sense to convert a SQL TIMESTAMP value to some other time zone as a TIMESTAMP has no time zone to convert from. What does it mean to convert 42 to Fahrenheit? It means nothing because 42 does not have temperature units. It's just a bare number. Similarly you can't convert a TIMESTAMP of 2020-07-22T10:38:00 to Americas/Los Angeles because 2020-07-22T10:30:00 is not in any time zone. It's not in UTC or GMT or anything else. It's a bare date time.

java.time.LocalDateTime is also a bare date time. It does not have a time zone, exactly like SQL TIMESTAMP. None of its methods apply any kind of time zone conversion which makes its behavior much easier to predict and understand. So don't use java.sql.Timestamp. Use java.time.LocalDateTime.

LocalDateTime ldt = rs.getObject(col, LocalDateTime.class);
ps.setObject(param, ldt, JDBCType.TIMESTAMP);

How to encode URL parameters?

Using new ES6 Object.entries(), it makes for a fun little nested map/join:

_x000D_
_x000D_
const encodeGetParams = p => _x000D_
  Object.entries(p).map(kv => kv.map(encodeURIComponent).join("=")).join("&");_x000D_
_x000D_
const params = {_x000D_
  user: "María Rodríguez",_x000D_
  awesome: true,_x000D_
  awesomeness: 64,_x000D_
  "ZOMG+&=*(": "*^%*GMOZ"_x000D_
};_x000D_
_x000D_
console.log("https://example.com/endpoint?" + encodeGetParams(params))
_x000D_
_x000D_
_x000D_

What are the options for storing hierarchical data in a relational database?

Adjacency Model + Nested Sets Model

I went for it because I could insert new items to the tree easily (you just need a branch's id to insert a new item to it) and also query it quite fast.

+-------------+----------------------+--------+-----+-----+
| category_id | name                 | parent | lft | rgt |
+-------------+----------------------+--------+-----+-----+
|           1 | ELECTRONICS          |   NULL |   1 |  20 |
|           2 | TELEVISIONS          |      1 |   2 |   9 |
|           3 | TUBE                 |      2 |   3 |   4 |
|           4 | LCD                  |      2 |   5 |   6 |
|           5 | PLASMA               |      2 |   7 |   8 |
|           6 | PORTABLE ELECTRONICS |      1 |  10 |  19 |
|           7 | MP3 PLAYERS          |      6 |  11 |  14 |
|           8 | FLASH                |      7 |  12 |  13 |
|           9 | CD PLAYERS           |      6 |  15 |  16 |
|          10 | 2 WAY RADIOS         |      6 |  17 |  18 |
+-------------+----------------------+--------+-----+-----+
  • Every time you need all children of any parent you just query the parent column.
  • If you needed all descendants of any parent you query for items which have their lft between lft and rgt of parent.
  • If you needed all parents of any node up to the root of the tree, you query for items having lft lower than the node's lft and rgt bigger than the node's rgt and sort the by parent.

I needed to make accessing and querying the tree faster than inserts, that's why I chose this

The only problem is to fix the left and right columns when inserting new items. well I created a stored procedure for it and called it every time I inserted a new item which was rare in my case but it is really fast. I got the idea from the Joe Celko's book, and the stored procedure and how I came up with it is explained here in DBA SE https://dba.stackexchange.com/q/89051/41481

Chaining Observables in RxJS

About promise composition vs. Rxjs, as this is a frequently asked question, you can refer to a number of previously asked questions on SO, among which :

Basically, flatMap is the equivalent of Promise.then.

For your second question, do you want to replay values already emitted, or do you want to process new values as they arrive? In the first case, check the publishReplay operator. In the second case, standard subscription is enough. However you might need to be aware of the cold. vs. hot dichotomy depending on your source (cf. Hot and Cold observables : are there 'hot' and 'cold' operators? for an illustrated explanation of the concept)

Syntax error "syntax error, unexpected end-of-input, expecting keyword_end (SyntaxError)"

Just posting in case it help someone else. The cause of this error for me was a missing do after creating a form with form_with. Hope that may help someone else

Docker: adding a file from a parent directory

Since -f caused another problem, I developed another solution.

  • Create a base image in the parent folder
  • Added the required files.
  • Used this image as a base image for the project which in a descendant folder.

The -f flag does not solved my problem because my onbuild image looks for a file in a folder and had to call like this:

-f foo/bar/Dockerfile foo/bar

instead of

-f foo/bar/Dockerfile .

Also note that this is only solution for some cases as -f flag

Request Monitoring in Chrome

Update

Chrome changed how to inspect requests and suggests now to use the Catapult Netlog Viewer with the logs exported from chrome://net-export/

chrome://net-export/

More Info

Old Chrome Versions

You also may use this link in Chrome for more detailed information than the inspector did it.

chrome://net-internals/#events

This shows the log of all requests of the browser while open

How to find MySQL process list and to kill those processes?

Here is the solution:

  1. Login to DB;
  2. Run a command show full processlist;to get the process id with status and query itself which causes the database hanging;
  3. Select the process id and run a command KILL <pid>; to kill that process.

Sometimes it is not enough to kill each process manually. So, for that we've to go with some trick:

  1. Login to MySQL;
  2. Run a query Select concat('KILL ',id,';') from information_schema.processlist where user='user'; to print all processes with KILL command;
  3. Copy the query result, paste and remove a pipe | sign, copy and paste all again into the query console. HIT ENTER. BooM it's done.

Replace Fragment inside a ViewPager

I doing something to similar to wize but in my answer yo can change between the two fragments whenever you want. And with the wize answer I have some problems when changing the orientation of the screen an things like that. This is the PagerAdapter looks like:

    public class MyAdapter extends FragmentPagerAdapter
{
    static final int NUM_ITEMS = 2;
    private final FragmentManager mFragmentManager;
    private Fragment mFragmentAtPos0;
     private Map<Integer, String> mFragmentTags;
     private boolean isNextFragment=false;

    public MyAdapter(FragmentManager fm)
    {
        super(fm);
        mFragmentManager = fm;
         mFragmentTags = new HashMap<Integer, String>();
    }

    @Override
    public Fragment getItem(int position)
    {
        if (position == 0)
        {


            if (isPager) {
                mFragmentAtPos0 = new FirstPageFragment();
            } else {
                mFragmentAtPos0 = new NextFragment();
            }
            return mFragmentAtPos0;
        }
        else
            return SecondPageFragment.newInstance();
    }

    @Override
    public int getCount()
    {
        return NUM_ITEMS;
    }


 @Override
    public Object instantiateItem(ViewGroup container, int position) {
        Object obj = super.instantiateItem(container, position);
        if (obj instanceof Fragment) {
            // record the fragment tag here.
            Fragment f = (Fragment) obj;
            String tag = f.getTag();
            mFragmentTags.put(position, tag);
        }
        return obj;
    }


    public void onChange(boolean isNextFragment) {

        if (mFragmentAtPos0 == null)
            mFragmentAtPos0 = getFragment(0);
        if (mFragmentAtPos0 != null)
            mFragmentManager.beginTransaction().remove(mFragmentAtPos0).commit();


        if (!isNextFragment) {
            mFragmentAtFlashcards = new FirstPageFragment();
        } else {
            mFragmentAtFlashcards = new NextFragment();
        }

        notifyDataSetChanged();


    }


    @Override
    public int getItemPosition(Object object)
    {
        if (object instanceof FirstPageFragment && mFragmentAtPos0 instanceof NextFragment)
            return POSITION_NONE;
         if (object instanceof NextFragment && mFragmentAtPos0 instanceof FirstPageFragment)
            return POSITION_NONE;
        return POSITION_UNCHANGED;
    }


    public Fragment getFragment(int position) {
        String tag = mFragmentTags.get(position);
        if (tag == null)
            return null;
        return mFragmentManager.findFragmentByTag(tag);
    }
}

The listener I implemented in the adapter container activity to put it to the fragment when attaching it, this is the activity:

    public class PagerContainerActivity extends AppCompatActivity implements ChangeFragmentListener {

//...

  @Override
    public void onChange(boolean isNextFragment) {
        if (pagerAdapter != null)
            pagerAdapter.onChange(isNextFragment);


    }

//...
}

Then in the fragment putting the listener when attach an calling it:

public class FirstPageFragment extends Fragment{


private ChangeFragmentListener changeFragmentListener;


//...
 @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        changeFragmentListener = ((PagerContainerActivity) activity);
    }

    @Override
    public void onDetach() {
        super.onDetach();
        changeFragmentListener = null;
    }
//...
//in the on click to change the fragment
changeFragmentListener.onChange(true);
//...
}

And finally the listener:

public interface changeFragmentListener {

    void onChange(boolean isNextFragment);

}

Why maven settings.xml file is not there?

Installation of Maven doesn't create the settings.xml file. You have to create it on your own. Just put it in your .m2 directory where you expected it, see http://maven.apache.org/settings.html for reference. The m2eclipse plugin will use the same settings file as the command line.

Declare and initialize a Dictionary in Typescript

Edit: This has since been fixed in the latest TS versions. Quoting @Simon_Weaver's comment on the OP's post:

Note: this has since been fixed (not sure which exact TS version). I get these errors in VS, as you would expect: Index signatures are incompatible. Type '{ firstName: string; }' is not assignable to type 'IPerson'. Property 'lastName' is missing in type '{ firstName: string; }'.


Apparently this doesn't work when passing the initial data at declaration. I guess this is a bug in TypeScript, so you should raise one at the project site.

You can make use of the typed dictionary by splitting your example up in declaration and initialization, like:

var persons: { [id: string] : IPerson; } = {};
persons["p1"] = { firstName: "F1", lastName: "L1" };
persons["p2"] = { firstName: "F2" }; // will result in an error

What is the difference between a framework and a library?

I forget where I saw this definition, but I think it's pretty nice.

A library is a module that you call from your code, and a framework is a module which calls your code.

Send form data with jquery ajax json

here is a simple one

here is my test.php for testing only

<?php

// this is just a test
//send back to the ajax request the request

echo json_encode($_POST);

here is my index.html

<!DOCTYPE html>
<html>

<head>

</head>
<body>

<form id="form" action="" method="post">
Name: <input type="text" name="name"><br>
Age: <input type="text" name="email"><br>
FavColor: <input type="text" name="favc"><br>
<input id="submit" type="button" name="submit" value="submit">
</form>




<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script>
    $(document).ready(function(){
        // click on button submit
        $("#submit").on('click', function(){
            // send ajax
            $.ajax({
                url: 'test.php', // url where to submit the request
                type : "POST", // type of action POST || GET
                dataType : 'json', // data type
                data : $("#form").serialize(), // post data || get data
                success : function(result) {
                    // you can see the result from the console
                    // tab of the developer tools
                    console.log(result);
                },
                error: function(xhr, resp, text) {
                    console.log(xhr, resp, text);
                }
            })
        });
    });

</script>
</body>
</html>

Both file are place in the same directory

What is the use of style="clear:both"?

When you use float without width, there remains some space in that row. To block this space you can use clear:both; in next element.

Undefined variable: $_SESSION

Turned out there was some extra code in the AppModel that was messing things up:

in beforeFind and afterFind:

App::Import("Session");
$session = new CakeSession();
$sim_id = $session->read("Simulation.id");

I don't know why, but that was what the problem was. Removing those lines fixed the issue I was having.

angularjs getting previous route path

You'll need to couple the event listener to $rootScope in Angular 1.x, but you should probably future proof your code a bit by not storing the value of the previous location on $rootScope. A better place to store the value would be a service:

var app = angular.module('myApp', [])
.service('locationHistoryService', function(){
    return {
        previousLocation: null,

        store: function(location){
            this.previousLocation = location;
        },

        get: function(){
            return this.previousLocation;
        }
})
.run(['$rootScope', 'locationHistoryService', function($location, locationHistoryService){
    $rootScope.$on('$locationChangeSuccess', function(e, newLocation, oldLocation){
        locationHistoryService.store(oldLocation);
    });
}]);

Dart SDK is not configured

Many answers here, but I believe most are missing the point.

You're running this command from a shell, and most if not all answers are related to running inside an IDE. There's a difference.

If you're using the shell to run your Dart / Flutter commands, make sure you've set up the environment variables necessary for the commands to know where to look for the right tools.

Personally, as I mostly work on a laptop, I've offloaded my main drive from all the space required by the development tools, moving everything to an external drive as described in this answer, so I have to tell the system where I've placed the various components.

Same goes for running commands from the command line vs. from an IDE, as an IDE can store this configuration, while the shell will not, unless you store it in the shell's startup files.

I use macOS, Homebrew and the ZShell, and I like to have the Dart SDK as a separate install, so I can track the DEV branch for Dart via Homebrew, while my Flutter install is using the BETA branch.

So, in my ~/.zprofile I have:

export HOMEBREW_PREFIX="$(brew --prefix)"

# Android / Java, Dart / Flutter related
export FLUTTER_ROOT="${SSD}/Lib/flutter" # Path to your main Flutter install
export DART_SDK="${HOMEBREW_PREFIX}/opt/dart/libexec" # Separate Dart SDK install
export JAVA_HOME="/Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home" # JDK
export ANDROID_SDK_ROOT="${SSD}/Lib/android/sdk" # Top-level Android SDK directory
export ANDROID_HOME="${SSD}/Lib/android/sdk" # Same as above, needed by other tools I use
export ANDROID_AVD_HOME="${SSD}/Lib/android/avd" # Path to the moved emulators etc

Then I make sure that the $PATH variable is set up in the right order, so when I do Dart specific commands, the up-to-date Dart DEV branch is being used, while Flutter commands will use the Flutter BETA branch.

If you're using Zsh or Bash, add the additional paths at the end of .zshrc or .bashrc respectively, as these are called for every Terminal / Shell you start after login:

# Prepending to already established PATH

export PATH="\
/Library/Java/JavaVirtualMachines/adoptopenjdk-8.jdk/Contents/Home/bin:\
${HOME}/.pub-cache/bin:\
${HOMEBREW_PREFIX}/opt/dart/libexec/bin:\
${SSD}/Lib/flutter/.pub-cache/bin:\
${SSD}/Lib/flutter/bin:\
${SSD}/Lib/android/sdk/platform-tools:\
${SSD}/Lib/android/sdk/tools/bin:\
${SSD}/Lib/android/sdk/emulator:\
${PATH}"

# If you're using Zsh, add this to clean up duplicate entries building up from running this 
# in every Terminal you launch:
# Remove duplicates from $PATH
typeset -aU path;

# Not sure, but in Bash, to remove duplicates you could do something like:
echo -n $PATH | awk -v RS=: '!($0 in a) {a[$0]; printf("%s%s", length(a) > 1 ? ":" : "", $0)}'

Now, that was a mouthful of stuff, but this is the way I maintain the order of operations...

Copy table from one database to another

Another method that can be used to copy tables from the source database to the destination one is the SQL Server Export and Import wizard, which is available in SQL Server Management Studio.

You have the choice to export from the source database or import from the destination one in order to transfer the data.

This method is a quick way to copy tables from the source database to the destination one, if you arrange to copy tables having no concern with the tables’ relationships and orders.

When using this method, the tables’ indexes and keys will not be transferred. If you are interested in copying it, you need to generate scripts for these database objects.

If these are Foreign Keys, connecting these tables together, you need to export the data in the correct order, otherwise the export wizard will fail.

Feel free to read more about this method, as well as about some more methods (including generate scripts, SELECT INTO and third party tools) in this article: https://www.sqlshack.com/how-to-copy-tables-from-one-database-to-another-in-sql-server/

How do I output lists as a table in Jupyter notebook?

I want to output a table where each column has the smallest possible width, where columns are padded with white space (but this can be changed) and rows are separated by newlines (but this can be changed) and where each item is formatted using str (but...).


def ftable(tbl, pad='  ', sep='\n', normalize=str):

    # normalize the content to the most useful data type
    strtbl = [[normalize(it) for it in row] for row in tbl] 

    # next, for each column we compute the maximum width needed
    w = [0 for _ in tbl[0]]
    for row in strtbl:
        for ncol, it in enumerate(row):
            w[ncol] = max(w[ncol], len(it))

    # a string is built iterating on the rows and the items of `strtbl`:
    #   items are  prepended white space to an uniform column width
    #   formatted items are `join`ed using `pad` (by default "  ")
    #   eventually we join the rows using newlines and return
    return sep.join(pad.join(' '*(wid-len(it))+it for wid, it in zip(w, row))
                                                      for row in strtbl)

The function signature, ftable(tbl, pad=' ', sep='\n', normalize=str), with its default arguments is intended to provide for maximum flexibility.

You can customize

  • the column padding,
  • the row separator, (e.g., pad='&', sep='\\\\\n' to have the bulk of a LaTeX table)
  • the function to be used to normalize the input to a common string format --- by default, for the maximum generality it is str but if you know that all your data is floating point lambda item: "%.4f"%item could be a reasonable choice, etc.

Superficial testing:

I need some test data, possibly involving columns of different width so that the algorithm needs to be a little more sophisticated (but just a little bit;)

In [1]: from random import randrange

In [2]: table = [[randrange(10**randrange(10)) for i in range(5)] for j in range(3)]

In [3]: table
Out[3]: 
[[974413992, 510, 0, 3114, 1],
 [863242961, 0, 94924, 782, 34],
 [1060993, 62, 26076, 75832, 833174]]

In [4]: print(ftable(table))
974413992  510      0   3114       1
863242961    0  94924    782      34
  1060993   62  26076  75832  833174

In [5]: print(ftable(table, pad='|'))
974413992|510|    0| 3114|     1
863242961|  0|94924|  782|    34
  1060993| 62|26076|75832|833174

Basic authentication for REST API using spring restTemplate

Use setBasicAuth to define credentials

HttpHeaders headers = new HttpHeaders();
headers.setBasicAuth("myUsername", myPassword);

Then create the request like you prefer.

Example:

HttpEntity<String> request = new HttpEntity<String>(headers);
ResponseEntity<String> response = restTemplate.exchange(url, HttpMethod.GET, 
request, String.class);
String body = response.getBody();

Python setup.py develop vs install

From the documentation. The develop will not install the package but it will create a .egg-link in the deployment directory back to the project source code directory.

So it's like installing but instead of copying to the site-packages it adds a symbolic link (the .egg-link acts as a multiplatform symbolic link).

That way you can edit the source code and see the changes directly without having to reinstall every time that you make a little change. This is useful when you are the developer of that project hence the name develop. If you are just installing someone else's package you should use install

iOS: Convert UTC NSDate to local Timezone

The easiest method I've found is this:

NSDate *someDateInUTC = …;
NSTimeInterval timeZoneSeconds = [[NSTimeZone localTimeZone] secondsFromGMT];
NSDate *dateInLocalTimezone = [someDateInUTC dateByAddingTimeInterval:timeZoneSeconds];

TypeScript static classes

This is one way:

class SomeClass {
    private static myStaticVariable = "whatever";
    private static __static_ctor = (() => { /* do static constructor stuff :) */ })();
}

__static_ctor here is an immediately invoked function expression. Typescript will output code to call it at the end of the generated class.

Update: For generic types in static constructors, which are no longer allowed to be referenced by static members, you will need an extra step now:

class SomeClass<T> {
    static myStaticVariable = "whatever";
    private ___static_ctor = (() => { var someClass:SomeClass<T> ; /* do static constructor stuff :) */ })();
    private static __static_ctor = SomeClass.prototype.___static_ctor();
}

In any case, of course, you could just call the generic type static constructor after the class, such as:

class SomeClass<T> {
    static myStaticVariable = "whatever";
    private __static_ctor = (() => { var example: SomeClass<T>; /* do static constructor stuff :) */ })();
}
SomeClass.prototype.__static_ctor();

Just remember to NEVER use this in __static_ctor above (obviously).

Is <div style="width: ;height: ;background: "> CSS?

Yes, it is called Inline CSS, Here you styling the div using some height, width, and background.

Here the example:

<div style="width:50px;height:50px;background color:red">

You can achieve same using Internal or External CSS

2.Internal CSS:

  <head>
    <style>
    div {
    height:50px;
    width:50px;
    background-color:red;
    foreground-color:white;
    }
    </style>
  </head>
  <body>
    <div></div>
  </body>

3.External CSS:

<head>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<div></div>
</body>

style.css /external css file/

 div {
        height:50px;
        width:50px;
        background-color:red;
    }

Dynamically create Bootstrap alerts box through JavaScript

function bootstrap_alert() {
        create = function (message, color) {
            $('#alert_placeholder')
                .html('<div class="alert alert-' + color
                    + '" role="alert"><a class="close" data-dismiss="alert">×</a><span>' + message
                    + '</span></div>');
        };
        warning = function (message) {
            create(message, "warning");
        };
        info = function (message) {
            create(message, "info");
        };
        light = function (message) {
            create(message, "light");
        };
        transparent = function (message) {
            create(message, "transparent");
        };
        return {
            warning: warning,
            info: info,
            light: light,
            transparent: transparent
        };
    }

Using parameters in batch files at Windows command line

Batch Files automatically pass the text after the program so long as their are variables to assign them to. They are passed in order they are sent; e.g. %1 will be the first string sent after the program is called, etc.

If you have Hello.bat and the contents are:

@echo off
echo.Hello, %1 thanks for running this batch file (%2)
pause

and you invoke the batch in command via

hello.bat APerson241 %date%

you should receive this message back:

Hello, APerson241 thanks for running this batch file (01/11/2013)

What is the "Illegal Instruction: 4" error and why does "-mmacosx-version-min=10.x" fix it?

In my case, I got this while overloading

ostream & operator << (ostream &out, const MyClass &obj)

and forgot to return out. In other systems this just generates a warning, but on macos it also generated an error (although it seems to print correctly).

The error was resolved by adding the correct return value. In my case, adding the -mmacosx-version-min flag had no effect.

mongod command not recognized when trying to connect to a mongodb server

Apart from having a Path variable, the directory C:\data\db is mandatory.

Create this and the error shall be solved.

Find Nth occurrence of a character in a string

Here's another LINQ solution:

string input = "dtststx";
char searchChar = 't';
int occurrencePosition = 3; // third occurrence of the char
var result = input.Select((c, i) => new { Char = c, Index = i })
                  .Where(item => item.Char == searchChar)
                  .Skip(occurrencePosition - 1)
                  .FirstOrDefault();

if (result != null)
{
    Console.WriteLine("Position {0} of '{1}' occurs at index: {2}",
                        occurrencePosition, searchChar, result.Index);
}
else
{
    Console.WriteLine("Position {0} of '{1}' not found!",
                        occurrencePosition, searchChar);
}

Just for fun, here's a Regex solution. I saw some people initially used Regex to count, but when the question changed no updates were made. Here is how it can be done with Regex - again, just for fun. The traditional approach is best for simplicity.

string input = "dtststx";
char searchChar = 't';
int occurrencePosition = 3; // third occurrence of the char

Match match = Regex.Matches(input, Regex.Escape(searchChar.ToString()))
                   .Cast<Match>()
                   .Skip(occurrencePosition - 1)
                   .FirstOrDefault();

if (match != null)
    Console.WriteLine("Index: " + match.Index);
else
    Console.WriteLine("Match not found!");

Is there any "font smoothing" in Google Chrome?

I will say before all that this will not always works, i have tested this with sans-serif font and external fonts like open sans

Sometimes, when you use huge fonts, try to approximate to font-size:49px and upper

font-size:48px

This is a header text with a size of 48px (font-size:48px; in the element that contains the text).

But, if you up the 48px to font-size:49px; (and 50px, 60px, 80px, etc...), something interesting happens

font-size:49px

The text automatically get smooth, and seems really good

For another side...

If you are looking for small fonts, you can try this, but isn't very effective.

To the parent of the text, just apply the next css property: -webkit-backface-visibility: hidden;

You can transform something like this:

-webkit-backface-visibility: visible;

To this:

-webkit-backface-visibility: hidden;

(the font is Kreon)

Consider that when you are not putting that property, -webkit-backface-visibility: visible; is inherit

But be careful, that practice will not give always good results, if you see carefully, Chrome just make the text look a little bit blurry.

Another interesting fact:

-webkit-backface-visibility: hidden; will works too when you transform a text in Chrome (with the -webkit-transform property, that includes rotations, skews, etc)

Without

Without -webkit-backface-visibility: hidden;

With

With -webkit-backface-visibility: hidden;

Well, I don't know why that practices works, but it does for me. Sorry for my weird english.

How do you run a Python script as a service in Windows?

Although I upvoted the chosen answer a couple of weeks back, in the meantime I struggled a lot more with this topic. It feels like having a special Python installation and using special modules to run a script as a service is simply the wrong way. What about portability and such?

I stumbled across the wonderful Non-sucking Service Manager, which made it really simple and sane to deal with Windows Services. I figured since I could pass options to an installed service, I could just as well select my Python executable and pass my script as an option.

I have not yet tried this solution, but I will do so right now and update this post along the process. I am also interested in using virtualenvs on Windows, so I might come up with a tutorial sooner or later and link to it here.

What is the correct Performance Counter to get CPU and Memory Usage of a Process?

From this post:

To get the entire PC CPU and Memory usage:

using System.Diagnostics;

Then declare globally:

private PerformanceCounter theCPUCounter = 
   new PerformanceCounter("Processor", "% Processor Time", "_Total"); 

Then to get the CPU time, simply call the NextValue() method:

this.theCPUCounter.NextValue();

This will get you the CPU usage

As for memory usage, same thing applies I believe:

private PerformanceCounter theMemCounter = 
   new PerformanceCounter("Memory", "Available MBytes");

Then to get the memory usage, simply call the NextValue() method:

this.theMemCounter.NextValue();

For a specific process CPU and Memory usage:

private PerformanceCounter theCPUCounter = 
   new PerformanceCounter("Process", "% Processor Time",              
   Process.GetCurrentProcess().ProcessName);

where Process.GetCurrentProcess().ProcessName is the process name you wish to get the information about.

private PerformanceCounter theMemCounter = 
   new PerformanceCounter("Process", "Working Set",
   Process.GetCurrentProcess().ProcessName);

where Process.GetCurrentProcess().ProcessName is the process name you wish to get the information about.

Note that Working Set may not be sufficient in its own right to determine the process' memory footprint -- see What is private bytes, virtual bytes, working set?

To retrieve all Categories, see Walkthrough: Retrieving Categories and Counters

The difference between Processor\% Processor Time and Process\% Processor Time is Processor is from the PC itself and Process is per individual process. So the processor time of the processor would be usage on the PC. Processor time of a process would be the specified processes usage. For full description of category names: Performance Monitor Counters

An alternative to using the Performance Counter

Use System.Diagnostics.Process.TotalProcessorTime and System.Diagnostics.ProcessThread.TotalProcessorTime properties to calculate your processor usage as this article describes.

WPF binding to Listbox selectedItem

For me, I usually use DataContext together in order to bind two-depth property such as this question.

<TextBlock DataContext="{Binding SelectedRule}" Text="{Binding Name}" />

Or, I prefer to use ElementName because it achieves bindings only with view controls.

<TextBlock DataContext="{Binding ElementName=lbRules, Path=SelectedItem}" Text="{Binding Name}" />

trigger body click with jQuery

Interestingly, when I replaced this:

$("body").trigger("click")

With this:

jQuery("body").trigger("click")

It works!

How do I parse JSON from a Java HTTPResponse?

Jackson appears to support some amount of JSON parsing straight from an InputStream. My understanding is that it runs on Android and is fairly quick. On the other hand, it is an extra JAR to include with your app, increasing download and on-flash size.

Fatal error: Call to undefined function mysqli_connect()

There is no error in the, but the mysqli PHP extension is not installed on your machine. Please contact your service provider to fix this issue.

Navigation drawer: How do I set the selected item at startup?

For some reason it's preferable to find the MenuItem using the ID's.

drawer.getMenu().findItem(R.id.action_something).setChecked(true);

Git - How to use .netrc file on Windows to save user and password

This will let Git authenticate on HTTPS using .netrc:

  • The file should be named _netrc and located in c:\Users\<username>.
  • You will need to set an environment variable called HOME=%USERPROFILE% (set system-wide environment variables using the System option in the control panel. Depending on the version of Windows, you may need to select "Advanced Options".).
  • The password stored in the _netrc file cannot contain spaces (quoting the password will not work).

How to getElementByClass instead of GetElementById with JavaScript?

Use it to access class in Javascript.

<script type="text/javascript">
var var_name = document.getElementsByClassName("class_name")[0];
</script>

Preloading images with jQuery

this jquery imageLoader plugin is just 1.39kb

usage:

$({}).imageLoader({
    images: [src1,src2,src3...],
    allcomplete:function(e,ui){
        //images are ready here
        //your code - site.fadeIn() or something like that
    }
});

there are also other options like whether you want to load the images synchronously or asychronously and a complete event for each individual image.

Traverse a list in reverse order in Python

I think the most elegant way is to transform enumerate and reversed using the following generator

(-(ri+1), val) for ri, val in enumerate(reversed(foo))

which generates a the reverse of the enumerate iterator

Example:

foo = [1,2,3]
bar = [3,6,9]
[
    bar[i] - val
    for i, val in ((-(ri+1), val) for ri, val in enumerate(reversed(foo)))
]

Result:

[6, 4, 2]

What's the best UI for entering date of birth?

As perhaps one of the older people here, and born late in the month, I find drop-down menus for birthdates to be frustrating. I typically have to scroll down on two drop-down menus, and that's awkward. I'd much rather type it in.

If you can have a control designed so that it can either accept drop-down menus or be typed into, and make it clear both work, that would be excellent.

Android emulator: How to monitor network traffic?

A current release of Android Studio did not correctly apply the -tcpdump argument. I was still able to capture a dump by passing the related parameter to qemu as follows:

tools/emulator -engine classic -tcpdump dump.cap -avd myAvd

how to find all indexes and their columns for tables, views and synonyms in oracle

SELECT * FROM user_cons_columns WHERE table_name = 'table_name';

What's the easiest way to call a function every 5 seconds in jQuery?

you can use window.setInterval and time must to be define in miliseconds, in below case the function will call after every single second (1000 miliseconds)

<script>
  var time = 3670;
window.setInterval(function(){

  // Time calculations for days, hours, minutes and seconds
    var h = Math.floor(time / 3600);
    var m = Math.floor(time % 3600 / 60);
    var s = Math.floor(time % 3600 % 60);

  // Display the result in the element with id="demo"
  document.getElementById("demo").innerHTML =  h + "h "
  + m + "m " + s + "s ";

  // If the count down is finished, write some text 
  if (time < 0) {
    clearInterval(x);
    document.getElementById("demo").innerHTML = "EXPIRED";
  }

  time--;
}, 1000);


</script>

jQuery Determine if a matched class has a given id

Check if element's ID is exist

_x000D_
_x000D_
if ($('#id').attr('id') == 'id')_x000D_
{_x000D_
  //OK_x000D_
}
_x000D_
_x000D_
_x000D_

Best way to store date/time in mongodb

The best way is to store native JavaScript Date objects, which map onto BSON native Date objects.

> db.test.insert({date: ISODate()})
> db.test.insert({date: new Date()})
> db.test.find()
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:42.389Z") }
{ "_id" : ObjectId("..."), "date" : ISODate("2014-02-10T10:50:57.240Z") }

The native type supports a whole range of useful methods out of the box, which you can use in your map-reduce jobs, for example.

If you need to, you can easily convert Date objects to and from Unix timestamps1), using the getTime() method and Date(milliseconds) constructor, respectively.

1) Strictly speaking, the Unix timestamp is measured in seconds. The JavaScript Date object measures in milliseconds since the Unix epoch.

How to multiply a BigDecimal by an integer in Java

First off, BigDecimal.multiply() returns a BigDecimal and you're trying to store that in an int.

Second, it takes another BigDecimal as the argument, not an int.

If you just use the BigDecimal for all variables involved in these calculations, it should work fine.

How to delete empty folders using windows command prompt?

A simpler way is to do xcopy to make a copy of the entire directory structure using /s switch. help for /s says Copies directories and subdirectories except empty ones.

xcopy dirA dirB /S

where dirA is source with Empty folders. DirB will be the copy without empty folders

Why does JSON.parse fail with the empty string?

Use try-catch to avoid it:

var result = null;
try {
  // if jQuery
  result = $.parseJSON(JSONstring);
  // if plain js
  result = JSON.parse(JSONstring);
}
catch(e) {
  // forget about it :)
}

Chrome not rendering SVG referenced via <img> tag

I also got the same issue with chrome, after adding DOCTYPE it works as expected

<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">

Before

    <?xml version="1.0" encoding="iso-8859-1"?>
<svg version="1.1" id="Capa_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
     width="792px" height="792px" viewBox="0 0 792 792" style="enable-background:new 0 0 792 792;" xml:space="preserve">
    <g fill="none" stroke="black" stroke-width="15">
  ......
  ......
  .......
  </g>
</svg>

After

    <?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1" id="Capa_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
     width="792px" height="792px" viewBox="0 0 792 792" style="enable-background:new 0 0 792 792;" xml:space="preserve">
    <g fill="none" stroke="black" stroke-width="15">
  ......
  ......
  .......
  </g>
</svg>

Entity Framework Code First - two Foreign Keys from same table

This is because Cascade Deletes are enabled by default. The problem is that when you call a delete on the entity, it will delete each of the f-key referenced entities as well. You should not make 'required' values nullable to fix this problem. A better option would be to remove EF Code First's Cascade delete convention:

modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>(); 

It's probably safer to explicitly indicate when to do a cascade delete for each of the children when mapping/config. the entity.

T-test in Pandas

I simplify the code a little bit.

from scipy.stats import ttest_ind
ttest_ind(*my_data.groupby('Category')['value'].apply(lambda x:list(x)))

How to import Swagger APIs into Postman?

You can do that: Postman -> Import -> Link -> {root_url}/v2/api-docs

Maven: Command to update repository after adding dependency to POM

I know it is an old question now, but for users who are using Maven plugin with Eclipse under Windows, you have two options:

  1. If you got Maven installed as a standalone application:

    You can use the following command in the CMD under your project path:

    mvn eclipse:eclipse
    

    It will update your repository with all the missing jars, according to your dependencies in your pom.xml file.

  2. If you haven't got Maven installed as a standalone application you can follow these steps on your eclipse:

    Right click on the project ->Run As -- >Run configurations.

    Then select mavenBuild.

    Then click new button to create a configuration of the selected type .Click on Browse workspace then select your project and in goals specify eclipse:eclipse

You can refer to how to run the command mvn eclipse:eclipse for further details.

Viewing localhost website from mobile device

First of all open applicationhost.config file in visual studio. address>>C:\Users\Your User Name\Documents\IISExpress\config\applicationhost.config

Then find this codes:

<site name="Your Site_Name" id="24">
        <application path="/" applicationPool="Clr4IntegratedAppPool"
        <virtualDirectory path="/" physicalPath="C:\Users\Your User         Name\Documents\Visual Studio 2013\Projects\Your Site Name" />
        </application>
         <bindings>      
           <binding protocol="http" bindingInformation="*:Port_Number:*" />
         </bindings>
   </site>

*)Port_Number:While your site running in IIS express on your computer, port number will visible in address bar of your browser like this: localhost:port_number/... When edit this file save it.

In the Second step you must run cmd as administrator and type this code: netsh http add urlacl url=http://*:port_Number/ user=everyone and press enter

In Third step you must Enable port on firewall

Go to the “Control Panel\System and Security\Windows Firewall”

Click “Advanced settings”

Select “Inbound Rules”

Click on “New Rule …” button

Select “Port”, click “Next”

Fill your IIS Express listening port number, click “Next”

Select “Allow the connection”, click “Next”

Check where you would like allow connection to IIS Express (Domain,Private, Public), click “Next”

Fill rule name (e.g “IIS Express), click “Finish”

I hopeful this answer be useful for you

Update for Visual Studio 2015 in this link: https://johan.driessen.se/posts/Accessing-an-IIS-Express-site-from-a-remote-computer

Javascript: How to check if a string is empty?

If you want to know if it's an empty string use === instead of ==.

if(variable === "") {
}

This is because === will only return true if the values on both sides are of the same type, in this case a string.

for example: (false == "") will return true, and (false === "") will return false.

Capturing count from an SQL query

You'll get converting errors with:

cmd.CommandText = "SELECT COUNT(*) FROM table_name";
Int32 count = (Int32) cmd.ExecuteScalar();

Use instead:

string stm = "SELECT COUNT(*) FROM table_name WHERE id="+id+";";
MySqlCommand cmd = new MySqlCommand(stm, conn);
Int32 count = Convert.ToInt32(cmd.ExecuteScalar());
if(count > 0){
    found = true; 
} else {
    found = false; 
}

How to determine day of week by passing specific date?

Yes. Depending on your exact case:

  • You can use java.util.Calendar:

    Calendar c = Calendar.getInstance();
    c.setTime(yourDate);
    int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
    
  • if you need the output to be Tue rather than 3 (Days of week are indexed starting at 1 for Sunday, see Calendar.SUNDAY), instead of going through a calendar, just reformat the string: new SimpleDateFormat("EE").format(date) (EE meaning "day of week, short version")

  • if you have your input as string, rather than Date, you should use SimpleDateFormat to parse it: new SimpleDateFormat("dd/M/yyyy").parse(dateString)

  • you can use joda-time's DateTime and call dateTime.dayOfWeek() and/or DateTimeFormat.

  • edit: since Java 8 you can now use java.time package instead of joda-time

What do I need to do to get Internet Explorer 8 to accept a self signed certificate?

I had the same issue while working with web services. Here Microsoft has a (long) walk-thru showing you how to install stuff on the client to basically say that your self-signed cert is ok. In the end, I just spent the $30 and bought a full certificate from Godaddy.com.

P.S. I know that you can code around the error message but we didn't want to do that for testing reasons.

CSS scale height to match width - possibly with a formfactor

Solution with Jquery

$(window).resize(function () {
    var width = $("#map").width();
    $("#map").height(width * 1.72);
});

Difference between an API and SDK

How about... It's like if you wanted to install a home theatre system in your house. Using an API is like getting all the wires, screws, bits, and pieces. The possibilities are endless (constrained only by the pieces you receive), but sometimes overwhelming. An SDK is like getting a kit. You still have to put it together, but it's more like getting pre-cut pieces and instructions for an IKEA bookshelf than a box of screws.

Display number with leading zeros

You can do this with f strings.

import numpy as np

print(f'{np.random.choice([1, 124, 13566]):0>8}')

This will print constant length of 8, and pad the rest with leading 0.

00000001
00000124
00013566

How to validate an email address in JavaScript

Regex for validating email address

[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])+

Linq : select value in a datatable column

Use linq and set the data table as Enumerable and select the fields from the data table field that matches what you are looking for.

Example

I want to get the currency Id and currency Name from the currency table where currency is local currency, and assign the currency id and name to a text boxes on the form:

DataTable dt = curData.loadCurrency();
            var curId = from c in dt.AsEnumerable()
                        where c.Field<bool>("LocalCurrency") == true
                        select c.Field<int>("CURID");

            foreach (int cid in curId)
            {
                txtCURID.Text = cid.ToString();
            }
            var curName = from c in dt.AsEnumerable()
                          where c.Field<bool>("LocalCurrency") == true
                          select c.Field<string>("CurName");
            foreach (string cName in curName)
            {
                txtCurrency.Text = cName.ToString();
            }

How to get current timestamp in string format in Java? "yyyy.MM.dd.HH.mm.ss"

You can use the following

new java.sql.Timestamp(System.currentTimeMillis()).getTime()

Result : 1539594988651

Hope this will help. Just my suggestion and not for reward points.

Can I clear cell contents without changing styling?

you can use ClearContents. ex,

Range("X").Cells.ClearContents

Removing items from a list

You cannot do it because you are already looping on it.

Inorder to avoid this situation use Iterator,which guarentees you to remove the element from list safely ...

List<Object> objs;
Iterator<Object> i = objs.iterator();
while (i.hasNext()) {
   Object o = i.next();
  //some condition
    i.remove();
}

C++ error 'Undefined reference to Class::Function()'

Specify the Class Card for the constructor-:

void Card::Card(Card::Rank rank, Card::Suit suit) {

And also define the default constructor and destructor.

Squash the first two commits in Git?

Squashing the first and second commit would result in the first commit being rewritten. If you have more than one branch that is based off the first commit, you'd cut off that branch.

Consider the following example:

a---b---HEAD
 \
  \
   '---d

Squashing a and b into a new commit "ab" would result in two distinct trees which in most cases is not desirable since git-merge and git-rebase will no longer work across the two branches.

ab---HEAD

a---d

If you really want this, it can be done. Have a look at git-filter-branch for a powerful (and dangerous) tool for history rewriting.

Where is adb.exe in windows 10 located?

If you are not able to find platform-tools folder, please open SDK Manager and install "Android SDK Platform-Tools" from SDK Tools tab.

Fastest way to check if string contains only digits

this will work perfectly, there is many other ways but this would work

bool IsDigitsOnly(string str)
    {
        if (str.Length > 0)//if contains characters
        {
            foreach (char c in str)//assign character to c
            {
                if (c < '0' || c > '9')//check if its outside digit range
                    return false;
            }
        }else//empty string
        {
            return false;//empty string 
        }

        return true;//only digits
    }

Find non-ASCII characters in varchar columns using SQL Server

To find which field has invalid characters:

SELECT * FROM Staging.APARMRE1 FOR XML AUTO, TYPE

You can test it with this query:

SELECT top 1 'char 31: '+char(31)+' (hex 0x1F)' field
from sysobjects
FOR XML AUTO, TYPE

The result will be:

Msg 6841, Level 16, State 1, Line 3 FOR XML could not serialize the data for node 'field' because it contains a character (0x001F) which is not allowed in XML. To retrieve this data using FOR XML, convert it to binary, varbinary or image data type and use the BINARY BASE64 directive.

It is very useful when you write xml files and get error of invalid characters when validate it.

Using `date` command to get previous, current and next month

The problem is that date takes your request quite literally and tries to use a date of 31st September (being 31st October minus one month) and then because that doesn't exist it moves to the next day which does. The date documentation (from info date) has the following advice:

The fuzz in units can cause problems with relative items. For example, `2003-07-31 -1 month' might evaluate to 2003-07-01, because 2003-06-31 is an invalid date. To determine the previous month more reliably, you can ask for the month before the 15th of the current month. For example:

 $ date -R
 Thu, 31 Jul 2003 13:02:39 -0700
 $ date --date='-1 month' +'Last month was %B?'
 Last month was July?
 $ date --date="$(date +%Y-%m-15) -1 month" +'Last month was %B!'
 Last month was June!

What is HEAD in Git?

Git is all about commits.
And Head points to the commit which you currently checked out.

$ git cat-file -t HEAD
commit

Whenever you checkout a branch, the HEAD points to the latest commit on that branch. Contents of HEAD can checked as below (for master branch):

$ cat .git/refs/heads/master
  b089141cc8a7d89d606b2f7c15bfdc48640a8e25

Do I need <class> elements in persistence.xml?

In Java SE environment, by specification you have to specify all classes as you have done:

A list of all named managed persistence classes must be specified in Java SE environments to insure portability

and

If it is not intended that the annotated persistence classes contained in the root of the persistence unit be included in the persistence unit, the exclude-unlisted-classes element should be used. The exclude-unlisted-classes element is not intended for use in Java SE environments.

(JSR-000220 6.2.1.6)

In Java EE environments, you do not have to do this as the provider scans for annotations for you.

Unofficially, you can try to set <exclude-unlisted-classes>false</exclude-unlisted-classes> in your persistence.xml. This parameter defaults to false in EE and truein SE. Both EclipseLink and Toplink supports this as far I can tell. But you should not rely on it working in SE, according to spec, as stated above.

You can TRY the following (may or may not work in SE-environments):

<persistence-unit name="eventractor" transaction-type="RESOURCE_LOCAL">
     <exclude-unlisted-classes>false</exclude-unlisted-classes>

    <properties>
            <property name="hibernate.hbm2ddl.auto" value="validate" />
            <property name="hibernate.show_sql" value="true" />
    </properties>
</persistence-unit>

PHP Check for NULL

Make sure that the value of the column is really NULL and not an empty string or 0.

How can I check if a string is null or empty in PowerShell?

PowerShell 2.0 replacement for [string]::IsNullOrWhiteSpace() is string -notmatch "\S"

("\S" = any non-whitespace character)

> $null  -notmatch "\S"
True
> "   "  -notmatch "\S"
True
> " x "  -notmatch "\S"
False

Performance is very close:

> Measure-Command {1..1000000 |% {[string]::IsNullOrWhiteSpace("   ")}}
TotalMilliseconds : 3641.2089

> Measure-Command {1..1000000 |% {"   " -notmatch "\S"}}
TotalMilliseconds : 4040.8453

XAMPP installation on Win 8.1 with UAC Warning

You can solve the issue by

  1. Ignore the warning and Install XAMPP directly under C:/ folder. It will solve your issue
  2. You can deactivate the UAC which i don't recommend. It's makes your PC less secure.

Enterprise app deployment doesn't work on iOS 7.1

I can confirm it works, But You have to put html AND plist on dropbox. It works also for non-enterprise OTA, i.e. You want to share app with your dev. team.

I did:

a) on my site I made a page with this link:

.. href="https://dl.dropboxusercontent.com/u//(your DB id)/ipa.html">MyApp

b) on DropBox I wrote another HTML page:

.. https://dl.dropboxusercontent.com/u/(your DB id)/MyApp.plist"> Tap to Install MyApp

c) moved plist on DropBox but leaving it to POINT to my old server (no https)

Keylistener in Javascript

Did you check the small Mousetrap library?

Mousetrap is a simple library for handling keyboard shortcuts in JavaScript.

Remove json element

if we want to remove one attribute say "firstName" from the array we can use map function along with delete as mentioned above

   var result= [
       {
           "FirstName": "Test1",
           "LastName":  "User",
       },
       {
           "FirstName": "user",
           "LastName":  "user",
       },
       {
           "FirstName": "Ropbert",
           "LastName":  "Jones",
       },
       {
           "FirstName": "hitesh",
           "LastName":  "prajapti",
       }
   ]

result.map( el=>{
    delete el["FirstName"]
})
console.log("OUT",result)

Flutter: RenderBox was not laid out

i

I used this code to fix the issue of displaying items in the horizontal list.

new Container(
      height: 20,
      child: Row(
        mainAxisAlignment: MainAxisAlignment.end,
        children: <Widget>[
          ListView.builder(
            scrollDirection: Axis.horizontal,
            shrinkWrap: true,
            itemCount: array.length,
            itemBuilder: (context, index){
              return array[index];
            },
          ),
        ],
      ),
    );

Detect Click into Iframe using JavaScript

Assumptions -

  1. Your script runs outside the iframe BUT NOT in the outermost window.top window. (For outermost window, other blur solutions are good enough)
  2. A new page is opened replacing the current page / a new page in a new tab and control is switched to new tab.

This works for both sourceful and sourceless iframes

var ifr = document.getElementById("my-iframe");
var isMouseIn;
ifr.addEventListener('mouseenter', () => {
    isMouseIn = true;
});
ifr.addEventListener('mouseleave', () => {
    isMouseIn = false;
});
window.document.addEventListener("visibilitychange", () => {
    if (isMouseIn && document.hidden) {
        console.log("Click Recorded By Visibility Change");
    }
});
window.addEventListener("beforeunload", (event) => {
    if (isMouseIn) {
        console.log("Click Recorded By Before Unload");
    }
});

If a new tab is opened / same page unloads and the mouse pointer is within the Iframe, a click is considered

How to use hex color values

This is a function that takes a hex string and returns a UIColor.
(You can enter hex strings with either format: #ffffff or ffffff)

Usage:

var color1 = hexStringToUIColor("#d3d3d3")

Swift 5: (Swift 4+)

func hexStringToUIColor (hex:String) -> UIColor {
    var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()

    if (cString.hasPrefix("#")) {
        cString.remove(at: cString.startIndex)
    }

    if ((cString.count) != 6) {
        return UIColor.gray
    }

    var rgbValue:UInt64 = 0
    Scanner(string: cString).scanHexInt64(&rgbValue)

    return UIColor(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
    )
}

Swift 3:

func hexStringToUIColor (hex:String) -> UIColor {
    var cString:String = hex.trimmingCharacters(in: .whitespacesAndNewlines).uppercased()

    if (cString.hasPrefix("#")) {
        cString.remove(at: cString.startIndex)
    }

    if ((cString.characters.count) != 6) {
        return UIColor.gray
    }

    var rgbValue:UInt32 = 0
    Scanner(string: cString).scanHexInt32(&rgbValue)

    return UIColor(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
    )
}

Swift 2:

func hexStringToUIColor (hex:String) -> UIColor {
    var cString:String = hex.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet() as NSCharacterSet).uppercaseString

    if (cString.hasPrefix("#")) {
      cString = cString.substringFromIndex(cString.startIndex.advancedBy(1))
    }

    if ((cString.characters.count) != 6) {
      return UIColor.grayColor()
    }

    var rgbValue:UInt32 = 0
    NSScanner(string: cString).scanHexInt(&rgbValue)

    return UIColor(
        red: CGFloat((rgbValue & 0xFF0000) >> 16) / 255.0,
        green: CGFloat((rgbValue & 0x00FF00) >> 8) / 255.0,
        blue: CGFloat(rgbValue & 0x0000FF) / 255.0,
        alpha: CGFloat(1.0)
    )
}



Source: arshad/gist:de147c42d7b3063ef7bc

Edit: Updated the code. Thanks, Hlung, jaytrixz, Ahmad F, Kegham K, and Adam Waite!

What's the difference between getRequestURI and getPathInfo methods in HttpServletRequest?

getPathInfo() gives the extra path information after the URI, used to access your Servlet, where as getRequestURI() gives the complete URI.

I would have thought they would be different, given a Servlet must be configured with its own URI pattern in the first place; I don't think I've ever served a Servlet from root (/).

For example if Servlet 'Foo' is mapped to URI '/foo' then I would have thought the URI:

/foo/path/to/resource

Would result in:

RequestURI = /foo/path/to/resource

and

PathInfo = /path/to/resource

How to use NSJSONSerialization

The issue seems to be with autorelease of objects. NSJSONSerialization JSONObjectWithData is obviously creating some autoreleased objects and passing it back to you. If you try to take that on to a different thread, it will not work since it cannot be deallocated on a different thread.

Trick might be to try doing a mutable copy of that dictionary or array and use it.

NSError *e = nil;
id jsonObject = [NSJSONSerialization 
JSONObjectWithData: data 
options: NSJSONReadingMutableContainers 
error: &e] mutableCopy];

Treating a NSDictionary as NSArray will not result in Bad access exception but instead will probably crash when a method call is made.

Also, may be the options do not really matter here but it is better to give NSJSONReadingMutableContainers | NSJSONReadingMutableContainers | NSJSONReadingAllowFragments but even if they are autoreleased objects it may not solve this issue.

Python: Number of rows affected by cursor.execute("SELECT ...)

when using count(*) the result is {'count(*)': 9}

-- where 9 represents the number of rows in the table, for the instance.

So, in order to fetch the just the number, this worked in my case, using mysql 8.

cursor.fetchone()['count(*)']

MAX(DATE) - SQL ORACLE

SELECT p.MEMBSHIP_ID
FROM user_payments as p
WHERE USER_ID = 1 AND PAYM_DATE = (
    SELECT MAX(p2.PAYM_DATE)
    FROM user_payments as p2
    WHERE p2.USER_ID = p.USER_ID
)

Get last key-value pair in PHP array

Another solution cold be:

$value = $arr[count($arr) - 1];

The above will count the amount of array values, substract 1 and then return the value.

Note: This can only be used if your array keys are numeric.

Capturing Groups From a Grep RegEx

str="1w 2d 1h"
regex="([0-9])w ([0-9])d ([0-9])h"
if [[ $str =~ $regex ]]
then
    week="${BASH_REMATCH[1]}"
    day="${BASH_REMATCH[2]}"
    hour="${BASH_REMATCH[3]}"
    echo $week --- $day ---- $hour
fi

output: 1 --- 2 ---- 1

Cannot construct instance of - Jackson

You need to use a concrete class and not an Abstract class while deserializing. if the Abstract class has several implementations then, in that case, you can use it as below-

  @JsonTypeInfo( use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
    @JsonSubTypes({ 
      @Type(value = Bike.class, name = "bike"), 
      @Type(value = Auto.class, name = "auto"), 
      @Type(value = Car.class, name = "car")
    })
    public abstract class Vehicle {
        // fields, constructors, getters, setters
    }

How to concat two ArrayLists?

var arr3 = new arraylist();
for(int i=0, j=0, k=0; i<arr1.size()+arr2.size(); i++){
    if(i&1)
        arr3.add(arr1[j++]);
    else
        arr3.add(arr2[k++]);
}

as you say, "the names and numbers beside each other".

How to create a file on Android Internal Storage?

You should create the media dir appended to what getLocalPath() returns.

How to get line count of a large file cheaply in Python?

I would use Python's file object method readlines, as follows:

with open(input_file) as foo:
    lines = len(foo.readlines())

This opens the file, creates a list of lines in the file, counts the length of the list, saves that to a variable and closes the file again.

jQuery scroll to ID from different page

I would like to recommend using the scrollTo plugin

http://demos.flesler.com/jquery/scrollTo/

You can the set scrollto by jquery css selector.

$('html,body').scrollTo( $(target), 800 );

I have had great luck with the accuracy of this plugin and its methods, where other methods of achieving the same effect like using .offset() or .position() have failed to be cross browser for me in the past. Not saying you can't use such methods, I'm sure there is a way to do it cross browser, I've just found scrollTo to be more reliable.

Is there a good reason I see VARCHAR(255) used so often (as opposed to another length)?

I'm going to answer the literal question: no, there isn't a good reason you see VARCHAR(255) used so often (there are indeed reasons, as discussed in the other answers, just not good ones). You won't find many examples of projects that have failed catastrophically because the architect chose VARCHAR(300) instead of VARCHAR(255). This would be an issue of near-total insignificance even if you were talking about CHAR instead of VARCHAR.

Echo a blank (empty) line to the console from a Windows batch file

Note: Though my original answer attracted several upvotes, I decided that I could do much better. You can find my original (simplistic and misguided) answer in the edit history.

If Microsoft had the intent of providing a means of outputting a blank line from cmd.exe, Microsoft surely would have documented such a simple operation. It is this omission that motivated me to ask this question.

So, because a means for outputting a blank line from cmd.exe is not documented, arguably one should consider any suggestion for how to accomplish this to be a hack. That means that there is no known method for outputting a blank line from cmd.exe that is guaranteed to work (or work efficiently) in all situations.

With that in mind, here is a discussion of methods that have been recommended for outputting a blank line from cmd.exe. All recommendations are based on variations of the echo command.


echo.

While this will work in many if not most situations, it should be avoided because it is slower than its alternatives and actually can fail (see here, here, and here). Specifically, cmd.exe first searches for a file named echo and tries to start it. If a file named echo happens to exist in the current working directory, echo. will fail with:

'echo.' is not recognized as an internal or external command,
operable program or batch file.

echo:
echo\

At the end of this answer, the author argues that these commands can be slow, for instance if they are executed from a network drive location. A specific reason for the potential slowness is not given. But one can infer that it may have something to do with accessing the file system. (Perhaps because : and \ have special meaning in a Windows file system path?)

However, some may consider these to be safe options since : and \ cannot appear in a file name. For that or another reason, echo: is recommended by SS64.com here.


echo(
echo+
echo,
echo/
echo;
echo=
echo[
echo]

This lengthy discussion includes what I believe to be all of these. Several of these options are recommended in this SO answer as well. Within the cited discussion, this post ends with what appears to be a recommendation for echo( and echo:.

My question at the top of this page does not specify a version of Windows. My experimentation on Windows 10 indicates that all of these produce a blank line, regardless of whether files named echo, echo+, echo,, ..., echo] exist in the current working directory. (Note that my question predates the release of Windows 10. So I concede the possibility that older versions of Windows may behave differently.)

In this answer, @jeb asserts that echo( always works. To me, @jeb's answer implies that other options are less reliable but does not provide any detail as to why that might be. Note that @jeb contributed much valuable content to other references I have cited in this answer.


Conclusion: Do not use echo.. Of the many other options I encountered in the sources I have cited, the support for these two appears most authoritative:

echo(
echo:

But I have not found any strong evidence that the use of either of these will always be trouble-free.


Example Usage:

@echo off
echo Here is the first line.
echo(
echo There is a blank line above this line.

Expected output:

Here is the first line.

There is a blank line above this line.

how to convert JSONArray to List of Object using camel-jackson

/*
 It has been answered in http://stackoverflow.com/questions/15609306/convert-string-to-json-array/33292260#33292260
 * put string into file jsonFileArr.json
 * [{"username":"Hello","email":"[email protected]","credits"
 * :"100","twitter_username":""},
 * {"username":"Goodbye","email":"[email protected]"
 * ,"credits":"0","twitter_username":""},
 * {"username":"mlsilva","email":"[email protected]"
 * ,"credits":"524","twitter_username":""},
 * {"username":"fsouza","email":"[email protected]"
 * ,"credits":"1052","twitter_username":""}]
 */

public class TestaGsonLista {

public static void main(String[] args) {
Gson gson = new Gson();
 try {
    BufferedReader br = new BufferedReader(new FileReader(
            "C:\\Temp\\jsonFileArr.json"));
    JsonArray jsonArray = new JsonParser().parse(br).getAsJsonArray();
    for (int i = 0; i < jsonArray.size(); i++) {
        JsonElement str = jsonArray.get(i);
        Usuario obj = gson.fromJson(str, Usuario.class);
        //use the add method from the list and returns it.
        System.out.println(obj);
        System.out.println(str);
        System.out.println("-------");
    }
 } catch (IOException e) {
    e.printStackTrace();
 }
}

How do I show the value of a #define at compile-time?

Take a look at the Boost documentation as well, regarding how you are using the macro:

In reference to BOOST_VERSION, from http://www.boost.org/doc/libs/1_37_0/libs/config/doc/html/boost_config/boost_macro_reference.html#boost_config.boost_macro_reference.boost_helper_macros:

Describes the boost version number in XXYYZZ format such that: (BOOST_VERSION % 100) is the sub-minor version, ((BOOST_VERSION / 100) % 1000) is the minor version, and (BOOST_VERSION / 100000) is the major version.

Create PostgreSQL ROLE (user) if it doesn't exist

The same solution as for Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL? should work - send a CREATE USER … to \gexec.

Workaround from within psql

SELECT 'CREATE USER my_user'
WHERE NOT EXISTS (SELECT FROM pg_catalog.pg_roles WHERE rolname = 'my_user')\gexec

Workaround from the shell

echo "SELECT 'CREATE USER my_user' WHERE NOT EXISTS (SELECT FROM pg_catalog.pg_roles WHERE rolname = 'my_user')\gexec" | psql

See accepted answer there for more details.

Enable vertical scrolling on textarea

Simply, change

<textarea rows="15" cols="50" id="aboutDescription"
style="resize: none;"></textarea>

to

<textarea rows="15" cols="50" id="aboutDescription"
style="resize: none;" data-role="none"></textarea>

ie, add:

data-role="none"

#define in Java

Simplest Answer is "No Direct method of getting it because there is no pre-compiler" But you can do it by yourself. Use classes and then define variables as final so that it can be assumed as constant throughout the program
Don't forget to use final and variable as public or protected not private otherwise you won't be able to access it from outside that class

MySQL SELECT last few days?

WHERE t.date >= DATE_ADD(CURDATE(), INTERVAL '-3' DAY);

use quotes on the -3 value

What's the best way to use R scripts on the command line (terminal)?

#!/path/to/R won't work because R is itself a script, so execve is unhappy.

I use R --slave -f script

Ansible: How to delete files and folders inside a directory?

While Ansible is still debating to implement state = empty https://github.com/ansible/ansible-modules-core/issues/902

my_folder: "/home/mydata/web/"
empty_path: "/tmp/empty"


- name: "Create empty folder for wiping."
  file:
    path: "{{ empty_path }}" 
    state: directory

- name: "Wipe clean {{ my_folder }} with empty folder hack."
  synchronize:
    mode: push

    #note the backslash here
    src: "{{ empty_path }}/" 

    dest: "{{ nl_code_path }}"
    recursive: yes
    delete: yes
  delegate_to: "{{ inventory_hostname }}"

Note though, with synchronize you should be able to sync your files (with delete) properly anyway.

How does one generate a random number in Apple's Swift language?

Updated: August 06, 2020.

Swift 5.3

Let's assume we have an array:

let numbers: [Int] = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]


For iOS and macOS you can use system-wide random source in Xcode's framework GameKit. Here you can find GKRandomSource class with its sharedRandom() class method:

import GameKit

private func randomNumberGenerator() -> Int {
    let random = GKRandomSource.sharedRandom().nextInt(upperBound: numbers.count)
    return numbers[random]
}

randomNumberGenerator()


Also you can use a randomElement() method that returns a random element of a collection:

let randomNumber = numbers.randomElement()!
print(randomNumber)


Or use arc4random_uniform(). Pay attention that this method returns UInt32.

let generator = Int(arc4random_uniform(10))
print(generator)


And, of course, we can use a makeIterator() method that returns an iterator over the elements of the collection.

let iterator: Int = (1...10).makeIterator().shuffled().first!
print(iterator)


The final example you see here returns a random value within the specified range with a help of static func random(in range: ClosedRange<Int>) -> Int.

let randomizer = Int.random(in: 1...10)
print(randomizer)

How do you add PostgreSQL Driver as a dependency in Maven?

Depending on your PostgreSQL version you would need to add the postgresql driver to your pom.xml file.

For PostgreSQL 9.1 this would be:

<project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <name>Your project name.</name>
    <dependencies>
        <dependency>
            <groupId>postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>9.1-901-1.jdbc4</version>
        </dependency>
    </dependencies>
</project>

You can get the code for the dependency (as well as any other dependency) from maven's central repository

If you are using postgresql 9.2+:

<project xmlns="http://maven.apache.org/POM/4.0.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

    <name>Your project name.</name>
    <dependencies>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.1</version>
        </dependency>
    </dependencies>
</project>

You can check the latest versions and dependency snippets from:

Assigning variables with dynamic names in Java

Try this way:

    HashMap<String, Integer> hashMap = new HashMap();

    for (int i=1; i<=3; i++) {
        hashMap.put("n" + i, 5);
    }

How can I inspect element in an Android browser?

Had to debug a site for native Android browser and came here. So I tried weinre on an OS X 10.9 (as weinre server) with Firefox 30.0 (weinre client) and an Android 4.1.2 (target). I'm really, really surprised of the result.

  1. Download and install node runtime from http://nodejs.org/download/
  2. Install weinre: sudo npm -g install weinre
  3. Find out your current IP address at Settings > Network
  4. Setup a weinre server on your machine: weinre --boundHost YOUR.IP.ADDRESS.HERE
  5. In your browser call: http://YOUR.IP.ADRESS.HERE:8080
  6. You'll see a script snippet, place it into your site: <script src="http://YOUR.IP.ADDRESS.HERE:8080/target/target-script-min.js"></script>
  7. Open the debug client in your local browser: http://YOUR.IP.ADDRESS.HERE:8080/client
  8. Finally on your Android: call the site you want to inspect (the one with the script inside) and see how it appears as "Target" in your local browser. Now you can open "Elements" or whatever you want.

Maybe 8080 isn't your default port. Then in step 4 you have to call weinre --httpPort YOURPORT --boundHost YOUR.IP.ADRESS.HERE.

And I don't remember exactly when it was, maybe somewhere after step 5, I had to accept incoming connections prompt, of course.

Happy debugging

P.S. I'm still overwhelmed how good that works. Even elements-highlighting work

Git copy changes from one branch to another

This is 2 step process

  • git checkout BranchB ( destination branch is BranchB, so we need the head on this branch)
  • git merge BranchA (it will merge BranchB with BranchA. Here you have merged code in branch B)

If you want to push your branch code to remote repo then do

  • git push origin master (it will push your BranchB code to remote repo)

Why does Date.parse give incorrect results?

According to http://blog.dygraphs.com/2012/03/javascript-and-dates-what-mess.html the format "yyyy/mm/dd" solves the usual problems. He says: "Stick to "YYYY/MM/DD" for your date strings whenever possible. It's universally supported and unambiguous. With this format, all times are local." I've set tests: http://jsfiddle.net/jlanus/ND2Qg/432/ This format: + avoids the day and month order ambiguity by using y m d ordering and a 4-digit year + avoids the UTC vs. local issue not complying with ISO format by using slashes + danvk, the dygraphs guy, says that this format is good in all browsers.

Javascript how to split newline

Good'ol javascript:

 var m = "Hello World";  
 var k = m.split(' ');  // I have used space, you can use any thing.
 for(i=0;i<k.length;i++)  
    alert(k[i]);  

How to search in an array with preg_match?

In this post I'll provide you with three different methods of doing what you ask for. I actually recommend using the last snippet, since it's easiest to comprehend as well as being quite neat in code.

How do I see what elements in an array that matches my regular expression?

There is a function dedicated for just this purpose, preg_grep. It will take a regular expression as first parameter, and an array as the second.

See the below example:

$haystack = array (
  'say hello',
  'hello stackoverflow',
  'hello world',
  'foo bar bas'
);

$matches  = preg_grep ('/^hello (\w+)/i', $haystack);

print_r ($matches);

output

Array
(
    [1] => hello stackoverflow
    [2] => hello world
)

Documentation


But I just want to get the value of the specified groups. How?

array_reduce with preg_match can solve this issue in clean manner; see the snippet below.

$haystack = array (
  'say hello',
  'hello stackoverflow',
  'hello world',
  'foo bar bas'
);

function _matcher ($m, $str) {
  if (preg_match ('/^hello (\w+)/i', $str, $matches))
    $m[] = $matches[1];

  return $m;
}

// N O T E :
// ------------------------------------------------------------------------------
// you could specify '_matcher' as an anonymous function directly to
// array_reduce though that kind of decreases readability and is therefore
// not recommended, but it is possible.

$matches = array_reduce ($haystack, '_matcher', array ());

print_r ($matches);

output

Array
(
    [0] => stackoverflow
    [1] => world
)

Documentation


Using array_reduce seems tedious, isn't there another way?

Yes, and this one is actually cleaner though it doesn't involve using any pre-existing array_* or preg_* function.

Wrap it in a function if you are going to use this method more than once.

$matches = array ();

foreach ($haystack as $str) 
  if (preg_match ('/^hello (\w+)/i', $str, $m))
    $matches[] = $m[1];

Documentation

JAXB: how to marshall map into <key>value</key>

Seems like this question is kind of duplicate with another one, where I've collect some marshal/unmarshal solutions into one post. You may check it here: Dynamic tag names with JAXB.

In short:

  1. A container class for @xmlAnyElement should be created
  2. An XmlAdapter can be used in pair with @XmlJavaTypeAdapter to convert between the container class and Map<>;

Style jQuery autocomplete in a Bootstrap input field

If you're using jQuery-UI, you must include the jQuery UI CSS package, otherwise the UI components don't know how to be styled.

If you don't like the jQuery UI styles, then you'll have to recreate all the styles it would have otherwise applied.

Here's an example and some possible fixes.

Minimal, Complete, and Verifiable example (i.e. broken)

Here's a demo in Stack Snippets without jquery-ui.css (doesn't work)

_x000D_
_x000D_
$(function() {_x000D_
  var availableTags = [_x000D_
    "ActionScript", "AppleScript", "Asp", "BASIC", "C", "C++",_x000D_
    "Clojure", "COBOL", "ColdFusion", "Erlang", "Fortran",_x000D_
    "Groovy", "Haskell", "Java", "JavaScript", "Lisp", "Perl",_x000D_
    "PHP", "Python", "Ruby", "Scala", "Scheme"_x000D_
  ];_x000D_
  _x000D_
  $(".autocomplete").autocomplete({_x000D_
    source: availableTags_x000D_
  });_x000D_
});
_x000D_
<link href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/css/bootstrap.css" rel="stylesheet"/>_x000D_
_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.2/jquery-ui.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/js/bootstrap.js"></script>_x000D_
_x000D_
<div class="container">_x000D_
_x000D_
  <div class="form-group">_x000D_
    <label>Languages</label>_x000D_
    <input class="form-control autocomplete" placeholder="Enter A" />_x000D_
  </div>_x000D_
  _x000D_
  <div class="form-group">_x000D_
    <label >Another Field</label>_x000D_
    <input class="form-control">_x000D_
  </div>_x000D_
_x000D_
</div>
_x000D_
_x000D_
_x000D_

Fix #1 - jQuery-UI Style

Just include jquery-ui.css and everything should work just fine with the latest supported versions of jquery.

_x000D_
_x000D_
$(function() {_x000D_
  var availableTags = [_x000D_
    "ActionScript", "AppleScript", "Asp", "BASIC", "C", "C++",_x000D_
    "Clojure", "COBOL", "ColdFusion", "Erlang", "Fortran",_x000D_
    "Groovy", "Haskell", "Java", "JavaScript", "Lisp", "Perl",_x000D_
    "PHP", "Python", "Ruby", "Scala", "Scheme"_x000D_
  ];_x000D_
  _x000D_
  $(".autocomplete").autocomplete({_x000D_
    source: availableTags_x000D_
  });_x000D_
});
_x000D_
<link href="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.2/jquery-ui.css" rel="stylesheet"/>_x000D_
<link href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/css/bootstrap.css" rel="stylesheet"/>_x000D_
_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.2/jquery-ui.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/js/bootstrap.js"></script>_x000D_
_x000D_
<div class="container">_x000D_
  <div class="form-group">_x000D_
    <label>Languages</label>_x000D_
    <input class="form-control autocomplete" placeholder="Enter A" />_x000D_
  </div>_x000D_
  _x000D_
  <div class="form-group">_x000D_
    <label >Another Field</label>_x000D_
    <input class="form-control">_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Fix #2 - Bootstrap Theme

There is a project that created a Bootstrap-esque theme for jQuery-UI components called jquery-ui-bootstrap. Just grab the stylesheet from there and you should be all set.

_x000D_
_x000D_
$(function() {_x000D_
  var availableTags = [_x000D_
    "ActionScript", "AppleScript", "Asp", "BASIC", "C", "C++",_x000D_
    "Clojure", "COBOL", "ColdFusion", "Erlang", "Fortran",_x000D_
    "Groovy", "Haskell", "Java", "JavaScript", "Lisp", "Perl",_x000D_
    "PHP", "Python", "Ruby", "Scala", "Scheme"_x000D_
  ];_x000D_
  _x000D_
  $(".autocomplete").autocomplete({_x000D_
    source: availableTags_x000D_
  });_x000D_
});
_x000D_
<link href="https://cdnjs.cloudflare.com/ajax/libs/jquery-ui-bootstrap/0.5pre/css/custom-theme/jquery-ui-1.10.0.custom.css" rel="stylesheet"/>_x000D_
<link href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/css/bootstrap.css" rel="stylesheet"/>_x000D_
_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.2/jquery-ui.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/js/bootstrap.js"></script>_x000D_
_x000D_
<div class="container">_x000D_
  <div class="form-group">_x000D_
    <label>Languages</label>_x000D_
    <input class="form-control autocomplete" placeholder="Enter A" />_x000D_
  </div>_x000D_
  _x000D_
  <div class="form-group">_x000D_
    <label >Another Field</label>_x000D_
    <input class="form-control">_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Fix #3 - Manual CSS

If you only need the AutoComplete widget from jQuery-UI's library, you should start by doing a custom build so you don't pull in resources you're not using.

After that, you'll need to style it yourself. Just look at some of the other styles that are applied to jquery's autocomplete.css and theme.css to figure out what styles you'll need to manually replace.

You can use bootstrap's dropdowns.less for inspiration.

Here's a sample CSS that fits pretty well with Bootstrap's default theme:

.ui-autocomplete {
    position: absolute;
    z-index: 1000;
    cursor: default;
    padding: 0;
    margin-top: 2px;
    list-style: none;
    background-color: #ffffff;
    border: 1px solid #ccc;
    -webkit-border-radius: 5px;
       -moz-border-radius: 5px;
            border-radius: 5px;
    -webkit-box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
       -moz-box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
            box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);
}
.ui-autocomplete > li {
  padding: 3px 20px;
}
.ui-autocomplete > li.ui-state-focus {
  background-color: #DDD;
}
.ui-helper-hidden-accessible {
  display: none;
}

_x000D_
_x000D_
$(function() {_x000D_
  var availableTags = [_x000D_
    "ActionScript", "AppleScript", "Asp", "BASIC", "C", "C++",_x000D_
    "Clojure", "COBOL", "ColdFusion", "Erlang", "Fortran",_x000D_
    "Groovy", "Haskell", "Java", "JavaScript", "Lisp", "Perl",_x000D_
    "PHP", "Python", "Ruby", "Scala", "Scheme"_x000D_
  ];_x000D_
  _x000D_
  $(".autocomplete").autocomplete({_x000D_
    source: availableTags_x000D_
  });_x000D_
});
_x000D_
.ui-autocomplete {_x000D_
    position: absolute;_x000D_
    z-index: 1000;_x000D_
    cursor: default;_x000D_
    padding: 0;_x000D_
    margin-top: 2px;_x000D_
    list-style: none;_x000D_
    background-color: #ffffff;_x000D_
    border: 1px solid #ccc_x000D_
    -webkit-border-radius: 5px;_x000D_
       -moz-border-radius: 5px;_x000D_
            border-radius: 5px;_x000D_
    -webkit-box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);_x000D_
       -moz-box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);_x000D_
            box-shadow: 0 5px 10px rgba(0, 0, 0, 0.2);_x000D_
}_x000D_
.ui-autocomplete > li {_x000D_
  padding: 3px 20px;_x000D_
}_x000D_
.ui-autocomplete > li.ui-state-focus {_x000D_
  background-color: #DDD;_x000D_
}_x000D_
.ui-helper-hidden-accessible {_x000D_
  display: none;_x000D_
}
_x000D_
<link href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/css/bootstrap.css" rel="stylesheet"/>_x000D_
_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.2/jquery-ui.js"></script>_x000D_
<script src="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.2/js/bootstrap.js"></script>_x000D_
_x000D_
<div class="container">_x000D_
  <div class="form-group ui-widget">_x000D_
    <label>Languages</label>_x000D_
    <input class="form-control autocomplete" placeholder="Enter A" />_x000D_
  </div>_x000D_
  _x000D_
  <div class="form-group ui-widget">_x000D_
    <label >Another Field</label>_x000D_
    <input class="form-control" />_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Tip: Since the dropdown menu hides every time you go to inspect the element (i.e. whenever the input loses focus), for easier debugging of the style, find the control with .ui-autocomplete and remove display: none;.

Mockito : doAnswer Vs thenReturn

You should use thenReturn or doReturn when you know the return value at the time you mock a method call. This defined value is returned when you invoke the mocked method.

thenReturn(T value) Sets a return value to be returned when the method is called.

@Test
public void test_return() throws Exception {
    Dummy dummy = mock(Dummy.class);
    int returnValue = 5;

    // choose your preferred way
    when(dummy.stringLength("dummy")).thenReturn(returnValue);
    doReturn(returnValue).when(dummy).stringLength("dummy");
}

Answer is used when you need to do additional actions when a mocked method is invoked, e.g. when you need to compute the return value based on the parameters of this method call.

Use doAnswer() when you want to stub a void method with generic Answer.

Answer specifies an action that is executed and a return value that is returned when you interact with the mock.

@Test
public void test_answer() throws Exception {
    Dummy dummy = mock(Dummy.class);
    Answer<Integer> answer = new Answer<Integer>() {
        public Integer answer(InvocationOnMock invocation) throws Throwable {
            String string = invocation.getArgumentAt(0, String.class);
            return string.length() * 2;
        }
    };

    // choose your preferred way
    when(dummy.stringLength("dummy")).thenAnswer(answer);
    doAnswer(answer).when(dummy).stringLength("dummy");
}

How can I show dots ("...") in a span with hidden overflow?

You can try this:

_x000D_
_x000D_
.classname{_x000D_
    width:250px;_x000D_
    overflow:hidden;_x000D_
    text-overflow:ellipsis;_x000D_
}
_x000D_
_x000D_
_x000D_

What does git rev-parse do?

Just to elaborate on the etymology of the command name rev-parse, Git consistently uses the term rev in plumbing commands as short for "revision" and generally meaning the 40-character SHA1 hash for a commit. The command rev-list for example prints a list of 40-char commit hashes for a branch or whatever.

In this case the name might be expanded to parse-a-commitish-to-a-full-SHA1-hash. While the command has the several ancillary functions mentioned in Tuxdude's answer, its namesake appears to be the use case of transforming a user-friendly reference like a branch name or abbreviated hash into the unambiguous 40-character SHA1 hash most useful for many programming/plumbing purposes.

I know I was thinking it was "reverse-parse" something for quite a while before I figured it out and had the same trouble making sense of the terms "massaging" and "manipulation" :)

Anyway, I find this "parse-to-a-revision" notion a satisfying way to think of it, and a reliable concept for bringing this command to mind when I need that sort of thing. Frequently in scripting Git you take a user-friendly commit reference as user input and generally want to get it resolved to a validated and unambiguous working reference as soon after receiving it as possible. Otherwise input translation and validation tends to proliferate through the script.

MySql Proccesslist filled with "Sleep" Entries leading to "Too many Connections"?

Increasing number of max-connections will not solve the problem.

We were experiencing the same situation on our servers. This is what happens

User open a page/view, that connect to the database, query the database, still query(queries) were not finished and user leave the page or move to some other page. So the connection that was open, will remains open, and keep increasing number of connections, if there are more users connecting with the db and doing something similar.

You can set interactive_timeout MySQL, bydefault it is 28800 (8hours) to 1 hour

SET interactive_timeout=3600

How do I compare two strings in Perl?

The obvious subtext of this question is:

why can't you just use == to check if two strings are the same?

Perl doesn't have distinct data types for text vs. numbers. They are both represented by the type "scalar". Put another way, strings are numbers if you use them as such.

if ( 4 == "4" ) { print "true"; } else { print "false"; }
true

if ( "4" == "4.0" ) { print "true"; } else { print "false"; }
true

print "3"+4
7

Since text and numbers aren't differentiated by the language, we can't simply overload the == operator to do the right thing for both cases. Therefore, Perl provides eq to compare values as text:

if ( "4" eq "4.0" ) { print "true"; } else { print "false"; }
false

if ( "4.0" eq "4.0" ) { print "true"; } else { print "false"; }
true

In short:

  • Perl doesn't have a data-type exclusively for text strings
  • use == or !=, to compare two operands as numbers
  • use eq or ne, to compare two operands as text

There are many other functions and operators that can be used to compare scalar values, but knowing the distinction between these two forms is an important first step.

How to generate a random String in Java

You can also use UUID class from java.util package, which returns random uuid of 32bit characters String.

java.util.UUID.randomUUID().toString()

http://java.sun.com/j2se/1.5.0/docs/api/java/util/UUID.html

javascript pushing element at the beginning of an array

Use .unshift() to add to the beginning of an array.

TheArray.unshift(TheNewObject);

See MDN for doc on unshift() and here for doc on other array methods.

FYI, just like there's .push() and .pop() for the end of the array, there's .shift() and .unshift() for the beginning of the array.

How to convert an integer (time) to HH:MM:SS::00 in SQL Server 2008?

CREATE FUNCTION [dbo].[_ICAN_FN_IntToTime](@Num INT)
  RETURNS NVARCHAR(13)
AS
-------------------------------------------------------------------------------------------------------------------
--INVENTIVE:Keyvan ARYAEE-MOEEN
-------------------------------------------------------------------------------------------------------------------
  BEGIN
    DECLARE @Hour VARCHAR(10)=CAST(@Num/3600 AS  VARCHAR(2))
    DECLARE @Minute VARCHAR(10)=CAST((@Num-@Hour*3600)/60 AS  VARCHAR(2))
    DECLARE @Time VARCHAR(13)=CASE WHEN @Hour<10 THEN '0'+@Hour ELSE @Hour END+':'+CASE WHEN @Minute<10 THEN '0'+@Minute ELSE @Minute END+':00.000'
    RETURN @Time
  END
-------------------------------------------------------------------------------------------------------------------
--SELECT dbo._ICAN_FN_IntToTime(25500)
-------------------------------------------------------------------------------------------------------------------

Ubuntu: Using curl to download an image

For those who don't have nor want to install wget, curl -O (capital "o", not a zero) will do the same thing as wget. E.g. my old netbook doesn't have wget, and is a 2.68 MB install that I don't need.

curl -O https://www.python.org/static/apple-touch-icon-144x144-precomposed.png

HTML Code for text checkbox '?'

Use the Unicode Character

&#10004;   =   ✔


My docker container has no internet

I had the problem on Ubuntu 18.04. However the problem was with the DNS. I was in a corporate network that has its own DNS server and block other DNS servers. This is to block some websites (porn, torrents, ... so on )

To resolve your problem

  1. find your DNS on host machine
  2. use --dns your_dns as suggested by @jobin

    docker run --dns your_dns -it --name cowsay --hostname cowsay debian bash

UIImageView - How to get the file name of the image assigned?

There is no native way to do this; however, you could easily create this behavior yourself.

You can subclass UIImageView and add a new instance variable:

NSString* imageFileName;

Then you could override setImage, first setting imageFileName to the filename of the image you're setting, and then calling [super setImage:imageFileName]. Something like this:

-(void) setImage:(NSString*)fileName
{
   imageFileName = fileName;
   [super setImage:fileName];
}

Just because it can't be done natively doesn't mean it isn't possible :)

Unable to run 'adb root' on a rooted Android phone

I finally found out how to do this! Basically you need to run adb shell first and then while you're in the shell run su, which will switch the shell to run as root!

$: adb shell
$: su

The one problem I still have is that sqlite3 is not installed so the command is not recognized.

How to open a page in a new window or tab from code-behind

Use:

Target= "_blank" property of anchor tag