Programs & Examples On #Braces

The symbols "{" and "}", commonly used in programming languages. Please use this tag only if the specific usage of these symbols is a relevant part of the question.

What is the meaning of curly braces?

A dictionary is something like an array that's accessed by keys (e.g. strings,...) rather than just plain sequential numbers. It contains key/value pairs, you can look up values using a key like using a phone book: key=name, number=value.

For defining such a dictionary, you use this syntax using curly braces, see also: http://wiki.python.org/moin/SimplePrograms

How do I use Apache tomcat 7 built in Host Manager gui?

Host Manager is a web application inside of Tomcat that creates/removes Virtual Hosts within Tomcat.

A Virtual Host allows you to define multiple hostnames on a single server, so you can use the same server to handles requests to, for example, ren.myserver.com and stimpy.myserver.com.

Unfortunately documentation on the GUI side of the Host Manager doesn't appear to exist, but documentation on configuring the virtual hosts manually in context.xml is here:

http://tomcat.apache.org/tomcat-7.0-doc/virtual-hosting-howto.html.

The full explanation of the Host parameters you can find here:

http://tomcat.apache.org/tomcat-7.0-doc/config/host.html.

Adding a virtual host

Once you have access to the host-manager (see other answers on setting up the permissions, the GUI will let you add a (temporary - see edit at the end of this post) virtual host.

Tomcat Host Manager - Add Virtual Host Panel

At a minimum you need the Name and App Base fields defined. Tomcat will then create the following directories:

{CATALINA_HOME}\conf\Catalina\{Name}
{CATALINA_HOME}\{App Base}
  • App Base will be where web applications will be deployed to the virtual host. Can be relative or absolute.
  • Name is usually the fully-qualified domain name (e.g. ren.myserver.com)
  • Alias can be used to extend the Name also where two addresses should resolve to the same host (e.g. www.ren.myserver.com). Note that this needs to be reflected in DNS records.

The checkboxes are as follows:

  • Auto Deploy: Automatically redeploy applications placed into App Base. Dangerous for Production environments!
  • Deploy On Startup: Automatically boot up applications under App Base when Tomcat starts
  • Deploy XML: Determines whether to parse the application's /META-INF/context.xml
  • Unpack WARs: Unpack WAR files placed or uploaded to the App Base, as opposed to running them directly from the WAR.
  • Tomcat 8 Copy XML: Copy an application's META-INF/context.xml to the App Base/XML Base on deployment, and use that exclusively, regardless of whether the application is updated. Irrelevant if Deploy XML is false.
  • Manager App: Add the manager application to the Virtual Host (Useful for controlling the applications you might have underneath ren.myserver.com)

Update: After playing around with this same process on Tomcat8, the behaviour I'm seeing is that adding a virtual host via the GUI isn't persistent - it doesn't get written to server.xml, even on shutdown. Therefore (unless I'm doing something terribly wrong), you can create it in the GUI, but you'll need to edit server.xml anyway, as per the first link above, to make it stick.

Not equal to != and !== in PHP

!== should match the value and data type

!= just match the value ignoring the data type

$num = '1';
$num2 = 1;

$num == $num2; // returns true    
$num === $num2; // returns false because $num is a string and $num2 is an integer

Clone only one branch

--single-branch” switch is your answer, but it only works if you have git version 1.8.X onwards, first check

#git --version 

If you already have git version 1.8.X installed then simply use "-b branch and --single branch" to clone a single branch

#git clone -b branch --single-branch git://github/repository.git

By default in Ubuntu 12.04/12.10/13.10 and Debian 7 the default git installation is for version 1.7.x only, where --single-branch is an unknown switch. In that case you need to install newer git first from a non-default ppa as below.

sudo add-apt-repository ppa:pdoes/ppa
sudo apt-get update
sudo apt-get install git
git --version

Once 1.8.X is installed now simply do:

git clone -b branch --single-branch git://github/repository.git

Git will now only download a single branch from the server.

Failed to find Build Tools revision 23.0.1

Two solutions: You have to instal the required buildToolVersion or set it as described above.
Notice that if you are trying to set the buildToolsVersion "23.0.3" using Android Studio 3.0 or more it won't work until you remove all builversion you have keeping just one last version you use. I read this somewhere else and this works for me. Hope this helps.

Correct way of getting Client's IP Addresses from http.Request

In PHP there are a lot of variables that I should check. Is it the same on Go?

This has nothing to do with Go (or PHP for that matter). It just depends on what the client, proxy, load-balancer, or server is sending. Get the one you need depending on your environment.

http.Request.RemoteAddr contains the remote IP address. It may or may not be your actual client.

And is the request case sensitive? for example x-forwarded-for is the same as X-Forwarded-For and X-FORWARDED-FOR? (from req.Header.Get("X-FORWARDED-FOR"))

No, why not try it yourself? http://play.golang.org/p/YMf_UBvDsH

Is it possible to use JS to open an HTML select to show its option list?

Unfortunately there's a simple answer to this question, and it's "No"

Spark: subtract two DataFrames

For me , df1.subtract(df2) was inconsistent. Worked correctly on one dataframe but not on the other . That was because of duplicates . df1.exceptAll(df2) returns a new dataframe with the records from df1 that do not exist in df2 , including any duplicates.

SQL not a single-group group function

Well the problem simply-put is that the SUM(TIME) for a specific SSN on your query is a single value, so it's objecting to MAX as it makes no sense (The maximum of a single value is meaningless).

Not sure what SQL database server you're using but I suspect you want a query more like this (Written with a MSSQL background - may need some translating to the sql server you're using):

SELECT TOP 1 SSN, SUM(TIME)
FROM downloads
GROUP BY SSN
ORDER BY 2 DESC

This will give you the SSN with the highest total time and the total time for it.

Edit - If you have multiple with an equal time and want them all you would use:

SELECT
SSN, SUM(TIME)
FROM downloads
GROUP BY SSN
HAVING SUM(TIME)=(SELECT MAX(SUM(TIME)) FROM downloads GROUP BY SSN))

Verify if file exists or not in C#

Simple answer is that you can't - you won't be able to check a for a file on their machine from an ASP website, as to do so would be a dangerous risk for them.

You have to give them a file upload control - and there's not much you can do with that control. For security reasons javascript can't really touch it.

<asp:FileUpload ID="FileUpload1" runat="server" />

They then pick a file to upload, and you have to deal with any empty file that they might send up server side.

Deep-Learning Nan loss reasons

Regularization can help. For a classifier, there is a good case for activity regularization, whether it is binary or a multi-class classifier. For a regressor, kernel regularization might be more appropriate.

How to describe table in SQL Server 2008?

I like the answer that attempts to do the translate, however, while using the code it doesn't like columns that are not VARCHAR type such as BIGINT or DATETIME. I needed something similar today so I took the time to modify it more to my liking. It is also now encapsulated in a function which is the closest thing I could find to just typing describe as oracle handles it. I may still be missing a few data types in my case statement but this works for everything I tried it on. It also orders by ordinal position. this could be expanded on to include primary key columns easily as well.

CREATE FUNCTION dbo.describe (@TABLENAME varchar(50))
returns table
as
RETURN
(
SELECT TOP 1000 column_name AS [ColumnName],
       IS_NULLABLE AS [IsNullable],
       DATA_TYPE + '(' + CASE 
                                    WHEN DATA_TYPE = 'varchar' or DATA_TYPE = 'char' THEN 
                                      CASE 
                                        WHEN Cast(CHARACTER_MAXIMUM_LENGTH AS VARCHAR(5)) = -1 THEN 'Max'
                                        ELSE Cast(CHARACTER_MAXIMUM_LENGTH AS VARCHAR(5))
                                      END
                                    WHEN DATA_TYPE = 'decimal' or DATA_TYPE = 'numeric' THEN
                                      Cast(NUMERIC_PRECISION AS VARCHAR(5))+', '+Cast(NUMERIC_SCALE AS VARCHAR(5))
                                    WHEN DATA_TYPE = 'bigint' or DATA_TYPE = 'int' THEN
                                      Cast(NUMERIC_PRECISION AS VARCHAR(5))
                                    ELSE ''
                                  END + ')' AS [DataType]
FROM   INFORMATION_SCHEMA.Columns
WHERE  table_name = @TABLENAME
order by ordinal_Position
);
GO

once you create the function here is a sample table that I used

create table dbo.yourtable
(columna bigint,
 columnb int,
 columnc datetime,
 columnd varchar(100),
 columne char(10),
 columnf bit,
 columng numeric(10,2),
 columnh decimal(10,2)
 )

Then you can execute it as follows

select * from describe ('yourtable')

It returns the following

ColumnName IsNullable DataType


columna NO bigint(19)
columnb NO int(10)
columnc NO datetime()
columnd NO varchar(100)
columne NO char(10)
columnf NO bit()
columng NO numeric(10, 2)
columnh NO decimal(10, 2)

hope this helps someone.

setting multiple column using one update

UPDATE some_table 
   SET this_column=x, that_column=y 
   WHERE something LIKE 'them'

ActiveModel::ForbiddenAttributesError when creating new user

Alternatively you can use the Protected Attributes gem, however this defeats the purpose of requiring strong params. However if you're upgrading an older app, Protected Attributes does provide an easy pathway to upgrade until such time that you can refactor the attr_accessible to strong params.

Run Python script at startup in Ubuntu

Create file ~/.config/autostart/MyScript.desktop with

[Desktop Entry]
Encoding=UTF-8
Name=MyScript
Comment=MyScript
Icon=gnome-info
Exec=python /home/your_path/script.py
Terminal=false
Type=Application
Categories=

X-GNOME-Autostart-enabled=true
X-GNOME-Autostart-Delay=0

It helps me!

Trim spaces from start and end of string

Note: As of 2015, all major browsers (including IE>=9) support String.prototype.trim(). This means that for most use cases simply doing str.trim() is the best way of achieving what the question asks.


Steven Levithan analyzed many different implementation of trim in Javascript in terms of performance.

His recommendation is:

function trim1 (str) {
    return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '');
}

for "general-purpose implementation which is fast cross-browser", and

function trim11 (str) {
    str = str.replace(/^\s+/, '');
    for (var i = str.length - 1; i >= 0; i--) {
        if (/\S/.test(str.charAt(i))) {
            str = str.substring(0, i + 1);
            break;
        }
    }
    return str;
}

"if you want to handle long strings exceptionally fast in all browsers".

References

HTML table: keep the same width for columns

well, why don't you (get rid of sidebar and) squeeze the table so it is without show/hide effect? It looks odd to me now. The table is too robust.
Otherwise I think scunliffe's suggestion should do it. Or if you wish, you can just set the exact width of table and set either percentage or pixel width for table cells.

How to grey out a button?

Set Clickable as false and change the backgroung color as:

callButton.setClickable(false);
callButton.setBackgroundColor(Color.parseColor("#808080"));

HTML Input Type Date, Open Calendar by default

This is not possible with native HTML input elements. You can use webshim polyfill, which gives you this option by using this markup.

<input type="date" data-date-inline-picker="true" />

Here is a small demo

How can I add a new column and data to a datatable that already contains data?

Only you want to set default value parameter. This calling third overloading method.

dt.Columns.Add("MyRow", type(System.Int32),0);

sed: print only matching group

The cut command is designed for this exact situation. It will "cut" on any delimiter and then you can specify which chunks should be output.

For instance: echo "foo bar <foo> bla 1 2 3.4" | cut -d " " -f 6-7

Will result in output of: 2 3.4

-d sets the delimiter

-f selects the range of 'fields' to output, in this case, it's the 6th through 7th chunks of the original string. You can also specify the range as a list, such as 6,7.

Remove duplicate elements from array in Ruby

You can remove the duplicate elements with the uniq method:

array.uniq  # => [1, 2, 4, 5, 6, 7, 8]

What might also be useful to know is that uniq takes a block, so if you have a have an array of keys:

["bucket1:file1", "bucket2:file1", "bucket3:file2", "bucket4:file2"]

and you want to know what the unique files are, you can find it out with:

a.uniq { |f| f[/\d+$/] }.map { |p| p.split(':').last }

How to pass data from Javascript to PHP and vice versa?

the other way to exchange data from php to javascript or vice versa is by using cookies, you can save cookies in php and read by your javascript, for this you don't have to use forms or ajax

How do I create a new Git branch from an old commit?

git checkout -b NEW_BRANCH_NAME COMMIT_ID

This will create a new branch called 'NEW_BRANCH_NAME' and check it out.

("check out" means "to switch to the branch")

git branch NEW_BRANCH_NAME COMMIT_ID

This just creates the new branch without checking it out.


in the comments many people seem to prefer doing this in two steps. here's how to do so in two steps:

git checkout COMMIT_ID
# you are now in the "detached head" state
git checkout -b NEW_BRANCH_NAME

How to set Spring profile from system variable?

I normally configure the applicationContext using Annotation based configuration rather than XML based configuration. Anyway, I believe both of them have the same priority.

*Answering your question, system variable has higher priority *


Getting profile based beans from applicationContext

  • Use @Profile on a Bean

@Component
@Profile("dev")
public class DatasourceConfigForDev

Now, the profile is dev

Note : if the Profile is given as @Profile("!dev") then the profile will exclude dev and be for all others.

  • Use profiles attribute in XML

<beans profile="dev">
    <bean id="DatasourceConfigForDev" class="org.skoolguy.profiles.DatasourceConfigForDev"/>
</beans>

Set the value for profile:

  • Programmatically via WebApplicationInitializer interface

    In web applications, WebApplicationInitializer can be used to configure the ServletContext programmatically
@Configuration
public class MyWebApplicationInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
            servletContext.setInitParameter("spring.profiles.active", "dev");
    }
}
  • Programmatically via ConfigurableEnvironment

    You can also set profiles directly on the environment:
    @Autowired
    private ConfigurableEnvironment env;

    // ...

    env.setActiveProfiles("dev");
  • Context Parameter in web.xml

    profiles can be activated in the web.xml of the web application as well, using a context parameter:
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/app-config.xml</param-value>
    </context-param>
    <context-param>
        <param-name>spring.profiles.active</param-name>
        <param-value>dev</param-value>
    </context-param>
  • JVM System Parameter

    The profile names passed as the parameter will be activated during application start-up:

    -Dspring.profiles.active=dev
    

    In IDEs, you can set the environment variables and values to use when an application runs. The following is the Run Configuration in Eclipse:

Eclipse Run Configuration - screenshot is unavailable

  • Environment Variable

    to set via command line : export spring_profiles_active=dev

Any bean that does not specify a profile belongs to “default” profile.


The priority order is :

  1. Context parameter in web.xml
  2. WebApplicationInitializer
  3. JVM System parameter
  4. Environment variable

Add a space (" ") after an element using :after

I needed this instead of using padding because I used inline-block containers to display a series of individual events in a workflow timeline. The last event in the timeline needed no arrow after it.

Ended up with something like:

.transaction-tile:after {
  content: "\f105";
}

.transaction-tile:last-child:after {
  content: "\00a0";
}

Used fontawesome for the gt (chevron) character. For whatever reason "content: none;" was producing alignment issues on the last tile.

Capture the screen shot using .NET

It's certainly possible to grab a screenshot using the .NET Framework. The simplest way is to create a new Bitmap object and draw into that using the Graphics.CopyFromScreen method.

Sample code:

using (Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width, 
                                            Screen.PrimaryScreen.Bounds.Height))
using (Graphics g = Graphics.FromImage(bmpScreenCapture))
{
    g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                     Screen.PrimaryScreen.Bounds.Y,
                     0, 0,
                     bmpScreenCapture.Size,
                     CopyPixelOperation.SourceCopy);
}

Caveat: This method doesn't work properly for layered windows. Hans Passant's answer here explains the more complicated method required to get those in your screen shots.

How to remove list elements in a for loop in Python?

How about creating a new list and adding elements you want to that new list. You cannot remove elements while iterating through a list

MINGW64 "make build" error: "bash: make: command not found"

You have to install mingw-get and after that you can run mingw-get install msys-make to have the command make available.

Here is a link for what you want http://www.mingw.org/wiki/getting_started

jQuery.inArray(), how to use it right?

inArray returns the index of the element in the array. If the element was not found, -1 will be returned else index of element.

if(jQuery.inArray("element", myarray) === -1) {
    console.log("Not exists in array");
} else {
    console.log("Exists in array");
}

Compile c++14-code with g++

Follow the instructions at https://gist.github.com/application2000/73fd6f4bf1be6600a2cf9f56315a2d91 to set up the gcc version you need - gcc 5 or gcc 6 - on Ubuntu 14.04. The instructions include configuring update-alternatives to allow you to switch between versions as you need to.

Plot multiple lines in one graph

Instead of using the outrageously convoluted data structures required by ggplot2, you can use the native R functions:

tab<-read.delim(text="
Company 2011 2013
Company1 300 350
Company2 320 430
Company3 310 420
",as.is=TRUE,sep=" ",row.names=1)

tab<-t(tab)

plot(tab[,1],type="b",ylim=c(min(tab),max(tab)),col="red",lty=1,ylab="Value",lwd=2,xlab="Year",xaxt="n")
lines(tab[,2],type="b",col="black",lty=2,lwd=2)
lines(tab[,3],type="b",col="blue",lty=3,lwd=2)
grid()
legend("topleft",legend=colnames(tab),lty=c(1,2,3),col=c("red","black","blue"),bg="white",lwd=2)
axis(1,at=c(1:nrow(tab)),labels=rownames(tab))

R multiple lines plot

Sorting a list using Lambda/Linq to objects

If you get sort column name and sort direction as string and don't want to use switch or if\else syntax to determine column, then this example may be interesting for you:

private readonly Dictionary<string, Expression<Func<IuInternetUsers, object>>> _sortColumns = 
        new Dictionary<string, Expression<Func<IuInternetUsers, object>>>()
    {
        { nameof(ContactSearchItem.Id),             c => c.Id },
        { nameof(ContactSearchItem.FirstName),      c => c.FirstName },
        { nameof(ContactSearchItem.LastName),       c => c.LastName },
        { nameof(ContactSearchItem.Organization),   c => c.Company.Company },
        { nameof(ContactSearchItem.CustomerCode),   c => c.Company.Code },
        { nameof(ContactSearchItem.Country),        c => c.CountryNavigation.Code },
        { nameof(ContactSearchItem.City),           c => c.City },
        { nameof(ContactSearchItem.ModifiedDate),   c => c.ModifiedDate },
    };

    private IQueryable<IuInternetUsers> SetUpSort(IQueryable<IuInternetUsers> contacts, string sort, string sortDir)
    {
        if (string.IsNullOrEmpty(sort))
        {
            sort = nameof(ContactSearchItem.Id);
        }

        _sortColumns.TryGetValue(sort, out var sortColumn);
        if (sortColumn == null)
        {
            sortColumn = c => c.Id;
        }

        if (string.IsNullOrEmpty(sortDir) || sortDir == SortDirections.AscendingSort)
        {
            contacts = contacts.OrderBy(sortColumn);
        }
        else
        {
            contacts = contacts.OrderByDescending(sortColumn);
        }

        return contacts;
    }

Solution based on using Dictionary that connects needed for sort column via Expression> and its key string.

org.hibernate.exception.SQLGrammarException: could not insert [com.sample.Person]

The problem in my case was that the database name was incorrect.
I solved the problem by referring the correct database name in the field as below

<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/myDatabase</property>

Apache2: 'AH01630: client denied by server configuration'

If you have https host then don't forget to make Require all granted changes for ssl config too.

Also, sometimes it's useful to check permissions as the apache user:

# ps -eFH | grep http # get the username used by httpd
...
apache   18837  2692  0 119996 9328   9 10:33 ?        00:00:00     /usr/sbin/httpd -DFOREGROUND
# su -s/bin/bash apache # switch to that user
bash-4.2$ whoami
apache
bash-4.2$ cd /home
bash-4.2$ ls
bash-4.2$ cd mysite.com
bash-4.2$ ls
bash-4.2$ cat file-which-does-not-work.txt

How to find nth occurrence of character in a string?

If your project already depends on Apache Commons you can use StringUtils.ordinalIndexOf, otherwise, here's an implementation:

public static int ordinalIndexOf(String str, String substr, int n) {
    int pos = str.indexOf(substr);
    while (--n > 0 && pos != -1)
        pos = str.indexOf(substr, pos + 1);
    return pos;
}

This post has been rewritten as an article here.

What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in it)

If it is a maven project

  1. right click on the pom.xml
  2. Add As Maven Project

Thanks

CSS3 selector to find the 2nd div of the same class

My original answer regarding :nth-of-type is simply wrong. Thanks to Paul for pointing this out.

The word "type" there refers only to the "element type" (like div). It turns out that the selectors div.bar:nth-of-type(2) and div:nth-of-type(2).bar mean the same thing. Both select elements that [a] are the second div of their parent, and [b] have class bar.

So the only pure CSS solution left that I'm aware of, if you want to select all elements of a certain selector except the first, is the general sibling selector:

.bar ~ .bar

http://www.w3schools.com/cssref/sel_gen_sibling.asp


My original (wrong) answer follows:

With the arrival of CSS3, there is another option. It may not have been available when the question was first asked:

.bar:nth-of-type(2)

http://www.w3schools.com/cssref/sel_nth-of-type.asp

This selects the second element that satisfies the .bar selector.

If you want the second and last of a specific kind of element (or all of them except the first), the general sibling selector would also work fine:

.bar ~ .bar

http://www.w3schools.com/cssref/sel_gen_sibling.asp

It's shorter. But of course, we don't like to duplicate code, right? :-)

Can I set subject/content of email using mailto:?

here is the trick http://neworganizing.com/content/blog/tip-prepopulate-mailto-links-with-subject-body-text

<a href="mailto:[email protected]?subject=Your+tip+on+mailto+links&body=Thanks+for+this+tip">tell a friend</a>

How to set the max value and min value of <input> in html5 by javascript or jquery?

jQuery makes it easy to set any attributes for an element - just use the .attr() method:

$(document).ready(function() {
    $("input").attr({
       "max" : 10,        // substitute your own
       "min" : 2          // values (or variables) here
    });
});

The document ready handler is not required if your script block appears after the element(s) you want to manipulate.

Using a selector of "input" will set the attributes for all inputs though, so really you should have some way to identify the input in question. If you gave it an id you could say:

$("#idHere").attr(...

...or with a class:

$(".classHere").attr(...

How to start Fragment from an Activity

You Can Start Activity and attach RecipientsFragment on it , but you cant start Fragment

How to update TypeScript to latest version with npm?

Open command prompt (cmd.exe/git bash)

Recommended:

npm install -g typescript@latest

or

yarn global add typescript@latest  // if you use yarn package manager

This will install the latest typescript version if not already installed, otherwise it will update the current installation to the latest version.

And then verify which version is installed:

tsc -v

enter image description here


If you have typescript already installed you could also use the following command to update to latest version, but as commentators have reported and I confirm it that the following command does not update to latest (as of now [ Feb 10 '17])!

npm update -g typescript@latest

Spring Boot REST API - request timeout?

if you are using RestTemplate than you should use following code to implement timeouts

@Bean
public RestTemplate restTemplate() {
    return new RestTemplate(clientHttpRequestFactory());
}

private ClientHttpRequestFactory clientHttpRequestFactory() {
    HttpComponentsClientHttpRequestFactory factory = new HttpComponentsClientHttpRequestFactory();
    factory.setReadTimeout(2000);
    factory.setConnectTimeout(2000);
    return factory;
}}

The xml configuration

<bean class="org.springframework.web.client.RestTemplate">
<constructor-arg>
    <bean class="org.springframework.http.client.HttpComponentsClientHttpRequestFactory"
        p:readTimeout="2000"
        p:connectTimeout="2000" />
</constructor-arg>

RegEx to exclude a specific string constant

This isn't easy, unless your regexp engine has special support for it. The easiest way would be to use a negative-match option, for example:

$var !~ /^foo$/
    or die "too much foo";

If not, you have to do something evil:

$var =~ /^(($)|([^f].*)|(f[^o].*)|(fo[^o].*)|(foo.+))$/
    or die "too much foo";

That one basically says "if it starts with non-f, the rest can be anything; if it starts with f, non-o, the rest can be anything; otherwise, if it starts fo, the next character had better not be another o".

Comprehensive methods of viewing memory usage on Solaris

Here are the basics. I'm not sure that any of these count as "clear and simple" though.

ps(1)

For process-level view:

$ ps -opid,vsz,rss,osz,args
  PID  VSZ  RSS   SZ COMMAND
 1831 1776 1008  222 ps -opid,vsz,rss,osz,args
 1782 3464 2504  433 -bash
$

vsz/VSZ: total virtual process size (kb)

rss/RSS: resident set size (kb, may be inaccurate(!), see man)

osz/SZ: total size in memory (pages)

To compute byte size from pages:

$ sz_pages=$(ps -o osz -p $pid | grep -v SZ )
$ sz_bytes=$(( $sz_pages * $(pagesize) ))
$ sz_mbytes=$(( $sz_bytes / ( 1024 * 1024 ) ))
$ echo "$pid OSZ=$sz_mbytes MB"

vmstat(1M)

$ vmstat 5 5 
 kthr      memory            page            disk          faults      cpu
 r b w   swap  free  re  mf pi po fr de sr rm s3 -- --   in   sy   cs us sy id
 0 0 0 535832 219880  1   2  0  0  0  0  0 -0  0  0  0  402   19   97  0  1 99
 0 0 0 514376 203648  1   4  0  0  0  0  0  0  0  0  0  402   19   96  0  1 99
^C

prstat(1M)

   PID USERNAME  SIZE   RSS STATE  PRI NICE      TIME  CPU PROCESS/NLWP       
  1852 martin   4840K 3600K cpu0    59    0   0:00:00 0.3% prstat/1
  1780 martin   9384K 2920K sleep   59    0   0:00:00 0.0% sshd/1
  ...

swap(1)

"Long listing" and "summary" modes:

$ swap -l
swapfile             dev  swaplo blocks   free
/dev/zvol/dsk/rpool/swap 256,1      16 1048560 1048560
$ swap -s 
total: 42352k bytes allocated + 20192k reserved = 62544k used, 607672k available
$

top(1)

An older version (3.51) is available on the Solaris companion CD from Sun, with the disclaimer that this is "Community (not Sun) supported". More recent binary packages available from sunfreeware.com or blastwave.org.

load averages:  0.02,  0.00,  0.00;                      up 2+12:31:38                                                                                            08:53:58
31 processes: 30 sleeping, 1 on cpu
CPU states: 98.0% idle,  0.0% user,  2.0% kernel,  0.0% iowait,  0.0% swap
Memory: 1024M phys mem, 197M free mem, 512M total swap, 512M free swap

   PID USERNAME LWP PRI NICE  SIZE   RES STATE    TIME    CPU COMMAND
  1898 martin     1  54    0 3336K 1808K cpu      0:00  0.96% top
     7 root      11  59    0   10M 7912K sleep    0:09  0.02% svc.startd

sar(1M)

And just what's wrong with sar? :)

Add new field to every document in a MongoDB collection

Since MongoDB version 3.2 you can use updateMany():

> db.yourCollection.updateMany({}, {$set:{"someField": "someValue"}})

How to trim white spaces of array values in php

array_walk() can be used with trim() to trim array

<?php
function trim_value(&$value) 
{ 
    $value = trim($value); 
}

$fruit = array('apple','banana ', ' cranberry ');
var_dump($fruit);

array_walk($fruit, 'trim_value');
var_dump($fruit);

?>

See 2nd example at http://www.php.net/manual/en/function.trim.php

Powershell get ipv4 address into a variable

I recently had the same issue. So I wrote a script to parse it from the ipconfig /all output. This script is easily modifiable to obtain any of the parameters of the interfaces and it works on Windows 7 also.

  1. Get output of IP config in LineNumber | Line format

$ip_config = $(ipconfig /all | % {$_ -split "rn"} | Select-String -Pattern ".*" | select LineNumber, Line)

  1. Get list of interfaces (+ last line of ipconfig output) in LineNumber | Line format

$interfaces = $($ip_config | where {$_.Line -notmatch '^\s*$'} | where {$_.Line -notmatch '^\s'}) + $($ip_config | Select -last 1)

  1. Filter through the interfaces list for the specific interface you want

$LAN = $($interfaces | where {$_.Line -match 'Wireless Network Connection:$'})

  1. Get the start and end line numbers of chosen interface from output

$i = $interfaces.IndexOf($LAN)
$start = $LAN.LineNumber
$end = $interfaces[$i+1].LineNumber

  1. Pick the lines from start..end

$LAN = $ip_config | where {$_.LineNumber -in ($start..$end)}

  1. Get IP(v4) address field (returns null if no IPv4 address present)

$LAN_IP = @($LAN | where {$_ -match 'IPv4.+:\s(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})'})
$LAN_IP = &{If ($LAN_IP.Count -gt 0) {$Matches[1]} Else {$null}}

Execute curl command within a Python script

If you are not tweaking the curl command too much you can also go and call the curl command directly

import shlex
cmd = '''curl -X POST -d  '{"nw_src": "10.0.0.1/32", "nw_dst": "10.0.0.2/32", "nw_proto": "ICMP", "actions": "ALLOW", "priority": "10"}' http://localhost:8080/firewall/rules/0000000000000001'''
args = shlex.split(cmd)
process = subprocess.Popen(args, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
stdout, stderr = process.communicate()

How to install an APK file on an Android phone?

For debugging:

  • Enable USB debugging on your phone (settings -> applications -> development).
  • Connect your phone to the computer, and make sure you have the correct drivers installed.
  • In Eclipse, run your project as an Android application (right click project -> run as -> Android application).

Installing the APK file:

  • Export the APK file, make sure you sign it (right click project -> Android tools -> export signed application package).
  • Connect your phone, USB debugging enabled.
  • from the terminal, use ADB to install the APK file (adb install path-to-your-apk-file.apk).

Testing web application on Mac/Safari when I don't own a Mac

https://turbo.net/ offers a browser sandbox in which containerised virtual machines run browser sessions for you. I tried it with Safari on my Windows development machine and it seems to work very well.

Smooth scroll without the use of jQuery

I recently set out to solve this problem in a situation where jQuery wasn't an option, so I'm logging my solution here just for posterity.

var scroll = (function() {

    var elementPosition = function(a) {
        return function() {
            return a.getBoundingClientRect().top;
        };
    };

    var scrolling = function( elementID ) {

        var el = document.getElementById( elementID ),
            elPos = elementPosition( el ),
            duration = 400,
            increment = Math.round( Math.abs( elPos() )/40 ),
            time = Math.round( duration/increment ),
            prev = 0,
            E;

        function scroller() {
            E = elPos();

            if (E === prev) {
                return;
            } else {
                prev = E;
            }

            increment = (E > -20 && E < 20) ? ((E > - 5 && E < 5) ? 1 : 5) : increment;

            if (E > 1 || E < -1) {

                if (E < 0) {
                    window.scrollBy( 0,-increment );
                } else {
                    window.scrollBy( 0,increment );
                }

                setTimeout(scroller, time);

            } else {

                el.scrollTo( 0,0 );

            }
        }

        scroller();
    };

    return {
        To: scrolling
    }

})();

/* usage */
scroll.To('elementID');

The scroll() function uses the Revealing Module Pattern to pass the target element's id to its scrolling() function, via scroll.To('id'), which sets the values used by the scroller() function.

Breakdown

In scrolling():

  • el : the target DOM object
  • elPos : returns a function via elememtPosition() which gives the position of the target element relative to the top of the page each time it's called.
  • duration : transition time in milliseconds.
  • increment : divides the starting position of the target element into 40 steps.
  • time : sets the timing of each step.
  • prev : the target element's previous position in scroller().
  • E : holds the target element's position in scroller().

The actual work is done by the scroller() function which continues to call itself (via setTimeout()) until the target element is at the top of the page or the page can scroll no more.

Each time scroller() is called it checks the current position of the target element (held in variable E) and if that is > 1 OR < -1 and if the page is still scrollable shifts the window by increment pixels - up or down depending if E is a positive or negative value. When E is neither > 1 OR < -1, or E === prev the function stops. I added the DOMElement.scrollTo() method on completion just to make sure the target element was bang on the top of the window (not that you'd notice it being out by a fraction of a pixel!).

The if statement on line 2 of scroller() checks to see if the page is scrolling (in cases where the target might be towards the bottom of the page and the page can scroll no further) by checking E against its previous position (prev).

The ternary condition below it reduce the increment value as E approaches zero. This stops the page overshooting one way and then bouncing back to overshoot the other, and then bouncing back to overshoot the other again, ping-pong style, to infinity and beyond.

If your page is more that c.4000px high you might want to increase the values in the ternary expression's first condition (here at +/-20) and/or the divisor which sets the increment value (here at 40).

Playing about with duration, the divisor which sets increment, and the values in the ternary condition of scroller() should allow you to tailor the function to suit your page.

  • JSFiddle

  • N.B.Tested in up-to-date versions of Firefox and Chrome on Lubuntu, and Firefox, Chrome and IE on Windows8.

Remove git mapping in Visual Studio 2015

The above answer did not work for me. The registry entries would just be automatically re-added when I opened the solution in Visual Studio. I found the resolution in one of the links in Matthews answer though so credit still goes to him for the correct answer.

Remove Git binding from Visual Studio 2013 solution?

Remove the hidden .git folder in your solutionfolder.

I also removed the .gitattributes and .gitignore files just to keep my folder clean.

Undoing accidental git stash pop

From git stash --help

Recovering stashes that were cleared/dropped erroneously
   If you mistakenly drop or clear stashes, they cannot be recovered through the normal safety mechanisms. However, you can try the
   following incantation to get a list of stashes that are still in your repository, but not reachable any more:

       git fsck --unreachable |
       grep commit | cut -d\  -f3 |
       xargs git log --merges --no-walk --grep=WIP

This helped me better than the accepted answer with the same scenario.

Nodejs - Redirect url

Use the following code this works fine in Native Nodejs

http.createServer(function (req, res) {
var q = url.parse(req.url, true);
if (q.pathname === '/') {
  //Home page code
} else if (q.pathname === '/redirect-to-google') {
  res.writeHead(301, { "Location": "http://google.com/" });
  return res.end();
} else if (q.pathname === '/redirect-to-interal-page') {
  res.writeHead(301, { "Location": "/path/within/site" });
  return res.end();
} else {
    //404 page code
}
res.end();
}).listen(8080);

Finding even or odd ID values

dividend % divisor

Dividend is the numeric expression to divide. Dividend must be any expression of integer data type in sql server.

Divisor is the numeric expression to divide the dividend. Divisor must be expression of integer data type except in sql server.

SELECT 15 % 2

Output
1

Dividend = 15

Divisor = 2

Let's say you wanted to query

Query a list of CITY names from STATION with even ID numbers only.

Schema structure for STATION:

ID Number

CITY varchar

STATE varchar


select CITY from STATION as st where st.id % 2 = 0

Will fetch the even set of records 


In order to fetch the odd records with Id as odd number.

select CITY from STATION as st where st.id % 2 <> 0

% function reduces the value to either 0 or 1

How can I cast int to enum?

Just cast it:

MyEnum e = (MyEnum)3;

You can check if it's in range using Enum.IsDefined:

if (Enum.IsDefined(typeof(MyEnum), 3)) { ... }

Get keys from HashMap in Java

Try this simple program:

public class HashMapGetKey {

public static void main(String args[]) {

      // create hash map

       HashMap map = new HashMap();

      // populate hash map

      map.put(1, "one");
      map.put(2, "two");
      map.put(3, "three");
      map.put(4, "four");

      // get keyset value from map

Set keyset=map.keySet();

      // check key set values

      System.out.println("Key set values are: " + keyset);
   }    
}

How to find current transaction level?

SELECT CASE  
          WHEN transaction_isolation_level = 1 
             THEN 'READ UNCOMMITTED' 
          WHEN transaction_isolation_level = 2 
               AND is_read_committed_snapshot_on = 1 
             THEN 'READ COMMITTED SNAPSHOT' 
          WHEN transaction_isolation_level = 2 
               AND is_read_committed_snapshot_on = 0 THEN 'READ COMMITTED' 
          WHEN transaction_isolation_level = 3 
             THEN 'REPEATABLE READ' 
          WHEN transaction_isolation_level = 4 
             THEN 'SERIALIZABLE' 
          WHEN transaction_isolation_level = 5 
             THEN 'SNAPSHOT' 
          ELSE NULL
       END AS TRANSACTION_ISOLATION_LEVEL 
FROM   sys.dm_exec_sessions AS s
       CROSS JOIN sys.databases AS d
WHERE  session_id = @@SPID
  AND  d.database_id = DB_ID();

Git:nothing added to commit but untracked files present

If you have already tried using the git add . command to add all your untracked files, make sure you're not under a subfolder of your root project.

git add . will stage all your files under the current subfolder.

Using $state methods with $stateChangeStart toState and fromState in Angular ui-router

Suggestion 1

When you add an object to $stateProvider.state that object is then passed with the state. So you can add additional properties which you can read later on when needed.

Example route configuration

$stateProvider
.state('public', {
    abstract: true,
    module: 'public'
})
.state('public.login', {
    url: '/login',
    module: 'public'
})
.state('tool', {
    abstract: true,
    module: 'private'
})
.state('tool.suggestions', {
    url: '/suggestions',
    module: 'private'
});

The $stateChangeStart event gives you acces to the toState and fromState objects. These state objects will contain the configuration properties.

Example check for the custom module property

$rootScope.$on('$stateChangeStart', function(e, toState, toParams, fromState, fromParams) {
    if (toState.module === 'private' && !$cookies.Session) {
        // If logged out and transitioning to a logged in page:
        e.preventDefault();
        $state.go('public.login');
    } else if (toState.module === 'public' && $cookies.Session) {
        // If logged in and transitioning to a logged out page:
        e.preventDefault();
        $state.go('tool.suggestions');
    };
});

I didn't change the logic of the cookies because I think that is out of scope for your question.

Suggestion 2

You can create a Helper to get you this to work more modular.

Value publicStates

myApp.value('publicStates', function(){
    return {
      module: 'public',
      routes: [{
        name: 'login', 
        config: { 
          url: '/login'
        }
      }]
    };
});

Value privateStates

myApp.value('privateStates', function(){
    return {
      module: 'private',
      routes: [{
        name: 'suggestions', 
        config: { 
          url: '/suggestions'
        }
      }]
    };
});

The Helper

myApp.provider('stateshelperConfig', function () {
  this.config = {
    // These are the properties we need to set
    // $stateProvider: undefined
    process: function (stateConfigs){
      var module = stateConfigs.module;
      $stateProvider = this.$stateProvider;
      $stateProvider.state(module, {
        abstract: true,
        module: module
      });
      angular.forEach(stateConfigs, function (route){
        route.config.module = module;
        $stateProvider.state(module + route.name, route.config);
      });
    }
  };

  this.$get = function () {
    return {
      config: this.config
    };
  };
});

Now you can use the helper to add the state configuration to your state configuration.

myApp.config(['$stateProvider', '$urlRouterProvider', 
    'stateshelperConfigProvider', 'publicStates', 'privateStates',
  function ($stateProvider, $urlRouterProvider, helper, publicStates, privateStates) {
    helper.config.$stateProvider = $stateProvider;
    helper.process(publicStates);
    helper.process(privateStates);
}]);

This way you can abstract the repeated code, and come up with a more modular solution.

Note: the code above isn't tested

How do I convert a float to an int in Objective C?

what's wrong with:

int myInt = myFloat;

bear in mind this'll use the default rounding rule, which is towards zero (i.e. -3.9f becomes -3)

Set transparent background of an imageview on Android

One more simple way:

mComponentName.setBackgroundResource(android.R.color.transparent);

Checking if my Windows application is running

public partial class App : System.Windows.Application
{
    public bool IsProcessOpen(string name)
    {
        foreach (Process clsProcess in Process.GetProcesses()) 
        {
            if (clsProcess.ProcessName.Contains(name))
            {
                return true;
            }
        }

        return false;
    }

    protected override void OnStartup(StartupEventArgs e)
    {
        // Get Reference to the current Process
        Process thisProc = Process.GetCurrentProcess();

        if (IsProcessOpen("name of application.exe") == false)
        {
            //System.Windows.MessageBox.Show("Application not open!");
            //System.Windows.Application.Current.Shutdown();
        }
        else
        {
            // Check how many total processes have the same name as the current one
            if (Process.GetProcessesByName(thisProc.ProcessName).Length > 1)
            {
                // If ther is more than one, than it is already running.
                System.Windows.MessageBox.Show("Application is already running.");
                System.Windows.Application.Current.Shutdown();
                return;
            }

            base.OnStartup(e);
        }
    }

getMinutes() 0-9 - How to display two digit numbers?

Elegant ES6 function to format a date into hh:mm:ss:

const leadingZero = (num) => `0${num}`.slice(-2);

const formatTime = (date) =>
  [date.getHours(), date.getMinutes(), date.getSeconds()]
  .map(leadingZero)
  .join(':');

Android: No Activity found to handle Intent error? How it will resolve

Intent intent=new Intent(String) is defined for parameter task, whereas you are passing parameter componentname into this, use instead:

Intent i = new Intent(Settings.this, com.scytec.datamobile.vd.gui.android.AppPreferenceActivity.class);
                    startActivity(i);

In this statement replace ActivityName by Name of Class of Activity, this code resides in.

Jenkins fails when running "service start jenkins"

In my case, the port 8080 was taken by some other service (Apache Airflow).

So I edit the HTTP port in this file:

sudo vi /etc/default/jenkins

And then started the service and it worked:

sudo service jenkins start

I was on Ubuntu 18.04 and installed openjdk-8

Why does JSON.parse fail with the empty string?

JSON.parse expects valid notation inside a string, whether that be object {}, array [], string "" or number types (int, float, doubles).

If there is potential for what is parsing to be an empty string then the developer should check for it.

If it was built into the function it would add extra cycles, since built in functions are expected to be extremely performant, it makes sense to not program them for the race case.

Declaring a xsl variable and assigning value to it

No, unlike in a lot of other languages, XSLT variables cannot change their values after they are created. You can however, avoid extraneous code with a technique like this:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes" omit-xml-declaration="yes"/>

  <xsl:variable name="mapping">
    <item key="1" v1="A" v2="B" />
    <item key="2" v1="X" v2="Y" />
  </xsl:variable>
  <xsl:variable name="mappingNode"
                select="document('')//xsl:variable[@name = 'mapping']" />

  <xsl:template match="....">
    <xsl:variable name="testVariable" select="'1'" />

    <xsl:variable name="values" select="$mappingNode/item[@key = $testVariable]" />

    <xsl:variable name="variable1" select="$values/@v1" />
    <xsl:variable name="variable2" select="$values/@v2" />
  </xsl:template>
</xsl:stylesheet>

In fact, once you've got the values variable, you may not even need separate variable1 and variable2 variables. You could just use $values/@v1 and $values/@v2 instead.

How to change column width in DataGridView?

Set the "AutoSizeColumnsMode" property to "Fill".. By default it is set to 'NONE'. Now columns will be filled across the DatagridView. Then you can set the width of other columns accordingly.

DataGridView1.Columns[0].Width=100;// The id column 
DataGridView1.Columns[1].Width=200;// The abbrevation columln
//Third Colulmns 'description' will automatically be resized to fill the remaining 
//space

Example JavaScript code to parse CSV data

Regular expressions to the rescue! These few lines of code handle properly quoted fields with embedded commas, quotes, and newlines based on the RFC 4180 standard.

function parseCsv(data, fieldSep, newLine) {
    fieldSep = fieldSep || ',';
    newLine = newLine || '\n';
    var nSep = '\x1D';
    var qSep = '\x1E';
    var cSep = '\x1F';
    var nSepRe = new RegExp(nSep, 'g');
    var qSepRe = new RegExp(qSep, 'g');
    var cSepRe = new RegExp(cSep, 'g');
    var fieldRe = new RegExp('(?<=(^|[' + fieldSep + '\\n]))"(|[\\s\\S]+?(?<![^"]"))"(?=($|[' + fieldSep + '\\n]))', 'g');
    var grid = [];
    data.replace(/\r/g, '').replace(/\n+$/, '').replace(fieldRe, function(match, p1, p2) {
        return p2.replace(/\n/g, nSep).replace(/""/g, qSep).replace(/,/g, cSep);
    }).split(/\n/).forEach(function(line) {
        var row = line.split(fieldSep).map(function(cell) {
            return cell.replace(nSepRe, newLine).replace(qSepRe, '"').replace(cSepRe, ',');
        });
        grid.push(row);
    });
    return grid;
}

const csv = 'A1,B1,C1\n"A ""2""","B, 2","C\n2"';
const separator = ',';      // field separator, default: ','
const newline = ' <br /> '; // newline representation in case a field contains newlines, default: '\n' 
var grid = parseCsv(csv, separator, newline);
// expected: [ [ 'A1', 'B1', 'C1' ], [ 'A "2"', 'B, 2', 'C <br /> 2' ] ]

You don't need a parser-generator such as lex/yacc. The regular expression handles RFC 4180 properly thanks to positive lookbehind, negative lookbehind, and positive lookahead.

Clone/download code at https://github.com/peterthoeny/parse-csv-js

What's the best way to break from nested loops in JavaScript?

Hmmm hi to the 10 years old party ?

Why not put some condition in your for ?

var condition = true
for (var i = 0 ; i < Args.length && condition ; i++) {
    for (var j = 0 ; j < Args[i].length && condition ; j++) {
        if (Args[i].obj[j] == "[condition]") {
            condition = false
        }
    }
}

Like this you stop when you want

In my case, using Typescript, we can use some() which go through the array and stop when condition is met So my code become like this :

Args.some((listObj) => {
    return listObj.some((obj) => {
        return !(obj == "[condition]")
    })
})

Like this, the loop stopped right after the condition is met

Reminder : This code run in TypeScript

Compiling dynamic HTML strings from database

You can use

ng-bind-html https://docs.angularjs.org/api/ng/service/$sce

directive to bind html dynamically. However you have to get the data via $sce service.

Please see the live demo at http://plnkr.co/edit/k4s3Bx

var app = angular.module('plunker', []);
app.controller('MainCtrl', function($scope,$sce) {
    $scope.getHtml=function(){
   return $sce.trustAsHtml("<b>Hi Rupesh hi <u>dfdfdfdf</u>!</b>sdafsdfsdf<button>dfdfasdf</button>");
   }
});

  <body ng-controller="MainCtrl">
<span ng-bind-html="getHtml()"></span>
  </body>

nodemon not working: -bash: nodemon: command not found

Install nodemon:

sudo npm install -g nodemon

Run server:

sudo nodemon server.js

Convert date yyyyMMdd to system.datetime format

string time = "19851231";
DateTime theTime= DateTime.ParseExact(time,
                                        "yyyyMMdd",
                                        CultureInfo.InvariantCulture,
                                        DateTimeStyles.None);

Column count doesn't match value count at row 1

You can resolve the error by providing the column names you are affecting.

> INSERT INTO table_name (column1,column2,column3)
 `VALUES(50,'Jon Snow','Eye');`

please note that the semi colon should be added only after the statement providing values

SQL query to make all data in a column UPPER CASE?

If you want to only update on rows that are not currently uppercase (instead of all rows), you'd need to identify the difference using COLLATE like this:

UPDATE MyTable
SET    MyColumn = UPPER(MyColumn)
WHERE  MyColumn != UPPER(MyColumn) COLLATE Latin1_General_CS_AS 

A Bit About Collation

Cases sensitivity is based on your collation settings, and is typically case insensitive by default.

Collation can be set at the Server, Database, Column, or Query Level:

-- Server
SELECT SERVERPROPERTY('COLLATION')
-- Database
SELECT name, collation_name FROM sys.databases
-- Column 
SELECT COLUMN_NAME, COLLATION_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE CHARACTER_SET_NAME IS NOT NULL

Collation Names specify how a string should be encoded and read, for example:

  • Latin1_General_CI_AS ? Case Insensitive
  • Latin1_General_CS_AS ? Case Sensitive

.NET data structures: ArrayList, List, HashTable, Dictionary, SortedList, SortedDictionary -- Speed, memory, and when to use each?

Most popular C# Data Structures and Collections

  • Array
  • ArrayList
  • List
  • LinkedList
  • Dictionary
  • HashSet
  • Stack
  • Queue
  • SortedList

C#.NET has a lot of different data structures, for example, one of the most common ones is an Array. However C# comes with many more basic data structures. Choosing the correct data structure to use is part of writing a well structured and efficient program.

In this article I will go over the built-in C# data structures, including the new ones introduces in C#.NET 3.5. Note that many of these data structures apply for other programming languages.

Array

The perhaps simplest and most common data structure is the array. A C# array is basically a list of objects. Its defining traits are that all the objects are the same type (in most cases) and there is a specific number of them. The nature of an array allows for very fast access to elements based on their position within the list (otherwise known as the index). A C# array is defined like this:

[object type][] myArray = new [object type][number of elements]

Some examples:

 int[] myIntArray = new int[5];
 int[] myIntArray2 = { 0, 1, 2, 3, 4 };

As you can see from the example above, an array can be intialized with no elements or from a set of existing values. Inserting values into an array is simple as long as they fit. The operation becomes costly when there are more elements than the size of the array, at which point the array needs to be expanded. This takes longer because all the existing elements must be copied over to the new, bigger array.

ArrayList

The C# data structure, ArrayList, is a dynamic array. What that means is an ArrayList can have any amount of objects and of any type. This data structure was designed to simplify the processes of adding new elements into an array. Under the hood, an ArrayList is an array whose size is doubled every time it runs out of space. Doubling the size of the internal array is a very effective strategy that reduces the amount of element-copying in the long run. We won't get into the proof of that here. The data structure is very simple to use:

    ArrayList myArrayList = new ArrayList();
    myArrayList.Add(56);
    myArrayList.Add("String");
    myArrayList.Add(new Form());

The downside to the ArrayList data structure is one must cast the retrived values back into their original type:

int arrayListValue = (int)myArrayList[0]

Sources and more info you can find here :

ASP.NET page life cycle explanation

There are 10 events in ASP.NET page life cycle, and the sequence is:

  1. Init
  2. Load view state
  3. Post back data
  4. Load
  5. Validate
  6. Events
  7. Pre-render
  8. Save view state
  9. Render
  10. Unload

Below is a pictorial view of ASP.NET Page life cycle with what kind of code is expected in that event. I suggest you read this article I wrote on the ASP.NET Page life cycle, which explains each of the 10 events in detail and when to use them.

ASP.NET life cycle

Image source: my own article at https://www.c-sharpcorner.com/uploadfile/shivprasadk/Asp-Net-application-and-page-life-cycle/ from 19 April 2010

How to edit an Android app?

You would need to decompile the apk as Davis suggested, can use tools such as apkTool , then if you need to change the source code you would need other tools to do that.

You would then need to put the apk back together and sign it, if you don't have the original key used to sign the apk this means the new apk will have a different signature.

If the developer employed any obfuscation or other techniques to protect the app then it gets more complicated.

In short its a pretty complex and technical procedure, so if the developer is really just out of reach, its better to wait until he is in reach. And ask for the source code next time.

Writing image to local server

Cleanest way of saving image locally using request:

const request = require('request');
request('http://link/to/your/image/file.png').pipe(fs.createWriteStream('fileName.png'))

If you need to add authentication token in headers do this:

const request = require('request');
request({
        url: 'http://link/to/your/image/file.png',
        headers: {
            "X-Token-Auth": TOKEN,
        }
    }).pipe(fs.createWriteStream('filename.png'))                    

Return index of greatest value in an array

Another solution of max using reduce:

[1,2,5,0,4].reduce((a,b,i) => a[0] < b ? [b,i] : a, [Number.MIN_VALUE,-1])
//[5,2]

This returns [5e-324, -1] if the array is empty. If you want just the index, put [1] after.

Min via (Change to > and MAX_VALUE):

[1,2,5,0,4].reduce((a,b,i) => a[0] > b ? [b,i] : a, [Number.MAX_VALUE,-1])
//[0, 3]

Excel - find cell with same value in another worksheet and enter the value to the left of it

The easiest way is probably with VLOOKUP(). This will require the 2nd worksheet to have the employee number column sorted though. In newer versions of Excel, apparently sorting is no longer required.

For example, if you had a "Sheet2" with two columns - A = the employee number, B = the employee's name, and your current worksheet had employee numbers in column D and you want to fill in column E, in cell E2, you would have:

=VLOOKUP($D2, Sheet2!$A$2:$B$65535, 2, FALSE)

Then simply fill this formula down the rest of column D.

Explanation:

  • The first argument $D2 specifies the value to search for.
  • The second argument Sheet2!$A$2:$B$65535 specifies the range of cells to search in. Excel will search for the value in the first column of this range (in this case Sheet2!A2:A65535). Note I am assuming you have a header cell in row 1.
  • The third argument 2 specifies a 1-based index of the column to return from within the searched range. The value of 2 will return the second column in the range Sheet2!$A$2:$B$65535, namely the value of the B column.
  • The fourth argument FALSE says to only return exact matches.

ConnectivityManager getNetworkInfo(int) deprecated

Here's how I check if the current network is using cellular or not on the latest Android versions:

val isCellular: Boolean get() {
    val cm = getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
    return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        cm.getNetworkCapabilities(cm.activeNetwork).hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)
    } else {
        cm.activeNetworkInfo?.type == ConnectivityManager.TYPE_MOBILE
    }
}

C# Java HashMap equivalent

Use Dictionary - it uses hashtable but is typesafe.

Also, your Java code for

int a = map.get(key);
//continue with your logic

will be best coded in C# this way:

int a;
if(dict.TryGetValue(key, out a)){
//continue with your logic
}

This way, you can scope the need of variable "a" inside a block and it is still accessible outside the block if you need it later.

How to write MySQL query where A contains ( "a" or "b" )

Two options:

  1. Use the LIKE keyword, along with percent signs in the string

    select * from table where field like '%a%' or field like '%b%'.
    

    (note: If your search string contains percent signs, you'll need to escape them)

  2. If you're looking for more a complex combination of strings than you've specified in your example, you could regular expressions (regex):

    See the MySQL manual for more on how to use them: http://dev.mysql.com/doc/refman/5.1/en/regexp.html

Of these, using LIKE is the most usual solution -- it's standard SQL, and in common use. Regex is less commonly used but much more powerful.

Note that whichever option you go with, you need to be aware of possible performance implications. Searching for sub-strings like this will mean that the query will have to scan the entire table. If you have a large table, this could make for a very slow query, and no amount of indexing is going to help.

If this is an issue for you, and you'r going to need to search for the same things over and over, you may prefer to do something like adding a flag field to the table which specifies that the string field contains the relevant sub-strings. If you keep this flag field up-to-date when you insert of update a record, you could simply query the flag when you want to search. This can be indexed, and would make your query much much quicker. Whether it's worth the effort to do that is up to you, it'll depend on how bad the performance is using LIKE.

How to extract extension from filename string in Javascript?

Use the lastIndexOf method to find the last period in the string, and get the part of the string after that:

var ext = fileName.substr(fileName.lastIndexOf('.') + 1);

Set Google Maps Container DIV width and height 100%

Setting Map Container to position to relative do the trick. Here is HTML.

<body>
    <!-- Map container -->
    <div id="map_canvas"></div>
</body>

And Simple CSS.

<style>
html, body, #map_canvas {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
}
#map_canvas {
    position: relative;
}
</style>

Tested on all browsers. Here is the Screenshot.

enter image description here

application/x-www-form-urlencoded or multipart/form-data?

Just a little hint from my side for uploading HTML5 canvas image data:

I am working on a project for a print-shop and had some problems due to uploading images to the server that came from an HTML5 canvas element. I was struggling for at least an hour and I did not get it to save the image correctly on my server.

Once I set the contentType option of my jQuery ajax call to application/x-www-form-urlencoded everything went the right way and the base64-encoded data was interpreted correctly and successfully saved as an image.


Maybe that helps someone!

firestore: PERMISSION_DENIED: Missing or insufficient permissions

GO to rules in firebase and edit rules ..... (provide a timestamp or set to false) My solution.

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if request.time < timestamp.date(2021, 8, 18);
    }
  }
}

how to use "tab space" while writing in text file

Use "\t". That's the tab space character.

You can find a list of many of the Java escape characters here: http://java.sun.com/docs/books/tutorial/java/data/characters.html

How can I get the count of milliseconds since midnight for the current?

I did the test using java 8 It wont matter the order the builder always takes 0 milliseconds and the concat between 26 and 33 milliseconds under and iteration of a 1000 concatenation

Hope it helps try it with your ide

public void count() {

        String result = "";

        StringBuilder builder = new StringBuilder();

        long millis1 = System.currentTimeMillis(),
            millis2;

        for (int i = 0; i < 1000; i++) {
            builder.append("hello world this is the concat vs builder test enjoy");
        }

        millis2 = System.currentTimeMillis();

        System.out.println("Diff: " + (millis2 - millis1));

        millis1 = System.currentTimeMillis();

        for (int i = 0; i < 1000; i++) {
            result += "hello world this is the concat vs builder test enjoy";
        }

        millis2 = System.currentTimeMillis();

        System.out.println("Diff: " + (millis2 - millis1));
    }

LaTex left arrow over letter in math mode

Use \overleftarrow to create a long arrow to the left.

\overleftarrow{blahblahblah}

LaTeX output

Getting a POST variable

In addition to using Request.Form and Request.QueryString and depending on your specific scenario, it may also be useful to check the Page's IsPostBack property.

if (Page.IsPostBack)
{
  // HTTP Post
}
else
{
  // HTTP Get
}

Disable future dates in jQuery UI Datepicker

http://stefangabos.ro/jquery/zebra-datepicker

use zebra date pickers:

$('#select_month1').Zebra_DatePicker({
  direction: false,
  format: 'Y-m-d',
  pair: $('#select_month2')
});

$('#select_month2').Zebra_DatePicker({
  direction: 1, format: 'Y-m-d',
});

How can I pass a parameter to a Java Thread?

One further option; this approach lets you use the Runnable item like an asynchronous function call. If your task does not need to return a result, e.g. it just performs some action you don't need to worry about how you pass back an "outcome".

This pattern lets you reuse an item, where you need some kind of internal state. When not passing parameter(s) in the constructor care is needed to mediate the programs access to parameters. You may need more checks if your use-case involves different callers, etc.

public class MyRunnable implements Runnable 
{
  private final Boolean PARAMETER_LOCK  = false;
  private X parameter;

  public MyRunnable(X parameter) {
     this.parameter = parameter;
  }

  public void setParameter( final X newParameter ){

      boolean done = false;
      synchronize( PARAMETER_LOCK )
      {
          if( null == parameter )
          {
              parameter = newParameter;
              done = true;
          }
      }
      if( ! done )
      {
          throw new RuntimeException("MyRunnable - Parameter not cleared." );
      }
  }


  public void clearParameter(){

      synchronize( PARAMETER_LOCK )
      {
          parameter = null;
      }
  }


  public void run() {

      X localParameter;

      synchronize( PARAMETER_LOCK )
      {
          localParameter = parameter;
      }

      if( null != localParameter )
      {
         clearParameter();   //-- could clear now, or later, or not at all ...
         doSomeStuff( localParameter );
      }

  }

}

Thread t = new Thread(new MyRunnable(parameter)); t.start();

If you need a result of processing, you will also need to coordinate completion of MyRunnable when the sub-task finishes. You could pass a call back or just wait on the Thread 't', etc.

Loop through Map in Groovy?

Quite simple with a closure:

def map = [
           'iPhone':'iWebOS',
           'Android':'2.3.3',
           'Nokia':'Symbian',
           'Windows':'WM8'
           ]

map.each{ k, v -> println "${k}:${v}" }

relative path in require_once doesn't work

In my case it doesn't work, even with __DIR__ or getcwd() it keeps picking the wrong path, I solved by defining a costant in every file I need with the absolute base path of the project:

if(!defined('THISBASEPATH')){ define('THISBASEPATH', '/mypath/'); }
require_once THISBASEPATH.'cache/crud.php';
/*every other require_once you need*/

I have MAMP with php 5.4.10 and my folder hierarchy is basilar:

q.php 
w.php 
e.php 
r.php 
cache/a.php 
cache/b.php 
setting/a.php 
setting/b.php

....

vba listbox multicolumn add

Simplified example (with counter):

With Me.lstbox
    .ColumnCount = 2
    .ColumnWidths = "60;60"
    .AddItem
    .List(i, 0) = Company_ID
    .List(i, 1) = Company_name 
    i = i + 1

end with

Make sure to start the counter with 0, not 1 to fill up a listbox.

HTTP status code 0 - Error Domain=NSURLErrorDomain?

There is no HTTP status code 0. What you see is a 0 returned by the API/library that you are using. You will have to check the documentation for that.

Is a Java hashmap search really O(1)?

Only in theoretical case, when hashcodes are always different and bucket for every hash code is also different, the O(1) will exist. Otherwise, it is of constant order i.e. on increment of hashmap, its order of search remains constant.

Fill formula down till last row in column

It's a one liner actually. No need to use .Autofill

Range("M3:M" & LastRow).Formula = "=G3&"",""&L3"

How to compare type of an object in Python?

i think this should do it

if isinstance(obj, str)

How to fix: Error device not found with ADB.exe

Try any of the following solutions. I get errors with adb every now and then. And one of the following always works.

Solution 1
Open command prompt as administrator and enter

  1. adb kill-server
  2. adb start-server

Solution 2
Install drivers for your phone if you're not testing on emulator.

Solution 3
Open android sdk manager and install "Google USB Driver" from extras folder. (attached screenshot)

Android SDK Google USB Driver missing

Solution 4
Go to settings > Developer Options > Enable USB Debugging.
(If you don't see Developer Options, Go to Settings > About Phone > Keep tapping "Build number" until it says "You're a developer!"

Enable USB Debugging

Create instance of generic type whose constructor requires a parameter?

As an addition to user1471935's suggestion:

To instantiate a generic class by using a constructor with one or more parameters, you can now use the Activator class.

T instance = Activator.CreateInstance(typeof(T), new object[] {...}) 

The list of objects are the parameters you want to supply. According to Microsoft:

CreateInstance [...] creates an instance of the specified type using the constructor that best matches the specified parameters.

There's also a generic version of CreateInstance (CreateInstance<T>()) but that one also does not allow you to supply constructor parameters.

Convert INT to VARCHAR SQL

You can use CAST function:

SELECT CAST(your_column_name AS varchar(10)) FROM your_table_name

SQL Server Jobs with SSIS packages - Failed to decrypt protected XML node "DTS:Password" with error 0x8009000B

For me the issue had to do with the parameters assigned to the package.

 In SSMS, Navigate to:
 "Integration Services Catalog -> SSISDB -> Project Folder Name -> Projects -> Project Name" 

Make sure you right click on your "Project Name" and then validate that 32-bit runtime is set correctly and that the parameters that are used by default are instantiated properly. Check parameter NAMES and initial values. For my package, I was using values that were not correct and so I had to repopulate the parameter defaults prior to executing my package. Check the values you are using against the defaults you have set for your parameters you have set up in your SSIS package. Once these match the issue should be resolved (for some)

Cluster analysis in R: determine the optimal number of clusters

The answers are great. If you want to give a chance to another clustering method you can use hierarchical clustering and see how data is splitting.

> set.seed(2)
> x=matrix(rnorm(50*2), ncol=2)
> hc.complete = hclust(dist(x), method="complete")
> plot(hc.complete)

enter image description here

Depending on how many classes you need you can cut your dendrogram as;

> cutree(hc.complete,k = 2)
 [1] 1 1 1 2 1 1 1 1 1 1 1 1 1 2 1 2 1 1 1 1 1 2 1 1 1
[26] 2 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 2 1 1 1 1 1 1 1 2

If you type ?cutree you will see the definitions. If your data set has three classes it will be simply cutree(hc.complete, k = 3). The equivalent for cutree(hc.complete,k = 2) is cutree(hc.complete,h = 4.9).

Google Chrome Printing Page Breaks

I had an issue similar to this but I found the solution eventually. I had overflow-x: hidden; applied to the <html> tag so no matter what I did below in the DOM, it would never allow page breaks. By reverting to overflow-x: visible; it worked fine.

Hopefully this helps somebody out there.

Date to milliseconds and back to date in Swift

//Date to milliseconds
func currentTimeInMiliseconds() -> Int {
    let currentDate = Date()
    let since1970 = currentDate.timeIntervalSince1970
    return Int(since1970 * 1000)
}

//Milliseconds to date
extension Int {
    func dateFromMilliseconds() -> Date {
        return Date(timeIntervalSince1970: TimeInterval(self)/1000)
    }
}

I removed seemingly useless conversion via string and all those random !.

How to call function on child component on parent events

You can use $emit and $on. Using @RoyJ code:

html:

<div id="app">
  <my-component></my-component>
  <button @click="click">Click</button>  
</div>

javascript:

var Child = {
  template: '<div>{{value}}</div>',
  data: function () {
    return {
      value: 0
    };
  },
  methods: {
    setValue: function(value) {
        this.value = value;
    }
  },
  created: function() {
    this.$parent.$on('update', this.setValue);
  }
}

new Vue({
  el: '#app',
  components: {
    'my-component': Child
  },
  methods: {
    click: function() {
        this.$emit('update', 7);
    }
  }
})

Running example: https://jsfiddle.net/rjurado/m2spy60r/1/

How to properly set the 100% DIV height to match document/window height?

The easiest way is to add the:

$('#ID').css("height", $(document).height());

after the correct page height is determined by the browser. If the document height is changed once more re-run the above code.

How to print a list of symbols exported from a dynamic library

Use otool:

otool -TV your.dylib

OR

nm -g your.dylib

Calculate distance between 2 GPS coordinates

    private double deg2rad(double deg)
    {
        return (deg * Math.PI / 180.0);
    }

    private double rad2deg(double rad)
    {
        return (rad / Math.PI * 180.0);
    }

    private double GetDistance(double lat1, double lon1, double lat2, double lon2)
    {
        //code for Distance in Kilo Meter
        double theta = lon1 - lon2;
        double dist = Math.Sin(deg2rad(lat1)) * Math.Sin(deg2rad(lat2)) + Math.Cos(deg2rad(lat1)) * Math.Cos(deg2rad(lat2)) * Math.Cos(deg2rad(theta));
        dist = Math.Abs(Math.Round(rad2deg(Math.Acos(dist)) * 60 * 1.1515 * 1.609344 * 1000, 0));
        return (dist);
    }

    private double GetDirection(double lat1, double lon1, double lat2, double lon2)
    {
        //code for Direction in Degrees
        double dlat = deg2rad(lat1) - deg2rad(lat2);
        double dlon = deg2rad(lon1) - deg2rad(lon2);
        double y = Math.Sin(dlon) * Math.Cos(lat2);
        double x = Math.Cos(deg2rad(lat1)) * Math.Sin(deg2rad(lat2)) - Math.Sin(deg2rad(lat1)) * Math.Cos(deg2rad(lat2)) * Math.Cos(dlon);
        double direct = Math.Round(rad2deg(Math.Atan2(y, x)), 0);
        if (direct < 0)
            direct = direct + 360;
        return (direct);
    }

    private double GetSpeed(double lat1, double lon1, double lat2, double lon2, DateTime CurTime, DateTime PrevTime)
    {
        //code for speed in Kilo Meter/Hour
        TimeSpan TimeDifference = CurTime.Subtract(PrevTime);
        double TimeDifferenceInSeconds = Math.Round(TimeDifference.TotalSeconds, 0);
        double theta = lon1 - lon2;
        double dist = Math.Sin(deg2rad(lat1)) * Math.Sin(deg2rad(lat2)) + Math.Cos(deg2rad(lat1)) * Math.Cos(deg2rad(lat2)) * Math.Cos(deg2rad(theta));
        dist = rad2deg(Math.Acos(dist)) * 60 * 1.1515 * 1.609344;
        double Speed = Math.Abs(Math.Round((dist / Math.Abs(TimeDifferenceInSeconds)) * 60 * 60, 0));
        return (Speed);
    }

    private double GetDuration(DateTime CurTime, DateTime PrevTime)
    {
        //code for speed in Kilo Meter/Hour
        TimeSpan TimeDifference = CurTime.Subtract(PrevTime);
        double TimeDifferenceInSeconds = Math.Abs(Math.Round(TimeDifference.TotalSeconds, 0));
        return (TimeDifferenceInSeconds);
    }

How to print variables in Perl

You should always include all relevant code when asking a question. In this case, the print statement that is the center of your question. The print statement is probably the most crucial piece of information. The second most crucial piece of information is the error, which you also did not include. Next time, include both of those.

print $ids should be a fairly hard statement to mess up, but it is possible. Possible reasons:

  1. $ids is undefined. Gives the warning undefined value in print
  2. $ids is out of scope. With use strict, gives fatal warning Global variable $ids needs explicit package name, and otherwise the undefined warning from above.
  3. You forgot a semi-colon at the end of the line.
  4. You tried to do print $ids $nIds, in which case perl thinks that $ids is supposed to be a filehandle, and you get an error such as print to unopened filehandle.

Explanations

1: Should not happen. It might happen if you do something like this (assuming you are not using strict):

my $var;
while (<>) {
    $Var .= $_;
}
print $var;

Gives the warning for undefined value, because $Var and $var are two different variables.

2: Might happen, if you do something like this:

if ($something) {
    my $var = "something happened!";
}
print $var;

my declares the variable inside the current block. Outside the block, it is out of scope.

3: Simple enough, common mistake, easily fixed. Easier to spot with use warnings.

4: Also a common mistake. There are a number of ways to correctly print two variables in the same print statement:

print "$var1 $var2";  # concatenation inside a double quoted string
print $var1 . $var2;  # concatenation
print $var1, $var2;   # supplying print with a list of args

Lastly, some perl magic tips for you:

use strict;
use warnings;

# open with explicit direction '<', check the return value
# to make sure open succeeded. Using a lexical filehandle.
open my $fh, '<', 'file.txt' or die $!;

# read the whole file into an array and
# chomp all the lines at once
chomp(my @file = <$fh>);
close $fh;

my $ids  = join(' ', @file);
my $nIds = scalar @file;
print "Number of lines: $nIds\n";
print "Text:\n$ids\n";

Reading the whole file into an array is suitable for small files only, otherwise it uses a lot of memory. Usually, line-by-line is preferred.

Variations:

  • print "@file" is equivalent to $ids = join(' ',@file); print $ids;
  • $#file will return the last index in @file. Since arrays usually start at 0, $#file + 1 is equivalent to scalar @file.

You can also do:

my $ids;
do {
    local $/;
    $ids = <$fh>;
}

By temporarily "turning off" $/, the input record separator, i.e. newline, you will make <$fh> return the entire file. What <$fh> really does is read until it finds $/, then return that string. Note that this will preserve the newlines in $ids.

Line-by-line solution:

open my $fh, '<', 'file.txt' or die $!; # btw, $! contains the most recent error
my $ids;
while (<$fh>) {
    chomp;
    $ids .= "$_ "; # concatenate with string
}
my $nIds = $.; # $. is Current line number for the last filehandle accessed.

Git : fatal: Could not read from remote repository. Please make sure you have the correct access rights and the repository exists

change your ssh url by an http url for your remote 'origin', use:

> git remote set-url origin https://github.com/<user_name>/<repo_name>.git

It will ask for your GitHub password on the git push.

open program minimized via command prompt

Local Windows 10 ActiveMQ server :

@echo off
start /min "" "C:\Install\apache-activemq\5.15.10\bin\win64\activemq.bat" start

How to export MySQL database with triggers and procedures?

I've created the following script and it worked for me just fine.

#! /bin/sh
cd $(dirname $0)
DB=$1
DBUSER=$2
DBPASSWD=$3
FILE=$DB-$(date +%F).sql
mysqldump --routines "--user=${DBUSER}"  --password=$DBPASSWD $DB > $PWD/$FILE
gzip $FILE
echo Created $PWD/$FILE*

and you call the script using command line arguments.

backupdb.sh my_db dev_user dev_password

Show ImageView programmatically

//LinearLayOut Setup
LinearLayout linearLayout= new LinearLayout(this);
linearLayout.setOrientation(LinearLayout.VERTICAL);

linearLayout.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));

//ImageView Setup
ImageView imageView = new ImageView(this);

//setting image resource
imageView.setImageResource(R.drawable.play);

//setting image position
imageView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, 
LayoutParams.WRAP_CONTENT));

//adding view to layout
linearLayout.addView(imageView);
//make visible to program
setContentView(linearLayout);

Using Python, how can I access a shared folder on windows network?

How did you try it? Maybe you are working with \ and omit proper escaping.

Instead of

open('\\HOST\share\path\to\file')

use either Johnsyweb's solution with the /s, or try one of

open(r'\\HOST\share\path\to\file')

or

open('\\\\HOST\\share\\path\\to\\file')

.

Python != operation vs "is not"

== is an equality test. It checks whether the right hand side and the left hand side are equal objects (according to their __eq__ or __cmp__ methods.)

is is an identity test. It checks whether the right hand side and the left hand side are the very same object. No methodcalls are done, objects can't influence the is operation.

You use is (and is not) for singletons, like None, where you don't care about objects that might want to pretend to be None or where you want to protect against objects breaking when being compared against None.

Html.ActionLink as a button or an image, not a link

Do what Mehrdad says - or use the url helper from an HtmlHelper extension method like Stephen Walther describes here and make your own extension method which can be used to render all of your links.

Then it will be easy to render all links as buttons/anchors or whichever you prefer - and, most importantly, you can change your mind later when you find out that you actually prefer some other way of making your links.

I want to get the type of a variable at runtime

So, strictly speaking, the "type of a variable" is always present, and can be passed around as a type parameter. For example:

val x = 5
def f[T](v: T) = v
f(x) // T is Int, the type of x

But depending on what you want to do, that won't help you. For instance, may want not to know what is the type of the variable, but to know if the type of the value is some specific type, such as this:

val x: Any = 5
def f[T](v: T) = v match {
  case _: Int    => "Int"
  case _: String => "String"
  case _         => "Unknown"
}
f(x)

Here it doesn't matter what is the type of the variable, Any. What matters, what is checked is the type of 5, the value. In fact, T is useless -- you might as well have written it def f(v: Any) instead. Also, this uses either ClassTag or a value's Class, which are explained below, and cannot check the type parameters of a type: you can check whether something is a List[_] (List of something), but not whether it is, for example, a List[Int] or List[String].

Another possibility is that you want to reify the type of the variable. That is, you want to convert the type into a value, so you can store it, pass it around, etc. This involves reflection, and you'll be using either ClassTag or a TypeTag. For example:

val x: Any = 5
import scala.reflect.ClassTag
def f[T](v: T)(implicit ev: ClassTag[T]) = ev.toString
f(x) // returns the string "Any"

A ClassTag will also let you use type parameters you received on match. This won't work:

def f[A, B](a: A, b: B) = a match {
  case _: B => "A is a B"
  case _ => "A is not a B"
}

But this will:

val x = 'c'
val y = 5
val z: Any = 5
import scala.reflect.ClassTag
def f[A, B: ClassTag](a: A, b: B) = a match {
  case _: B => "A is a B"
  case _ => "A is not a B"
}
f(x, y) // A (Char) is not a B (Int)
f(x, z) // A (Char) is a B (Any)

Here I'm using the context bounds syntax, B : ClassTag, which works just like the implicit parameter in the previous ClassTag example, but uses an anonymous variable.

One can also get a ClassTag from a value's Class, like this:

val x: Any = 5
val y = 5
import scala.reflect.ClassTag
def f(a: Any, b: Any) = {
  val B = ClassTag(b.getClass)
  ClassTag(a.getClass) match {
    case B => "a is the same class as b"
    case _ => "a is not the same class as b"
  }
}
f(x, y) == f(y, x) // true, a is the same class as b

A ClassTag is limited in that it only covers the base class, but not its type parameters. That is, the ClassTag for List[Int] and List[String] is the same, List. If you need type parameters, then you must use a TypeTag instead. A TypeTag however, cannot be obtained from a value, nor can it be used on a pattern match, due to JVM's erasure.

Examples with TypeTag can get quite complex -- not even comparing two type tags is not exactly simple, as can be seen below:

import scala.reflect.runtime.universe.TypeTag
def f[A, B](a: A, b: B)(implicit evA: TypeTag[A], evB: TypeTag[B]) = evA == evB
type X = Int
val x: X = 5
val y = 5
f(x, y) // false, X is not the same type as Int

Of course, there are ways to make that comparison return true, but it would require a few book chapters to really cover TypeTag, so I'll stop here.

Finally, maybe you don't care about the type of the variable at all. Maybe you just want to know what is the class of a value, in which case the answer is rather simple:

val x = 5
x.getClass // int -- technically, an Int cannot be a class, but Scala fakes it

It would be better, however, to be more specific about what you want to accomplish, so that the answer can be more to the point.

How to add action listener that listens to multiple buttons

There are good answers here but let me address the more global point of adding action listener that listens to multiple buttons.

There are two popular approaches.

Using a Common Action Listener

You can get the source of the action in your actionPerformed(ActionEvent e) implementation:

JButton button1, button2; //your button

@Override
public void actionPerformed(ActionEvent e) {

    JButton actionSource = (JButton) e.getSource();

    if(actionSource.equals(button1)){
        // YOU BUTTON 1 CODE HERE
    } else if (actionSource.equals(button2)) {
        // YOU BUTTON 2 CODE HERE
    }
}

Using ActionCommand

With this approach you setting the actionCommand field of your button which later will allow you to use switch:

button1.setActionCommand("actionName1");
button2.setActionCommand("actionName2");

And later:

@Override
public void actionPerformed(ActionEvent e) {
    String actionCommand = ((JButton) e.getSource()).getActionCommand();

    switch (actionCommand) {
        case "actionName1": 
            // YOU BUTTON 1 CODE HERE
        break;
        case "actionName2": 
            // YOU BUTTON 2 CODE HERE
        break;
    }
}

Check out to learn more about JFrame Buttons, Listeners and Fields.

JavaScript variable number of arguments to function

As mentioned already, you can use the arguments object to retrieve a variable number of function parameters.

If you want to call another function with the same arguments, use apply. You can even add or remove arguments by converting arguments to an array. For example, this function inserts some text before logging to console:

log() {
    let args = Array.prototype.slice.call(arguments);
    args = ['MyObjectName', this.id_].concat(args);
    console.log.apply(console, args);
}

spacing between form fields

In your CSS file:

input { margin-bottom: 10px; }

Undo working copy modifications of one file in Git?

If it is already committed, you can revert the change for the file and commit again, then squash new commit with last commit.

setTimeout in for-loop does not print consecutive values

Well, another working solution based on Cody's answer but a little more general can be something like this:

function timedAlert(msg, timing){
    setTimeout(function(){
        alert(msg);    
    }, timing);
}

function yourFunction(time, counter){
    for (var i = 1; i <= counter; i++) {
        var msg = i, timing = i * time * 1000; //this is in seconds
        timedAlert (msg, timing);
    };
}

yourFunction(timeInSeconds, counter); // well here are the values of your choice.

When to use EntityManager.find() vs EntityManager.getReference() with JPA

Because a reference is 'managed', but not hydrated, it can also allow you to remove an entity by ID, without needing to load it into memory first.

As you can't remove an unmanaged entity, it's just plain silly to load all fields using find(...) or createQuery(...), only to immediately delete it.

MyLargeObject myObject = em.getReference(MyLargeObject.class, objectId);
em.remove(myObject);

read word by word from file in C++

If I may I could give you some new code for the same task, in my code you can create a so called 'document'(not really)and it is saved, and can be opened up again. It is also stored as a string file though(not a document). Here is the code:

#include "iostream"

#include "windows.h"

#include "string"

#include "fstream"

using namespace std;

int main() {

string saveload;


cout << "---------------------------" << endl;
cout << "|enter 'text' to write your document    |" << endl;
cout << "|enter 'open file' to open the document |" << endl;
cout << "----------------------------------------" << endl;
while (true){
    getline(cin, saveload);

    if (saveload == "open file"){
        string filenamet;
        cout << "file name? " << endl;
        getline(cin, filenamet, '*');
        ifstream loadFile;

        loadFile.open(filenamet, ifstream::in);

        cout << "the text you entered was: ";

        while (loadFile.good()){

            cout << (char)loadFile.get();

            Sleep(100);
        }

        cout << "" << endl;

        loadFile.close();

    }

    if (saveload == "text") {
        string filename;
        cout << "file name: " << endl;
        getline(cin, filename,'*');
        string textToSave;
        cout << "Enter your text: " << endl;
        getline(cin, textToSave,'*');

        ofstream saveFile(filename);

        saveFile << textToSave;

        saveFile.close();

    }
}
return 0;
}

Just take this code and change it to serve your purpose. DREAM BIG,THINK BIG, DO BIG

make sounds (beep) with c++

There are a few OS-specific routines for beeping.

  • On a Unix-like OS, try the (n)curses beep() function. This is likely to be more portable than writing '\a' as others have suggested, although for most terminal emulators that will probably work.

  • In some *BSDs there is a PC speaker device. Reading the driver source, the SPKRTONE ioctl seems to correspond to the raw hardware interface, but there also seems to be a high-level language built around write()-ing strings to the driver, described in the manpage.

  • It looks like Linux has a similar driver (see this article for example; there is also some example code on this page if you scroll down a bit.).

  • In Windows there is a function called Beep().

How to get datetime in JavaScript?

If the format is "fixed" meaning you don't have to use other format you can have pure JavaScript instead of using whole library to format the date:

_x000D_
_x000D_
//Pad given value to the left with "0"_x000D_
function AddZero(num) {_x000D_
    return (num >= 0 && num < 10) ? "0" + num : num + "";_x000D_
}_x000D_
_x000D_
window.onload = function() {_x000D_
    var now = new Date();_x000D_
    var strDateTime = [[AddZero(now.getDate()), _x000D_
        AddZero(now.getMonth() + 1), _x000D_
        now.getFullYear()].join("/"), _x000D_
        [AddZero(now.getHours()), _x000D_
        AddZero(now.getMinutes())].join(":"), _x000D_
        now.getHours() >= 12 ? "PM" : "AM"].join(" ");_x000D_
    document.getElementById("Console").innerHTML = "Now: " + strDateTime;_x000D_
};
_x000D_
<div id="Console"></div>
_x000D_
_x000D_
_x000D_

The variable strDateTime will hold the date/time in the format you desire and you should be able to tweak it pretty easily if you need.

I'm using join as good practice, nothing more, it's better than adding strings together.

Sockets: Discover port availability using Java

It appears that as of Java 7, David Santamaria's answer doesn't work reliably any more. It looks like you can still reliably use a Socket to test the connection, however.

private static boolean available(int port) {
    System.out.println("--------------Testing port " + port);
    Socket s = null;
    try {
        s = new Socket("localhost", port);

        // If the code makes it this far without an exception it means
        // something is using the port and has responded.
        System.out.println("--------------Port " + port + " is not available");
        return false;
    } catch (IOException e) {
        System.out.println("--------------Port " + port + " is available");
        return true;
    } finally {
        if( s != null){
            try {
                s.close();
            } catch (IOException e) {
                throw new RuntimeException("You should handle this error." , e);
            }
        }
    }
}

WPF TabItem Header Styling

Try this style instead, it modifies the template itself. In there you can change everything you need to transparent:

<Style TargetType="{x:Type TabItem}">
  <Setter Property="Template">
    <Setter.Value>
      <ControlTemplate TargetType="{x:Type TabItem}">
        <Grid>
          <Border Name="Border" Margin="0,0,0,0" Background="Transparent"
                  BorderBrush="Black" BorderThickness="1,1,1,1" CornerRadius="5">
            <ContentPresenter x:Name="ContentSite" VerticalAlignment="Center"
                              HorizontalAlignment="Center"
                              ContentSource="Header" Margin="12,2,12,2"
                              RecognizesAccessKey="True">
              <ContentPresenter.LayoutTransform>
            <RotateTransform Angle="270" />
          </ContentPresenter.LayoutTransform>
        </ContentPresenter>
          </Border>
        </Grid>
        <ControlTemplate.Triggers>
          <Trigger Property="IsSelected" Value="True">
            <Setter Property="Panel.ZIndex" Value="100" />
            <Setter TargetName="Border" Property="Background" Value="Red" />
            <Setter TargetName="Border" Property="BorderThickness" Value="1,1,1,0" />
          </Trigger>
          <Trigger Property="IsEnabled" Value="False">
            <Setter TargetName="Border" Property="Background" Value="DarkRed" />
            <Setter TargetName="Border" Property="BorderBrush" Value="Black" />
            <Setter Property="Foreground" Value="DarkGray" />
          </Trigger>
        </ControlTemplate.Triggers>
      </ControlTemplate>
    </Setter.Value>
  </Setter>
</Style>

Anybody knows any knowledge base open source?

I heard of RTM (The RT FAQ Manager). Never used it, however.

Change first commit of project with Git?

As mentioned by ecdpalma below, git 1.7.12+ (August 2012) has enhanced the option --root for git rebase:

"git rebase [-i] --root $tip" can now be used to rewrite all the history leading to "$tip" down to the root commit.

That new behavior was initially discussed here:

I personally think "git rebase -i --root" should be made to just work without requiring "--onto" and let you "edit" even the first one in the history.
It is understandable that nobody bothered, as people are a lot less often rewriting near the very beginning of the history than otherwise.

The patch followed.


(original answer, February 2010)

As mentioned in the Git FAQ (and this SO question), the idea is:

  1. Create new temporary branch
  2. Rewind it to the commit you want to change using git reset --hard
  3. Change that commit (it would be top of current HEAD, and you can modify the content of any file)
  4. Rebase branch on top of changed commit, using:

    git rebase --onto <tmp branch> <commit after changed> <branch>`
    

The trick is to be sure the information you want to remove is not reintroduced by a later commit somewhere else in your file. If you suspect that, then you have to use filter-branch --tree-filter to make sure the content of that file does not contain in any commit the sensible information.

In both cases, you end up rewriting the SHA1 of every commit, so be careful if you have already published the branch you are modifying the contents of. You probably shouldn’t do it unless your project isn’t yet public and other people haven’t based work off the commits you’re about to rewrite.

How to set the first option on a select box using jQuery?

Here is how I got it to work if you just want to get it back to your first option e.g. "Choose an option" "Select_id_wrap" is obviously the div around the select, but I just want to make that clear just in case it has any bearing on how this works. Mine resets to a click function but I'm sure it will work inside of an on change as well...

$("#select_id_wrap").find("select option").prop("selected", false);

Unbound classpath container in Eclipse

I got the Similar issue while importing the project.

The issue is you select "Use an execution environment JRE" and which is lower then the libraries used in the projects being imported.

There are two ways to resolve this issue:

1.While first time importing the project:

in JRE tab select "USE project specific JRE" instead of "Use an execution environment JRE".

2.Delete the Project from your work space and import again. This time:

select "Check out as a project in the workspace" instead of "Check out as a project configured using the new Project Wizard"

How can I get a list of locally installed Python modules?

Here is a python code solution that will return a list of modules installed. One can easily modify the code to include version numbers.

import subprocess
import sys
from pprint import pprint

installed_packages = reqs = subprocess.check_output([sys.executable, '-m', 'pip', 'freeze']).decode('utf-8')
installed_packages = installed_packages.split('\r\n')
installed_packages = [pkg.split('==')[0] for pkg in installed_packages if pkg != '']
pprint(installed_packages)

How to pass data between fragments

From the Fragment documentation:

Often you will want one Fragment to communicate with another, for example to change the content based on a user event. All Fragment-to-Fragment communication is done through the associated Activity. Two Fragments should never communicate directly.

So I suggest you have look on the basic fragment training docs in the documentation. They're pretty comprehensive with an example and a walk-through guide.

Making a div vertically scrollable using CSS

You can use this code instead.

<div id="" style="overflow-y:scroll; overflow-x:hidden; height:400px;">


overflow-x: The overflow-x property specifies what to do with the left/right edges of the content - if it overflows the element's content area.
overflow-y: The overflow-y property specifies what to do with the top/bottom edges of the content - if it overflows the element's content area.

Values
visible: Default value. The content is not clipped, and it may be rendered outside the content box.
hidden: The content is clipped - and no scrolling mechanism is provided.
scroll: The content is clipped and a scrolling mechanism is provided.
auto: Should cause a scrolling mechanism to be provided for overflowing boxes.
initial: Sets this property to its default value.
inherit Inherits this property from its parent element.

What are native methods in Java and where should they be used?

Native methods allow you to use code from other languages such as C or C++ in your java code. You use them when java doesn't provide the functionality that you need. For example, if I were writing a program to calculate some equation and create a line graph of it, I would use java, because it is the language I am best in. However, I am also proficient in C. Say in part of my program I need to calculate a really complex equation. I would use a native method for this, because I know some C++ and I know that C++ is much faster than java, so if I wrote my method in C++ it would be quicker. Also, say I want to interact with another program or device. This would also use a native method, because C++ has something called pointers, which would let me do that.

"No backupset selected to be restored" SQL Server 2012

Another potential reason for this glitch appears to be Google Drive. Google Drive is compressing bak files or something, so if you want to transfer a database backup via Google Drive, it appears you must zip it first.

MongoDB "root" user

Mongodb user management:

roles list:

read
readWrite
dbAdmin
userAdmin
clusterAdmin
readAnyDatabase
readWriteAnyDatabase
userAdminAnyDatabase
dbAdminAnyDatabase

create user:

db.createUser(user, writeConcern)

db.createUser({ user: "user",
  pwd: "pass",
  roles: [
    { role: "read", db: "database" } 
  ]
})

update user:

db.updateUser("user",{
  roles: [
    { role: "readWrite", db: "database" } 
  ]
})

drop user:

db.removeUser("user")

or

db.dropUser("user")

view users:

db.getUsers();

more information: https://docs.mongodb.com/manual/reference/security/#read

For-loop vs while loop in R

And about timing:

fn1 <- function (N) {
    for(i in as.numeric(1:N)) { y <- i*i }
}
fn2 <- function (N) {
    i=1
    while (i <= N) {
        y <- i*i
        i <- i + 1
    }
}

system.time(fn1(60000))
# user  system elapsed 
# 0.06    0.00    0.07 
system.time(fn2(60000))
# user  system elapsed 
# 0.12    0.00    0.13

And now we know that for-loop is faster than while-loop. You cannot ignore warnings during timing.

How to make a JFrame button open another JFrame class in Netbeans?

Double Click the Login Button in the NETBEANS or add the Event Listener on Click Event (ActionListener)

btnLogin.addActionListener(new ActionListener() 
{
    public void actionPerformed(ActionEvent e) {
        this.setVisible(false);
        new FrmMain().setVisible(true); // Main Form to show after the Login Form..
    }
});

Check whether specific radio button is checked

I think you're using the wrong approach. You should set the value attribute of your input elements. Check the docs for .val() for examples of setting and returning the .val() of input elements.

ie.

<input type="radio" runat="server" name="testGroup" value="test2" />

return $('input:radio[name=testGroup]:checked').val() == 'test2';

How to get names of enum entries?

The code you posted will work; it will print out all the members of the enum, including the values of the enum members. For example, the following code:

enum myEnum { bar, foo }

for (var enumMember in myEnum) {
   console.log("enum member: ", enumMember);
}

Will print the following:

Enum member: 0
Enum member: 1
Enum member: bar
Enum member: foo

If you instead want only the member names, and not the values, you could do something like this:

for (var enumMember in myEnum) {
   var isValueProperty = parseInt(enumMember, 10) >= 0
   if (isValueProperty) {
      console.log("enum member: ", myEnum[enumMember]);
   }
}

That will print out just the names:

Enum member: bar  
Enum member: foo

Caveat: this slightly relies on an implementation detail: TypeScript compiles enums to a JS object with the enum values being members of the object. If TS decided to implement them different in the future, the above technique could break.

What is a classpath and how do I set it?

CLASSPATH is an environment variable (i.e., global variables of the operating system available to all the processes) needed for the Java compiler and runtime to locate the Java packages used in a Java program. (Why not call PACKAGEPATH?) This is similar to another environment variable PATH, which is used by the CMD shell to find the executable programs.

CLASSPATH can be set in one of the following ways:

CLASSPATH can be set permanently in the environment: In Windows, choose control panel ? System ? Advanced ? Environment Variables ? choose "System Variables" (for all the users) or "User Variables" (only the currently login user) ? choose "Edit" (if CLASSPATH already exists) or "New" ? Enter "CLASSPATH" as the variable name ? Enter the required directories and JAR files (separated by semicolons) as the value (e.g., ".;c:\javaproject\classes;d:\tomcat\lib\servlet-api.jar"). Take note that you need to include the current working directory (denoted by '.') in the CLASSPATH.

To check the current setting of the CLASSPATH, issue the following command:

> SET CLASSPATH

CLASSPATH can be set temporarily for that particular CMD shell session by issuing the following command:

> SET CLASSPATH=.;c:\javaproject\classes;d:\tomcat\lib\servlet-api.jar

Instead of using the CLASSPATH environment variable, you can also use the command-line option -classpath or -cp of the javac and java commands, for example,

> java –classpath c:\javaproject\classes com.abc.project1.subproject2.MyClass3

Using a bitmask in C#

To combine bitmasks you want to use bitwise-or. In the trivial case where every value you combine has exactly 1 bit on (like your example), it's equivalent to adding them. If you have overlapping bits however, or'ing them handles the case gracefully.

To decode the bitmasks you and your value with a mask, like so:

if(val & (1<<1)) SusanIsOn();
if(val & (1<<2)) BobIsOn();
if(val & (1<<3)) KarenIsOn();

Clear android application user data

If you want to do manually then You also can clear your user data by clicking “Clear Data” button in Settings–>Applications–>Manage Aplications–> YOUR APPLICATION

or Is there any other way to do that?

Then Download code here

enter image description here

Good way of getting the user's location in Android

This is my solution which works fairly well:

private Location bestLocation = null;
private Looper looper;
private boolean networkEnabled = false, gpsEnabled = false;

private synchronized void setLooper(Looper looper) {
    this.looper = looper;
}

private synchronized void stopLooper() {
    if (looper == null) return;
    looper.quit();
}

@Override
protected void runTask() {
    final LocationManager locationManager = (LocationManager) service
            .getSystemService(Context.LOCATION_SERVICE);
    final SharedPreferences prefs = getPreferences();
    final int maxPollingTime = Integer.parseInt(prefs.getString(
            POLLING_KEY, "0"));
    final int desiredAccuracy = Integer.parseInt(prefs.getString(
            DESIRED_KEY, "0"));
    final int acceptedAccuracy = Integer.parseInt(prefs.getString(
            ACCEPTED_KEY, "0"));
    final int maxAge = Integer.parseInt(prefs.getString(AGE_KEY, "0"));
    final String whichProvider = prefs.getString(PROVIDER_KEY, "any");
    final boolean canUseGps = whichProvider.equals("gps")
            || whichProvider.equals("any");
    final boolean canUseNetwork = whichProvider.equals("network")
            || whichProvider.equals("any");
    if (canUseNetwork)
        networkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);
    if (canUseGps)
        gpsEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);
    // If any provider is enabled now and we displayed a notification clear it.
    if (gpsEnabled || networkEnabled) removeErrorNotification();
    if (gpsEnabled)
        updateBestLocation(locationManager
                .getLastKnownLocation(LocationManager.GPS_PROVIDER));
    if (networkEnabled)
        updateBestLocation(locationManager
                .getLastKnownLocation(LocationManager.NETWORK_PROVIDER));
    if (desiredAccuracy == 0
            || getLocationQuality(desiredAccuracy, acceptedAccuracy,
                    maxAge, bestLocation) != LocationQuality.GOOD) {
        // Define a listener that responds to location updates
        LocationListener locationListener = new LocationListener() {

            public void onLocationChanged(Location location) {
                updateBestLocation(location);
                if (desiredAccuracy != 0
                        && getLocationQuality(desiredAccuracy,
                                acceptedAccuracy, maxAge, bestLocation)
                                == LocationQuality.GOOD)
                    stopLooper();
            }

            public void onProviderEnabled(String provider) {
                if (isSameProvider(provider,
                        LocationManager.NETWORK_PROVIDER))networkEnabled =true;
                else if (isSameProvider(provider,
                        LocationManager.GPS_PROVIDER)) gpsEnabled = true;
                // The user has enabled a location, remove any error
                // notification
                if (canUseGps && gpsEnabled || canUseNetwork
                        && networkEnabled) removeErrorNotification();
            }

            public void onProviderDisabled(String provider) {
                if (isSameProvider(provider,
                        LocationManager.NETWORK_PROVIDER))networkEnabled=false;
                else if (isSameProvider(provider,
                        LocationManager.GPS_PROVIDER)) gpsEnabled = false;
                if (!gpsEnabled && !networkEnabled) {
                    showErrorNotification();
                    stopLooper();
                }
            }

            public void onStatusChanged(String provider, int status,
                    Bundle extras) {
                Log.i(LOG_TAG, "Provider " + provider + " statusChanged");
                if (isSameProvider(provider,
                        LocationManager.NETWORK_PROVIDER)) networkEnabled = 
                        status == LocationProvider.AVAILABLE
                        || status == LocationProvider.TEMPORARILY_UNAVAILABLE;
                else if (isSameProvider(provider,
                        LocationManager.GPS_PROVIDER))
                    gpsEnabled = status == LocationProvider.AVAILABLE
                      || status == LocationProvider.TEMPORARILY_UNAVAILABLE;
                // None of them are available, stop listening
                if (!networkEnabled && !gpsEnabled) {
                    showErrorNotification();
                    stopLooper();
                }
                // The user has enabled a location, remove any error
                // notification
                else if (canUseGps && gpsEnabled || canUseNetwork
                        && networkEnabled) removeErrorNotification();
            }
        };
        if (networkEnabled || gpsEnabled) {
            Looper.prepare();
            setLooper(Looper.myLooper());
            // Register the listener with the Location Manager to receive
            // location updates
            if (canUseGps)
                locationManager.requestLocationUpdates(
                        LocationManager.GPS_PROVIDER, 1000, 1,
                        locationListener, Looper.myLooper());
            if (canUseNetwork)
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER, 1000, 1,
                        locationListener, Looper.myLooper());
            Timer t = new Timer();
            t.schedule(new TimerTask() {

                @Override
                public void run() {
                    stopLooper();
                }
            }, maxPollingTime * 1000);
            Looper.loop();
            t.cancel();
            setLooper(null);
            locationManager.removeUpdates(locationListener);
        } else // No provider is enabled, show a notification
        showErrorNotification();
    }
    if (getLocationQuality(desiredAccuracy, acceptedAccuracy, maxAge,
            bestLocation) != LocationQuality.BAD) {
        sendUpdate(new Event(EVENT_TYPE, locationToString(desiredAccuracy,
                acceptedAccuracy, maxAge, bestLocation)));
    } else Log.w(LOG_TAG, "LocationCollector failed to get a location");
}

private synchronized void showErrorNotification() {
    if (notifId != 0) return;
    ServiceHandler handler = service.getHandler();
    NotificationInfo ni = NotificationInfo.createSingleNotification(
            R.string.locationcollector_notif_ticker,
            R.string.locationcollector_notif_title,
            R.string.locationcollector_notif_text,
            android.R.drawable.stat_notify_error);
    Intent intent = new Intent(
            android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS);
    ni.pendingIntent = PendingIntent.getActivity(service, 0, intent,
            PendingIntent.FLAG_UPDATE_CURRENT);
    Message msg = handler.obtainMessage(ServiceHandler.SHOW_NOTIFICATION);
    msg.obj = ni;
    handler.sendMessage(msg);
    notifId = ni.id;
}

private void removeErrorNotification() {
    if (notifId == 0) return;
    ServiceHandler handler = service.getHandler();
    if (handler != null) {
        Message msg = handler.obtainMessage(
                ServiceHandler.CLEAR_NOTIFICATION, notifId, 0);
        handler.sendMessage(msg);
        notifId = 0;
    }
}

@Override
public void interrupt() {
    stopLooper();
    super.interrupt();
}

private String locationToString(int desiredAccuracy, int acceptedAccuracy,
        int maxAge, Location location) {
    StringBuilder sb = new StringBuilder();
    sb.append(String.format(
            "qual=%s time=%d prov=%s acc=%.1f lat=%f long=%f",
            getLocationQuality(desiredAccuracy, acceptedAccuracy, maxAge,
                    location), location.getTime() / 1000, // Millis to
                                                            // seconds
            location.getProvider(), location.getAccuracy(), location
                    .getLatitude(), location.getLongitude()));
    if (location.hasAltitude())
        sb.append(String.format(" alt=%.1f", location.getAltitude()));
    if (location.hasBearing())
        sb.append(String.format(" bearing=%.2f", location.getBearing()));
    return sb.toString();
}

private enum LocationQuality {
    BAD, ACCEPTED, GOOD;

    public String toString() {
        if (this == GOOD) return "Good";
        else if (this == ACCEPTED) return "Accepted";
        else return "Bad";
    }
}

private LocationQuality getLocationQuality(int desiredAccuracy,
        int acceptedAccuracy, int maxAge, Location location) {
    if (location == null) return LocationQuality.BAD;
    if (!location.hasAccuracy()) return LocationQuality.BAD;
    long currentTime = System.currentTimeMillis();
    if (currentTime - location.getTime() < maxAge * 1000
            && location.getAccuracy() <= desiredAccuracy)
        return LocationQuality.GOOD;
    if (acceptedAccuracy == -1
            || location.getAccuracy() <= acceptedAccuracy)
        return LocationQuality.ACCEPTED;
    return LocationQuality.BAD;
}

private synchronized void updateBestLocation(Location location) {
    bestLocation = getBestLocation(location, bestLocation);
}

protected Location getBestLocation(Location location,
        Location currentBestLocation) {
    if (currentBestLocation == null) {
        // A new location is always better than no location
        return location;
    }
    if (location == null) return currentBestLocation;
    // Check whether the new location fix is newer or older
    long timeDelta = location.getTime() - currentBestLocation.getTime();
    boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
    boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
    boolean isNewer = timeDelta > 0;
    // If it's been more than two minutes since the current location, use
    // the new location
    // because the user has likely moved
    if (isSignificantlyNewer) {
        return location;
        // If the new location is more than two minutes older, it must be
        // worse
    } else if (isSignificantlyOlder) {
        return currentBestLocation;
    }
    // Check whether the new location fix is more or less accurate
    int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation
            .getAccuracy());
    boolean isLessAccurate = accuracyDelta > 0;
    boolean isMoreAccurate = accuracyDelta < 0;
    boolean isSignificantlyLessAccurate = accuracyDelta > 200;
    // Check if the old and new location are from the same provider
    boolean isFromSameProvider = isSameProvider(location.getProvider(),
            currentBestLocation.getProvider());
    // Determine location quality using a combination of timeliness and
    // accuracy
    if (isMoreAccurate) {
        return location;
    } else if (isNewer && !isLessAccurate) {
        return location;
    } else if (isNewer && !isSignificantlyLessAccurate
            && isFromSameProvider) {
        return location;
    }
    return bestLocation;
}

/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
    if (provider1 == null) return provider2 == null;
    return provider1.equals(provider2);
}

jQuery: get parent, parent id?

$(this).parent().parent().attr('id');

Is how you would get the id of the parent's parent.

EDIT:

$(this).closest('ul').attr('id');

Is a more foolproof solution for your case.

How to programmatically set drawableLeft on Android button?

Kotlin Version

Use below snippet to add a drawable left to the button:

val drawable = ContextCompat.getDrawable(context, R.drawable.ic_favorite_white_16dp)
button.setCompoundDrawablesWithIntrinsicBounds(drawable, null, null, null)

.

Important Point in Using Android Vector Drawable

When you are using an android vector drawable and want to have backward compatibility for API below 21, add the following codes to:

In app level build.gradle:

android {
    defaultConfig {
        vectorDrawables.useSupportLibrary = true
    }
}

In Application class:

class MyApplication : Application() {

    override fun onCreate() {
        super.onCreate()

        AppCompatDelegate.setCompatVectorFromResourcesEnabled(true)
    }

}

Matching a Forward Slash with a regex

In regular expressions, "/" is a special character which needs to be escaped (AKA flagged by placing a \ before it thus negating any specialized function it might serve).

Here's what you need:

var word = /\/(\w+)/ig; //   /abc Match

Read up on RegEx special characters here: http://www.regular-expressions.info/characters.html

Bash scripting, multiple conditions in while loop

The extra [ ] on the outside of your second syntax are unnecessary, and possibly confusing. You may use them, but if you must you need to have whitespace between them.

Alternatively:

while [ $stats -gt 300 ] || [ $stats -eq 0 ]

How do I find out what all symbols are exported from a shared object?

The cross-platform way (not only cross-platform itself, but also working, at the very least, with both *.so and *.dll) is using reverse-engineering framework radare2. E.g.:

$ rabin2 -s glew32.dll | head -n 5 
[Symbols]
vaddr=0x62afda8d paddr=0x0005ba8d ord=000 fwd=NONE sz=0 bind=GLOBAL type=FUNC name=glew32.dll___GLEW_3DFX_multisample
vaddr=0x62afda8e paddr=0x0005ba8e ord=001 fwd=NONE sz=0 bind=GLOBAL type=FUNC name=glew32.dll___GLEW_3DFX_tbuffer
vaddr=0x62afda8f paddr=0x0005ba8f ord=002 fwd=NONE sz=0 bind=GLOBAL type=FUNC name=glew32.dll___GLEW_3DFX_texture_compression_FXT1
vaddr=0x62afdab8 paddr=0x0005bab8 ord=003 fwd=NONE sz=0 bind=GLOBAL type=FUNC name=glew32.dll___GLEW_AMD_blend_minmax_factor

As a bonus, rabin2 recognizes C++ name mangling, for example (and also with .so file):

$ rabin2 -s /usr/lib/libabw-0.1.so.1.0.1 | head -n 5
[Symbols]
vaddr=0x00027590 paddr=0x00027590 ord=124 fwd=NONE sz=430 bind=GLOBAL type=FUNC name=libabw::AbiDocument::isFileFormatSupported
vaddr=0x0000a730 paddr=0x0000a730 ord=125 fwd=NONE sz=58 bind=UNKNOWN type=FUNC name=boost::exception::~exception
vaddr=0x00232680 paddr=0x00032680 ord=126 fwd=NONE sz=16 bind=UNKNOWN type=OBJECT name=typeinfoforboost::exception_detail::clone_base
vaddr=0x00027740 paddr=0x00027740 ord=127 fwd=NONE sz=235 bind=GLOBAL type=FUNC name=libabw::AbiDocument::parse

Works with object files too:

$ g++ test.cpp -c -o a.o
$ rabin2 -s a.o | head -n 5
Warning: Cannot initialize program headers
Warning: Cannot initialize dynamic strings
Warning: Cannot initialize dynamic section
[Symbols]
vaddr=0x08000149 paddr=0x00000149 ord=006 fwd=NONE sz=1 bind=LOCAL type=OBJECT name=std::piecewise_construct
vaddr=0x08000149 paddr=0x00000149 ord=007 fwd=NONE sz=1 bind=LOCAL type=OBJECT name=std::__ioinit
vaddr=0x080000eb paddr=0x000000eb ord=017 fwd=NONE sz=73 bind=LOCAL type=FUNC name=__static_initialization_and_destruction_0
vaddr=0x08000134 paddr=0x00000134 ord=018 fwd=NONE sz=21 bind=LOCAL type=FUNC name=_GLOBAL__sub_I__Z4funcP6Animal

Which data structures and algorithms book should I buy?

Introduction to Algorithms by Cormen et. al. is a standard introductory algorithms book, and is used by many universities, including my own. It has pretty good coverage and is very approachable.

And anything by Robert Sedgewick is good too.

How to get only the date value from a Windows Forms DateTimePicker control?

Try this

var store = dtpDateTimePicker.Value.Date;

store can be anything entity object etc.

Refresh Page C# ASP.NET

I use

Response.Redirect(Page.Request.Path);

If you have to check for the Request.Params when the page is refresh use below. This will not rewrite the Request.Params to the URL.

Response.Redirect(Page.Request.Path + "?Remove=1");

How can I embed a YouTube video on GitHub wiki pages?

Adding a link with the thumbnail, originally used by YouTube is a solution, that works. The thumbnail, used by YouTube is accessible the following way:

  • if the official video link is: https://www.youtube.com/watch?v=5yLzZikS15k
  • then the thumbnail is: https://img.youtube.com/vi/5yLzZikS15k/0.jpg

Following this logic, the code below produces flawless results:

_x000D_
_x000D_
<div align="left">
      <a href="https://www.youtube.com/watch?v=5yLzZikS15k">
         <img src="https://img.youtube.com/vi/5yLzZikS15k/0.jpg" style="width:100%;">
      </a>
</div>
_x000D_
_x000D_
_x000D_

How to execute a JavaScript function when I have its name as a string

Don't use eval unless you absolutely, positively have no other choice.

As has been mentioned, using something like this would be the best way to do it:

window["functionName"](arguments);

That, however, will not work with a namespace'd function:

window["My.Namespace.functionName"](arguments); // fail

This is how you would do that:

window["My"]["Namespace"]["functionName"](arguments); // succeeds

In order to make that easier and provide some flexibility, here is a convenience function:

function executeFunctionByName(functionName, context /*, args */) {
  var args = Array.prototype.slice.call(arguments, 2);
  var namespaces = functionName.split(".");
  var func = namespaces.pop();
  for(var i = 0; i < namespaces.length; i++) {
    context = context[namespaces[i]];
  }
  return context[func].apply(context, args);
}

You would call it like so:

executeFunctionByName("My.Namespace.functionName", window, arguments);

Note, you can pass in whatever context you want, so this would do the same as above:

executeFunctionByName("Namespace.functionName", My, arguments);

Fast Bitmap Blur For Android SDK

Android Blur Guide 2016

with Showcase/Benchmark App and Source on Github. Also check out the Blur framework I'm currently working on: Dali.

After experimenting a lot I can now safely give you some solid recommendations that will make your life easier in Android when using the Android Framework.

Load and Use a downscaled Bitmap (for very blurry images)

Never use a the full size of a Bitmap. The bigger the image the more needs to be blurred and also the higher the blur radius needs to be and usually, the higher the blur radius the longer the algorithm takes.

final BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize = 8;
Bitmap blurTemplate = BitmapFactory.decodeResource(getResources(), R.drawable.myImage, options);

This will load the bitmap with inSampleSize 8, so only 1/64 of the original image. Test what inSampleSize suits your needs, but keep it 2^n (2,4,8,...) to avoid degrading quality due to scaling. See Google doc for more

Another really big advantage is that bitmap loading will be really fast. In my early blur testing I figured that the longest time during the whole blur process was the image loading. So to load a 1920x1080 image from disk my Nexus 5 needed 500ms while the blurring only took another 250 ms or so.

Use Renderscript

Renderscript provides ScriptIntrinsicBlur which is a Gaussian blur filter. It has good visual quality and is just the fastest you realistically get on Android. Google claims to be "typically 2-3x faster than a multithreaded C implementation and often 10x+ faster than a Java implementation". Renderscript is really sophisticated (using the fastest processing device (GPU, ISP, etc.), etc.) and there is also the v8 support library for it making it compatible down to 2.2. Well at least in theory, through my own tests and reports from other devs it seems that it is not possible to use Renderscript blindly, since the hardware/driver fragmentation seems to cause problems with some devices, even with higher sdk lvl (e.g. I had troubles with the 4.1 Nexus S) so be careful and test on a lot of devices. Here's a simple example that will get you started:

//define this only once if blurring multiple times
RenderScript rs = RenderScript.create(context);

(...)
//this will blur the bitmapOriginal with a radius of 8 and save it in bitmapOriginal
final Allocation input = Allocation.createFromBitmap(rs, bitmapOriginal); //use this constructor for best performance, because it uses USAGE_SHARED mode which reuses memory
final Allocation output = Allocation.createTyped(rs, input.getType());
final ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
script.setRadius(8f);
script.setInput(input);
script.forEach(output);
output.copyTo(bitmapOriginal);

When using the v8 support with Gradle, which is specifically recommended by Google "because they include the latest improvements", you only need to add 2 lines to your build script and use android.support.v8.renderscript with current build tools (updated syntax for android Gradle plugin v14+)

android {
    ...
    defaultConfig {
        ...
        renderscriptTargetApi 19
        renderscriptSupportModeEnabled true
    }
}

Simple benchmark on a Nexus 5 - comparing RenderScript with different other java and Renderscript implementations:

The average runtime per blur on different pic sizes The average runtime per blur on different pic sizes

Megapixels per sec that can be blurred Megapixels per sec that can be blurred

Each value is the avg of 250 rounds. RS_GAUSS_FAST is ScriptIntrinsicBlur (and nearly always the fastest), others that start with RS_ are mostly convolve implementations with simple kernels. The details of the algorithms can be found here. This is not purely blurring, since a good portion is garbage collection that is measured. This can be seen in this here (ScriptIntrinsicBlur on a 100x100 image with about 500 rounds)

enter image description here

The spikes are gc.

You can check for yourself, the benchmark app is in the playstore: BlurBenchmark

Reuses Bitmap wherever possible (if prio: performance > memory footprint)

If you need multiple blurs for a live blur or similar and your memory allows it do not load the bitmap from drawables multiple times, but keep it "cached" in a member variable. In this case always try to use the same variables, to keep garbage collecting to a minimum.

Also check out the new inBitmap option when loading from a file or drawable which will reuse the bitmap memory and save garbage collection time.

For blending from sharp to blurry

The simple and naive method is just to use 2 ImageViews, one blurred, and alpha fade them. But if you want a more sophisticated look that smoothly fades from sharp to blurry, then check out Roman Nurik's post about how to do it like in his Muzei app.

Basically he explains that he pre-blurs some frames with different blur extents and uses them as keyframes in an animation that looks really smooth.

Diagram where Nurik exaplains his approach

Check if string has space in between (or anywhere)

This functions should help you...

bool isThereSpace(String s){
    return s.Contains(" ");
}

how to display excel sheet in html page

Try this it will work...

<iframe src="Tmp.XLS" width="100%" height="500"></iframe>

But you can not save changes that you have done...It is used only for displaying purpose..

What's the difference between commit() and apply() in SharedPreferences

I'm experiencing some problems using apply() instead commit(). As stated before in other responses, the apply() is asynchronous. I'm getting the problem that the changes formed to a "string set" preference are never written to the persistent memory.

It happens if you "force detention" of the program or, in the ROM that I have installed on my device with Android 4.1, when the process is killed by the system due to memory necessities.

I recommend to use "commit()" instead "apply()" if you want your preferences alive.

Gradle, Android and the ANDROID_HOME SDK location

I came across a similar problem. Somehow, I did not have a build folder in my project. By copying this folder from another project to my project I was having an issue with, this fixed this problem.

Open Source Javascript PDF viewer

There are some guys at Mozilla working on implementing a PDF reader using HTML5 and JavaScript. It is called pdf.js and one of the developers just made an interesting blog post about the project.

Looping Over Result Sets in MySQL

Use cursors.

A cursor can be thought of like a buffered reader, when reading through a document. If you think of each row as a line in a document, then you would read the next line, perform your operations, and then advance the cursor.

How to add an image to an svg container using D3.js

In SVG (contrasted with HTML), you will want to use <image> instead of <img> for elements.

Try changing your last block with:

var imgs = svg.selectAll("image").data([0]);
            imgs.enter()
            .append("svg:image")
            ...

How to delete columns in numpy.array

>>> A = array([[ 1,  2,  3,  4],
               [ 5,  6,  7,  8],
               [ 9, 10, 11, 12]])

>>> A = A.transpose()

>>> A = A[1:].transpose()

How many bytes in a JavaScript string?

The size of a JavaScript string is

  • Pre-ES6: 2 bytes per character
  • ES6 and later: 2 bytes per character, or 5 or more bytes per character

Pre-ES6
Always 2 bytes per character. UTF-16 is not allowed because the spec says "values must be 16-bit unsigned integers". Since UTF-16 strings can use 3 or 4 byte characters, it would violate 2 byte requirement. Crucially, while UTF-16 cannot be fully supported, the standard does require that the two byte characters used are valid UTF-16 characters. In other words, Pre-ES6 JavaScript strings support a subset of UTF-16 characters.

ES6 and later
2 bytes per character, or 5 or more bytes per character. The additional sizes come into play because ES6 (ECMAScript 6) adds support for Unicode code point escapes. Using a unicode escape looks like this: \u{1D306}

Practical notes

  • This doesn't relate to the internal implemention of a particular engine. For example, some engines use data structures and libraries with full UTF-16 support, but what they provide externally doesn't have to be full UTF-16 support. Also an engine may provide external UTF-16 support as well but is not mandated to do so.

  • For ES6, practically speaking characters will never be more than 5 bytes long (2 bytes for the escape point + 3 bytes for the Unicode code point) because the latest version of Unicode only has 136,755 possible characters, which fits easily into 3 bytes. However this is technically not limited by the standard so in principal a single character could use say, 4 bytes for the code point and 6 bytes total.

  • Most of the code examples here for calculating byte size don't seem to take into account ES6 Unicode code point escapes, so the results could be incorrect in some cases.

how to remove only one style property with jquery

You can also replace "-moz-user-select:none" with "-moz-user-select:inherit". This will inherit the style value from any parent style or from the default style if no parent style was defined.

How to decorate a class?

No one has explained that you can dynamically define classes. So you can have a decorator that defines (and returns) a subclass:

def addId(cls):

    class AddId(cls):

        def __init__(self, id, *args, **kargs):
            super(AddId, self).__init__(*args, **kargs)
            self.__id = id

        def getId(self):
            return self.__id

    return AddId

Which can be used in Python 2 (the comment from Blckknght which explains why you should continue to do this in 2.6+) like this:

class Foo:
    pass

FooId = addId(Foo)

And in Python 3 like this (but be careful to use super() in your classes):

@addId
class Foo:
    pass

So you can have your cake and eat it - inheritance and decorators!

Angular directives - when and how to use compile, controller, pre-link and post-link

Controller function

Each directive's controller function is called whenever a new related element is instantiated.

Officially, the controller function is where one:

  • Defines controller logic (methods) that may be shared between controllers.
  • Initiates scope variables.

Again, it is important to remember that if the directive involves an isolated scope, any properties within it that inherit from the parent scope are not yet available.

Do:

  • Define controller logic
  • Initiate scope variables

Do not:

  • Inspect child elements (they may not be rendered yet, bound to scope, etc.).

Dynamically display a CSV file as an HTML table on a web page

The previously linked solution is a horrible piece of code; nearly every line contains a bug. Use fgetcsv instead:

<?php
echo "<html><body><table>\n\n";
$f = fopen("so-csv.csv", "r");
while (($line = fgetcsv($f)) !== false) {
        echo "<tr>";
        foreach ($line as $cell) {
                echo "<td>" . htmlspecialchars($cell) . "</td>";
        }
        echo "</tr>\n";
}
fclose($f);
echo "\n</table></body></html>";

TLS 1.2 in .NET Framework 4.0

There are two possible scenarios,

  1. If your application runs on .net framework 4.5 or less, and you can easily deploy new code to the production then you can use of below solution.

    You can add the below line of code before making the API call,

    ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12; // .NET 4.5
    ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072; // .NET 4.0
    
  2. If you cannot deploy new code and you want to resolve the issue with the same code which is present in the production, then you have two options.

Option 1 :

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30319]
"SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\.NETFramework\v4.0.30319]
"SchUseStrongCrypto"=dword:00000001


then create a file with extension .reg and install.

Note : This setting will apply at registry level and is applicable to all application present on that machine and if you want to restrict to only single application then you can use Option 2

Option 2 : This can be done by changing some configuration setting in config file. You can add either in your config file.

<runtime>
    <AppContextSwitchOverrides value="Switch.System.Net.DontEnableSchUseStrongCrypto=false"/>
</runtime>

or

<runtime>
  <AppContextSwitchOverrides value="Switch.System.Net.DontEnableSystemDefaultTlsVersions=false"
</runtime>

caching JavaScript files

or in the .htaccess file

AddOutputFilter DEFLATE css js
ExpiresActive On
ExpiresByType application/x-javascript A2592000

C# looping through an array

Here is a more general solution:

int increment = 3;
for(int i = 0; i < theData.Length; i += increment)
{
   for(int j = 0; j < increment; j++)
   {
      if(i+j < theData.Length) {
         //theData[i + j] for the current index
      }
   }

}

How can I get the "network" time, (from the "Automatic" setting called "Use network-provided values"), NOT the time on the phone?

Get the library from http://commons.apache.org/net/download_net.cgi

//NTP server list: http://tf.nist.gov/tf-cgi/servers.cgi
public static final String TIME_SERVER = "time-a.nist.gov";

public static long getCurrentNetworkTime() {
    NTPUDPClient timeClient = new NTPUDPClient();
    InetAddress inetAddress = InetAddress.getByName(TIME_SERVER);
    TimeInfo timeInfo = timeClient.getTime(inetAddress);
    //long returnTime = timeInfo.getReturnTime();   //local device time
    long returnTime = timeInfo.getMessage().getTransmitTimeStamp().getTime();   //server time

    Date time = new Date(returnTime);
    Log.d(TAG, "Time from " + TIME_SERVER + ": " + time);

    return returnTime;
}

getReturnTime() is same as System.currentTimeMillis().

getReceiveTimeStamp() or getTransmitTimeStamp() method should be used.

You can see the difference after setting system time to 1 hour ago.

local time :
System.currentTimeMillis()
timeInfo.getReturnTime()
timeInfo.getMessage().getOriginateTimeStamp().getTime()

NTP server time :
timeInfo.getMessage().getReceiveTimeStamp().getTime()
timeInfo.getMessage().getTransmitTimeStamp().getTime()

sql ORDER BY multiple values in specific order?

I found a much cleaner solution for this:

ORDER BY array_position(ARRAY['f', 'p', 'i', 'a']::varchar[], x_field)

Note: array_position needs Postgres v9.5 or higher.

How to execute only one test spec with angular-cli

In a bash terminal I like to use the double dash. Using VS Code, you can right click on the spec file in the explorer, or on the open tab. Then select 'Copy Relative Path'. Run the command below pasting the relative path in from the clipboard.

npm t -- --include relative/path/to/file.spec.ts

The double dash signals the end of your command options for npm t and passes anything after that to the next command which is pointing to ng t. It's doesn't require any modification and quickly gives desired results.

Load an image from a url into a PictureBox

Here's the solution I use. I can't remember why I couldn't just use the PictureBox.Load methods. I'm pretty sure it's because I wanted to properly scale & center the downloaded image into the PictureBox control. If I recall, all the scaling options on PictureBox either stretch the image, or will resize the PictureBox to fit the image. I wanted a properly scaled and centered image in the size I set for PictureBox.

Now, I just need to make a async version...

Here's my methods:

   #region Image Utilities

    /// <summary>
    /// Loads an image from a URL into a Bitmap object.
    /// Currently as written if there is an error during downloading of the image, no exception is thrown.
    /// </summary>
    /// <param name="url"></param>
    /// <returns></returns>
    public static Bitmap LoadPicture(string url)
    {
        System.Net.HttpWebRequest wreq;
        System.Net.HttpWebResponse wresp;
        Stream mystream;
        Bitmap bmp;

        bmp = null;
        mystream = null;
        wresp = null;
        try
        {
            wreq = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(url);
            wreq.AllowWriteStreamBuffering = true;

            wresp = (System.Net.HttpWebResponse)wreq.GetResponse();

            if ((mystream = wresp.GetResponseStream()) != null)
                bmp = new Bitmap(mystream);
        }
        catch
        {
            // Do nothing... 
        }
        finally
        {
            if (mystream != null)
                mystream.Close();

            if (wresp != null)
                wresp.Close();
        }

        return (bmp);
    }

    /// <summary>
    /// Takes in an image, scales it maintaining the proper aspect ratio of the image such it fits in the PictureBox's canvas size and loads the image into picture box.
    /// Has an optional param to center the image in the picture box if it's smaller then canvas size.
    /// </summary>
    /// <param name="image">The Image you want to load, see LoadPicture</param>
    /// <param name="canvas">The canvas you want the picture to load into</param>
    /// <param name="centerImage"></param>
    /// <returns></returns>

    public static Image ResizeImage(Image image, PictureBox canvas, bool centerImage ) 
    {
        if (image == null || canvas == null)
        {
            return null;
        }

        int canvasWidth = canvas.Size.Width;
        int canvasHeight = canvas.Size.Height;
        int originalWidth = image.Size.Width;
        int originalHeight = image.Size.Height;

        System.Drawing.Image thumbnail =
            new Bitmap(canvasWidth, canvasHeight); // changed parm names
        System.Drawing.Graphics graphic =
                     System.Drawing.Graphics.FromImage(thumbnail);

        graphic.InterpolationMode = InterpolationMode.HighQualityBicubic;
        graphic.SmoothingMode = SmoothingMode.HighQuality;
        graphic.PixelOffsetMode = PixelOffsetMode.HighQuality;
        graphic.CompositingQuality = CompositingQuality.HighQuality;

        /* ------------------ new code --------------- */

        // Figure out the ratio
        double ratioX = (double)canvasWidth / (double)originalWidth;
        double ratioY = (double)canvasHeight / (double)originalHeight;
        double ratio = ratioX < ratioY ? ratioX : ratioY; // use whichever multiplier is smaller

        // now we can get the new height and width
        int newHeight = Convert.ToInt32(originalHeight * ratio);
        int newWidth = Convert.ToInt32(originalWidth * ratio);

        // Now calculate the X,Y position of the upper-left corner 
        // (one of these will always be zero)
        int posX = Convert.ToInt32((canvasWidth - (image.Width * ratio)) / 2);
        int posY = Convert.ToInt32((canvasHeight - (image.Height * ratio)) / 2);

        if (!centerImage)
        {
            posX = 0;
            posY = 0;
        }
        graphic.Clear(Color.White); // white padding
        graphic.DrawImage(image, posX, posY, newWidth, newHeight);

        /* ------------- end new code ---------------- */

        System.Drawing.Imaging.ImageCodecInfo[] info =
                         ImageCodecInfo.GetImageEncoders();
        EncoderParameters encoderParameters;
        encoderParameters = new EncoderParameters(1);
        encoderParameters.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality,
                         100L);

        Stream s = new System.IO.MemoryStream();
        thumbnail.Save(s, info[1],
                          encoderParameters);

        return Image.FromStream(s);
    }

    #endregion

Here's the required includes. (Some might be needed by other code, but including all to be safe)

using System.Windows.Forms;
using System.Drawing.Drawing2D;
using System.IO;
using System.Drawing.Imaging;
using System.Text.RegularExpressions;
using System.Drawing;

How I generally use it:

 ImageUtil.ResizeImage(ImageUtil.LoadPicture( "http://someurl/img.jpg", pictureBox1, true);

How to use DbContext.Database.SqlQuery<TElement>(sql, params) with stored procedure? EF Code First CTP5

Most answers are brittle because they rely on the order of the SP's parameters. Better to name the Stored Proc's params and give parameterized values to those.

In order to use Named params when calling your SP, without worrying about the order of parameters

Using SQL Server named parameters with ExecuteStoreQuery and ExecuteStoreCommand

Describes the best approach. Better than Dan Mork's answer here.

  • Doesn't rely on concatenating strings, and doesn't rely on the order of parameters defined in the SP.

E.g.:

var cmdText = "[DoStuff] @Name = @name_param, @Age = @age_param";
var sqlParams = new[]{
   new SqlParameter("name_param", "Josh"),
   new SqlParameter("age_param", 45)
};

context.Database.SqlQuery<myEntityType>(cmdText, sqlParams)

How to share my Docker-Image without using the Docker-Hub?

Sending a docker image to a remote server can be done in 3 simple steps:

  1. Locally, save docker image as a .tar:
docker save -o <path for created tar file> <image name>
  1. Locally, use scp to transfer .tar to remote

  2. On remote server, load image into docker:

docker load -i <path to docker image tar file>

How to apply style classes to td classes?

Simply create a Class Name and define your style there like this :

table.tdfont td {
  font-size: 0.9em;
}

Spring 3.0 - Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/security]

if adding dependencies haven`t solved your problem, create WAR archive again. In my case, I used obsolete WAR file without security-web and security-conf jars

How do I create a self-signed certificate for code signing on Windows?

Roger's answer was very helpful.

I had a little trouble using it, though, and kept getting the red "Windows can't verify the publisher of this driver software" error dialog. The key was to install the test root certificate with

certutil -addstore Root Demo_CA.cer

which Roger's answer didn't quite cover.

Here is a batch file that worked for me (with my .inf file, not included). It shows how to do it all from start to finish, with no GUI tools at all (except for a few password prompts).

REM Demo of signing a printer driver with a self-signed test certificate.
REM Run as administrator (else devcon won't be able to try installing the driver)
REM Use a single 'x' as the password for all certificates for simplicity.

PATH %PATH%;"c:\Program Files\Microsoft SDKs\Windows\v7.1\Bin";"c:\Program Files\Microsoft SDKs\Windows\v7.0\Bin";c:\WinDDK\7600.16385.1\bin\selfsign;c:\WinDDK\7600.16385.1\Tools\devcon\amd64

makecert -r -pe -n "CN=Demo_CA" -ss CA -sr CurrentUser ^
   -a sha256 -cy authority -sky signature ^
   -sv Demo_CA.pvk Demo_CA.cer

makecert -pe -n "CN=Demo_SPC" -a sha256 -cy end ^
   -sky signature ^
   -ic Demo_CA.cer -iv Demo_CA.pvk ^
   -sv Demo_SPC.pvk Demo_SPC.cer

pvk2pfx -pvk Demo_SPC.pvk -spc Demo_SPC.cer ^
   -pfx Demo_SPC.pfx ^
   -po x

inf2cat /drv:driver /os:XP_X86,Vista_X64,Vista_X86,7_X64,7_X86 /v

signtool sign /d "description" /du "www.yoyodyne.com" ^
   /f Demo_SPC.pfx ^
   /p x ^
   /v driver\demoprinter.cat

certutil -addstore Root Demo_CA.cer

rem Needs administrator. If this command works, the driver is properly signed.
devcon install driver\demoprinter.inf LPTENUM\Yoyodyne_IndustriesDemoPrinter_F84F

rem Now uninstall the test driver and certificate.
devcon remove driver\demoprinter.inf LPTENUM\Yoyodyne_IndustriesDemoPrinter_F84F

certutil -delstore Root Demo_CA

How to switch text case in visual studio code

Echoing justanotherdev's comment:

Mind-blowing and useful:

  1. Command Palette: CTRL + SHIFT + p (Mac: CMD + SHIFT + p)
  2. type >transform pick upper/lower case and press enter

enter image description here

Getting one value from a tuple

For anyone in the future looking for an answer, I would like to give a much clearer answer to the question.

# for making a tuple
my_tuple = (89, 32)
my_tuple_with_more_values = (1, 2, 3, 4, 5, 6)

# to concatenate tuples
another_tuple = my_tuple + my_tuple_with_more_values
print(another_tuple)
# (89, 32, 1, 2, 3, 4, 5, 6)

# getting a value from a tuple is similar to a list
first_val = my_tuple[0]
second_val = my_tuple[1]

# if you have a function called my_tuple_fun that returns a tuple,
# you might want to do this
my_tuple_fun()[0]
my_tuple_fun()[1]

# or this
v1, v2 = my_tuple_fun()

Hope this clears things up further for those that need it.

Spring Boot: Cannot access REST Controller on localhost (404)

Try adding the following to your InventoryApp class

@SpringBootApplication
@ComponentScan(basePackageClasses = ItemInventoryController.class)
public class InventoryApp {
...

spring-boot will scan for components in packages below com.nice.application, so if your controller is in com.nice.controller you need to scan for it explicitly.

text-align: right; not working for <label>

As stated in other answers, label is an inline element. However, you can apply display: inline-block to the label and then center with text-align.

#name_label {
    display: inline-block;
    width: 90%;
    text-align: right;
}

Why display: inline-block and not display: inline? For the same reason that you can't align label, it's inline.

Why display: inline-block and not display: block? You could use display: block, but it will be on another line. display: inline-block combines the properties of inline and block. It's inline, but you can also give it a width, height, and align it.

SQL Error: ORA-00933: SQL command not properly ended

its very true on oracle as well as sql is "users" is a reserved words just change it , it will serve u the best if u like change it to this

UPDATE system_info set field_value = 'NewValue' 

FROM system_users users JOIN system_info info ON users.role_type = info.field_desc where users.user_name = 'uname'

AngularJS - Does $destroy remove event listeners?

Event listeners

First off it's important to understand that there are two kinds of "event listeners":

  1. Scope event listeners registered via $on:

    $scope.$on('anEvent', function (event, data) {
      ...
    });
    
  2. Event handlers attached to elements via for example on or bind:

    element.on('click', function (event) {
      ...
    });
    

$scope.$destroy()

When $scope.$destroy() is executed it will remove all listeners registered via $on on that $scope.

It will not remove DOM elements or any attached event handlers of the second kind.

This means that calling $scope.$destroy() manually from example within a directive's link function will not remove a handler attached via for example element.on, nor the DOM element itself.


element.remove()

Note that remove is a jqLite method (or a jQuery method if jQuery is loaded before AngularjS) and is not available on a standard DOM Element Object.

When element.remove() is executed that element and all of its children will be removed from the DOM together will all event handlers attached via for example element.on.

It will not destroy the $scope associated with the element.

To make it more confusing there is also a jQuery event called $destroy. Sometimes when working with third-party jQuery libraries that remove elements, or if you remove them manually, you might need to perform clean up when that happens:

element.on('$destroy', function () {
  scope.$destroy();
});

What to do when a directive is "destroyed"

This depends on how the directive is "destroyed".

A normal case is that a directive is destroyed because ng-view changes the current view. When this happens the ng-view directive will destroy the associated $scope, sever all the references to its parent scope and call remove() on the element.

This means that if that view contains a directive with this in its link function when it's destroyed by ng-view:

scope.$on('anEvent', function () {
 ...
});

element.on('click', function () {
 ...
});

Both event listeners will be removed automatically.

However, it's important to note that the code inside these listeners can still cause memory leaks, for example if you have achieved the common JS memory leak pattern circular references.

Even in this normal case of a directive getting destroyed due to a view changing there are things you might need to manually clean up.

For example if you have registered a listener on $rootScope:

var unregisterFn = $rootScope.$on('anEvent', function () {});

scope.$on('$destroy', unregisterFn);

This is needed since $rootScope is never destroyed during the lifetime of the application.

The same goes if you are using another pub/sub implementation that doesn't automatically perform the necessary cleanup when the $scope is destroyed, or if your directive passes callbacks to services.

Another situation would be to cancel $interval/$timeout:

var promise = $interval(function () {}, 1000);

scope.$on('$destroy', function () {
  $interval.cancel(promise);
});

If your directive attaches event handlers to elements for example outside the current view, you need to manually clean those up as well:

var windowClick = function () {
   ...
};

angular.element(window).on('click', windowClick);

scope.$on('$destroy', function () {
  angular.element(window).off('click', windowClick);
});

These were some examples of what to do when directives are "destroyed" by Angular, for example by ng-view or ng-if.

If you have custom directives that manage the lifecycle of DOM elements etc. it will of course get more complex.

What's the difference between a web site and a web application?

The technical difference according to two features:
1. Where the "work" is done
2. What is being transferred to/from the server

Web app
1. The "work" is done at the browser (JavaScript)
2. Data is being transferred from/to the server
In comparison: Faster

Website
1. The "work" (most of it) is done at the server
2. Rendered pages (data + UI) are being transferred from the server
In comparison: Easier SEO

How to get char from string by index?

This should further clarify the points:

a = int(raw_input('Enter the index'))
str1 = 'Example'
leng = len(str1)
if (a < (len-1)) and (a > (-len)):
    print str1[a]
else:
    print('Index overflow')

Input 3 Output m

Input -3 Output p

How to remove the arrow from a select element in Firefox

While not a complete solution I've found that…

-moz-appearance: window;

…works to some extent. You can't change the background (-color or -image) but the element can be rendered invisible with color: transparent. Not perfect but it's a start and you don't need to replace the system level element with a js one.