Programs & Examples On #Ofstream

Output file streams are C++ standard library objects used to write to files.

Read file line by line using ifstream in C++

Reading a file line by line in C++ can be done in some different ways.

[Fast] Loop with std::getline()

The simplest approach is to open an std::ifstream and loop using std::getline() calls. The code is clean and easy to understand.

#include <fstream>

std::ifstream file(FILENAME);
if (file.is_open()) {
    std::string line;
    while (std::getline(file, line)) {
        // using printf() in all tests for consistency
        printf("%s", line.c_str());
    }
    file.close();
}

[Fast] Use Boost's file_description_source

Another possibility is to use the Boost library, but the code gets a bit more verbose. The performance is quite similar to the code above (Loop with std::getline()).

#include <boost/iostreams/device/file_descriptor.hpp>
#include <boost/iostreams/stream.hpp>
#include <fcntl.h>

namespace io = boost::iostreams;

void readLineByLineBoost() {
    int fdr = open(FILENAME, O_RDONLY);
    if (fdr >= 0) {
        io::file_descriptor_source fdDevice(fdr, io::file_descriptor_flags::close_handle);
        io::stream <io::file_descriptor_source> in(fdDevice);
        if (fdDevice.is_open()) {
            std::string line;
            while (std::getline(in, line)) {
                // using printf() in all tests for consistency
                printf("%s", line.c_str());
            }
            fdDevice.close();
        }
    }
}

[Fastest] Use C code

If performance is critical for your software, you may consider using the C language. This code can be 4-5 times faster than the C++ versions above, see benchmark below

FILE* fp = fopen(FILENAME, "r");
if (fp == NULL)
    exit(EXIT_FAILURE);

char* line = NULL;
size_t len = 0;
while ((getline(&line, &len, fp)) != -1) {
    // using printf() in all tests for consistency
    printf("%s", line);
}
fclose(fp);
if (line)
    free(line);

Benchmark -- Which one is faster?

I have done some performance benchmarks with the code above and the results are interesting. I have tested the code with ASCII files that contain 100,000 lines, 1,000,000 lines and 10,000,000 lines of text. Each line of text contains 10 words in average. The program is compiled with -O3 optimization and its output is forwarded to /dev/null in order to remove the logging time variable from the measurement. Last, but not least, each piece of code logs each line with the printf() function for consistency.

The results show the time (in ms) that each piece of code took to read the files.

The performance difference between the two C++ approaches is minimal and shouldn't make any difference in practice. The performance of the C code is what makes the benchmark impressive and can be a game changer in terms of speed.

                             10K lines     100K lines     1000K lines
Loop with std::getline()         105ms          894ms          9773ms
Boost code                       106ms          968ms          9561ms
C code                            23ms          243ms          2397ms

enter image description here

How to check what user php is running as?

$_SERVER["USER"]

$_SERVER["USERNAME"] 

Programmatically scroll to a specific position in an Android ListView

Handling listView scrolling using UP/ Down using.button

If someone is interested in handling listView one row up/down using button. then.

public View.OnClickListener onChk = new View.OnClickListener() {
             public void onClick(View v) {

                 int index = list.getFirstVisiblePosition();
                 getListView().smoothScrollToPosition(index+1); // For increment. 

}
});

GZIPInputStream reading line by line

GZIPInputStream gzip = new GZIPInputStream(new FileInputStream("F:/gawiki-20090614-stub-meta-history.xml.gz"));
BufferedReader br = new BufferedReader(new InputStreamReader(gzip));
br.readLine();

read file in classpath

Try getting Spring to inject it, assuming you're using Spring as a dependency-injection framework.

In your class, do something like this:

public void setSqlResource(Resource sqlResource) {
    this.sqlResource = sqlResource;
}

And then in your application context file, in the bean definition, just set a property:

<bean id="someBean" class="...">
    <property name="sqlResource" value="classpath:com/somecompany/sql/sql.txt" />
</bean>

And Spring should be clever enough to load up the file from the classpath and give it to your bean as a resource.

You could also look into PropertyPlaceholderConfigurer, and store all your SQL in property files and just inject each one separately where needed. There are lots of options.

Concatenate chars to form String in java

Use str = ""+a+b+c;

Here the first + is String concat, so the result will be a String. Note where the "" lies is important.

Or (maybe) better, use a StringBuilder.

How to display HTML tags as plain text

Replace < with &lt; and > with &gt;.

Remove all multiple spaces in Javascript and replace with single space

You can also replace without a regular expression.

while(str.indexOf('  ')!=-1)str.replace('  ',' ');

Storyboard doesn't contain a view controller with identifier

Use your identifier(@"drivingDetails") as Storyboard ID.

C# string reference type?

"A picture is worth a thousand words".

I have a simple example here, it's similar to your case.

string s1 = "abc";
string s2 = s1;
s1 = "def";
Console.WriteLine(s2);
// Output: abc

This is what happened:

enter image description here

  • Line 1 and 2: s1 and s2 variables reference to the same "abc" string object.
  • Line 3: Because strings are immutable, so the "abc" string object do not modify itself (to "def"), but a new "def" string object is created instead, and then s1 references to it.
  • Line 4: s2 still references to "abc" string object, so that's the output.

Running Python on Windows for Node.js dependencies

If you're trying to use this on Cygwin, then you need to follow the instructions in this answer. (It's a problem how Cygwin treats Windows symlinks.)

PHP substring extraction. Get the string before the first '/' or the whole string

You can also use this one line solution

list($substring) = explode("/", $string);

SQL Server: Is it possible to insert into two tables at the same time?

//if you want to insert the same as first table

$qry = "INSERT INTO table (one, two, three) VALUES('$one','$two','$three')";

$result = @mysql_query($qry);

$qry2 = "INSERT INTO table2 (one,two, three) VVALUES('$one','$two','$three')";

$result = @mysql_query($qry2);

//or if you want to insert certain parts of table one

 $qry = "INSERT INTO table (one, two, three) VALUES('$one','$two','$three')";


  $result = @mysql_query($qry);

 $qry2 = "INSERT INTO table2 (two) VALUES('$two')";

 $result = @mysql_query($qry2);

//i know it looks too good to be right, but it works and you can keep adding query's just change the

    "$qry"-number and number in @mysql_query($qry"")

I have 17 tables this has worked in.

ASP.NET Web Api: The requested resource does not support http method 'GET'

If you have not configured any HttpMethod on your action in controller, it is assumed to be only HttpPost in RC. In Beta, it is assumed to support all methods - GET, PUT, POST and Delete. This is a small change from beta to RC. You could easily decore more than one httpmethod on your action with [AcceptVerbs("GET", "POST")].

How to add app icon within phonegap projects?

FAQ: ICON / SPLASH SCREEN (Cordova 5.x / 2015)

I present my answer as a general FAQ that may help you to solve many problems I've encountered while dealing with icons/splash screens. You may find out like me that the documentation is not always very clear nor up to date. This will probably go to StackOverflow documentation when available.

First: answering the question

How can I add custom app icons for iOS and Android with phonegap?

In your version of Cordova the icon tag is useless. It is not even documented in Cordova 3.0.0. You should use the documentation version that fits the cli you are using and not the latest one!

The icon tag does not work for Android at all before the version 3.5.0 according to what I can see in the different versions of the documentation. In 3.4.0 they still advice to manually copy the files

In newer versions: your config.xml looks better for newer Cordova versions. However there are still many things you may want to know. If you decide to upgrade here are some useful things to modify:

  • You don't need the gap: namespace
  • You need <preference name="SplashScreen" value="screen" /> for Android

Here are more details of the questions you might ask yourself when trying to deal with icons and splash screen:

Can I use an old version of Cordova / Phonegap

No, the icon/splashscreen feature was not in former versions of Cordova so you must use a recent version. In former versions, only Phonegap Build did handle the icons/splash screen so building locally and handling icons was only possible with a hook. I don't know the minimum version to use this feature but with 5.1.1 it works fine in both Cordova/Phonegap cli. With Cordova 3.5 it didn't work for me.

Edit: for Android you must use at least 3.5.0

How can I debug the build process about icons?

The cli use a CP command. If you provide an invalid icon path, it will show a cp error:

sebastien@sebastien-xps:cordova (dev *+$%)$ cordova run android --device
cp: no such file or directory: /home/sebastien/Desktop/Stample-react/cordova/res/www/stample_splash.png

Edit: you have use cordova build <platform> --verbose to get logs of cp command usage to see where your icons gets copied

The icons should go in a folder according to the config. For me it goes in many subfolders in : platforms/android/build/intermediates/res/armv7/debug/drawable-hdpi-v4/icon.png

Then you can find the APK, and open it as a zip archive to check the icons are present. They must be in a res/drawable* folder because it's a special folder for Android.

Where should I put the icons/splash screens in my project?

In many examples you will find the icons/splash screens are declared inside a res folder. This res is a special Android folder in the output APK, but it does not mean you have to use a res folder in your project.

You can put your icon anywhere, but the path you use must be relative to the root of the project, and not www so take care! This is documented, but not clearly because all the examples are using res and you don't know where this folder is :(

I mean if you put the icon in www/icon.png you absolutly must include www in your path.

Edit Mars 2016: after upgrading my versions, now it seems that icons are relative to www folder but documentation has not been changed (issue)

Does <icon src="icon.png"/> work?

No it does not!.

On Android, it seems it used to work before (when the density attribute was not supported yet?) but not anymore. See this Cordova issue

On iOS, it seems using this global declaration may override more specific declarations so take care and build with --verbose to ensure everything works as expected.

Can I use the same icon/splash screen file for all the densities.

Yes you can. You can even use the same file for both the icon, and splash screen (just to test!). I have used a "big" icon file of 65kb without any problem.

What's the difference when using the platform tag vs the platform attribute

<icon src="icon.png" platform="android" density="ldpi" />

is the same as

<platform name="android">
    <icon src="www/stample_icon.png" density="ldpi" />
</platform>

Should I use the gap: namespace if using Phonegap?

In my experience new versions of Phonegap or Cordova are both able to understand icon declarations without using any gap: xml namespace.

However I'm still waiting for a valid answer here: cordova/phonegap plugin add VS config.xml

As far as I understand, some features with the gap: namespace may be available earlier in PhonegapBuild, then in Phonegap and then being ported to Cordova (?)

Is <preference name="SplashScreen" value="screen" /> required?

At least for Android yes it is. I opened an issue with additional explainations.

Does icon declaration order matters?

Yes it does! It may not have any impact on Android but it has on iOS according to my tests. This is unexpected and undocumented behavior so I opened another issue.

Do I need cordova-plugin-splashscreen?

Yes this is absolutly required if you want the splash screen to work. The documentation is not clear (issue) and let us think that the plugin is required only to offer a splash screen javascript API.

How can I resize the images for all width/height/densities fastly

There are tools to help you do that. The best one for me is http://makeappicon.com/ but it requires to provide an email address.

Other possible solutions are:

Can you give me an example config?

Yes. Here's my real config.xml

<?xml version='1.0' encoding='utf-8'?>
<widget id="co.x" version="0.2.6" xmlns="http://www.w3.org/ns/widgets" xmlns:android="http://schemas.android.com/apk/res/android" xmlns:cdv="http://cordova.apache.org/ns/1.0" xmlns:gap="http://phonegap.com/ns/1.0">
    <name>x</name>
    <description>
        x
    </description>
    <author email="[email protected]" href="https://x.co">
        x
    </author>
    <content src="index.html" />
    <preference name="permissions"                  value="none" />
    <preference name="webviewbounce"                value="false" />
    <preference name="StatusBarOverlaysWebView"     value="false" />
    <preference name="StatusBarBackgroundColor"     value="#0177C6" />
    <preference name="detect-data-types"            value="true" />
    <preference name="stay-in-webview"              value="false" />
    <preference name="android-minSdkVersion"        value="14" />
    <preference name="android-targetSdkVersion"     value="22" />
    <preference name="phonegap-version"             value="cli-5.1.1" />

    <preference name="SplashScreenDelay"            value="10000" />
    <preference name="SplashScreen"                 value="screen" />


    <plugin name="cordova-plugin-device"                spec="1.0.1" />
    <plugin name="cordova-plugin-console"               spec="1.0.1" />
    <plugin name="cordova-plugin-whitelist"             spec="1.1.0" />
    <plugin name="cordova-plugin-crosswalk-webview"     spec="1.2.0" />
    <plugin name="cordova-plugin-statusbar"             spec="1.0.1" />
    <plugin name="cordova-plugin-screen-orientation"    spec="1.3.6" />
    <plugin name="cordova-plugin-splashscreen"          spec="2.1.0" />

    <access origin="http://*" />
    <access origin="https://*" />

    <access launch-external="yes" origin="tel:*" />
    <access launch-external="yes" origin="geo:*" />
    <access launch-external="yes" origin="mailto:*" />
    <access launch-external="yes" origin="sms:*" />
    <access launch-external="yes" origin="market:*" />

    <platform name="android">
        <icon src="www/stample_icon.png" density="ldpi" />
        <icon src="www/stample_icon.png" density="mdpi" />
        <icon src="www/stample_icon.png" density="hdpi" />
        <icon src="www/stample_icon.png" density="xhdpi" />
        <icon src="www/stample_icon.png" density="xxhdpi" />
        <icon src="www/stample_icon.png" density="xxxhdpi" />
        <splash src="www/stample_splash.png" density="land-hdpi"/>
        <splash src="www/stample_splash.png" density="land-ldpi"/>
        <splash src="www/stample_splash.png" density="land-mdpi"/>
        <splash src="www/stample_splash.png" density="land-xhdpi"/>
        <splash src="www/stample_splash.png" density="land-xhdpi"/>
        <splash src="www/stample_splash.png" density="land-xhdpi"/>
        <splash src="www/stample_splash.png" density="port-hdpi"/>
        <splash src="www/stample_splash.png" density="port-ldpi"/>
        <splash src="www/stample_splash.png" density="port-mdpi"/>
        <splash src="www/stample_splash.png" density="port-xhdpi"/>
        <splash src="www/stample_splash.png" density="port-xxhdpi"/>
        <splash src="www/stample_splash.png" density="port-xxxhdpi"/>
    </platform>

    <platform name="ios">
        <icon src="www/stample_icon.png" width="180" height="180" />
        <icon src="www/stample_icon.png" width="60" height="60" />
        <icon src="www/stample_icon.png" width="120" height="120" />
        <icon src="www/stample_icon.png" width="76" height="76" />
        <icon src="www/stample_icon.png" width="152" height="152" />
        <icon src="www/stample_icon.png" width="40" height="40" />
        <icon src="www/stample_icon.png" width="80" height="80" />
        <icon src="www/stample_icon.png" width="57" height="57" />
        <icon src="www/stample_icon.png" width="114" height="114" />
        <icon src="www/stample_icon.png" width="72" height="72" />
        <icon src="www/stample_icon.png" width="144" height="144" />
        <icon src="www/stample_icon.png" width="29" height="29" />
        <icon src="www/stample_icon.png" width="58" height="58" />
        <icon src="www/stample_icon.png" width="50" height="50" />
        <icon src="www/stample_icon.png" width="100" height="100" />
        <splash src="www/stample_splash.png" width="320" height="480"/>
        <splash src="www/stample_splash.png" width="640" height="960"/>
        <splash src="www/stample_splash.png" width="768" height="1024"/>
        <splash src="www/stample_splash.png" width="1536" height="2048"/>
        <splash src="www/stample_splash.png" width="1024" height="768"/>
        <splash src="www/stample_splash.png" width="2048" height="1536"/>
        <splash src="www/stample_splash.png" width="640" height="1136"/>
        <splash src="www/stample_splash.png" width="750" height="1334"/>
        <splash src="www/stample_splash.png" width="1242" height="2208"/>
        <splash src="www/stample_splash.png" width="2208" height="1242"/>
    </platform>

    <allow-intent href="*" />
    <engine name="browser" spec="^3.6.0" />
    <engine name="android" spec="^4.0.2" />
</widget>

A good source of examples are starter kits. Like phonegap-start or Ionic starter

php & mysql query not echoing in html with tags?

Change <?php echo $proxy ?> to ' . $proxy . '.

You use <?php when you're outputting HTML by leaving PHP mode with ?>. When you using echo, you have to use concatenation, or wrap your string in double quotes and use interpolation.

Easy way to build Android UI?

DroidDraw seems to be very useful. It has a clean and easy interface and it is a freeware. Available for Windows, Linux and Mac OS X. I advice a donation.

If you don't like it, you should take a look at this site. There are some other options and other useful tools.

Export and import table dump (.sql) using pgAdmin

  1. In pgAdmin, select the required target schema in object tree (databases->your_db_name->schemas->your_target_schema)
  2. Click on Plugins/PSQL Console (in top-bar)
  3. Write \i /path/to/yourfile.sql
  4. Press enter

Pass multiple parameters to rest API - Spring

(1) Is it possible to pass a JSON object to the url like in Ex.2?

No, because http://localhost:8080/api/v1/mno/objectKey/{"id":1, "name":"Saif"} is not a valid URL.

If you want to do it the RESTful way, use http://localhost:8080/api/v1/mno/objectKey/1/Saif, and defined your method like this:

@RequestMapping(path = "/mno/objectKey/{id}/{name}", method = RequestMethod.GET)
public Book getBook(@PathVariable int id, @PathVariable String name) {
    // code here
}

(2) How can we pass and parse the parameters in Ex.1?

Just add two request parameters, and give the correct path.

@RequestMapping(path = "/mno/objectKey", method = RequestMethod.GET)
public Book getBook(@RequestParam int id, @RequestParam String name) {
    // code here
}

UPDATE (from comment)

What if we have a complicated parameter structure ?

"A": [ {
    "B": 37181,
    "timestamp": 1160100436,
    "categories": [ {
        "categoryID": 2653,
        "timestamp": 1158555774
    }, {
        "categoryID": 4453,
        "timestamp": 1158555774
    } ]
} ]

Send that as a POST with the JSON data in the request body, not in the URL, and specify a content type of application/json.

@RequestMapping(path = "/mno/objectKey", method = RequestMethod.POST, consumes = "application/json")
public Book getBook(@RequestBody ObjectKey objectKey) {
    // code here
}

django order_by query set, ascending and descending

Reserved.objects.filter(client=client_id).order_by('-check_in')

A hyphen "-" in front of "check_in" indicates descending order. Ascending order is implied.

We don't have to add an all() before filter(). That would still work, but you only need to add all() when you want all objects from the root QuerySet.

More on this here: https://docs.djangoproject.com/en/dev/topics/db/queries/#retrieving-specific-objects-with-filters

How to pass parameters to a modal?

You can simply create a controller funciton and pass your parameters with the $scope object.

$scope.Edit = function (modalParam) {
var modalInstance = $modal.open({
      templateUrl: '/app/views/admin/addeditphone.html',
      controller: function($scope) {
        $scope.modalParam = modalParam;
      }
    });
}

How to use regex in file find

Just little elaboration of regex for search a directory and file

Find a directroy with name like book

find . -name "*book*" -type d

Find a file with name like book word

find . -name "*book*" -type f

How to select where ID in Array Rails ActiveRecord without exception

Update: This answer is more relevant for Rails 4.x

Do this:

current_user.comments.where(:id=>[123,"456","Michael Jackson"])

The stronger side of this approach is that it returns a Relation object, to which you can join more .where clauses, .limit clauses, etc., which is very helpful. It also allows non-existent IDs without throwing exceptions.

The newer Ruby syntax would be:

current_user.comments.where(id: [123, "456", "Michael Jackson"])

Toggle button using two image on different state

You can try something like this. Here on click of image button I toggle the imageview.

holder.imgitem.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
            if(!onclick){
            mSparseBooleanArray.put((Integer) view.getTag(), true);
            holder.imgoverlay.setImageResource(R.drawable.ipad_768x1024_editmode_delete_overlay_com);
            onclick=true;}
            else if(onclick)
            {
                 mSparseBooleanArray.put((Integer) view.getTag(), false);
                  holder.imgoverlay.setImageResource(R.drawable.ipad_768x1024_editmode_selection_com);

            onclick=false;
            }
        }
    });

Java: is there a map function?

Be very careful with Collections2.transform() from guava. That method's greatest advantage is also its greatest danger: its laziness.

Look at the documentation of Lists.transform(), which I believe applies also to Collections2.transform():

The function is applied lazily, invoked when needed. This is necessary for the returned list to be a view, but it means that the function will be applied many times for bulk operations like List.contains(java.lang.Object) and List.hashCode(). For this to perform well, function should be fast. To avoid lazy evaluation when the returned list doesn't need to be a view, copy the returned list into a new list of your choosing.

Also in the documentation of Collections2.transform() they mention you get a live view, that change in the source list affect the transformed list. This sort of behaviour can lead to difficult-to-track problems if the developer doesn't realize the way it works.

If you want a more classical "map", that will run once and once only, then you're better off with FluentIterable, also from Guava, which has an operation which is much more simple. Here is the google example for it:

FluentIterable
       .from(database.getClientList())
       .filter(activeInLastMonth())
       .transform(Functions.toStringFunction())
       .limit(10)
       .toList();

transform() here is the map method. It uses the same Function<> "callbacks" as Collections.transform(). The list you get back is read-only though, use copyInto() to get a read-write list.

Otherwise of course when java8 comes out with lambdas, this will be obsolete.

Swift double to string

var b = String(stringInterpolationSegment: a)

This works for me. You may have a try

Putty: Getting Server refused our key Error

I'm using a PUTTYgen file with psftp, and I encountered this problem on my Windows Server when we were required to create new keys for a client. The private_key_name.ppk file and the open_ssh.txt file must be in the same directory for the connection to work.

Determine on iPhone if user has enabled push notifications

Unfortunately none of these solutions provided really solve the problem because at the end of the day the APIs are seriously lacking when it comes to providing the pertinent information. You can make a few guesses however using currentUserNotificationSettings (iOS8+) just isn't sufficient in its current form to really answer the question. Although a lot of the solutions here seem to suggest that either that or isRegisteredForRemoteNotifications is more of a definitive answer it really is not.

Consider this:

with isRegisteredForRemoteNotifications documentation states:

Returns YES if the application is currently registered for remote notifications, taking into account any systemwide settings...

However if you throw a simply NSLog into your app delegate to observe the behavior it is clear this does not behave the way we are anticipating it will work. It actually pertains directly to remote notifications having been activated for this app/device. Once activated for the first time this will always return YES. Even turning them off in settings (notifications) will still result in this returning YES this is because, as of iOS8, an app may register for remote notifications and even send to a device without the user having notifications enabled, they just may not do Alerts, Badges and Sound without the user turning that on. Silent notifications are a good example of something you may continue to do even with notifications turned off.

As far as currentUserNotificationSettings it indicates one of four things:

Alerts are on Badges are on Sound is on None are on.

This gives you absolutely no indication whatsoever about the other factors or the Notification switch itself.

A user may in fact turn off badges, sound and alerts but still have show on lockscreen or in notification center. This user should still be receiving push notifications and be able to see them both on the lock screen and in the notification center. They have the notification switch on. BUT currentUserNotificationSettings will return: UIUserNotificationTypeNone in that case. This is not truly indicative of the users actual settings.

A few guesses one can make:

  • if isRegisteredForRemoteNotifications is NO then you can assume that this device has never successfully registered for remote notifications.
  • after the first time of registering for remote notifications a callback to application:didRegisterUserNotificationSettings: is made containing user notification settings at this time since this is the first time a user has been registered the settings should indicate what the user selected in terms of the permission request. If the settings equate to anything other than: UIUserNotificationTypeNone then push permission was granted, otherwise it was declined. The reason for this is that from the moment you begin the remote registration process the user only has the ability to accept or decline, with the initial settings of an acceptance being the settings you setup during the registration process.

Excel VBA code to copy a specific string to clipboard

If the place you're gonna paste have no problem with pasting a table formating (like the browser URL bar), I think the easiest way is this:

Sheets(1).Range("A1000").Value = string
Sheets(1).Range("A1000").Copy
MsgBox "Paste before closing this dialog."
Sheets(1).Range("A1000").Value = ""

[] and {} vs list() and dict(), which is better?

there is one difference in behavior between [] and list() as example below shows. we need to use list() if we want to have the list of numbers returned, otherwise we get a map object! No sure how to explain it though.

sth = [(1,2), (3,4),(5,6)]
sth2 = map(lambda x: x[1], sth) 
print(sth2) # print returns object <map object at 0x000001AB34C1D9B0>

sth2 = [map(lambda x: x[1], sth)]
print(sth2) # print returns object <map object at 0x000001AB34C1D9B0>
type(sth2) # list 
type(sth2[0]) # map

sth2 = list(map(lambda x: x[1], sth))
print(sth2) #[2, 4, 6]
type(sth2) # list
type(sth2[0]) # int

Implicit function declarations in C

To complete the picture, since -Werror might considered too "invasive",
for gcc (and llvm) a more precise solution is to transform just this warning in an error, using the option:

-Werror=implicit-function-declaration

See Make one gcc warning an error?

Regarding general use of -Werror: Of course, having warningless code is recommendable, but in some stage of development it might slow down the prototyping.

Run PHP function on html button click

A php file is run whenever you access it via an HTTP request be it GET,POST, PUT.

You can use JQuery/Ajax to send a request on a button click, or even just change the URL of the browser to navigate to the php address.

Depending on the data sent in the POST/GET you can have a switch statement running a different function.

Specifying Function via GET

You can utilize the code here: How to call PHP function from string stored in a Variable along with a switch statement to automatically call the appropriate function depending on data sent.

So on PHP side you can have something like this:

<?php

//see http://php.net/manual/en/function.call-user-func-array.php how to use extensively
if(isset($_GET['runFunction']) && function_exists($_GET['runFunction']))
call_user_func($_GET['runFunction']);
else
echo "Function not found or wrong input";

function test()
{
echo("test");
}

function hello()
{
echo("hello");
}

?>

and you can make the simplest get request using the address bar as testing:

http://127.0.0.1/test.php?runFunction=hellodddddd

results in:

Function not found or wrong input

http://127.0.0.1/test.php?runFunction=hello

results in:

hello

Sending the Data

GET Request via JQuery

See: http://api.jquery.com/jQuery.get/

$.get("test.cgi", { name: "John"})
.done(function(data) {
  alert("Data Loaded: " + data);
});

POST Request via JQuery

See: http://api.jquery.com/jQuery.post/

$.post("test.php", { name: "John"} );

GET Request via Javascript location

See: http://www.javascripter.net/faq/buttonli.htm

<input type=button 
value="insert button text here"
onClick="self.location='Your_URL_here.php?name=hello'">

Reading the Data (PHP)

See PHP Turotial for reading post and get: http://www.tizag.com/phpT/postget.php

Useful Links

http://php.net/manual/en/function.call-user-func.php http://php.net/manual/en/function.function-exists.php

Is it not possible to stringify an Error using JSON.stringify?

I was working on a JSON format for log appenders and ended up here trying to solve a similar problem. After a while, I realized I could just make Node do the work:

const util = require("util");
...
return JSON.stringify(obj, (name, value) => {
    if (value instanceof Error) {
        return util.format(value);
    } else {
        return value;
    }
}

How does Python's super() work with multiple inheritance?

In python 3.5+ inheritance looks predictable and very nice for me. Please looks at this code:

class Base(object):
  def foo(self):
    print("    Base(): entering")
    print("    Base(): exiting")


class First(Base):
  def foo(self):
    print("   First(): entering Will call Second now")
    super().foo()
    print("   First(): exiting")


class Second(Base):
  def foo(self):
    print("  Second(): entering")
    super().foo()
    print("  Second(): exiting")


class Third(First, Second):
  def foo(self):
    print(" Third(): entering")
    super().foo()
    print(" Third(): exiting")


class Fourth(Third):
  def foo(self):
    print("Fourth(): entering")
    super().foo()
    print("Fourth(): exiting")

Fourth().foo()
print(Fourth.__mro__)

Outputs:

Fourth(): entering
 Third(): entering
   First(): entering Will call Second now
  Second(): entering
    Base(): entering
    Base(): exiting
  Second(): exiting
   First(): exiting
 Third(): exiting
Fourth(): exiting
(<class '__main__.Fourth'>, <class '__main__.Third'>, <class '__main__.First'>, <class '__main__.Second'>, <class '__main__.Base'>, <class 'object'>)

As you can see, it calls foo exactly ONE time for each inherited chain in the same order as it was inherited. You can get that order by calling .mro :

Fourth -> Third -> First -> Second -> Base -> object

Find all files in a directory with extension .txt in Python

Something like this will work:

>>> import os
>>> path = '/usr/share/cups/charmaps'
>>> text_files = [f for f in os.listdir(path) if f.endswith('.txt')]
>>> text_files
['euc-cn.txt', 'euc-jp.txt', 'euc-kr.txt', 'euc-tw.txt', ... 'windows-950.txt']

Convert String To date in PHP

Try this:

$new_date=date('d-m-Y', strtotime($date));

SQL Joins Vs SQL Subqueries (Performance)?

The two queries may not be semantically equivalent. If a employee works for more than one department (possible in the enterprise I work for; admittedly, this would imply your table is not fully normalized) then the first query would return duplicate rows whereas the second query would not. To make the queries equivalent in this case, the DISTINCT keyword would have to be added to the SELECT clause, which may have an impact on performance.

Note there is a design rule of thumb that states a table should model an entity/class or a relationship between entities/classes but not both. Therefore, I suggest you create a third table, say OrgChart, to model the relationship between employees and departments.

How to center links in HTML

you would put them inside a <p> or a <div>

<p style="text-align:center">
    <a href="http//www.google.com">Search</a> 
    <a href="Contact Us">Contact Us</a>
</p>

sample: http://jsfiddle.net/X8HM4/1/

Spring: Returning empty HTTP Responses with ResponseEntity<Void> doesn't work

NOTE: This is true for the version mentioned in the question, 4.1.1.RELEASE.

Spring MVC handles a ResponseEntity return value through HttpEntityMethodProcessor.

When the ResponseEntity value doesn't have a body set, as is the case in your snippet, HttpEntityMethodProcessor tries to determine a content type for the response body from the parameterization of the ResponseEntity return type in the signature of the @RequestMapping handler method.

So for

public ResponseEntity<Void> taxonomyPackageExists( @PathVariable final String key ) {

that type will be Void. HttpEntityMethodProcessor will then loop through all its registered HttpMessageConverter instances and find one that can write a body for a Void type. Depending on your configuration, it may or may not find any.

If it does find any, it still needs to make sure that the corresponding body will be written with a Content-Type that matches the type(s) provided in the request's Accept header, application/xml in your case.

If after all these checks, no such HttpMessageConverter exists, Spring MVC will decide that it cannot produce an acceptable response and therefore return a 406 Not Acceptable HTTP response.

With ResponseEntity<String>, Spring will use String as the response body and find StringHttpMessageConverter as a handler. And since StringHttpMessageHandler can produce content for any media type (provided in the Accept header), it will be able to handle the application/xml that your client is requesting.

Spring MVC has since been changed to only return 406 if the body in the ResponseEntity is NOT null. You won't see the behavior in the original question if you're using a more recent version of Spring MVC.


In iddy85's solution, which seems to suggest ResponseEntity<?>, the type for the body will be inferred as Object. If you have the correct libraries in your classpath, ie. Jackson (version > 2.5.0) and its XML extension, Spring MVC will have access to MappingJackson2XmlHttpMessageConverter which it can use to produce application/xml for the type Object. Their solution only works under these conditions. Otherwise, it will fail for the same reason I've described above.

Remove the legend on a matplotlib figure

According to the information from @naitsirhc, I wanted to find the official API documentation. Here are my finding and some sample code.

  1. I created a matplotlib.Axes object by seaborn.scatterplot().
  2. The ax.get_legend() will return a matplotlib.legned.Legend instance.
  3. Finally, you call .remove() function to remove the legend from your plot.
ax = sns.scatterplot(......)
_lg = ax.get_legend()
_lg.remove()

If you check the matplotlib.legned.Legend API document, you won't see the .remove() function.

The reason is that the matplotlib.legned.Legend inherited the matplotlib.artist.Artist. Therefore, when you call ax.get_legend().remove() that basically call matplotlib.artist.Artist.remove().

In the end, you could even simplify the code into two lines.

ax = sns.scatterplot(......)
ax.get_legend().remove()

Xcode 6.1 - How to uninstall command line tools?

An excerpt from an apple technical note (Thanks to matthias-bauch)

Xcode includes all your command-line tools. If it is installed on your system, remove it to uninstall your tools.

If your tools were downloaded separately from Xcode, then they are located at /Library/Developer/CommandLineTools on your system. Delete the CommandLineTools folder to uninstall them.

you could easily delete using terminal:

Here is an article that explains how to remove the command line tools but do it at your own risk.Try this only if any of the above doesn't work.

How to dynamically insert a <script> tag via jQuery after page load?

Try the following:

<script type="text/javascript">
// Use any event to append the code
$(document).ready(function() 
{
    var s = document.createElement("script");
    s.type = "text/javascript";
    s.src = "http://scriptlocation/das.js";
    // Use any selector
    $("head").append(s);
});

http://api.jquery.com/append

Why maven? What are the benefits?

I've never come across point 2? Can you explain why you think this affects deployment in any way. If anything maven allows you to structure your projects in a modularised way that actually allows hot fixes for bugs in a particular tier, and allows independent development of an API from the remainder of the project for example.

It is possible that you are trying to cram everything into a single module, in which case the problem isn't really maven at all, but the way you are using it.

Get data from fs.readFile

var content;
fs.readFile('./Index.html', function read(err, data) {
    if (err) {
        throw err;
    }
    content = data;
});
console.log(content);

This is just because node is asynchronous and it will not wait for the read function and as soon as the program starts it will console the value as undefined, Which is actually true because there is no value assigned to content variable. To handle we can use promises, generators etc. We can use promise in this way.

new Promise((resolve,reject)=>{
    fs.readFile('./index.html','utf-8',(err, data)=>{
        if (err) {
            reject(err); // in the case of error, control flow goes to the catch block with the error occured.
        }
        else{
            resolve(data);  // in the case of success, control flow goes to the then block with the content of the file.
        }
    });
})
.then((data)=>{
    console.log(data); // use your content of the file here (in this then).    
})
.catch((err)=>{
    throw err; //  handle error here.
})

How can I upload fresh code at github?

In Linux use below command to upload code in git
1 ) git clone repository
ask for user name and password.
2) got to respositiory directory.
3) git add project name.
4) git commit -m ' messgage '.
5) git push origin master.
- user name ,password

Update new Change code into Github

->Goto Directory That your github up code
->git commit ProjectName -m 'Message'
->git push origin master.

Cordova app not displaying correctly on iPhone X (Simulator)

In my case where each splash screen was individually designed instead of autogenerated or laid out in a story board format, I had to stick with my Legacy Launch screen configuration and add portrait and landscape images to target iPhoneX 1125×2436 orientations to the config.xml like so:

<splash height="2436" src="resources/ios/splash/Default-2436h.png" width="1125" />
<splash height="1125" src="resources/ios/splash/Default-Landscape-2436h.png" width="2436" />

After adding these to config.xml ("viewport-fit=cover" was already set in index.hml) my app built with Ionic Pro fills the entire screen on iPhoneX devices.

Multi value Dictionary

I don't think you can do that directly. You could create a class containing both your object and double and put an instance of it in the dictionary though.

class Pair
{
    object obj;
    double dbl;
}

Dictionary<int, Pair> = new Dictionary<int, Pair>();

Avoid Adding duplicate elements to a List C#

If you don't want duplicates in a list, use a HashSet. That way it will be clear to anyone else reading your code what your intention was and you'll have less code to write since HashSet already handles what you are trying to do.

Remove object from a list of objects in python

If you want to remove multiple object from a list. There are various ways to delete an object from a list

Try this code. a is list with all object, b is list object you want to remove.

example :

a = [1,2,3,4,5,6]
b = [2,3]

for i in b:
   if i in a:
      a.remove(i)

print(a)

the output is [1,4,5,6] I hope, it will work for you

Convert Enumeration to a Set/List

When using guava (See doc) there is Iterators.forEnumeration. Given an Enumeration x you can do the following:

to get a immutable Set:

ImmutableSet.copyOf(Iterators.forEnumeration(x));

to get a immutable List:

ImmutableList.copyOf(Iterators.forEnumeration(x));

to get a hashSet:

Sets.newHashSet(Iterators.forEnumeration(x));

Angular 4 Pipe Filter

Here is a working plunkr with a filter and sortBy pipe. https://plnkr.co/edit/vRvnNUULmBpkbLUYk4uw?p=preview

As developer033 mentioned in a comment, you are passing in a single value to the filter pipe, when the filter pipe is expecting an array of values. I would tell the pipe to expect a single value instead of an array

export class FilterPipe implements PipeTransform {
    transform(items: any[], term: string): any {
        // I am unsure what id is here. did you mean title?
        return items.filter(item => item.id.indexOf(term) !== -1);
    }
}

I would agree with DeborahK that impure pipes should be avoided for performance reasons. The plunkr includes console logs where you can see how much the impure pipe is called.

Redirecting Output from within Batch file

Add these two lines near the top of your batch file, all stdout and stderr after will be redirected to log.txt:

if not "%1"=="STDOUT_TO_FILE"  %0 STDOUT_TO_FILE %*  >log.txt 2>&1
shift /1

How to get rid of blank pages in PDF exported from SSRS

Have you tried to see if there is any white space on the right of your report? If so you can drag it back to the end of your report and then drag the report background back to the same spot.

How can I hide select options with JavaScript? (Cross browser)

On pure JS:

let select = document.getElementById("select_id")                   
let to_hide = select[select.selectedIndex];
to_hide.setAttribute('hidden', 'hidden');

to unhide just

to_hide.removeAttr('hidden');

or

to_hide.hidden = true;   // to hide
to_hide.hidden = false;  // to unhide

Get day of week in SQL Server 2005/2008

Even though SQLMenace's answer has been accepted, there is one important SET option you should be aware of

SET DATEFIRST

DATENAME will return correct date name but not the same DATEPART value if the first day of week has been changed as illustrated below.

declare @DefaultDateFirst int
set @DefaultDateFirst = @@datefirst
--; 7 First day of week is "Sunday" by default
select  [@DefaultDateFirst] = @DefaultDateFirst 

set datefirst @DefaultDateFirst
select datename(dw,getdate()) -- Saturday
select datepart(dw,getdate()) -- 7

--; Set the first day of week to * TUESDAY * 
--; (some people start their week on Tuesdays...)
set datefirst 2
select datename(dw,getdate()) -- Saturday
--; Returns 5 because Saturday is the 5th day since Tuesday.
--; Tue 1, Wed 2, Th 3, Fri 4, Sat 5
select datepart(dw,getdate()) -- 5 <-- It's not 7!
set datefirst @DefaultDateFirst

How can I make an "are you sure" prompt in a Windows batchfile?

Here is a simple example which I use in a backup (.bat / batch) script on Windows 10, which allows me to have different options when making backups.

...

:choice
set /P c=Do you want to rsync the archives to someHost[Y/N]?
if /I "%c%" EQU "Y" goto :syncthefiles
if /I "%c%" EQU "N" goto :doonotsyncthefiles
goto :choice

:syncthefiles
echo rsync files to somewhere ...
bash -c "rsync -vaz /mnt/d/Archive/Backup/ user@host:/home/user/Backup/blabla/"
echo done

:doonotsyncthefiles
echo Backup Complete!

...

You can have as many as you need of these blocks.

Get random item from array

echo $items[array_rand($items)];

array_rand()

How do I add FTP support to Eclipse?

I'm not sure if this works for you, but when I do small solo PHP projects with Eclipse, the first thing I set up is an Ant script for deploying the project to a remote testing environment. I code away locally, and whenever I want to test it, I just hit the shortcut which updates the remote site.

Eclipse has good Ant support out of the box, and the scripts aren't hard to make.

What happened to the .pull-left and .pull-right classes in Bootstrap 4?

Thay are removed.

Use float-left instead of pull-left. And float-right instead of pull-right.

Check bootstrap Documentation here:

Added .float-{sm,md,lg,xl}-{left,right,none} classes for responsive floats and removed .pull-left and .pull-right since they’re redundant to .float-left and .float-right.

How to open the command prompt and insert commands using Java?

Please, place your command in a parameter like the mentioned below.

Runtime.getRuntime().exec("cmd.exe /c start cmd /k \" parameter \"");

How can I load the contents of a text file into a batch file variable?

You can use:

set content=
for /f "delims=" %%i in ('type text.txt') do set content=!content! %%i

Powershell folder size of folders without listing Subdirectories

My proposal:

$dir="C:\temp\"
get-childitem $dir -file -Rec | group Directory | where Name -eq $dir | select Name, @{N='Size';E={(($_.Group.Length | measure -Sum).Sum / 1MB)}}

Why do I keep getting Delete 'cr' [prettier/prettier]?

In my windows machine, I solved this by adding the below code snippet in rules object of .eslintrc.js file present in my current project's directory.

    "prettier/prettier": [
      "error",
      {
        "endOfLine": "auto"
      },
    ],

This worked on my Mac as well

Bootstrap modal opening on page load

Use a document.ready() event around your call.

$(document).ready(function () {

    $('#memberModal').modal('show');

});

jsFiddle updated - http://jsfiddle.net/uvnggL8w/1/

How to show what a commit did?

I found out that "git show --stat" is the best out of all here, gives you a brief summary of the commit, what files did you add and modify without giving you whole bunch of stuff, especially if you changed a lot files.

Find and replace words/lines in a file

You might want to use Scanner to parse through and find the specific sections you want to modify. There's also Split and StringTokenizer that may work, but at the level you're working at Scanner might be what's needed.

Here's some additional info on what the difference is between them: Scanner vs. StringTokenizer vs. String.Split

How to convert a const char * to std::string

What you want is this constructor: std::string ( const string& str, size_t pos, size_t n = npos ), passing pos as 0. Your const char* c-style string will get implicitly cast to const string for the first parameter.

const char *c_style = "012abd";
std::string cpp_style = new std::string(c_style, 0, 10);

c# open file with default application and parameters

you can try with

Process process = new Process();
process.StartInfo.FileName = "yourProgram.exe";
process.StartInfo.Arguments = ..... //your parameters
process.Start();

How do you increase the max number of concurrent connections in Apache?

change the MaxClients directive. it is now on 256.

How can I process each letter of text using Javascript?

Try this code

    function myFunction() {
    var text =(document.getElementById("htext").value); 
    var meow = " <p> <,> </p>";
    var i;


    for (i = 0; i < 9000; i++) {

        text+=text[i] ;



    }

    document.getElementById("demo2").innerHTML = text;

}
</script>
<p>Enter your text: <input type="text" id="htext"/>

    <button onclick="myFunction();">click on me</button>
</p>

'Conda' is not recognized as internal or external command

I have Windows 10 64 bit, this worked for me, This solution can work for both (Anaconda/MiniConda) distributions.

  1. First of all try to uninstall anaconda/miniconda which is causing problem.
  2. After that delete '.anaconda' and '.conda' folders from 'C:\Users\'
  3. If you have any antivirus software installed then try to exclude all the folders,subfolders inside 'C:\ProgramData\Anaconda3\' from

    • Behaviour detection.
    • Virus detection.
    • DNA scan.
    • Suspicious files scan.
    • Any other virus protection mode.

    *(Note: 'C:\ProgramData\Anaconda3' this folder is default installation folder, you can change it just replace your excluded path at installation destination prompt while installing Anaconda)*

  4. Now install Anaconda with admin privileges.
    • Set the installation path as 'C:\ProgramData\Anaconda3' or you can specify your custom path just remember it should not contain any white space and it should be excluded from virus detection.
    • At Advanced Installation Options you can check "Add Anaconda to my PATH environment variable(optional)" and "Register Anaconda as my default Python 3.6"
    • Install it with further default settings. Click on finish after done.
    • Restart your computer.

Now open Command prompt or Anaconda prompt and check installation using following command

conda list

If you get any package list then the anaconda/miniconda is successfully installed.

How to get the unix timestamp in C#

The simple code that I am using:

public static long CurrentTimestamp()
{
   return (long)(DateTime.UtcNow.Subtract(new DateTime(1970, 1, 1)).TotalSeconds * 1000);
}

This code is giving unix timestamp, total milliseconds from 1970-01-01 to now.

Convert DataTable to List<T>

The method ConvertToList that is posted below and uses reflection works perfectly for me. Thanks.

I made a slight modification to make it work with conversions on the T property types.

public List<T> ConvertToList<T>(DataTable dt)
{
    var columnNames = dt.Columns.Cast<DataColumn>()
            .Select(c => c.ColumnName)
            .ToList();
    var properties = typeof(T).GetProperties();
    return dt.AsEnumerable().Select(row =>
    {
        var objT = Activator.CreateInstance<T>();
        foreach (var pro in properties)
        {
            if (columnNames.Contains(pro.Name))
            {
                 PropertyInfo pI = objT.GetType().GetProperty(pro.Name);
                 pro.SetValue(objT, row[pro.Name] == DBNull.Value ? null : Convert.ChangeType(row[pro.Name], pI.PropertyType));
            }
        }
        return objT;
   }).ToList();
}

Hope it helps. Regards.

Interesting 'takes exactly 1 argument (2 given)' Python error

try using:

def extractAll(self,tag):

attention to self

Error in plot.window(...) : need finite 'xlim' values

The problem is that you're (probably) trying to plot a vector that consists exclusively of missing (NA) values. Here's an example:

> x=rep(NA,100)
> y=rnorm(100)
> plot(x,y)
Error in plot.window(...) : need finite 'xlim' values
In addition: Warning messages:
1: In min(x) : no non-missing arguments to min; returning Inf
2: In max(x) : no non-missing arguments to max; returning -Inf

In your example this means that in your line plot(costs,pseudor2,type="l"), costs is completely NA. You have to figure out why this is, but that's the explanation of your error.


From comments:

Scott C Wilson: Another possible cause of this message (not in this case, but in others) is attempting to use character values as X or Y data. You can use the class function to check your x and Y values to be sure if you think this might be your issue.

stevec: Here is a quick and easy solution to that problem (basically wrap x in as.factor(x))

Convert Time DataType into AM PM Format:

    select right(convert(varchar(20),getdate(),100),7)

How to execute logic on Optional if not present?

First of all, your dao.find() should either return an Optional<Obj> or you will have to create one.

e.g.

Optional<Obj> = dao.find();

or you can do it yourself like:

Optional<Obj> = Optional.ofNullable(dao.find());

this one will return Optional<Obj> if present or Optional.empty() if not present.

So now let's get to the solution,

public Obj getObjectFromDB() {
   return Optional.ofNullable(dao.find()).flatMap(ob -> {
            ob.setAvailable(true);
            return Optional.of(ob);    
        }).orElseGet(() -> {
            logger.fatal("Object not available");
            return null;
        });
    }

This is the one liner you're looking for :)

Regular expression for letters, numbers and - _

To actually cover your pattern, i.e, valid file names according to your rules, I think that you need a little more. Note this doesn't match legal file names from a system perspective. That would be system dependent and more liberal in what it accepts. This is intended to match your acceptable patterns.

^([a-zA-Z0-9]+[_-])*[a-zA-Z0-9]+\.[a-zA-Z0-9]+$

Explanation:

  • ^ Match the start of a string. This (plus the end match) forces the string to conform to the exact expression, not merely contain a substring matching the expression.
  • ([a-zA-Z0-9]+[_-])* Zero or more occurrences of one or more letters or numbers followed by an underscore or dash. This causes all names that contain a dash or underscore to have letters or numbers between them.
  • [a-zA-Z0-9]+ One or more letters or numbers. This covers all names that do not contain an underscore or a dash.
  • \. A literal period (dot). Forces the file name to have an extension and, by exclusion from the rest of the pattern, only allow the period to be used between the name and the extension. If you want more than one extension that could be handled as well using the same technique as for the dash/underscore, just at the end.
  • [a-zA-Z0-9]+ One or more letters or numbers. The extension must be at least one character long and must contain only letters and numbers. This is typical, but if you wanted allow underscores, that could be addressed as well. You could also supply a length range {2,3} instead of the one or more + matcher, if that were more appropriate.
  • $ Match the end of the string. See the starting character.

SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified

Had the same issue then I used the connection string without ./ (like DESKTOP-E53DUML instead of this ./DESKTOP-E53DUML)

JavaScript Editor Plugin for Eclipse

JavaScript that allows for syntax checking

JSHint-Eclipse

and autosuggestions for .js files in Eclipse?

  1. Use JSDoc more as JSDT has nice support for the standard, so you will get more suggestions for your own code.
  2. There is new TernIDE that provide additional hints for .js and AngulatJS .html. Get them together as Anide from http://www.nodeclipse.org/updates/anide/

As Nodeclipse lead, I am always looking for what is available in Eclipse ecosystem. Nodeclipse site has even more links, and I am inviting to collaborate on the JavaScript tools on GitHub

Wrap long lines in Python

I'm surprised no one mentioned the implicit style above. My preference is to use parens to wrap the string while lining the string lines up visually. Personally I think this looks cleaner and more compact than starting the beginning of the string on a tabbed new line.

Note that these parens are not part of a method call — they're only implicit string literal concatenation.

Python 2:

def fun():
    print ('{0} Here is a really '
           'long sentence with {1}').format(3, 5)

Python 3 (with parens for print function):

def fun():
    print(('{0} Here is a really '
           'long sentence with {1}').format(3, 5))

Personally I think it's cleanest to separate concatenating the long string literal from printing it:

def fun():
    s = ('{0} Here is a really '
         'long sentence with {1}').format(3, 5)
    print(s)

Change keystore password from no password to a non blank password

On my system the password is 'changeit'. On blank if I hit enter then it complains about short password. Hope this helps

enter image description here

New line in JavaScript alert box

alert("text\nnew Line Text");

Documentation: Window.alert()


Firefox:
firefox demo

Chrome:
chrome demo

Edge:
edge demo

Adding a month to a date in T SQL

Use DATEADD:

DATEADD(month, 1, reference_dt)

How to convert date to timestamp?

There are two problems here. First, you can only call getTime on an instance of the date. You need to wrap new Date in brackets or assign it to variable.

Second, you need to pass it a string in a proper format.

Working example:

(new Date("2012-02-26")).getTime();

Convert all strings in a list to int

Here is a simple solution with explanation for your query.

 a=['1','2','3','4','5'] #The integer represented as a string in this list
 b=[] #Fresh list
 for i in a: #Declaring variable (i) as an item in the list (a).
     b.append(int(i)) #Look below for explanation
 print(b)

Here, append() is used to add items ( i.e integer version of string (i) in this program ) to the end of the list (b).

Note: int() is a function that helps to convert an integer in the form of string, back to its integer form.

Output console:

[1, 2, 3, 4, 5]

So, we can convert the string items in the list to an integer only if the given string is entirely composed of numbers or else an error will be generated.

Returning an array using C

You can do it using heap memory (through malloc() invocation) like other answers reported here, but you must always manage the memory (use free() function everytime you call your function). You can also do it with a static array:

char* returnArrayPointer() 
{
static char array[SIZE];

// do something in your array here

return array; 
}

You can than use it without worrying about memory management.

int main() 
{
char* myArray = returnArrayPointer();
/* use your array here */
/* don't worry to free memory here */
}

In this example you must use static keyword in array definition to set to application-long the array lifetime, so it will not destroyed after return statement. Of course, in this way you occupy SIZE bytes in your memory for the entire application life, so size it properly!

Why do Sublime Text 3 Themes not affect the sidebar?

Here's the short version:

  1. .sublime-theme files change the look of the UI including the Sidebar and File Tabs.
  2. Defining these are a tremendous pain, so save yourself a lot of time and install the Theme Menu Switcher package.

Update: Sublime Text 3 has fundamentally changed the way Color Schemes and Themes work, and has broken many of the packages that were built to handle them. I can no longer confirm the accuracy of this post, nor the functionality of the packages mentioned herein because the Sublime developers have not fully explained the changes to the customization system nor addressed how to fix them. And, at the very best, they are far more difficult to change.

At this point, this post should only be used as a reference to the differences between "themes" and "color schemes" in Sublime Text 2, as I myself have yet to successfully change a theme nor color scheme in Sublime Text 3.

I will update this post as I can dedicate more time to unraveling this Sublime Customization Quagmire.


Here's the long version:

tmTheme vs sublime-theme file type affection areas Figure 1: The difference between "Color Schemes" and "Themes" - In the Sublime Community these terms are often confused and used interchangeably.

Changing the look of Sublime is a relatively difficult endeavor, for three main reasons:

  • Poorly chosen terminology
  • Misinformation in the Sublime Community
  • Installation Nightmare

Terminology

There are 2 different sections of Sublime that can be customized:

  • the editable region (the purple regions)
  • the User Interface (the green regions)

These use two different file types, and they do not accurately reflect the terminology.

The "Why?" of this decision is compatibility, and for brevity's sake I won't get into it here, but the fallout of this effort is:

The file type called tmTheme does not affect the theme, it affects the Color Scheme.

Color Schemes (highlighted in purple)

  • affect the look of the editable region (more specifically, the editable characters, ie what color they are when highlighted or not highlighted, etc).
  • relatively easy to produce
  • Color Schemes are Mistakenly called "Themes" all over the Sublime Community.

Themes (highlighted in green)

  • .sublime-theme files change the Theme, or the UI aspects of Sublime.
  • difficult to produce
  • It is difficult to find true Sublime Themes, compared to "Color Schemes"

Misinformation

Many packages claim to change the Theme, but actually change the Color Scheme. This is usually because the people producing them don't know that "Theme" specifically refers to the UI.

So another level of difficulty is finding a true "Theme" package, rather than Color Scheme.

Even some legit websites do not correctly make a distinction between the two, which adds to the challenges. For instance, colorsublime.com has a tutorial on changing the sublime "theme", but actually references the "Color Scheme" file type (.tmTheme).

Installation Pains

Themes and Color Schemes are hard to install and define. In fact, it's shocking how difficult the process is. The difficulty is further exacerbated with a fundamental change in installation and definition requirements in Sublime Text 3 that are not fully explained, which breaks many of the packages we once were reliant upon to change the Themes and Color Schemes.

It requires installing an actual Theme package (good luck finding one by browsing Packages in Package Control), defining it in settings, and then restarting Sublime. And, if you did something wrong, Sublime will simply replace your user-defined theme setting with the default. Yes, you heard me right, without notice or error message, Sublime will overwrite your theme definition.

But with Themes Menu Switcher All you need to do is go to Preferences > Theme and you'll see a list of all themes you have installed. You can also easily switch between themes without restarting Sublime.

Here's a sample from the website:Theme Switcher gif

I have no affiliation with Theme Menu Switcher at all, I'm just a fan.

Again, Theme Menu Switcher does not work the same in Sublime Text 3. If you need to have a customized look, I recommend not to update to Sublime Text 3.

Get Current Session Value in JavaScript?

The way i resolved was, i have written a function in controller and accessed it via ajax on jquery click event

First of all i want to thank @Stefano Altieri for giving me an idea of how to implement the above scenario,you are absolutely right we cannot access current session value from clientside when the session expires.

Also i would like to say that proper reading of question will help us to answer the question carefully.

Can a table have two foreign keys?

CREATE TABLE User (
user_id INT NOT NULL AUTO_INCREMENT,
userName VARCHAR(100) NOT NULL,
password VARCHAR(255) NOT NULL,
email VARCHAR(255) NOT NULL,
userImage  LONGBLOB NOT NULL, 
Favorite VARCHAR(255) NOT NULL,
PRIMARY KEY (user_id)
);

and

CREATE TABLE Event (
    EventID INT NOT NULL AUTO_INCREMENT, 
    PRIMARY KEY (EventID),
    EventName VARCHAR(100) NOT NULL,
    EventLocation VARCHAR(100) NOT NULL,
    EventPriceRange VARCHAR(100) NOT NULL,
    EventDate Date NOT NULL,
    EventTime Time NOT NULL,
    EventDescription VARCHAR(255) NOT NULL,
    EventCategory VARCHAR(255) NOT NULL,
    EventImage  LONGBLOB NOT NULL,     
    index(EventID),
    FOREIGN KEY (EventID) REFERENCES User(user_id)
);

Why doesn't margin:auto center an image?

I have found... margin: 0 auto; works for me. But I have also seen it NOT work due to the class being trumped by another specificity that had ... float:left; so watch for that you may need to add ... float:none; this worked in my case as I was coding a media query.

Setting the default ssh key location

If you are only looking to point to a different location for you identity file, the you can modify your ~/.ssh/config file with the following entry:

IdentityFile ~/.foo/identity

man ssh_config to find other config options.

ab load testing

Steps to set up Apache Bench(AB) on windows (IMO - Recommended).

Step 1 - Install Xampp.
Step 2 - Open CMD.
Step 3 - Go to the apache bench destination (cd C:\xampp\apache\bin) from CMD
Step 4 - Paste the command (ab -n 100 -c 10 -k -H "Accept-Encoding: gzip, deflate" http://localhost:yourport/)
Step 5 - Wait for it. Your done

Set textarea width to 100% in bootstrap modal

I had the same problem. I fixed it by adding this piece of code inside the text area's style.

resize: vertical;

You can check the Bootstrap reference here

How can I add "href" attribute to a link dynamically using JavaScript?

First, try changing <a>Link</a> to <span id=test><a>Link</a></span>.

Then, add something like this in the javascript function that you're calling:

var abc = 'somelink';
document.getElementById('test').innerHTML = '<a href="' + abc + '">Link</a>';

This way the link will look like this:

<a href="somelink">Link</a>

What is the function of the push / pop instructions used on registers in x86 assembly?

pushing a value (not necessarily stored in a register) means writing it to the stack.

popping means restoring whatever is on top of the stack into a register. Those are basic instructions:

push 0xdeadbeef      ; push a value to the stack
pop eax              ; eax is now 0xdeadbeef

; swap contents of registers
push eax
mov eax, ebx
pop ebx

What is the difference between 'java', 'javaw', and 'javaws'?

I have checked that the output redirection works with javaw:

javaw -cp ... mypath.MyClass ... arguments 1>log.txt 2>err.txt

It means, if the Java application prints out anything via System.out or System.err, it is written to those files, as also with using java (without w). Especially on starting java, the JRE may write starting errors (class not found) on the error output pipe. In this respect, it is essential to know about errors. I suggest to use the console redirection in any case if javaw is invoked.

In opposite if you use

start java .... 1>log.txt 2>err.txt

With the Windows console start command, the console output redirection does not work with java nor with javaw.

Explanation why it is so: I think that javaw opens an internal process in the OS (adequate using the java.lang.Process class), and transfers a known output redirection to this process. If no redirection is given on the command line, nothing is redirected and the internal started process for javaw doesn't have any console outputs. The behavior for java.lang.Process is similar. The virtual machine may use this internal feature for javaw too.

If you use 'start', the Windows console creates a new process for Windows to execute the command after start, but this mechanism does not use a given redirection for the started sub process, unfortunately.

Styling text input caret

Here are some vendors you might me looking for

::-webkit-input-placeholder {color: tomato}
::-moz-placeholder          {color: tomato;} /* Firefox 19+ */
:-moz-placeholder           {color: tomato;} /* Firefox 18- */
:-ms-input-placeholder      {color: tomato;}

You can also style different states, such as focus

:focus::-webkit-input-placeholder {color: transparent}
:focus::-moz-placeholder          {color: transparent}
:focus:-moz-placeholder           {color: transparent}
:focus:-ms-input-placeholder      {color: transparent}

You can also do certain transitions on it, like

::-VENDOR-input-placeholder       {text-indent: 0px;   transition: text-indent 0.3s ease;}
:focus::-VENDOR-input-placeholder  {text-indent: 500px; transition: text-indent 0.3s ease;}

Hibernate throws org.hibernate.AnnotationException: No identifier specified for entity: com..domain.idea.MAE_MFEView

TL;DR

You are missing the @Id entity property, and that's why Hibernate is throwing that exception.

Entity identifiers

Any JPA entity must have an identifier property, that is marked with the Id annotation.

There are two types of identifiers:

  • assigned
  • auto-generated

Assigned identifiers

An assigned identifier looks as follows:

@Id
private Long id;

Notice that we are using a wrapper (e.g., Long, Integer) instead of a primitive type (e.g., long, int). Using a wrapper type is a better choice when using Hibernate because, by checking if the id is null or not, Hibernate can better determine if an entity is transient (it does not have an associated table row) or detached (it has an associated table row, but it's not managed by the current Persistence Context).

The assigned identifier must be set manually by the application prior to calling persist:

Post post = new Post();
post.setId(1L);

entityManager.persist(post);

Auto-generated identifiers

An auto-generated identifier requires the @GeneratedValue annotation besides the @Id:

@Id
@GeneratedValue
private int id;

There are 3 strategies Hibernate can use to auto-generate the entity identifier:

  • IDENTITY
  • SEQUENCE
  • TABLE

The IDENTITY strategy is to be avoided if the underlying database supports sequences (e.g., Oracle, PostgreSQL, MariaDB since 10.3, SQL Server since 2012). The only major database that does not support sequences is MySQL.

The problem with IDENTITY is that automatic Hibernate batch inserts are disabled for this strategy.

The SEQUENCE strategy is the best choice unless you are using MySQL. For the SEQUENCE strategy, you also want to use the pooled optimizer to reduce the number of database roundtrips when persisting multiple entities in the same Persistence Context.

The TABLE generator is a terrible choice because it does not scale. For portability, you are better off using SEQUENCE by default and switch to IDENTITY for MySQL only.

VARCHAR to DECIMAL

I came up with the following solution:

SELECT [Str], DecimalParsed = CASE 
WHEN ISNUMERIC([Str]) = 1 AND CHARINDEX('.', [Str])=0 AND LEN(REPLACE(REPLACE([Str], '-', ''), '+', '')) < 29 THEN CONVERT(decimal(38,10), [Str])
WHEN ISNUMERIC([Str]) = 1 AND (CHARINDEX('.', [Str])!=0 AND CHARINDEX('.', REPLACE(REPLACE([Str], '-', ''), '+', ''))<=29) THEN 
    CONVERT(decimal(38,10), 
            CASE WHEN LEN([Str]) - LEN(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE([Str], '0', ''), '1', ''), '2', ''), '3', ''), '4', ''), '5', ''), '6', ''), '7', ''), '8', ''), '9', '')) <= 38 
                 THEN [Str] 
                 ELSE SUBSTRING([Str], 1, 38 + LEN(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE([Str], '0', ''), '1', ''), '2', ''), '3', ''), '4', ''), '5', ''), '6', ''), '7', ''), '8', ''), '9', ''))) END)
ELSE NULL END
FROM TestStrToDecimal

I know it looks like an overkill and probably it is, but it works for me (checked both positive, negative, big and small numbers of different precision and scale - everything is converted to decimal(38,10) or NULL).

It is hard-coded to decimal(38,10) type, so if you need different precision, change the constants in the code (38, 10, 29).

How it works? The result is:

  • if conversion is simple without overflow or precision loss (e.g. 123 or 123.456), then it just convert it.
  • if number is not too big, but has too many digits after decimal point (e.g. 123.1234567890123456789012345678901234567890), then it trims the exceeding digits at the end keeping only 38 first digits.
  • if number is too big and can't be converted to decimal without an overflow (e.g. 9876543210987654321098765432109876543210), then NULL is returned

each case is separate WHEN statement inthe code above.

Here are few examples of conversion: enter image description here

Chosen Jquery Plugin - getting selected values

if you want to get text of a selected option (chosen get display selected value)

 $("#select-id").chosen().find("option:selected" ).text();

Java: parse int value from a char

That's probably the best from the performance point of view, but it's rough:

String element = "el5";
String s;
int x = element.charAt(2)-'0';

It works if you assume your character is a digit, and only in languages always using Unicode, like Java...

How to change Tkinter Button state from disabled to normal?

I think a quick way to change the options of a widget is using the configure method.

In your case, it would look like this:

self.x.configure(state=NORMAL)

vertical-align with Bootstrap 3

Try this in the CSS of the div:

display: table-cell;
vertical-align: middle;

MySQL Fire Trigger for both Insert and Update

In response to @Zxaos request, since we can not have AND/OR operators for MySQL triggers, starting with your code, below is a complete example to achieve the same.

1. Define the INSERT trigger:

DELIMITER //
DROP TRIGGER IF EXISTS my_insert_trigger//
CREATE DEFINER=root@localhost TRIGGER my_insert_trigger
    AFTER INSERT ON `table`
    FOR EACH ROW

BEGIN
    -- Call the common procedure ran if there is an INSERT or UPDATE on `table`
    -- NEW.id is an example parameter passed to the procedure but is not required
    -- if you do not need to pass anything to your procedure.
    CALL procedure_to_run_processes_due_to_changes_on_table(NEW.id);
END//
DELIMITER ;

2. Define the UPDATE trigger

DELIMITER //
DROP TRIGGER IF EXISTS my_update_trigger//

CREATE DEFINER=root@localhost TRIGGER my_update_trigger
    AFTER UPDATE ON `table`
    FOR EACH ROW
BEGIN
    -- Call the common procedure ran if there is an INSERT or UPDATE on `table`
    CALL procedure_to_run_processes_due_to_changes_on_table(NEW.id);
END//
DELIMITER ;

3. Define the common PROCEDURE used by both these triggers:

DELIMITER //
DROP PROCEDURE IF EXISTS procedure_to_run_processes_due_to_changes_on_table//

CREATE DEFINER=root@localhost PROCEDURE procedure_to_run_processes_due_to_changes_on_table(IN table_row_id VARCHAR(255))
READS SQL DATA
BEGIN

    -- Write your MySQL code to perform when a `table` row is inserted or updated here

END//
DELIMITER ;

You note that I take care to restore the delimiter when I am done with my business defining the triggers and procedure.

array.select() in javascript

There's also Array.find() in ES6 which returns the first matching element it finds.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find

const myArray = [1, 2, 3]

const myElement = myArray.find((element) => element === 2)

console.log(myElement)
// => 2

Why catch and rethrow an exception in C#?

In the example in the code you have posted there is, in fact, no point in catching the exception as there is nothing done on the catch it is just re-thown, in fact it does more harm than good as the call stack is lost.

You would, however catch an exception to do some logic (for example closing sql connection of file lock, or just some logging) in the event of an exception the throw it back to the calling code to deal with. This would be more common in a business layer than front end code as you may want the coder implementing your business layer to handle the exception.

To re-iterate though the There is NO point in catching the exception in the example you posted. DON'T do it like that!

Case-insensitive search

Yeah, use .match, rather than .search. The result from the .match call will return the actual string that was matched itself, but it can still be used as a boolean value.

var string = "Stackoverflow is the BEST";
var result = string.match(/best/i);
// result == 'BEST';

if (result){
    alert('Matched');
}

Using a regular expression like that is probably the tidiest and most obvious way to do that in JavaScript, but bear in mind it is a regular expression, and thus can contain regex metacharacters. If you want to take the string from elsewhere (eg, user input), or if you want to avoid having to escape a lot of metacharacters, then you're probably best using indexOf like this:

matchString = 'best';
// If the match string is coming from user input you could do
// matchString = userInput.toLowerCase() here.

if (string.toLowerCase().indexOf(matchString) != -1){
    alert('Matched');
}

Does Python have a package/module management system?

Poetry is what you're looking for. It takes care of dependency management, virtual environments, running.

Why does an onclick property set with setAttribute fail to work in IE?

There is a LARGE collection of attributes you can't set in IE using .setAttribute() which includes every inline event handler.

See here for details:

http://webbugtrack.blogspot.com/2007/08/bug-242-setattribute-doesnt-always-work.html

keycloak Invalid parameter: redirect_uri

Your redirect URI in your code(keycloak.init) should be the same as the redirect URI set on Keycloak server (client -> Valid Uri) click to view image of my code click to view my keycloak settings

Get a UTC timestamp

"... that are independent of their timezone"

var timezone =  d.getTimezoneOffset() // difference in minutes from GMT

how to access downloads folder in android?

Updated

getExternalStoragePublicDirectory() is deprecated.

To get the download folder from a Fragment,

val downloadFolder = requireContext().getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)

From an Activity,

val downloadFolder = getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS)

downloadFolder.listFiles() will list the Files.

downloadFolder?.path will give you the String path of the download folder.

How to pass argument to Makefile from command line?

Here is a generic working solution based on @Beta's

I'm using GNU Make 4.1 with SHELL=/bin/bash atop my Makefile, so YMMV!

This allows us to accept extra arguments (by doing nothing when we get a job that doesn't match, rather than throwing an error).

%:
    @:

And this is a macro which gets the args for us:

args = `arg="$(filter-out $@,$(MAKECMDGOALS))" && echo $${arg:-${1}}`

Here is a job which might call this one:

test:
    @echo $(call args,defaultstring)

The result would be:

$ make test
defaultstring
$ make test hi
hi

Note! You might be better off using a "Taskfile", which is a bash pattern that works similarly to make, only without the nuances of Maketools. See https://github.com/adriancooney/Taskfile

Getting number of days in a month

 int days = DateTime.DaysInMonth(int year,int month);

or

 int days=System.Globalization.CultureInfo.CurrentCulture.Calendar.GetDaysInMonth(int year,int month);

you have to pass year and month as int then days in month will be return on currespoting year and month

Select method of Range class failed via VBA

I believe you are having the same problem here.
The sheet must be active before you can select a range on it.

Also, don't omit the sheet name qualifier:

Sheets("BxWsn Simulation").Select
Sheets("BxWsn Simulation").Range("Result").Select

Or,

With Sheets("BxWsn Simulation")
  .Select
  .Range("Result").Select
End WIth

which is the same.

Using WGET to run a cronjob PHP

If you want get output only when php fail:

php -r 'echo file_get_contents(http://www.example.com/cronit.php);'

This way you receive an email from cronjob only when the script fails and not whenever the php is called.

Pan & Zoom Image

Try this Zoom Control: http://wpfextensions.codeplex.com

usage of the control is very simple, reference to the wpfextensions assembly than:

<wpfext:ZoomControl>
    <Image Source="..."/>
</wpfext:ZoomControl>

Scrollbars not supported at this moment. (It will be in the next release which will be available in one or two week).

Babel command not found

This is common issue and its looking for .cmd file from your root directory where you installed babel-cli. Try the below command.

./node_modules/.bin/babel.cmd

Once you are able to see your source code in the command prompt. Your next step is to install one more npm module babel-preset-es2015.

Follow the below answer to install babel-preset-es2015 and see why babel need this.

babel-file-is-copied-without-being-transformed

Visual Studio 64 bit?

no, but it runs fine on win64, and can create win64 .EXEs

Linux Script to check if process is running and act on the result

If you changed awk '{print $1}' to '{ $1=""; print $0}' you will get all processes except for the first as a result. It will start with the field separator (a space generally) but I don't recall killall caring. So:

#! /bin/bash

logfile="/var/oscamlog/oscam1check.log"

case "$(pidof oscam1 | wc -w)" in

0)  echo "oscam1 not running, restarting oscam1:     $(date)" >> $logfile
    /usr/local/bin/oscam1 -b -c /usr/local/etc/oscam1 -t /usr/local/tmp.oscam1 &
    ;;
2)  echo "oscam1 running, all OK:     $(date)" >> $logfile
    ;;
*)  echo "multiple instances of oscam1 running. Stopping & restarting oscam1:     $(date)" >> $logfile
    kill $(pidof oscam1 | awk '{ $1=""; print $0}')
    ;;
esac

It is worth noting that the pidof route seems to work fine for commands that have no spaces, but you would probably want to go back to a ps-based string if you were looking for, say, a python script named myscript that showed up under ps like

root 22415 54.0 0.4 89116 79076 pts/1 S 16:40 0:00 /usr/bin/python /usr/bin/myscript

Just an FYI

Algorithm to randomly generate an aesthetically-pleasing color palette

You could average the RGB values of random colors with those of a constant color:

(example in Java)

public Color generateRandomColor(Color mix) {
    Random random = new Random();
    int red = random.nextInt(256);
    int green = random.nextInt(256);
    int blue = random.nextInt(256);

    // mix the color
    if (mix != null) {
        red = (red + mix.getRed()) / 2;
        green = (green + mix.getGreen()) / 2;
        blue = (blue + mix.getBlue()) / 2;
    }

    Color color = new Color(red, green, blue);
    return color;
}


Mixing random colors with white (255, 255, 255) creates neutral pastels by increasing the lightness while keeping the hue of the original color. These randomly generated pastels usually go well together, especially in large numbers.

Here are some pastel colors generated using the above method:

First


You could also mix the random color with a constant pastel, which results in a tinted set of neutral colors. For example, using a light blue creates colors like these:

Second


Going further, you could add heuristics to your generator that take into account complementary colors or levels of shading, but it all depends on the impression you want to achieve with your random colors.

Some additional resources:

Applying function with multiple arguments to create a new pandas column

One more dict style clean syntax:

df["new_column"] = df.apply(lambda x: x["A"] * x["B"], axis = 1)

or,

df["new_column"] = df["A"] * df["B"]

How do I determine the size of my array in C?

The macro ARRAYELEMENTCOUNT(x) that everyone is making use of evaluates incorrectly. This, realistically, is just a sensitive matter, because you can't have expressions that result in an 'array' type.

/* Compile as: CL /P "macro.c" */
# define ARRAYELEMENTCOUNT(x) (sizeof (x) / sizeof (x[0]))

ARRAYELEMENTCOUNT(p + 1);

Actually evaluates as:

(sizeof (p + 1) / sizeof (p + 1[0]));

Whereas

/* Compile as: CL /P "macro.c" */
# define ARRAYELEMENTCOUNT(x) (sizeof (x) / sizeof (x)[0])

ARRAYELEMENTCOUNT(p + 1);

It correctly evaluates to:

(sizeof (p + 1) / sizeof (p + 1)[0]);

This really doesn't have a lot to do with the size of arrays explicitly. I've just noticed a lot of errors from not truly observing how the C preprocessor works. You always wrap the macro parameter, not an expression in might be involved in.


This is correct; my example was a bad one. But that's actually exactly what should happen. As I previously mentioned p + 1 will end up as a pointer type and invalidate the entire macro (just like if you attempted to use the macro in a function with a pointer parameter).

At the end of the day, in this particular instance, the fault doesn't really matter (so I'm just wasting everyone's time; huzzah!), because you don't have expressions with a type of 'array'. But really the point about preprocessor evaluation subtles I think is an important one.

Jersey stopped working with InjectionManagerFactory not found

As far as I can see dependencies have changed between 2.26-b03 and 2.26-b04 (HK2 was moved to from compile to testCompile)... there might be some change in the jersey dependencies that has not been completed yet (or which lead to a bug).

However, right now the simple solution is to stick to an older version :-)

PHP: Split a string in to an array foreach char

you can convert a string to array with str_split and use foreach

$chars = str_split($str);
foreach($chars as $char){
    // your code
}

How do you clear the console screen in C?

printf("\e[1;1H\e[2J");

This function will work on ANSI terminals, demands POSIX. I assume there is a version that might also work on window's console, since it also supports ANSI escape sequences.

#include <unistd.h>

void clearScreen()
{
  const char *CLEAR_SCREEN_ANSI = "\e[1;1H\e[2J";
  write(STDOUT_FILENO, CLEAR_SCREEN_ANSI, 12);
}

There are some other alternatives, some of which don't move the cursor to {1,1}.

How to push object into an array using AngularJS

You should try this way. It will definitely work.

(function() {

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

 app.controller('myController', ['$scope', function($scope) {

    $scope.myText = "Object Push inside ";

    $scope.arrayText = [

        ];

    $scope.addText = function() {
        $scope.arrayText.push(this.myText);
    }

 }]);

})();

In your case $scope.arrayText is an object. You should initialize as a array.

Collapsing Sidebar with Bootstrap

Bootstrap 3

Yes, it's possible. This "off-canvas" example should help to get you started.

https://codeply.com/p/esYgHWB2zJ

Basically you need to wrap the layout in an outer div, and use media queries to toggle the layout on smaller screens.

/* collapsed sidebar styles */
@media screen and (max-width: 767px) {
  .row-offcanvas {
    position: relative;
    -webkit-transition: all 0.25s ease-out;
    -moz-transition: all 0.25s ease-out;
    transition: all 0.25s ease-out;
  }
  .row-offcanvas-right
  .sidebar-offcanvas {
    right: -41.6%;
  }

  .row-offcanvas-left
  .sidebar-offcanvas {
    left: -41.6%;
  }
  .row-offcanvas-right.active {
    right: 41.6%;
  }
  .row-offcanvas-left.active {
    left: 41.6%;
  }
  .sidebar-offcanvas {
    position: absolute;
    top: 0;
    width: 41.6%;
  }
  #sidebar {
    padding-top:0;
  }
}

Also, there are several more Bootstrap sidebar examples here


Bootstrap 4

Create a responsive navbar sidebar "drawer" in Bootstrap 4?

How do you append to a file?

You probably want to pass "a" as the mode argument. See the docs for open().

with open("foo", "a") as f:
    f.write("cool beans...")

There are other permutations of the mode argument for updating (+), truncating (w) and binary (b) mode but starting with just "a" is your best bet.

Bootstrap 3, 4 and 5 .container-fluid with grid adding unwanted padding

Please find the actual css from Bootstrap

.container-fluid {
  padding-right: 15px;
  padding-left: 15px;
  margin-right: auto;
  margin-left: auto;
}
.row {
  margin-right: -15px;
  margin-left: -15px;
}

When you add a .container-fluid class, it adds a horizontal padding of 15px, and the same will be removed when you add a .row class as a child element by the negative margin set on row.

overlay opaque div over youtube iframe

Note that the wmode=transparent fix only works if it's first so

http://www.youtube.com/embed/K3j9taoTd0E?wmode=transparent&rel=0

Not

http://www.youtube.com/embed/K3j9taoTd0E?rel=0&wmode=transparent

How to write a JSON file in C#?

Update 2020: It's been 7 years since I wrote this answer. It still seems to be getting a lot of attention. In 2013 Newtonsoft Json.Net was THE answer to this problem. Now it's still a good answer to this problem but it's no longer the the only viable option. To add some up-to-date caveats to this answer:

  • .Net Core now has the spookily similar System.Text.Json serialiser (see below)
  • The days of the JavaScriptSerializer have thankfully passed and this class isn't even in .Net Core. This invalidates a lot of the comparisons ran by Newtonsoft.
  • It's also recently come to my attention, via some vulnerability scanning software we use in work that Json.Net hasn't had an update in some time. Updates in 2020 have dried up and the latest version, 12.0.3, is over a year old.
  • The speed tests quoted below are comparing an older version of Json.Nt (version 6.0 and like I said the latest is 12.0.3) with an outdated .Net Framework serialiser.

Are Json.Net's days numbered? It's still used a LOT and it's still used by MS librarties. So probably not. But this does feel like the beginning of the end for this library that may well of just run it's course.


Update since .Net Core 3.0

A new kid on the block since writing this is System.Text.Json which has been added to .Net Core 3.0. Microsoft makes several claims to how this is, now, better than Newtonsoft. Including that it is faster than Newtonsoft. as below, I'd advise you to test this yourself .


I would recommend Json.Net, see example below:

List<data> _data = new List<data>();
_data.Add(new data()
{
    Id = 1,
    SSN = 2,
    Message = "A Message"
});

string json = JsonConvert.SerializeObject(_data.ToArray());

//write string to file
System.IO.File.WriteAllText(@"D:\path.txt", json);

Or the slightly more efficient version of the above code (doesn't use a string as a buffer):

//open file stream
using (StreamWriter file = File.CreateText(@"D:\path.txt"))
{
     JsonSerializer serializer = new JsonSerializer();
     //serialize object directly into file stream
     serializer.Serialize(file, _data);
}

Documentation: Serialize JSON to a file


Why? Here's a feature comparison between common serialisers as well as benchmark tests .

Below is a graph of performance taken from the linked article:

enter image description here

This separate post, states that:

Json.NET has always been memory efficient, streaming the reading and writing large documents rather than loading them entirely into memory, but I was able to find a couple of key places where object allocations could be reduced...... (now) Json.Net (6.0) allocates 8 times less memory than JavaScriptSerializer


Benchmarks appear to be Json.Net 5, the current version (on writing) is 10. What version of standard .Net serialisers used is not mentioned

These tests are obviously from the developers who maintain the library. I have not verified their claims. If in doubt test them yourself.

Property [title] does not exist on this collection instance

You Should Used Collection keyword in Controller. Like Here..

public function ApiView(){
    return User::collection(Profile::all());
}

Here, User is Resource Name and Profile is Model Name. Thank You.

What static analysis tools are available for C#?

The tool NDepend is quoted as Quality Metric Tools but it is pretty much also a Code violation detection tool. Disclaimer: I am one of the developers of the tool

With NDepend, one can write Code Rule over LINQ Queries (what we call CQLinq). More than 200 CQLinq code rules are proposed by default. The strength of CQLinq is that it is straightforward to write a code rule, and get immediately results. Facilities are proposed to browse matched code elements. For example:

CQLinq code rule

Beside that, NDepend comes with many others static analysis like features. These include:

How to insert strings containing slashes with sed?

replace.txt should be

s/?page=/\/page\//g
s/&//g

jQuery & CSS - Remove/Add display:none

jQuery's .show() and .hide() functions are probably your best bet.

Convert a PHP object to an associative array

You can quickly convert deeply nested objects to associative arrays by relying on the behavior of the JSON encode/decode functions:

$array = json_decode(json_encode($nested_object), true);

install cx_oracle for python

Thanks Burhan Khalid. Your advice to make a a soft link make my installation finally work.

To recap:

  1. You need both the basic version and the SDK version of instant client

  2. You need to set both LD_LIBRARY_PATH and ORACLE_HOME

  3. You need to create a soft link (ln -s libclntsh.so.12.1 libclntsh.so in my case)

None of this is documented anywhere, which is quite unbelievable and quite frustrating. I spent over 3 hours yesterday with failed builds because I didn't know to create a soft link.

How to get http headers in flask?

from flask import request
request.headers.get('your-header-name')

request.headers behaves like a dictionary, so you can also get your header like you would with any dictionary:

request.headers['your-header-name']

ASP.NET MVC 3 Razor - Adding class to EditorFor

There isn't any EditorFor override that lets you pass in an anonymous object whose properties would somehow get added as attributes on some tag, especially for the built-in editor templates. You would need to write your own custom editor template and pass the value you want as additional viewdata.

How do I use Access-Control-Allow-Origin? Does it just go in between the html head tags?

<?php header("Access-Control-Allow-Origin: http://example.com"); ?>

This command disables only first console warning info

console

Result: console result

"Could not run curl-config: [Errno 2] No such file or directory" when installing pycurl

in my case this fixed the problem:

sudo apt-get install libssl-dev libcurl4-openssl-dev python-dev

as explained here

How do you debug PHP scripts?

Usually I find create a custom log function able to save on file, store debug info, and eventually re-print on a common footer.

You can also override common Exception class, so that this type of debugging is semi-automated.

React Modifying Textarea Values

I think you want something along the line of:

Parent:

<Editor name={this.state.fileData} />

Editor:

var Editor = React.createClass({
  displayName: 'Editor',
  propTypes: {
    name: React.PropTypes.string.isRequired
  },
  getInitialState: function() { 
    return {
      value: this.props.name
    };
  },
  handleChange: function(event) {
    this.setState({value: event.target.value});
  },
  render: function() {
    return (
      <form id="noter-save-form" method="POST">
        <textarea id="noter-text-area" name="textarea" value={this.state.value} onChange={this.handleChange} />
        <input type="submit" value="Save" />
      </form>
    );
  }
});

This is basically a direct copy of the example provided on https://facebook.github.io/react/docs/forms.html

Update for React 16.8:

import React, { useState } from 'react';

const Editor = (props) => {
    const [value, setValue] = useState(props.name);

    const handleChange = (event) => {
        setValue(event.target.value);
    };

    return (
        <form id="noter-save-form" method="POST">
            <textarea id="noter-text-area" name="textarea" value={value} onChange={handleChange} />
            <input type="submit" value="Save" />
        </form>
    );
}

Editor.propTypes = {
    name: PropTypes.string.isRequired
};

Detect changes in the DOM

How about extending a jquery for this?

   (function () {
        var ev = new $.Event('remove'),
            orig = $.fn.remove;
        var evap = new $.Event('append'),
           origap = $.fn.append;
        $.fn.remove = function () {
            $(this).trigger(ev);
            return orig.apply(this, arguments);
        }
        $.fn.append = function () {
            $(this).trigger(evap);
            return origap.apply(this, arguments);
        }
    })();
    $(document).on('append', function (e) { /*write your logic here*/ });
    $(document).on('remove', function (e) { /*write your logic here*/ });

Jquery 1.9+ has built support for this(I have heard not tested).

What Does 'zoom' do in CSS?

zoom is a css3 spec for the @viewport descriptor, as described here

http://dev.w3.org/csswg/css-device-adapt/#zoom-desc

used to zoom the entire viewport ('screen'). it also happens to zoom individuals elements in a lot of browsers, but not all. css3 specifies transform:scale should be used to achieve such an effect:

http://www.w3.org/TR/css3-transforms/#transform-functions

but it works a little different than the 'element zoom' in those browsers that support it.

Sorting a DropDownList? - C#, ASP.NET

DropDownList takes any IEnumerable as a DataSource.

Just sort it using LINQ.

Find most frequent value in SQL column

Let us consider table name as tblperson and column name as city. I want to retrieve the most repeated city from the city column:

 select city,count(*) as nor from tblperson
        group by city
          having count(*) =(select max(nor) from 
            (select city,count(*) as nor from tblperson group by city) tblperson)

Here nor is an alias name.

Check file uploaded is in csv format

simple use "accept" and "required" in and avoiding so much typical and unwanted coding.

querySelector and querySelectorAll vs getElementsByClassName and getElementById in JavaScript

collecting from Mozilla Documentation:

The NodeSelector interface This specification adds two new methods to any objects implementing the Document, DocumentFragment, or Element interfaces:

querySelector

Returns the first matching Element node within the node's subtree. If no matching node is found, null is returned.

querySelectorAll

Returns a NodeList containing all matching Element nodes within the node's subtree, or an empty NodeList if no matches are found.

and

Note: The NodeList returned by querySelectorAll() is not live, which means that changes in the DOM are not reflected in the collection. This is different from other DOM querying methods that return live node lists.

String to object in JS

If you have a string like foo: 1, bar: 2 you can convert it to a valid obj with:

str
  .split(',')
  .map(x => x.split(':').map(y => y.trim()))
  .reduce((a, x) => {
    a[x[0]] = x[1];
    return a;
  }, {});

Thanks to niggler in #javascript for that.

Update with explanations:

const obj = 'foo: 1, bar: 2'
  .split(',') // split into ['foo: 1', 'bar: 2']
  .map(keyVal => { // go over each keyVal value in that array
    return keyVal
      .split(':') // split into ['foo', '1'] and on the next loop ['bar', '2']
      .map(_ => _.trim()) // loop over each value in each array and make sure it doesn't have trailing whitespace, the _ is irrelavent because i'm too lazy to think of a good var name for this
  })
  .reduce((accumulator, currentValue) => { // reduce() takes a func and a beginning object, we're making a fresh object
    accumulator[currentValue[0]] = currentValue[1]
    // accumulator starts at the beginning obj, in our case {}, and "accumulates" values to it
    // since reduce() works like map() in the sense it iterates over an array, and it can be chained upon things like map(),
    // first time through it would say "okay accumulator, accumulate currentValue[0] (which is 'foo') = currentValue[1] (which is '1')
    // so first time reduce runs, it starts with empty object {} and assigns {foo: '1'} to it
    // second time through, it "accumulates" {bar: '2'} to it. so now we have {foo: '1', bar: '2'}
    return accumulator
  }, {}) // when there are no more things in the array to iterate over, it returns the accumulated stuff

console.log(obj)

Confusing MDN docs:

Demo: http://jsbin.com/hiduhijevu/edit?js,console

Function:

const str2obj = str => {
  return str
    .split(',')
    .map(keyVal => {
      return keyVal
        .split(':')
        .map(_ => _.trim())
    })
    .reduce((accumulator, currentValue) => {
      accumulator[currentValue[0]] = currentValue[1]
      return accumulator
    }, {})
}

console.log(str2obj('foo: 1, bar: 2')) // see? works!

What is a callback URL in relation to an API?

Another use case could be something like OAuth, it's may not be called by the API directly, instead the callback URL will be called by the browser after completing the authencation with the identity provider.

Normally after end user key in the username password, the identity service provider will trigger a browser redirect to your "callback" url with the temporary authroization code, e.g.

https://example.com/callback?code=AUTHORIZATION_CODE

Then your application could use this authorization code to request a access token with the identity provider which has a much longer lifetime.

How to display full (non-truncated) dataframe information in html when converting from pandas dataframe to html?

pd.set_option('display.max_columns', None)  

id (second argument) can fully show the columns.

Convert int to a bit array in .NET

int value = 3;

var array = Convert.ToString(value, 2).PadLeft(8, '0').ToArray();

getCurrentPosition() and watchPosition() are deprecated on insecure origins

Found a likely answer in /jstillwell's posts here: https://github.com/stefanocudini/leaflet-gps/issues/15 basically this feature will not be supported (in Chrome only?) in the future, but only for HTTP sites. HTTPS will still be ok, and there are no plans to create an equivalent replacement for HTTP use.

Equals(=) vs. LIKE

If you search for an exact match, you can use both, = and LIKE.

Using "=" is a tiny bit faster in this case (searching for an exact match) - you can check this yourself by having the same query twice in SQL Server Management Studio, once using "=", once using "LIKE", and then using the "Query" / "Include actual execution plan".

Execute the two queries and you should see your results twice, plus the two actual execution plans. In my case, they were split 50% vs. 50%, but the "=" execution plan has a smaller "estimated subtree cost" (displayed when you hover over the left-most "SELECT" box) - but again, it's really not a huge difference.

But when you start searching with wildcards in your LIKE expression, search performance will dimish. Search "LIKE Mill%" can still be quite fast - SQL Server can use an index on that column, if there is one. Searching "LIKE %expression%" is horribly slow, since the only way SQL Server can satisfy this search is by doing a full table scan. So be careful with your LIKE's !

Marc

How can I add new dimensions to a Numpy array?

This worked for me:

image = image[..., None]

LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup

In my case, it's because I accidentally removed (not deleted) the stdafx.h and targetver.h files in the Header Files section.

Add these files back to Header Files and the problem is solved.

I had these:

#pragma comment( linker, "/entry:\"mainCRTStartup\"" ) // set the entry point to be main()

I just need to comment that (by prepending //) and it's good.

Failed to load resource: net::ERR_CONTENT_LENGTH_MISMATCH

In my case it was a proxy issue (requests proxied from nginx to a varnish cache) that caused the issue. I needed to add the following to my proxy definition

        proxy_set_header Connection keep-alive; 

I found the answer here: https://stackoverflow.com/a/55341260/1062129

Argument of type 'X' is not assignable to parameter of type 'X'

For what it worth, if anyone has this problem only in VSCode, just restart VSCode and it should fix it. Sometimes, Intellisense seems to mess up with imports or types.

Related to Typescript: Argument of type 'RegExpMatchArray' is not assignable to parameter of type 'string'

When do you use map vs flatMap in RxJava?

In that scenario use map, you don't need a new Observable for it.

you should use Exceptions.propagate, which is a wrapper so you can send those checked exceptions to the rx mechanism

Observable<String> obs = Observable.from(jsonFile).map(new Func1<File, String>() { 
    @Override public String call(File file) {
        try { 
            return new Gson().toJson(new FileReader(file), Object.class);
        } catch (FileNotFoundException e) {
            throw Exceptions.propagate(t); /will propagate it as error
        } 
    } 
});

You then should handle this error in the subscriber

obs.subscribe(new Subscriber<String>() {
    @Override 
    public void onNext(String s) { //valid result }

    @Override 
    public void onCompleted() { } 

    @Override 
    public void onError(Throwable e) { //e might be the FileNotFoundException you got }
};); 

There is an excellent post for it: http://blog.danlew.net/2015/12/08/error-handling-in-rxjava/

navbar color in Twitter Bootstrap

You can customize your own version on the Bootstrap official website.

How do I fix "The expression of type List needs unchecked conversion...'?

Since getEntries returns a raw List, it could hold anything.

The warning-free approach is to create a new List<SyndEntry>, then cast each element of the sf.getEntries() result to SyndEntry before adding it to your new list. Collections.checkedList does not do this checking for you—although it would have been possible to implement it to do so.

By doing your own cast up front, you're "complying with the warranty terms" of Java generics: if a ClassCastException is raised, it will be associated with a cast in the source code, not an invisible cast inserted by the compiler.

Sending a JSON to server and retrieving a JSON in return, without JQuery

Sending and receiving data in JSON format using POST method

// Sending and receiving data in JSON format using POST method
//
var xhr = new XMLHttpRequest();
var url = "url";
xhr.open("POST", url, true);
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onreadystatechange = function () {
    if (xhr.readyState === 4 && xhr.status === 200) {
        var json = JSON.parse(xhr.responseText);
        console.log(json.email + ", " + json.password);
    }
};
var data = JSON.stringify({"email": "[email protected]", "password": "101010"});
xhr.send(data);

Sending and receiving data in JSON format using GET method

// Sending a receiving data in JSON format using GET method
//      
var xhr = new XMLHttpRequest();
var url = "url?data=" + encodeURIComponent(JSON.stringify({"email": "[email protected]", "password": "101010"}));
xhr.open("GET", url, true);
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onreadystatechange = function () {
    if (xhr.readyState === 4 && xhr.status === 200) {
        var json = JSON.parse(xhr.responseText);
        console.log(json.email + ", " + json.password);
    }
};
xhr.send();

Handling data in JSON format on the server-side using PHP

<?php
// Handling data in JSON format on the server-side using PHP
//
header("Content-Type: application/json");
// build a PHP variable from JSON sent using POST method
$v = json_decode(stripslashes(file_get_contents("php://input")));
// build a PHP variable from JSON sent using GET method
$v = json_decode(stripslashes($_GET["data"]));
// encode the PHP variable to JSON and send it back on client-side
echo json_encode($v);
?>

The limit of the length of an HTTP Get request is dependent on both the server and the client (browser) used, from 2kB - 8kB. The server should return 414 (Request-URI Too Long) status if an URI is longer than the server can handle.

Note Someone said that I could use state names instead of state values; in other words I could use xhr.readyState === xhr.DONE instead of xhr.readyState === 4 The problem is that Internet Explorer uses different state names so it's better to use state values.

Find files with size in Unix

Assuming you have GNU find:

find . -size +10000k -printf '%s %f\n'

If you want a constant width for the size field, you can do something like:

find . -size +10000k -printf '%10s %f\n'

Note that -size +1000k selects files of at least 10,240,000 bytes (k is 1024, not 1000). You said in a comment that you want files bigger than 1M; if that's 1024*1024 bytes, then this:

find . -size +1M ...

will do the trick -- except that it will also print the size and name of files that are exactly 1024*1024 bytes. If that matters, you could use:

find . -size +1048575c ...

You need to decide just what criterion you want.

How can I get href links from HTML using Python?

Here's a lazy version of @stephen's answer

import html.parser
import itertools
import urllib.request

class LinkParser(html.parser.HTMLParser):
    def reset(self):
        super().reset()
        self.links = iter([])

    def handle_starttag(self, tag, attrs):
        if tag == 'a':
            for (name, value) in attrs:
                if name == 'href':
                    self.links = itertools.chain(self.links, [value])


def gen_links(stream, parser):
    encoding = stream.headers.get_content_charset() or 'UTF-8'
    for line in stream:
        parser.feed(line.decode(encoding))
        yield from parser.links

Use it like so:

>>> parser = LinkParser()
>>> stream = urllib.request.urlopen('http://stackoverflow.com/questions/3075550')
>>> links = gen_links(stream, parser)
>>> next(links)
'//stackoverflow.com'

C# Threading - How to start and stop a thread

Use a static AutoResetEvent in your spawned threads to call back to the main thread using the Set() method. This guy has a fairly good demo in SO on how to use it.

AutoResetEvent clarification

How to crop(cut) text files based on starting and ending line-numbers in cygwin?

Sounds like a job for sed:

sed -n '8,12p' yourfile

...will send lines 8 through 12 of yourfile to standard out.

If you want to prepend the line number, you may wish to use cat -n first:

cat -n yourfile | sed -n '8,12p'

Convert string to title case with JavaScript

Simple way to convert an individual word to title case

Using the "Slice" method and String concatenation

str.slice(0, 1).toUpperCase() + str.slice(1, str.length)

*Add .toLowerCase() to the end if you want to lowercase the rest of the word

Using ES6 Spread Operator, Map, and Join

[...str].map((w, i) => i === 0 ? w[0].toUpperCase() : w).join('')

Remove a string from the beginning of a string

Nice speed, but this is hard-coded to depend on the needle ending with _. Is there a general version? – toddmo Jun 29 at 23:26

A general version:

$parts = explode($start, $full, 2);
if ($parts[0] === '') {
    $end = $parts[1];
} else {
    $fail = true;
}

Some benchmarks:

<?php

$iters = 100000;
$start = "/aaaaaaa/bbbbbbbbbb";
$full = "/aaaaaaa/bbbbbbbbbb/cccccccccc/dddddddddd/eeeeeeeeee";
$end = '';

$fail = false;

$t0 = microtime(true);
for ($i = 0; $i < $iters; $i++) {
    if (strpos($full, $start) === 0) {
        $end = substr($full, strlen($start));
    } else {
        $fail = true;
    }
}
$t = microtime(true) - $t0;
printf("%16s : %f s\n", "strpos+strlen", $t);

$t0 = microtime(true);
for ($i = 0; $i < $iters; $i++) {
    $parts = explode($start, $full, 2);
    if ($parts[0] === '') {
        $end = $parts[1];
    } else {
        $fail = true;
    }
}
$t = microtime(true) - $t0;
printf("%16s : %f s\n", "explode", $t);

On my quite old home PC:

$ php bench.php

Outputs:

   strpos+strlen : 0.158388 s
         explode : 0.126772 s

Sharing a variable between multiple different threads

AtomicBoolean

The succinct Answer by NPE sums up your three options. I'll add some example code for the second item listed there: AtomicBoolean.

You can think of the AtomicBoolean class as providing some thread-safety wrapping around a boolean value.

If you instantiate the AtomicBoolean only once, then you need not worry about the visibility issue in the Java Memory Model that requires volatile as a solution (the first item in that other Answer). Also, you need not concern yourself with synchronization (the third item in that other Answer) because AtomicBoolean performs that function of protecting multi-threaded access to its internal boolean value.

Let's look at some example code.

Firstly, in modern Java we generally do not address the Thread class directly. We now have the Executors framework to simplify handling of threads.

This code below is using Project Loom technology, coming to a future version of Java. Preliminary builds available now, built on early-access Java 16. This makes for simpler coding, with ExecutorService being AutoCloseable for convenient use with try-with-resources syntax. But Project Loom is not related to the point of this Answer; it just makes for simpler code that is easier to understand as “structured concurrency”.

The idea here is that we have three threads: the original thread, plus a ExecutorService that will create two more threads. The two new threads both report the value of our AtomicBoolean. The first new thread does so immediately, while the other waits 10 seconds before reporting. Meanwhile, our main thread sleeps for 5 seconds, wakes, changes the AtomicBoolean object’s contained value, and then waits for that second thread to wake and complete its work the report on the now-altered AtomicBoolean contained value. While we are installing seconds between each event, this is merely for dramatic demonstration. The real point is that these threads could coincidently try to access the AtomicBoolean simultaneously, but that object will protect access to its internal boolean value in a thread-safe manner. Protecting against simultaneous access is the job of the Atomic… classes.

try (
        ExecutorService executorService = Executors.newVirtualThreadExecutor() ;
)
{
    AtomicBoolean flag = new AtomicBoolean( true );

    // This task, when run, will immediately report the flag.
    Runnable task1 = ( ) -> System.out.println( "First task reporting flag = " + flag.get() + ". " + Instant.now() );

    // This task, when run, will wait several seconds, then report the flag. Meanwhile, code below waits a shorter time before *changing* the flag.
    Runnable task2 = ( ) -> {
        try { Thread.sleep( Duration.ofSeconds( 10 ) ); } catch ( InterruptedException e ) { e.printStackTrace(); }
        System.out.println( "Second task reporting flag = " + flag.get() + ". " + Instant.now() );
    };

    executorService.submit( task1 );
    executorService.submit( task2 );

    // Wait for first task to complete, so sleep here briefly. But wake before the sleeping second task awakens.
    try { Thread.sleep( Duration.ofSeconds( 5 ) ); } catch ( InterruptedException e ) { e.printStackTrace(); }
    System.out.println( "INFO - Original thread waking up, and setting flag to false. " + Instant.now() );
    flag.set( false );
}
// At this point, with Project Loom technology, the flow-of-control blocks until the submitted tasks are done.
// Also, the `ExecutorService` is automatically closed/shutdown by this point, via try-with-resources syntax.
System.out.println( "INFO - Tasks on background threads are done. The `AtomicBoolean` and threads are gone." + Instant.now() );

Methods such as AtomicBoolean#get and AtomicBoolean#set are built to be thread-safe, to internally protect access to the boolean value nested within. Read up on the various other methods as well.

When run:

First task reporting flag = true. 2021-01-05T06:42:17.367337Z
INFO - Original thread waking up, and setting flag to false. 2021-01-05T06:42:22.367456Z
Second task reporting flag = false. 2021-01-05T06:42:27.369782Z
INFO - Tasks on background threads are done. The `AtomicBoolean` and threads are gone.2021-01-05T06:42:27.372597Z

Pro Tip: When engaging in threaded code in Java, always study the excellent book, Java Concurrency in Practice by Brian Goetz et al.

PHP __get and __set magic methods

To expand on Berry's answer, that setting the access level to protected allows __get and __set to be used with explicitly declared properties (when accessed outside the class, at least) and the speed being considerably slower, I'll quote a comment from another question on this topic and make a case for using it anyway:

I agree that __get is more slow to a custom get function (doing the same things), this is 0.0124455 the time for __get() and this 0.0024445 is for custom get() after 10000 loops. – Melsi Nov 23 '12 at 22:32 Best practice: PHP Magic Methods __set and __get

According to Melsi's tests, considerably slower is about 5 times slower. That is definitely considerably slower, but also note that the tests show that you can still access a property with this method 10,000 times, counting time for loop iteration, in roughly 1/100 of a second. It is considerably slower in comparison with actual get and set methods defined, and that is an understatement, but in the grand scheme of things, even 5 times slower is never actually slow.

The computing time of the operation is still negligible and not worth considering in 99% of real world applications. The only time it should really be avoided is when you're actually going to be accessing the properties over 10,000 times in a single request. High traffic sites are doing something really wrong if they can't afford throwing a few more servers up to keep their applications running. A single line text ad on the footer of a high traffic site where the access rate becomes an issue could probably pay for a farm of 1,000 servers with that line of text. The end user is never going to be tapping their fingers wondering what is taking the page so long to load because your application's property access takes a millionth of a second.

I say this speaking as a developer coming from a background in .NET, but invisible get and set methods to the consumer is not .NET's invention. They simply aren't properties without them, and these magic methods are PHP's developer's saving grace for even calling their version of properties "properties" at all. Also, the Visual Studio extension for PHP does support intellisense with protected properties, with that trick in mind, I'd think. I would think with enough developers using the magic __get and __set methods in this way, the PHP developers would tune up the execution time to cater to the developer community.

Edit: In theory, protected properties seemed like it'd work in most situation. In practice, it turns out that there's a lot of times you're going to want to use your getters and setters when accessing properties within the class definition and extended classes. A better solution is a base class and interface for when extending other classes, so you can just copy the few lines of code from the base class into the implementing class. I'm doing a bit more with my project's base class, so I don't have an interface to provide right now, but here is the untested stripped down class definition with magic property getting and setting using reflection to remove and move the properties to a protected array:

/** Base class with magic property __get() and __set() support for defined properties. */
class Component {
    /** Gets the properties of the class stored after removing the original
     * definitions to trigger magic __get() and __set() methods when accessed. */
    protected $properties = array();

    /** Provides property get support. Add a case for the property name to
     * expand (no break;) or replace (break;) the default get method. When
     * overriding, call parent::__get($name) first and return if not null,
     * then be sure to check that the property is in the overriding class
     * before doing anything, and to implement the default get routine. */
    public function __get($name) {
        $caller = array_shift(debug_backtrace());
        $max_access = ReflectionProperty::IS_PUBLIC;
        if (is_subclass_of($caller['class'], get_class($this)))
            $max_access = ReflectionProperty::IS_PROTECTED;
        if ($caller['class'] == get_class($this))
            $max_access = ReflectionProperty::IS_PRIVATE;
        if (!empty($this->properties[$name])
            && $this->properties[$name]->class == get_class()
            && $this->properties[$name]->access <= $max_access)
            switch ($name) {
                default:
                    return $this->properties[$name]->value;
            }
    }

    /** Provides property set support. Add a case for the property name to
     * expand (no break;) or replace (break;) the default set method. When
     * overriding, call parent::__set($name, $value) first, then be sure to
     * check that the property is in the overriding class before doing anything,
     * and to implement the default set routine. */
    public function __set($name, $value) {
        $caller = array_shift(debug_backtrace());
        $max_access = ReflectionProperty::IS_PUBLIC;
        if (is_subclass_of($caller['class'], get_class($this)))
            $max_access = ReflectionProperty::IS_PROTECTED;
        if ($caller['class'] == get_class($this))
            $max_access = ReflectionProperty::IS_PRIVATE;
        if (!empty($this->properties[$name])
            && $this->properties[$name]->class == get_class()
            && $this->properties[$name]->access <= $max_access)
            switch ($name) {
                default:
                    $this->properties[$name]->value = $value;
            }
    }

    /** Constructor for the Component. Call first when overriding. */
    function __construct() {
        // Removing and moving properties to $properties property for magic
        // __get() and __set() support.
        $reflected_class = new ReflectionClass($this);
        $properties = array();
        foreach ($reflected_class->getProperties() as $property) {
            if ($property->isStatic()) { continue; }
            $properties[$property->name] = (object)array(
                'name' => $property->name, 'value' => $property->value
                , 'access' => $property->getModifier(), 'class' => get_class($this));
            unset($this->{$property->name}); }
        $this->properties = $properties;
    }
}

My apologies if there are any bugs in the code.

The Definitive C Book Guide and List

Beginner

Introductory, no previous programming experience

  • C++ Primer * (Stanley Lippman, Josée Lajoie, and Barbara E. Moo) (updated for C++11) Coming at 1k pages, this is a very thorough introduction into C++ that covers just about everything in the language in a very accessible format and in great detail. The fifth edition (released August 16, 2012) covers C++11. [Review]

    * Not to be confused with C++ Primer Plus (Stephen Prata), with a significantly less favorable review.

  • Programming: Principles and Practice Using C++ (Bjarne Stroustrup, 2nd Edition - May 25, 2014) (updated for C++11/C++14) An introduction to programming using C++ by the creator of the language. A good read, that assumes no previous programming experience, but is not only for beginners.

Introductory, with previous programming experience

  • A Tour of C++ (Bjarne Stroustrup) (2nd edition for C++17) The “tour” is a quick (about 180 pages and 14 chapters) tutorial overview of all of standard C++ (language and standard library, and using C++11) at a moderately high level for people who already know C++ or at least are experienced programmers. This book is an extended version of the material that constitutes Chapters 2-5 of The C++ Programming Language, 4th edition.

  • Accelerated C++ (Andrew Koenig and Barbara Moo, 1st Edition - August 24, 2000) This basically covers the same ground as the C++ Primer, but does so on a fourth of its space. This is largely because it does not attempt to be an introduction to programming, but an introduction to C++ for people who've previously programmed in some other language. It has a steeper learning curve, but, for those who can cope with this, it is a very compact introduction to the language. (Historically, it broke new ground by being the first beginner's book to use a modern approach to teaching the language.) Despite this, the C++ it teaches is purely C++98. [Review]

Best practices

  • Effective C++ (Scott Meyers, 3rd Edition - May 22, 2005) This was written with the aim of being the best second book C++ programmers should read, and it succeeded. Earlier editions were aimed at programmers coming from C, the third edition changes this and targets programmers coming from languages like Java. It presents ~50 easy-to-remember rules of thumb along with their rationale in a very accessible (and enjoyable) style. For C++11 and C++14 the examples and a few issues are outdated and Effective Modern C++ should be preferred. [Review]

  • Effective Modern C++ (Scott Meyers) This is basically the new version of Effective C++, aimed at C++ programmers making the transition from C++03 to C++11 and C++14.

  • Effective STL (Scott Meyers) This aims to do the same to the part of the standard library coming from the STL what Effective C++ did to the language as a whole: It presents rules of thumb along with their rationale. [Review]


Intermediate

  • More Effective C++ (Scott Meyers) Even more rules of thumb than Effective C++. Not as important as the ones in the first book, but still good to know.

  • Exceptional C++ (Herb Sutter) Presented as a set of puzzles, this has one of the best and thorough discussions of the proper resource management and exception safety in C++ through Resource Acquisition is Initialization (RAII) in addition to in-depth coverage of a variety of other topics including the pimpl idiom, name lookup, good class design, and the C++ memory model. [Review]

  • More Exceptional C++ (Herb Sutter) Covers additional exception safety topics not covered in Exceptional C++, in addition to discussion of effective object-oriented programming in C++ and correct use of the STL. [Review]

  • Exceptional C++ Style (Herb Sutter) Discusses generic programming, optimization, and resource management; this book also has an excellent exposition of how to write modular code in C++ by using non-member functions and the single responsibility principle. [Review]

  • C++ Coding Standards (Herb Sutter and Andrei Alexandrescu) “Coding standards” here doesn't mean “how many spaces should I indent my code?” This book contains 101 best practices, idioms, and common pitfalls that can help you to write correct, understandable, and efficient C++ code. [Review]

  • C++ Templates: The Complete Guide (David Vandevoorde and Nicolai M. Josuttis) This is the book about templates as they existed before C++11. It covers everything from the very basics to some of the most advanced template metaprogramming and explains every detail of how templates work (both conceptually and at how they are implemented) and discusses many common pitfalls. Has excellent summaries of the One Definition Rule (ODR) and overload resolution in the appendices. A second edition covering C++11, C++14 and C++17 has been already published. [Review]

  • C++ 17 - The Complete Guide (Nicolai M. Josuttis) This book describes all the new features introduced in the C++17 Standard covering everything from the simple ones like 'Inline Variables', 'constexpr if' all the way up to 'Polymorphic Memory Resources' and 'New and Delete with overaligned Data'. [Review]

  • C++ in Action (Bartosz Milewski). This book explains C++ and its features by building an application from ground up. [Review]

  • Functional Programming in C++ (Ivan Cukic). This book introduces functional programming techniques to modern C++ (C++11 and later). A very nice read for those who want to apply functional programming paradigms to C++.

  • Professional C++ (Marc Gregoire, 5th Edition - Feb 2021) Provides a comprehensive and detailed tour of the C++ language implementation replete with professional tips and concise but informative in-text examples, emphasizing C++20 features. Uses C++20 features, such as modules and std::format throughout all examples.


Advanced

  • Modern C++ Design (Andrei Alexandrescu) A groundbreaking book on advanced generic programming techniques. Introduces policy-based design, type lists, and fundamental generic programming idioms then explains how many useful design patterns (including small object allocators, functors, factories, visitors, and multi-methods) can be implemented efficiently, modularly, and cleanly using generic programming. [Review]

  • C++ Template Metaprogramming (David Abrahams and Aleksey Gurtovoy)

  • C++ Concurrency In Action (Anthony Williams) A book covering C++11 concurrency support including the thread library, the atomics library, the C++ memory model, locks and mutexes, as well as issues of designing and debugging multithreaded applications. A second edition covering C++14 and C++17 has been already published. [Review]

  • Advanced C++ Metaprogramming (Davide Di Gennaro) A pre-C++11 manual of TMP techniques, focused more on practice than theory. There are a ton of snippets in this book, some of which are made obsolete by type traits, but the techniques, are nonetheless useful to know. If you can put up with the quirky formatting/editing, it is easier to read than Alexandrescu, and arguably, more rewarding. For more experienced developers, there is a good chance that you may pick up something about a dark corner of C++ (a quirk) that usually only comes about through extensive experience.


Reference Style - All Levels

  • The C++ Programming Language (Bjarne Stroustrup) (updated for C++11) The classic introduction to C++ by its creator. Written to parallel the classic K&R, this indeed reads very much like it and covers just about everything from the core language to the standard library, to programming paradigms to the language's philosophy. [Review] Note: All releases of the C++ standard are tracked in the question "Where do I find the current C or C++ standard documents?".

  • C++ Standard Library Tutorial and Reference (Nicolai Josuttis) (updated for C++11) The introduction and reference for the C++ Standard Library. The second edition (released on April 9, 2012) covers C++11. [Review]

  • The C++ IO Streams and Locales (Angelika Langer and Klaus Kreft) There's very little to say about this book except that, if you want to know anything about streams and locales, then this is the one place to find definitive answers. [Review]

C++11/14/17/… References:

  • The C++11/14/17 Standard (INCITS/ISO/IEC 14882:2011/2014/2017) This, of course, is the final arbiter of all that is or isn't C++. Be aware, however, that it is intended purely as a reference for experienced users willing to devote considerable time and effort to its understanding. The C++17 standard is released in electronic form for 198 Swiss Francs.

  • The C++17 standard is available, but seemingly not in an economical form – directly from the ISO it costs 198 Swiss Francs (about $200 US). For most people, the final draft before standardization is more than adequate (and free). Many will prefer an even newer draft, documenting new features that are likely to be included in C++20.

  • Overview of the New C++ (C++11/14) (PDF only) (Scott Meyers) (updated for C++14) These are the presentation materials (slides and some lecture notes) of a three-day training course offered by Scott Meyers, who's a highly respected author on C++. Even though the list of items is short, the quality is high.

  • The C++ Core Guidelines (C++11/14/17/…) (edited by Bjarne Stroustrup and Herb Sutter) is an evolving online document consisting of a set of guidelines for using modern C++ well. The guidelines are focused on relatively higher-level issues, such as interfaces, resource management, memory management and concurrency affecting application architecture and library design. The project was announced at CppCon'15 by Bjarne Stroustrup and others and welcomes contributions from the community. Most guidelines are supplemented with a rationale and examples as well as discussions of possible tool support. Many rules are designed specifically to be automatically checkable by static analysis tools.

  • The C++ Super-FAQ (Marshall Cline, Bjarne Stroustrup and others) is an effort by the Standard C++ Foundation to unify the C++ FAQs previously maintained individually by Marshall Cline and Bjarne Stroustrup and also incorporating new contributions. The items mostly address issues at an intermediate level and are often written with a humorous tone. Not all items might be fully up to date with the latest edition of the C++ standard yet.

  • cppreference.com (C++03/11/14/17/…) (initiated by Nate Kohl) is a wiki that summarizes the basic core-language features and has extensive documentation of the C++ standard library. The documentation is very precise but is easier to read than the official standard document and provides better navigation due to its wiki nature. The project documents all versions of the C++ standard and the site allows filtering the display for a specific version. The project was presented by Nate Kohl at CppCon'14.


Classics / Older

Note: Some information contained within these books may not be up-to-date or no longer considered best practice.

  • The Design and Evolution of C++ (Bjarne Stroustrup) If you want to know why the language is the way it is, this book is where you find answers. This covers everything before the standardization of C++.

  • Ruminations on C++ - (Andrew Koenig and Barbara Moo) [Review]

  • Advanced C++ Programming Styles and Idioms (James Coplien) A predecessor of the pattern movement, it describes many C++-specific “idioms”. It's certainly a very good book and might still be worth a read if you can spare the time, but quite old and not up-to-date with current C++.

  • Large Scale C++ Software Design (John Lakos) Lakos explains techniques to manage very big C++ software projects. Certainly, a good read, if it only was up to date. It was written long before C++ 98 and misses on many features (e.g. namespaces) important for large-scale projects. If you need to work in a big C++ software project, you might want to read it, although you need to take more than a grain of salt with it. The first volume of a new edition is released in 2019.

  • Inside the C++ Object Model (Stanley Lippman) If you want to know how virtual member functions are commonly implemented and how base objects are commonly laid out in memory in a multi-inheritance scenario, and how all this affects performance, this is where you will find thorough discussions of such topics.

  • The Annotated C++ Reference Manual (Bjarne Stroustrup, Margaret A. Ellis) This book is quite outdated in the fact that it explores the 1989 C++ 2.0 version - Templates, exceptions, namespaces and new casts were not yet introduced. Saying that however, this book goes through the entire C++ standard of the time explaining the rationale, the possible implementations, and features of the language. This is not a book to learn programming principles and patterns on C++, but to understand every aspect of the C++ language.

  • Thinking in C++ (Bruce Eckel, 2nd Edition, 2000). Two volumes; is a tutorial style free set of intro level books. Downloads: vol 1, vol 2. Unfortunately they're marred by a number of trivial errors (e.g. maintaining that temporaries are automatically const), with no official errata list. A partial 3rd party errata list is available at http://www.computersciencelab.com/Eckel.htm, but it is apparently not maintained.

  • Scientific and Engineering C++: An Introduction to Advanced Techniques and Examples (John Barton and Lee Nackman) It is a comprehensive and very detailed book that tried to explain and make use of all the features available in C++, in the context of numerical methods. It introduced at the time several new techniques, such as the Curiously Recurring Template Pattern (CRTP, also called Barton-Nackman trick). It pioneered several techniques such as dimensional analysis and automatic differentiation. It came with a lot of compilable and useful code, ranging from an expression parser to a Lapack wrapper. The code is still available online. Unfortunately, the books have become somewhat outdated in the style and C++ features, however, it was an incredible tour-de-force at the time (1994, pre-STL). The chapters on dynamics inheritance are a bit complicated to understand and not very useful. An updated version of this classic book that includes move semantics and the lessons learned from the STL would be very nice.

Force flushing of output to a file while bash script is still running

I had this problem with a background process in Mac OS X using the StartupItems. This is how I solve it:

If I make sudo ps aux I can see that mytool is launched.

I found that (due to buffering) when Mac OS X shuts down mytool never transfers the output to the sed command. However, if I execute sudo killall mytool, then mytool transfers the output to the sed command. Hence, I added a stop case to the StartupItems that is executed when Mac OS X shuts down:

start)
    if [ -x /sw/sbin/mytool ]; then
      # run the daemon
      ConsoleMessage "Starting mytool"
      (mytool | sed .... >> myfile.txt) & 
    fi
    ;;
stop)
    ConsoleMessage "Killing mytool"
    killall mytool
    ;;

javascript set cookie with expire time

Your browser may be configured to accept only session cookies; if this is your case, any expiry time is transformed into session by your browser, you can change this setting of your browser or try another browser without such a configuration

Could not find tools.jar. Please check that C:\Program Files\Java\jre1.8.0_151 contains a valid JDK installation

you have to added jdk path org.gradle.java.home=C:\Program Files\Java\jdk1.8.0_102 to gradle.properties make sure you write your jdk version which installed in you system.

Converting Integer to String with comma for thousands

 int value = 35634646;
 DecimalFormat myFormatter = new DecimalFormat("#,###");
 String output = myFormatter.format(value);
 System.out.println(output);

Output: 35,634,646

Converting an OpenCV Image to Black and White

Simply you can write the following code snippet to convert an OpenCV image into a grey scale image

import cv2
image = cv2.imread('image.jpg',0)
cv2.imshow('grey scale image',image)

Observe that the image.jpg and the code must be saved in same folder.

Note that:

  • ('image.jpg') gives a RGB image
  • ('image.jpg',0) gives Grey Scale Image.

How do I extract data from a DataTable?

  var table = Tables[0]; //get first table from Dataset
  foreach (DataRow row in table.Rows)
     {
       foreach (var item in row.ItemArray)
         {
            console.Write("Value:"+item);
         }
     }

How do you check that a number is NaN in JavaScript?

It seems that isNaN() is not supported in Node.js out of the box.
I worked around with

var value = 1;
if (parseFloat(stringValue)+"" !== "NaN") value = parseFloat(stringValue);

How does one extract each folder name from a path?

Inspired by the earlier answers, but simpler, and without recursion. Also, it does not care what the separation symbol is, as Dir.Parent covers this:

    /// <summary>
    /// Split a directory in its components.
    /// Input e.g: a/b/c/d.
    /// Output: d, c, b, a.
    /// </summary>
    /// <param name="Dir"></param>
    /// <returns></returns>
    public static IEnumerable<string> DirectorySplit(this DirectoryInfo Dir)
    {
        while (Dir != null)
        {
            yield return Dir.Name;
            Dir = Dir.Parent;
        }
    }

Either stick this in a static class to create a nice extension method, or just leave out the this (and static).

Usage example (as an extension method) to access the path parts by number:

    /// <summary>
    /// Return one part of the directory path.
    /// Path e.g.: a/b/c/d. PartNr=0 is a, Nr 2 = c.
    /// </summary>
    /// <param name="Dir"></param>
    /// <param name="PartNr"></param>
    /// <returns></returns>
    public static string DirectoryPart(this DirectoryInfo Dir, int PartNr)
    {
        string[] Parts = Dir.DirectorySplit().ToArray();
        int L = Parts.Length;
        return PartNr >= 0 && PartNr < L ? Parts[L - 1 - PartNr] : "";
    }

Both above methods are now in my personal library, hence the xml comments. Usage example:

    DirectoryInfo DI_Data = new DirectoryInfo(@"D:\Hunter\Data\2019\w38\abc\000.d");
    label_Year.Text = DI_Data.DirectoryPart(3); // --> 2019
    label_Entry.Text = DI_Data.DirectoryPart(6);// --> 000.d

How to create a self-signed certificate for a domain name for development?

With IIS's self-signed certificate feature, you cannot set the common name (CN) for the certificate, and therefore cannot create a certificate bound to your choice of subdomain.

One way around the problem is to use makecert.exe, which is bundled with the .Net 2.0 SDK. On my server it's at:

C:\Program Files\Microsoft.Net\SDK\v2.0 64bit\Bin\makecert.exe

You can create a signing authority and store it in the LocalMachine certificates repository as follows (these commands must be run from an Administrator account or within an elevated command prompt):

makecert.exe -n "CN=My Company Development Root CA,O=My Company,
 OU=Development,L=Wallkill,S=NY,C=US" -pe -ss Root -sr LocalMachine
 -sky exchange -m 120 -a sha1 -len 2048 -r

You can then create a certificate bound to your subdomain and signed by your new authority:

(Note that the the value of the -in parameter must be the same as the CN value used to generate your authority above.)

makecert.exe -n "CN=subdomain.example.com" -pe -ss My -sr LocalMachine
 -sky exchange -m 120 -in "My Company Development Root CA" -is Root
 -ir LocalMachine -a sha1 -eku 1.3.6.1.5.5.7.3.1

Your certificate should then appear in IIS Manager to be bound to your site as explained in Tom Hall's post.

All kudos for this solution to Mike O'Brien for his excellent blog post at http://www.mikeobrien.net/blog/creating-self-signed-wildcard

In MySQL, can I copy one row to insert into the same table?

Update 07/07/2014 - The answer based on my answer, by Grim..., is a better solution as it improves on my solution below, so I'd suggest using that.

You can do this without listing all the columns with the following syntax:

CREATE TEMPORARY TABLE tmptable SELECT * FROM table WHERE primarykey = 1;
UPDATE tmptable SET primarykey = 2 WHERE primarykey = 1;
INSERT INTO table SELECT * FROM tmptable WHERE primarykey = 2;

You may decide to change the primary key in another way.

How can I switch to a tag/branch in hg?

Once you have cloned the repo, you have everything: you can then hg up branchname or hg up tagname to update your working copy.

UP: hg up is a shortcut of hg update, which also has hg checkout alias for people with git habits.

Assign multiple values to array in C

If you are doing these same assignments a lot in your program and want a shortcut, the most straightforward solution might be to just add a function

static inline void set_coordinates(
        GLfloat coordinates[static 8],
        GLfloat c0, GLfloat c1, GLfloat c2, GLfloat c3,
        GLfloat c4, GLfloat c5, GLfloat c6, GLfloat c7)
{
    coordinates[0] = c0;
    coordinates[1] = c1;
    coordinates[2] = c2;
    coordinates[3] = c3;
    coordinates[4] = c4;
    coordinates[5] = c5;
    coordinates[6] = c6;
    coordinates[7] = c7;
}

and then simply call

GLfloat coordinates[8];
// ...
set_coordinates(coordinates, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 0.0f, 0.0f);

Most pythonic way to delete a file which may not exist

Another way to know if the file (or files) exists, and to remove it, is using the module glob.

from glob import glob
import os

for filename in glob("*.csv"):
    os.remove(filename)

Glob finds all the files that could select the pattern with a *nix wildcard, and loops the list.

html <input type="text" /> onchange event not working

HTML5 defines an oninput event to catch all direct changes. it works for me.

Can I update a JSF component from a JSF backing bean method?

Everything is possible only if there is enough time to research :)

What I got to do is like having people that I iterate into a ui:repeat and display names and other fields in inputs. But one of fields was singleSelect - A and depending on it value update another input - B. even ui:repeat do not have id I put and it appeared in the DOM tree

<ui:repeat id="peopleRepeat"
value="#{myBean.people}"
var="person" varStatus="status">

Than the ids in the html were something like:

myForm:peopleRepeat:0:personType
myForm:peopleRepeat:1:personType

Than in the view I got one method like:

<p:ajax event="change"
listener="#{myBean.onPersonTypeChange(person, status.index)}"/>

And its implementation was in the bean like:

String componentId = "myForm:peopleRepeat" + idx + "personType";
PrimeFaces.current().ajax().update(componentId);

So this way I updated the element from the bean with no issues. PF version 6.2

Good luck and happy coding :)

How to reset / remove chrome's input highlighting / focus border?

You should be able to remove it using

outline: none;

but keep in mind this is potentially bad for usability: It will be hard to tell whether an element is focused, which can suck when you walk through all a form's elements using the Tab key - you should reflect somehow when an element is focused.

Using custom std::set comparator

1. Modern C++20 solution

auto cmp = [](int a, int b) { return ... };
std::set<int, decltype(cmp)> s;

We use lambda function as comparator. As usual, comparator should return boolean value, indicating whether the element passed as first argument is considered to go before the second in the specific strict weak ordering it defines.

Online demo

2. Modern C++11 solution

auto cmp = [](int a, int b) { return ... };
std::set<int, decltype(cmp)> s(cmp);

Before C++20 we need to pass lambda as argument to set constructor

Online demo

3. Similar to first solution, but with function instead of lambda

Make comparator as usual boolean function

bool cmp(int a, int b) {
    return ...;
}

Then use it, either this way:

std::set<int, decltype(cmp)*> s(cmp);

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or this way:

std::set<int, decltype(&cmp)> s(&cmp);

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4. Old solution using struct with () operator

struct cmp {
    bool operator() (int a, int b) const {
        return ...
    }
};

// ...
// later
std::set<int, cmp> s;

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5. Alternative solution: create struct from boolean function

Take boolean function

bool cmp(int a, int b) {
    return ...;
}

And make struct from it using std::integral_constant

#include <type_traits>
using Cmp = std::integral_constant<decltype(&cmp), &cmp>;

Finally, use the struct as comparator

std::set<X, Cmp> set;

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How to browse for a file in java swing library?

In WebStart and the new 6u10 PlugIn you can use the FileOpenService, even without security permissions. For obvious reasons, you only get the file contents, not the file path.

Concat strings by & and + in VB.Net

You can write '&' to add string and integer :

processDetails=objProcess.ProcessId & ":" & objProcess.name
message = msgbox(processDetails,16,"Details")

output will be:

5577:wscript.exe

R Markdown - changing font size and font type in html output

You can change the font size in R Markdown with HTML code tags <font size="1"> your text </font> . This code is added to the R Markdown document and will alter the output of the HTML output.

For example:

_x000D_
_x000D_
 <font size="1"> This is my text number1</font> _x000D_
_x000D_
 <font size="2"> This is my text number 2 </font>_x000D_
 _x000D_
 <font size="3"> This is my text number 3</font> _x000D_
 _x000D_
 <font size="4"> This is my text number 4</font> _x000D_
 _x000D_
 <font size="5"> This is my text number 5</font> _x000D_
 _x000D_
 <font size="6"> This is my text number 6</font>
_x000D_
_x000D_
_x000D_

How to query SOLR for empty fields?

You can also use it like this.

fq=!id:['' TO *]

Change Date Format(DD/MM/YYYY) in SQL SELECT Statement

Try like this...

select CONVERT (varchar(10), getdate(), 103) AS [DD/MM/YYYY]

For more info : http://www.sql-server-helper.com/tips/date-formats.aspx

Customize list item bullets using CSS

You can wrap the contents of the li in another element such as a span. Then, give the li a larger font-size, and set a normal font-size back on the span:

http://jsfiddle.net/RZr2r/

li {
    font-size: 36px;
}
li span {
    font-size: 18px;
}
<ul>
    <li><span>Item 1</span></li>
    <li><span>Item 2</span></li>
    <li><span>Item 3</span></li>
</ul>

Selecting one row from MySQL using mysql_* API

What you should get as output with this code is:

Array ()

... this is exactly how you get just one row, you don't need a while loop. Are you sure you're printing the right variable?