Programs & Examples On #Nvidia

An American global technology company based in Santa Clara, California, best known for its graphics processors (GPUs).

NVIDIA NVML Driver/library version mismatch

For completeness, I ran into this issue as well. In my case it turned out that because I had set Clang as my default compiler (using update-alternatives), nvidia-driver-440 failed to compile (check /var/crash/) even though apt didn't post any warnings. For me, the solution was to apt purge nvidia-*, set cc back to use gcc, reboot, and reinstall nvidia-driver-440.

Difference between nVidia Quadro and Geforce cards?

Surfing the web, you will find many technical justifications for Quadro price. Real answer is in "demand for reliable and task specific graphic cards".

Imagine you have an architectural firm with many fat projects on deadline. Your computers are only used in working with one specific CAD software. If foundation of your business is supposed to rely on these computers, you would want to make sure this foundation is strong.

For such clients, Nvidia engineered cards like Quadro, providing what they call "Professional Solution". And if you are among the targeted clients, you would really appreciate reliability of these graphic cards.

Many believe Geforce have become powerful and reliable enough to take Quadro's place. But in the end, it depends on the software you are mostly going to use and importance of reliability in what you do.

Error Message : Cannot find or open the PDB file

  1. Please check if the setting Generate Debug Info is Yes which under Project Propeties > Configuration Properties > Linker > Debugging tab. If not, try to change it to Yes.

  2. Those perticular pdb's ( for ntdll.dll, mscoree.dll, kernel32.dll, etc ) are for the windows API and shouldn't be needed for simple apps. However, if you cannot find pdb's for your own compiled projects, I suggest making sure the Project Properties > Configuration Properties > Debugging > Working Directory uses the value from Project Properties > Configuration Properties > General > Output Directory .

  3. You need to run Visual c++ in "Run as Administrator" mode.Right click on the executable and click "Run as Administrator"

How do I select which GPU to run a job on?

In case of someone else is doing it in Python and it is not working, try to set it before do the imports of pycuda and tensorflow.

I.e.:

import os
os.environ["CUDA_DEVICE_ORDER"] = "PCI_BUS_ID"
os.environ["CUDA_VISIBLE_DEVICES"] = "0"
...
import pycuda.autoinit
import tensorflow as tf
...

As saw here.

How to check if pytorch is using the GPU?

Create a tensor on the GPU as follows:

$ python
>>> import torch
>>> print(torch.rand(3,3).cuda()) 

Do not quit, open another terminal and check if the python process is using the GPU using:

$ nvidia-smi

Is it possible to run CUDA on AMD GPUs?

I think it is going to be possible soon in AMD FirePro GPU's, see press release here but support is coming 2016 Q1 for the developing tools:

An early access program for the "Boltzmann Initiative" tools is planned for Q1 2016.

Understanding CUDA grid dimensions, block dimensions and threads organization (simple explanation)

Suppose a 9800GT GPU:

  • it has 14 multiprocessors (SM)
  • each SM has 8 thread-processors (AKA stream-processors, SP or cores)
  • allows up to 512 threads per block
  • warpsize is 32 (which means each of the 14x8=112 thread-processors can schedule up to 32 threads)

https://www.tutorialspoint.com/cuda/cuda_threads.htm

A block cannot have more active threads than 512 therefore __syncthreads can only synchronize limited number of threads. i.e. If you execute the following with 600 threads:

func1();
__syncthreads();
func2();
__syncthreads();

then the kernel must run twice and the order of execution will be:

  1. func1 is executed for the first 512 threads
  2. func2 is executed for the first 512 threads
  3. func1 is executed for the remaining threads
  4. func2 is executed for the remaining threads

Note:

The main point is __syncthreads is a block-wide operation and it does not synchronize all threads.


I'm not sure about the exact number of threads that __syncthreads can synchronize, since you can create a block with more than 512 threads and let the warp handle the scheduling. To my understanding it's more accurate to say: func1 is executed at least for the first 512 threads.

Before I edited this answer (back in 2010) I measured 14x8x32 threads were synchronized using __syncthreads.

I would greatly appreciate if someone test this again for a more accurate piece of information.

How do I choose grid and block dimensions for CUDA kernels?

The answers above point out how the block size can impact performance and suggest a common heuristic for its choice based on occupancy maximization. Without wanting to provide the criterion to choose the block size, it would be worth mentioning that CUDA 6.5 (now in Release Candidate version) includes several new runtime functions to aid in occupancy calculations and launch configuration, see

CUDA Pro Tip: Occupancy API Simplifies Launch Configuration

One of the useful functions is cudaOccupancyMaxPotentialBlockSize which heuristically calculates a block size that achieves the maximum occupancy. The values provided by that function could be then used as the starting point of a manual optimization of the launch parameters. Below is a little example.

#include <stdio.h>

/************************/
/* TEST KERNEL FUNCTION */
/************************/
__global__ void MyKernel(int *a, int *b, int *c, int N) 
{ 
    int idx = threadIdx.x + blockIdx.x * blockDim.x; 

    if (idx < N) { c[idx] = a[idx] + b[idx]; } 
} 

/********/
/* MAIN */
/********/
void main() 
{ 
    const int N = 1000000;

    int blockSize;      // The launch configurator returned block size 
    int minGridSize;    // The minimum grid size needed to achieve the maximum occupancy for a full device launch 
    int gridSize;       // The actual grid size needed, based on input size 

    int* h_vec1 = (int*) malloc(N*sizeof(int));
    int* h_vec2 = (int*) malloc(N*sizeof(int));
    int* h_vec3 = (int*) malloc(N*sizeof(int));
    int* h_vec4 = (int*) malloc(N*sizeof(int));

    int* d_vec1; cudaMalloc((void**)&d_vec1, N*sizeof(int));
    int* d_vec2; cudaMalloc((void**)&d_vec2, N*sizeof(int));
    int* d_vec3; cudaMalloc((void**)&d_vec3, N*sizeof(int));

    for (int i=0; i<N; i++) {
        h_vec1[i] = 10;
        h_vec2[i] = 20;
        h_vec4[i] = h_vec1[i] + h_vec2[i];
    }

    cudaMemcpy(d_vec1, h_vec1, N*sizeof(int), cudaMemcpyHostToDevice);
    cudaMemcpy(d_vec2, h_vec2, N*sizeof(int), cudaMemcpyHostToDevice);

    float time;
    cudaEvent_t start, stop;
    cudaEventCreate(&start);
    cudaEventCreate(&stop);
    cudaEventRecord(start, 0);

    cudaOccupancyMaxPotentialBlockSize(&minGridSize, &blockSize, MyKernel, 0, N); 

    // Round up according to array size 
    gridSize = (N + blockSize - 1) / blockSize; 

    cudaEventRecord(stop, 0);
    cudaEventSynchronize(stop);
    cudaEventElapsedTime(&time, start, stop);
    printf("Occupancy calculator elapsed time:  %3.3f ms \n", time);

    cudaEventRecord(start, 0);

    MyKernel<<<gridSize, blockSize>>>(d_vec1, d_vec2, d_vec3, N); 

    cudaEventRecord(stop, 0);
    cudaEventSynchronize(stop);
    cudaEventElapsedTime(&time, start, stop);
    printf("Kernel elapsed time:  %3.3f ms \n", time);

    printf("Blocksize %i\n", blockSize);

    cudaMemcpy(h_vec3, d_vec3, N*sizeof(int), cudaMemcpyDeviceToHost);

    for (int i=0; i<N; i++) {
        if (h_vec3[i] != h_vec4[i]) { printf("Error at i = %i! Host = %i; Device = %i\n", i, h_vec4[i], h_vec3[i]); return; };
    }

    printf("Test passed\n");

}

EDIT

The cudaOccupancyMaxPotentialBlockSize is defined in the cuda_runtime.h file and is defined as follows:

template<class T>
__inline__ __host__ CUDART_DEVICE cudaError_t cudaOccupancyMaxPotentialBlockSize(
    int    *minGridSize,
    int    *blockSize,
    T       func,
    size_t  dynamicSMemSize = 0,
    int     blockSizeLimit = 0)
{
    return cudaOccupancyMaxPotentialBlockSizeVariableSMem(minGridSize, blockSize, func, __cudaOccupancyB2DHelper(dynamicSMemSize), blockSizeLimit);
}

The meanings for the parameters is the following

minGridSize     = Suggested min grid size to achieve a full machine launch.
blockSize       = Suggested block size to achieve maximum occupancy.
func            = Kernel function.
dynamicSMemSize = Size of dynamically allocated shared memory. Of course, it is known at runtime before any kernel launch. The size of the statically allocated shared memory is not needed as it is inferred by the properties of func.
blockSizeLimit  = Maximum size for each block. In the case of 1D kernels, it can coincide with the number of input elements.

Note that, as of CUDA 6.5, one needs to compute one's own 2D/3D block dimensions from the 1D block size suggested by the API.

Note also that the CUDA driver API contains functionally equivalent APIs for occupancy calculation, so it is possible to use cuOccupancyMaxPotentialBlockSize in driver API code in the same way shown for the runtime API in the example above.

Where is git.exe located?

Sometimes it can be at: C:\Users\user-name\AppData\Local\Programs\Git\cmd. Checking your PATH environment variable for USER and for SYSTEM can give you that.

Express.js req.body undefined

This is also one possibility: Make Sure that you should write this code before the route in your app.js(or index.js) file.

app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

Apache SSL Configuration Error (SSL Connection Error)

I encounter this problem, because I have <VirtualHost> defined both in httpd.conf and httpd-ssl.conf.

in httpd.conf, it's defined as

<VirtualHost localhost>

in httpd-ssl.conf, it's defined as

<VirtualHost _default_:443>

The following change solved this problem, add :80 in httpd.conf

<VirtualHost localhost:80>

Best way to check if object exists in Entity Framework?

I just check if object is null , it works 100% for me

    try
    {
        var ID = Convert.ToInt32(Request.Params["ID"]);
        var Cert = (from cert in db.TblCompCertUploads where cert.CertID == ID select cert).FirstOrDefault();
        if (Cert != null)
        {
            db.TblCompCertUploads.DeleteObject(Cert);
            db.SaveChanges();
            ViewBag.Msg = "Deleted Successfully";
        }
        else
        {
            ViewBag.Msg = "Not Found !!";
        }                           
    }
    catch
    {
        ViewBag.Msg = "Something Went wrong";
    }

Recommended SQL database design for tags or tagging

Three tables (one for storing all items, one for all tags, and one for the relation between the two), properly indexed, with foreign keys set running on a proper database, should work well and scale properly.

Table: Item
Columns: ItemID, Title, Content

Table: Tag
Columns: TagID, Title

Table: ItemTag
Columns: ItemID, TagID

How to write macro for Notepad++?

Macros in Notepad++ are just a bunch of encoded operations: you start recording, operate on the buffer, perhaps activating menus, stop recording then play the macro.
After investigation, I found out they are saved in the file shortcuts.xml in the Macros section. For example, I have there:

<Macro name="Trim Trailing and save" Ctrl="no" Alt="yes" Shift="yes" Key="83">
    <Action type="1" message="2170" wParam="0" lParam="0" sParam=" " />
    <Action type="1" message="2170" wParam="0" lParam="0" sParam=" " />
    <Action type="1" message="2170" wParam="0" lParam="0" sParam=" " />
    <Action type="0" message="2327" wParam="0" lParam="0" sParam="" />
    <Action type="0" message="2327" wParam="0" lParam="0" sParam="" />
    <Action type="2" message="0" wParam="42024" lParam="0" sParam="" />
    <Action type="2" message="0" wParam="41006" lParam="0" sParam="" />
</Macro>

I haven't looked at the source, but from the look, I would say we have messages sent to Scintilla (the editing component, perhaps type 0 and 1), and to Notepad++ itself (probably activating menu items).
I don't think it will record actions in dialogs (like search/replace).

Looking at Scintilla.iface file, we can see that 2170 is the code of ReplaceSel (ie. insert string is nothing is selected), 2327 is Tab command, and Resource Hacker (just have it handy...) shows that 42024 is "Trim Trailing Space" menu item and 41006 is "Save".
I guess action type 0 is for Scintilla commands with numerical params, type 1 is for commands with string parameter, 2 is for Notepad++ commands.

Problem: Scintilla doesn't have a "Replace all" command: it is the task of the client to do the iteration, with or without confirmation, etc.
Another problem: it seems type 1 action is limited to 1 char (I edited manually, when exiting N++ it was truncated).
I tried some tricks, but I fear such task is beyond the macro capabilities.

Maybe that's where SciTE with its Lua scripting ability (or Programmer's Notepad which seems to be scriptable with Python) has an edge... :-)

[EDIT] Looks like I got the above macro from this thread or a similar place... :-) I guess the first lines are unnecessary (side effect or recording) but they were good examples of macro code anyway.

What does from __future__ import absolute_import actually do?

The difference between absolute and relative imports come into play only when you import a module from a package and that module imports an other submodule from that package. See the difference:

$ mkdir pkg
$ touch pkg/__init__.py
$ touch pkg/string.py
$ echo 'import string;print(string.ascii_uppercase)' > pkg/main1.py
$ python2
Python 2.7.9 (default, Dec 13 2014, 18:02:08) [GCC] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pkg.main1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "pkg/main1.py", line 1, in <module>
    import string;print(string.ascii_uppercase)
AttributeError: 'module' object has no attribute 'ascii_uppercase'
>>> 
$ echo 'from __future__ import absolute_import;import string;print(string.ascii_uppercase)' > pkg/main2.py
$ python2
Python 2.7.9 (default, Dec 13 2014, 18:02:08) [GCC] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pkg.main2
ABCDEFGHIJKLMNOPQRSTUVWXYZ
>>> 

In particular:

$ python2 pkg/main2.py
Traceback (most recent call last):
  File "pkg/main2.py", line 1, in <module>
    from __future__ import absolute_import;import string;print(string.ascii_uppercase)
AttributeError: 'module' object has no attribute 'ascii_uppercase'
$ python2
Python 2.7.9 (default, Dec 13 2014, 18:02:08) [GCC] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pkg.main2
ABCDEFGHIJKLMNOPQRSTUVWXYZ
>>> 
$ python2 -m pkg.main2
ABCDEFGHIJKLMNOPQRSTUVWXYZ

Note that python2 pkg/main2.py has a different behaviour then launching python2 and then importing pkg.main2 (which is equivalent to using the -m switch).

If you ever want to run a submodule of a package always use the -m switch which prevents the interpreter for chaining the sys.path list and correctly handles the semantics of the submodule.

Also, I much prefer using explicit relative imports for package submodules since they provide more semantics and better error messages in case of failure.

String concatenation in Ruby

If you are just concatenating paths you can use Ruby's own File.join method.

source = File.join(ROOT_DIR, project, 'App.config')

Clear and refresh jQuery Chosen dropdown list

If in case trigger("chosen:updated"); doesn't works for you. You can try $('#ddl').trigger('change'); as in my case its work for me.

Change a Nullable column to NOT NULL with Default Value

you need to execute two queries:

One - to add the default value to the column required

ALTER TABLE 'Table_Name` ADD DEFAULT 'value' FOR 'Column_Name'

i want add default value to Column IsDeleted as below:

Example: ALTER TABLE [dbo].[Employees] ADD Default 0 for IsDeleted

Two - to alter the column value nullable to not null

ALTER TABLE 'table_name' ALTER COLUMN 'column_name' 'data_type' NOT NULL

i want to make the column IsDeleted as not null

ALTER TABLE [dbo].[Employees] Alter Column IsDeleted BIT NOT NULL

How to remove duplicate values from an array in PHP

$array = array("a" => "moon", "star", "b" => "moon", "star", "sky");

// Deleting the duplicate items
$result = array_unique($array);
print_r($result);

ref : Demo

How can I kill all sessions connecting to my oracle database?

Try trigger on logon

Insted of trying disconnect users you should not allow them to connect.

There is and example of such trigger.

CREATE OR REPLACE TRIGGER rds_logon_trigger
AFTER LOGON ON DATABASE
BEGIN
  IF SYS_CONTEXT('USERENV','IP_ADDRESS') not in ('192.168.2.121','192.168.2.123','192.168.2.233') THEN
    RAISE_APPLICATION_ERROR(-20003,'You are not allowed to connect to the database');
  END IF;

  IF (to_number(to_char(sysdate,'HH24'))< 6) and (to_number(to_char(sysdate,'HH24')) >18) THEN
    RAISE_APPLICATION_ERROR(-20005,'Logon only allowed during business hours');
  END IF;

END;

How enable auto-format code for Intellij IDEA?

Eclipse has an option to format automatically when saving the file. There is no option for this in IntelliJ although you can configure a macro for the Ctrl+S (Cmd+S on Mac) keys to format the code and save it.

Intellij reformat on file save

Error: "dictionary update sequence element #0 has length 1; 2 is required" on Django 1.4

I got the same issue and found that it was due to wrong parameters. In views.py, I used:

return render(request, 'demo.html',{'items', items})    

But I found the issue: {'items', items}. Changing to {'items': items} resolved the issue.

Styling an input type="file" button

Here we use a span to trigger input of type file and we simply customized that span, so we can add any styling using this way.

Note that we use input tag with visibility:hidden option and trigger it in the span.

_x000D_
_x000D_
.attachFileSpan{_x000D_
color:#2b6dad;_x000D_
cursor:pointer;_x000D_
}_x000D_
.attachFileSpan:hover{_x000D_
text-decoration: underline;_x000D_
}
_x000D_
<h3> Customized input of type file </h3>_x000D_
<input id="myInput" type="file" style="visibility:hidden"/>_x000D_
_x000D_
        <span title="attach file" class="attachFileSpan" onclick="document.getElementById('myInput').click()">_x000D_
        Attach file_x000D_
        </span>
_x000D_
_x000D_
_x000D_

Reference

Why does Node.js' fs.readFile() return a buffer instead of string?

Try:

    fs.readFile("test.txt", "utf8", function(err, data) {...});

Basically, you need to specify the encoding.

Angular exception: Can't bind to 'ngForIn' since it isn't a known native property

Watching this course https://app.pluralsight.com/library/courses/angular-2-getting-started-update/discussion

The author explains that new version of JavaScript has for of and for in, the for of is to enumerate objects and the for in is to enumerate the index of the array.

Resize image proportionally with CSS?

img {
    max-width:100%;
}

div {
    width:100px;
}

with this snippet you can do it in a more efficient way

random.seed(): What does it do?

Set the seed(x) before generating a set of random numbers and use the same seed to generate the same set of random numbers. Useful in case of reproducing the issues.

>>> from random import *
>>> seed(20)
>>> randint(1,100)
93
>>> randint(1,100)
88
>>> randint(1,100)
99
>>> seed(20)
>>> randint(1,100)
93
>>> randint(1,100)
88
>>> randint(1,100)
99
>>> 

App installation failed due to application-identifier entitlement

You will get this error when your AppID prefix does not match the prefix of the previously installed app. If your app is already in the App Store, you will not be able to submit updates without restoring the original AppID prefix or contacting Apple.

Apple's instructions for handling this problem: https://developer.apple.com/library/content/technotes/tn2319/_index.html#//apple_ref/doc/uid/DTS40013778-CH1-ERRORMESSAGES-UPGRADE_S_APPLICATION_IDENTIFIER_DOES_NOT_MATCH_THE_INSTALLED_APP

If you did not intend to change the AppID prefix then Xcode is signing your app with the wrong provisioning profile.

If you do intend to change the AppID prefix (because the app was transferred to a new developer, or you are migrating from an old pre-2011 AppID) you must contact Apple to migrate an existing AppID to a new prefix.

You must also add the previous-application-identifiers entitlement to your app, listing all previous AppIDs (with old prefixes). And you must ask Apple to generate a provisioning profile for you that includes the previous-application-identifiers entitlement.

How do I select the "last child" with a specific class name in CSS?

I suggest that you take advantage of the fact that you can assign multiple classes to an element like so:

<ul>
    <li class="list">test1</li>
    <li class="list">test2</li>
    <li class="list last">test3</li>
    <li>test4</li>
</ul>

The last element has the list class like its siblings but also has the last class which you can use to set any CSS property you want, like so:

ul li.list {
    color: #FF0000;
}

ul li.list.last {
    background-color: #000;
}

How to execute a command prompt command from python

It's very simple. You need just two lines of code with just using the built-in function and also it takes the input and runs forever until you stop it. Also that 'cmd' in quotes, leave it and don't change it. Here is the code:

import os
os.system('cmd')

Now just run this code and see the whole windows command prompt in your python project!

Can I install Python 3.x and 2.x on the same Windows computer?

I would assume so, I have Python 2.4, 2.5 and 2.6 installed side-by-side on the same computer.

How to find Google's IP address?

On Windows, open command prompt and type tracert google.com and press enter, or on Linux, open terminal and type nslookup google.com and press enter:

Server:     127.0.1.1
Address:    127.0.1.1#53

Non-authoritative answer:

Name:   google.com
Address: 74.125.236.199
Name:   google.com
Address: 74.125.236.201
Name:   google.com
Address: 74.125.236.194
Name:   google.com
Address: 74.125.236.198
Name:   google.com
Address: 74.125.236.206
Name:   google.com
Address: 74.125.236.193
Name:   google.com
Address: 74.125.236.196
Name:   google.com
Address: 74.125.236.192
Name:   google.com
Address: 74.125.236.197
Name:   google.com
Address: 74.125.236.195
Name:   google.com
Address: 74.125.236.200

How to show disable HTML select option in by default?

Use hidden.

_x000D_
_x000D_
<select>_x000D_
   <option hidden>Choose</option>_x000D_
   <option>Item 1</option>_x000D_
   <option>Item 2</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_

This doesn't unset it but you can however hide it in the options while it's displayed by default.

Android LinearLayout Gradient Background

In XML Drawable File:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <gradient android:angle="90"
                android:endColor="#9b0493"
                android:startColor="#38068f"
                android:type="linear" />
        </shape>
    </item>
</selector>

In your layout file: android:background="@drawable/gradient_background"

  <?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@drawable/gradient_background"
        android:orientation="vertical"
        android:padding="20dp">
        .....

</LinearLayout>

enter image description here

Remove duplicate rows in MySQL

Delete duplicate rows using DELETE JOIN statement MySQL provides you with the DELETE JOIN statement that you can use to remove duplicate rows quickly.

The following statement deletes duplicate rows and keeps the highest id:

DELETE t1 FROM contacts t1
    INNER JOIN
contacts t2 WHERE
t1.id < t2.id AND t1.email = t2.email;

This Row already belongs to another table error when trying to add rows?

you can give some id to the columns and name it uniquely.

Check if key exists and iterate the JSON array using Python

You can use a try-except

try:
   print(str.to.id)
except AttributeError: # Not a Retweet
   print('null')

Gulp error: The following tasks did not complete: Did you forget to signal async completion?

Workaround: We need to call the callback functions (Task and Anonymous):

function electronTask(callbackA)
{
    return gulp.series(myFirstTask, mySeccondTask, (callbackB) =>
    {
        callbackA();
        callbackB();
    })();    
}

What is "String args[]"? parameter in main method Java

The String[] args parameter is an array of Strings passed as parameters when you are running your application through command line in the OS.

So, imagine you have compiled and packaged a myApp.jar Java application. You can run your app by double clicking it in the OS, of course, but you could also run it using command line way, like (in Linux, for example):

user@computer:~$ java -jar myApp.jar

When you call your application passing some parameters, like:

user@computer:~$ java -jar myApp.jar update notify

The java -jar command will pass your Strings update and notify to your public static void main() method.

You can then do something like:

System.out.println(args[0]); //Which will print 'update'
System.out.println(args[1]); //Which will print 'notify'

What does "export default" do in JSX?

In Simple Words -

The export statement is used when creating JavaScript modules to export functions, objects, or primitive values from the module so they can be used by other programs with the import statement.

Here is a link to get clear understanding : MDN Web Docs

Why use prefixes on member variables in C++ classes

You have to be careful with using a leading underscore. A leading underscore before a capital letter in a word is reserved. For example:

_Foo

_L

are all reserved words while

_foo

_l

are not. There are other situations where leading underscores before lowercase letters are not allowed. In my specific case, I found the _L happened to be reserved by Visual C++ 2005 and the clash created some unexpected results.

I am on the fence about how useful it is to mark up local variables.

Here is a link about which identifiers are reserved: What are the rules about using an underscore in a C++ identifier?

Is there a C# case insensitive equals operator?

System.Collections.CaseInsensitiveComparer

or

System.StringComparer.OrdinalIgnoreCase

Regex to extract URLs from href attribute in HTML with Python

The best answer is...

Don't use a regex

The expression in the accepted answer misses many cases. Among other things, URLs can have unicode characters in them. The regex you want is here, and after looking at it, you may conclude that you don't really want it after all. The most correct version is ten-thousand characters long.

Admittedly, if you were starting with plain, unstructured text with a bunch of URLs in it, then you might need that ten-thousand-character-long regex. But if your input is structured, use the structure. Your stated aim is to "extract the url, inside the anchor tag's href." Why use a ten-thousand-character-long regex when you can do something much simpler?

Parse the HTML instead

For many tasks, using Beautiful Soup will be far faster and easier to use:

>>> from bs4 import BeautifulSoup as Soup
>>> html = Soup(s, 'html.parser')           # Soup(s, 'lxml') if lxml is installed
>>> [a['href'] for a in html.find_all('a')]
['http://example.com', 'http://example2.com']

If you prefer not to use external tools, you can also directly use Python's own built-in HTML parsing library. Here's a really simple subclass of HTMLParser that does exactly what you want:

from html.parser import HTMLParser

class MyParser(HTMLParser):
    def __init__(self, output_list=None):
        HTMLParser.__init__(self)
        if output_list is None:
            self.output_list = []
        else:
            self.output_list = output_list
    def handle_starttag(self, tag, attrs):
        if tag == 'a':
            self.output_list.append(dict(attrs).get('href'))

Test:

>>> p = MyParser()
>>> p.feed(s)
>>> p.output_list
['http://example.com', 'http://example2.com']

You could even create a new method that accepts a string, calls feed, and returns output_list. This is a vastly more powerful and extensible way than regular expressions to extract information from html.

I want to align the text in a <td> to the top

I was facing such a problem, look at the picture below

enter image description here

and here is its HTML

<tr class="li1">
    <td valign="top">1.</td>
    <td colspan="5" valign="top">
        <p>How to build e-book learning environment</p>
    </td>
</tr>

so I fix it by changing valign Attribute in both td tags to baseline

and it worked

here is the result enter image description here

hope this help you

Does Google Chrome work with Selenium IDE (as Firefox does)?

Just fyi . This is available as nuget package in visual studio environment. Please let me know if you need more information as I have used it. URL can be found Link to nuget

You can also find some information here. Blog with more details

How to avoid Number Format Exception in java?

Try to convert Prize into decimal format...

import java.math.BigDecimal;
import java.math.RoundingMode;

public class Bigdecimal {
    public static boolean isEmpty (String st) {
        return st == null || st.length() < 1; 
    }
    public static BigDecimal bigDecimalFormat(String Preis){        
        //MathContext   mi = new MathContext(2);
        BigDecimal bd = new BigDecimal(0.00);

                         bd = new BigDecimal(Preis);


            return bd.setScale(2, RoundingMode.HALF_UP);

        }
    public static void main(String[] args) {
        String cost = "12.12";
        if (!isEmpty(cost) ){
            try {
               BigDecimal intCost = bigDecimalFormat(cost);
               System.out.println(intCost);
               List<Book> books = bookService.findBooksCheaperThan(intCost);  
            } catch (NumberFormatException e) {
               System.out.println("This is not a number");
               System.out.println(e.getMessage());
            }
        }

}
}

Write to Windows Application Event Log

Yes, there is a way to write to the event log you are looking for. You don't need to create a new source, just simply use the existent one, which often has the same name as the EventLog's name and also, in some cases like the event log Application, can be accessible without administrative privileges*.

*Other cases, where you cannot access it directly, are the Security EventLog, for example, which is only accessed by the operating system.

I used this code to write directly to the event log Application:

using (EventLog eventLog = new EventLog("Application")) 
{
    eventLog.Source = "Application"; 
    eventLog.WriteEntry("Log message example", EventLogEntryType.Information, 101, 1); 
}

As you can see, the EventLog source is the same as the EventLog's name. The reason of this can be found in Event Sources @ Windows Dev Center (I bolded the part which refers to source name):

Each log in the Eventlog key contains subkeys called event sources. The event source is the name of the software that logs the event. It is often the name of the application or the name of a subcomponent of the application if the application is large. You can add a maximum of 16,384 event sources to the registry.

Split string and get first value only

You can do it:

var str = "Doctor Who,Fantasy,Steven Moffat,David Tennant";

var title = str.Split(',').First();

Also you can do it this way:

var index = str.IndexOf(",");
var title = index < 0 ? str : str.Substring(0, index);

Error: Node Sass version 5.0.0 is incompatible with ^4.0.0

If you happen to use CRA with default yarn package manager use the following. Worked for me.

yarn remove node-sass 
yarn add [email protected]

How to add button tint programmatically

checkbox.ButtonTintList = ColorStateList.ValueOf(Android.Color.White);

Use ButtonTintList instead of BackgroundTintList

YouTube Video Embedded via iframe Ignoring z-index?

Just add one of these two to the src url:

&wmode=Opaque

&wmode=transparent

<iframe id="videoIframe" width="500" height="281" src="http://www.youtube.com/embed/xxxxxx?rel=0&wmode=transparent" frameborder="0" allowfullscreen></iframe>

http to https through .htaccess

There are better and more secure ways to make sure that all your traffic goes over https. For example setting up two virtual hosts and redirecting all traffic from your http to your https host. Read more on this in this answer here on security.stackexchange.com.

With setting up a virtual host for redirecting you can send a 301 status (redirect permanently) so the browser understands that all the following requests should be sent to the https server where it was redirected to. Hence no further http requests will be made after the first redirect response.

You should also carefully check the given answers because with the wrong rewrite rules set you might loose the query params from your incoming requests.

set default schema for a sql query

A quick google pointed me to this page. It explains that from sql server 2005 onwards you can set the default schema of a user with the ALTER USER statement. Unfortunately, that means that you change it permanently, so if you need to switch between schemas, you would need to set it every time you execute a stored procedure or a batch of statements. Alternatively, you could use the technique described here.

If you are using sql server 2000 or older this page explains that users and schemas are then equivalent. If you don't prepend your table name with a schema\user, sql server will first look at the tables owned by the current user and then the ones owned by the dbo to resolve the table name. It seems that for all other tables you must prepend the schema\user.

How do you check if a selector matches something in jQuery?

As the other commenters are suggesting the most efficient way to do it seems to be:

if ($(selector).length ) {
    // Do something
}

If you absolutely must have an exists() function - which will be slower- you can do:

jQuery.fn.exists = function(){return this.length>0;}

Then in your code you can use

if ($(selector).exists()) {
    // Do something
}

As answered here

Easiest way to activate PHP and MySQL on Mac OS 10.6 (Snow Leopard), 10.7 (Lion), 10.8 (Mountain Lion)?

This help me a lot:

http://maestric.com/doc/mac/apache_php_mysql_snow_leopard

It also works for Mac OS X Lion :D

.:EDIT:. On my case the prefepane only allows to start and stop mysql, but after some issues i've uninstalled him. If you need a application to run queries and create DB, you could use: Sequel Pro (it's free) or Navicat

If you need start and stop mysql in ~/.bash_profile you can add these lines:

#For MySQL
alias mysql_start="/Library/StartupItems/MySQLCOM/MySQLCOM start"
alias mysql_stop="/Library/StartupItems/MySQLCOM/MySQLCOM stop"

After reloaded the console just call:

$mysql_start 

or

$mysql_stop 

agreding the desired action. Hope helped you.

OpenVPN failed connection / All TAP-Win32 adapters on this system are currently in use

I found a solution to this. It's bloody witchcraft, but it works.

When you install the client, open Control Panel > Network Connections.

You'll see a disabled network connection that was added by the TAP installer (Local Area Connection 3 or some such).

Right Click it, click Enable.

The device will not reset itself to enabled, but that's ok; try connecting w/ the client again. It'll work.

How to extract the first two characters of a string in shell scripting?

If you want to use shell scripting and not rely on non-posix extensions (such as so-called bashisms), you can use techniques that do not require forking external tools such as grep, sed, cut, awk, etc., which then make your script less efficient. Maybe efficiency and posix portability is not important in your use case. But in case it is (or just as a good habit), you can use the following parameter expansion option method to extract the first two characters of a shell variable:

$ sh -c 'var=abcde; echo "${var%${var#??}}"'
ab

This uses "smallest prefix" parameter expansion to remove the first two characters (this is the ${var#??} part), then "smallest suffix" parameter expansion (the ${var% part) to remove that all-but-the-first-two-characters string from the original value.

This method was previously described in this answer to the "Shell = Check if variable begins with #" question. That answer also describes a couple similar parameter expansion methods that can be used in a slightly different context that the one that applies to the original question here.

How to resolve "Input string was not in a correct format." error?

Replace with

imageWidth = 1 * Convert.ToInt32(Label1.Text);

Pagination on a list using ng-repeat

If you have not too much data, you can definitely do pagination by just storing all the data in the browser and filtering what's visible at a certain time.

Here's a simple pagination example: http://jsfiddle.net/2ZzZB/56/

That example was on the list of fiddles on the angular.js github wiki, which should be helpful: https://github.com/angular/angular.js/wiki/JsFiddle-Examples

EDIT: http://jsfiddle.net/2ZzZB/16/ to http://jsfiddle.net/2ZzZB/56/ (won't show "1/4.5" if there is 45 results)

Escaping backslash in string - javascript

Add an input id to the element and do something like that:

document.getElementById('inputId').value.split(/[\\$]/).pop()

How do I use Linq to obtain a unique list of properties from a list of objects?

        int[] numbers = {1,2,3,4,5,3,6,4,7,8,9,1,0 };
        var nonRepeats = (from n in numbers select n).Distinct();


        foreach (var d in nonRepeats)
        {

            Response.Write(d);
        }

OUTPUT

1234567890

How to merge two arrays of objects by ID using lodash?

Create dictionaries for both arrays using _.keyBy(), merge the dictionaries, and convert the result to an array with _.values(). In this way, the order of the arrays doesn't matter. In addition, it can also handle arrays of different length.

_x000D_
_x000D_
const ObjectId = (id) => id; // mock of ObjectId_x000D_
const arr1 = [{"member" : ObjectId("57989cbe54cf5d2ce83ff9d8"),"bank" : ObjectId("575b052ca6f66a5732749ecc"),"country" : ObjectId("575b0523a6f66a5732749ecb")},{"member" : ObjectId("57989cbe54cf5d2ce83ff9d6"),"bank" : ObjectId("575b052ca6f66a5732749ecc"),"country" : ObjectId("575b0523a6f66a5732749ecb")}];_x000D_
const arr2 = [{"member" : ObjectId("57989cbe54cf5d2ce83ff9d6"),"name" : 'xxxxxx',"age" : 25},{"member" : ObjectId("57989cbe54cf5d2ce83ff9d8"),"name" : 'yyyyyyyyyy',"age" : 26}];_x000D_
_x000D_
const merged = _(arr1) // start sequence_x000D_
  .keyBy('member') // create a dictionary of the 1st array_x000D_
  .merge(_.keyBy(arr2, 'member')) // create a dictionary of the 2nd array, and merge it to the 1st_x000D_
  .values() // turn the combined dictionary to array_x000D_
  .value(); // get the value (array) out of the sequence_x000D_
_x000D_
console.log(merged);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.14.0/lodash.min.js"></script>
_x000D_
_x000D_
_x000D_

Using ES6 Map

Concat the arrays, and reduce the combined array to a Map. Use Object#assign to combine objects with the same member to a new object, and store in map. Convert the map to an array with Map#values and spread:

_x000D_
_x000D_
const ObjectId = (id) => id; // mock of ObjectId_x000D_
const arr1 = [{"member" : ObjectId("57989cbe54cf5d2ce83ff9d8"),"bank" : ObjectId("575b052ca6f66a5732749ecc"),"country" : ObjectId("575b0523a6f66a5732749ecb")},{"member" : ObjectId("57989cbe54cf5d2ce83ff9d6"),"bank" : ObjectId("575b052ca6f66a5732749ecc"),"country" : ObjectId("575b0523a6f66a5732749ecb")}];_x000D_
const arr2 = [{"member" : ObjectId("57989cbe54cf5d2ce83ff9d6"),"name" : 'xxxxxx',"age" : 25},{"member" : ObjectId("57989cbe54cf5d2ce83ff9d8"),"name" : 'yyyyyyyyyy',"age" : 26}];_x000D_
_x000D_
const merged = [...arr1.concat(arr2).reduce((m, o) => _x000D_
  m.set(o.member, Object.assign(m.get(o.member) || {}, o))_x000D_
, new Map()).values()];_x000D_
_x000D_
console.log(merged);
_x000D_
_x000D_
_x000D_

How to hide only the Close (x) button?

Well you can hide the close button by changing the FormBorderStyle from the properties section or programmatically in the constructor using:

public Form1()
{
InitializeComponent();
this.FormBorderStyle = FormBorderStyle.None;
}

then you create a menu strip item to exit the application.

cheers

Writing a Python list of lists to a csv file

If you don't want to import csv module for that, you can write a list of lists to a csv file using only Python built-ins

with open("output.csv", "w") as f:
    for row in a:
        f.write("%s\n" % ','.join(str(col) for col in row))

this is error ORA-12154: TNS:could not resolve the connect identifier specified?

ORA-12154: TNS:could not resolve the connect identifier specified?

In case the TNS is not defined you can also try this one:

If you are using C#.net 2010 or other version of VS and oracle 10g express edition or lower version, and you make a connection string like this:

static string constr = @"Data Source=(DESCRIPTION=
    (ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=yourhostname )(PORT=1521)))
    (CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=XE)));
    User Id=system ;Password=yourpasswrd"; 

After that you get error message ORA-12154: TNS:could not resolve the connect identifier specified then first you have to do restart your system and run your project.

And if Your windows is 64 bit then you need to install oracle 11g 32 bit and if you installed 11g 64 bit then you need to Install Oracle 11g Oracle Data Access Components (ODAC) with Oracle Developer Tools for Visual Studio version 11.2.0.1.2 or later from OTN and check it in Oracle Universal Installer Please be sure that the following are checked:

Oracle Data Provider for .NET 2.0

Oracle Providers for ASP.NET

Oracle Developer Tools for Visual Studio

Oracle Instant Client 

And then restart your Visual Studio and then run your project .... NOTE:- SYSTEM RESTART IS necessary TO SOLVE THIS TYPES OF ERROR.......

How can I change the default credentials used to connect to Visual Studio Online (TFSPreview) when loading Visual Studio up?

After failing with cleaning the Credentials from the Manager and clearing the VS cache, consider to repair Visual Studio from the Visual Studio Installer (VS2017). I personally found no other solution working.

Sum values from an array of key-value pairs in JavaScript

I would use reduce

var myData = new Array(['2013-01-22', 0], ['2013-01-29', 0], ['2013-02-05', 0], ['2013-02-12', 0], ['2013-02-19', 0], ['2013-02-26', 0], ['2013-03-05', 0], ['2013-03-12', 0], ['2013-03-19', 0], ['2013-03-26', 0], ['2013-04-02', 21], ['2013-04-09', 2]);

var sum = myData.reduce(function(a, b) {
    return a + b[1];
}, 0);

$("#result").text(sum);

Available on jsfiddle

How to build x86 and/or x64 on Windows from command line with CMAKE?

Besides CMAKE_GENERATOR_PLATFORM variable, there is also the -A switch

cmake -G "Visual Studio 16 2019" -A Win32
cmake -G "Visual Studio 16 2019" -A x64

https://cmake.org/cmake/help/v3.16/generator/Visual%20Studio%2016%202019.html#platform-selection

  -A <platform-name>           = Specify platform name if supported by
                                 generator.

Is there a difference between /\s/g and /\s+/g?

In the first regex, each space character is being replaced, character by character, with the empty string.

In the second regex, each contiguous string of space characters is being replaced with the empty string because of the +.

However, just like how 0 multiplied by anything else is 0, it seems as if both methods strip spaces in exactly the same way.

If you change the replacement string to '#', the difference becomes much clearer:

var str = '  A B  C   D EF ';
console.log(str.replace(/\s/g, '#'));  // ##A#B##C###D#EF#
console.log(str.replace(/\s+/g, '#')); // #A#B#C#D#EF#

setValue:forUndefinedKey: this class is not key value coding-compliant for the key

I encountered this same problem today. As suggested in this answer, the problem was an unclean xib. In my case the unclean xib was the result of updating a xib that was being loaded by something other than the view controller it was associated with.

Xcode let me create and populate a new outlet and connected it to the file's owner even though I explicitly connected it to the source of the correct view controller. Here's the code generated by Xcode:

    <placeholder placeholderIdentifier="IBFilesOwner" id="-1" userLabel="File's Owner" customClass="LoginViewController"]]>
        <connections>
            <outlet property="hostLabel" destination="W4x-T2-Mcm" id="c3E-1U-sVf"/>
        </connections>
    </placeholder>

When I ran my app it crashed with the same not key value coding-compliant error. To correct the problem, I removed the outlet from the File's Owner in Interface Builder and connected it explicitly to the view controller object on the left outline instead of to the code in the assistant editor.

How do I call REST API from an android app?

  1. If you want to integrate Retrofit (all steps defined here):

Goto my blog : retrofit with kotlin

  1. Please use android-async-http library.

the link below explains everything step by step.

http://loopj.com/android-async-http/

Here are sample apps:

  1. http://www.techrepublic.com/blog/software-engineer/calling-restful-services-from-your-android-app/

  2. http://blog.strikeiron.com/bid/73189/Integrate-a-REST-API-into-Android-Application-in-less-than-15-minutes

Create a class :

public class HttpUtils {
  private static final String BASE_URL = "http://api.twitter.com/1/";
 
  private static AsyncHttpClient client = new AsyncHttpClient();

  public static void get(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(getAbsoluteUrl(url), params, responseHandler);
  }

  public static void post(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.post(getAbsoluteUrl(url), params, responseHandler);
  }
      
  public static void getByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.get(url, params, responseHandler);
  }

  public static void postByUrl(String url, RequestParams params, AsyncHttpResponseHandler responseHandler) {
      client.post(url, params, responseHandler);
  }

  private static String getAbsoluteUrl(String relativeUrl) {
      return BASE_URL + relativeUrl;
  }
}

Call Method :

    RequestParams rp = new RequestParams();
    rp.add("username", "aaa"); rp.add("password", "aaa@123");
                    
    HttpUtils.post(AppConstant.URL_FEED, rp, new JsonHttpResponseHandler() {
        @Override
        public void onSuccess(int statusCode, Header[] headers, JSONObject response) {
            // If the response is JSONObject instead of expected JSONArray
            Log.d("asd", "---------------- this is response : " + response);
            try {
                JSONObject serverResp = new JSONObject(response.toString());                                                
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }                   
        }
            
        @Override
        public void onSuccess(int statusCode, Header[] headers, JSONArray timeline) {
            // Pull out the first event on the public timeline
                    
        }
    });

Please grant internet permission in your manifest file.

 <uses-permission android:name="android.permission.INTERNET" />

you can add compile 'com.loopj.android:android-async-http:1.4.9' for Header[] and compile 'org.json:json:20160212' for JSONObject in build.gradle file if required.

Using margin:auto to vertically-align a div

I know the question is from 2012, but I found the easiest way ever, and I wanted to share.

HTML:

<div id="parent">
     <div id="child">Content here</div>
</div>

and CSS:

#parent{
     height: 100%;
     display: table;
}    
#child {
     display: table-cell;
     vertical-align: middle; 
}

Error handling with PHPMailer

PHPMailer uses Exceptions. Try to adopt the following code:

require_once '../class.phpmailer.php';

$mail = new PHPMailer(true); //defaults to using php "mail()"; the true param means it will throw exceptions on errors, which we need to catch

try {
  $mail->AddReplyTo('[email protected]', 'First Last');
  $mail->AddAddress('[email protected]', 'John Doe');
  $mail->SetFrom('[email protected]', 'First Last');
  $mail->AddReplyTo('[email protected]', 'First Last');
  $mail->Subject = 'PHPMailer Test Subject via mail(), advanced';
  $mail->AltBody = 'To view the message, please use an HTML compatible email viewer!'; // optional - MsgHTML will create an alternate automatically
  $mail->MsgHTML(file_get_contents('contents.html'));
  $mail->AddAttachment('images/phpmailer.gif');      // attachment
  $mail->AddAttachment('images/phpmailer_mini.gif'); // attachment
  $mail->Send();
  echo "Message Sent OK\n";
} catch (phpmailerException $e) {
  echo $e->errorMessage(); //Pretty error messages from PHPMailer
} catch (Exception $e) {
  echo $e->getMessage(); //Boring error messages from anything else!
}

C# Double - ToString() formatting with two decimal places but no rounding

The c# function, as expressed by Kyle Rozendo:

string DecimalPlaceNoRounding(double d, int decimalPlaces = 2)
{
    d = d * Math.Pow(10, decimalPlaces);
    d = Math.Truncate(d);
    d = d / Math.Pow(10, decimalPlaces);
    return string.Format("{0:N" + Math.Abs(decimalPlaces) + "}", d);
}

My Application Could not open ServletContext resource

Make sure your maven war plugin block in pom.xml includes all files (especially xml files) while building the war. But you don't need to include the .java files though.

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-war-plugin</artifactId>
  <version>2.5</version>

  <configuration>
    <webResources>
      <resources>
        <directory>WebContent</directory>
        <includes>
          <include>**/*.*</include> <!--this line includes the xml files into the war, which will be found when it is exploded in server during deployment -->
        </includes>
        <excludes>
          <exclude>*.java</exclude>
        </excludes>
      </resources>
    </webResources>
    <webXml>WebContent/WEB-INF/web.xml</webXml>
  </configuration>
</plugin> 

Is a slash ("/") equivalent to an encoded slash ("%2F") in the path portion of an HTTP URL

What to do if :foo in its natural form contains slashes? You wouldn't want it to Isn't that the distinction the recommendation is attempting to preserve? It specifically notes,

The similarity to unix and other disk operating system filename conventions should be taken as purely coincidental, and should not be taken to indicate that URIs should be interpreted as file names.

If one was building an online interface to a backup program, and wished to express the path as a part of the URL path, it would make sense to encode the slashes in the file path, as that is not really part of the hierarchy of the resource - and more importantly, the route. /backups/2016-07-28content//home/dan/ loses the root of the filesystem in the double slash. Escaping the slashes is the appropriate way to distinguish, as I read it.

How to Set OnClick attribute with value containing function in ie8?

You also can use:

element.addEventListener("click", function(){
    // call execute function here...
}, false);

Set variable in jinja

Nice shorthand for Multiple variable assignments

{% set label_cls, field_cls = "col-md-7", "col-md-3" %}

How do I set ANDROID_SDK_HOME environment variable?

Copy your SDK path and assign it to the environment variable ANDROID_SDK_ROOT

Refer pic below:

enter image description here

Multiple github accounts on the same computer?

All you need to do is configure your SSH setup with multiple SSH keypairs.

Also, if you're working with multiple repositories using different personas, you need to make sure that your individual repositories have the user settings overridden accordingly:

Setting user name, email and GitHub token – Overriding settings for individual repos https://help.github.com/articles/setting-your-commit-email-address-in-git/

Hope this helps.

Note: Some of you may require different emails to be used for different repositories, from git 2.13 you can set the email on a directory basis by editing the global config file found at: ~/.gitconfig using conditionals like so:

[user]
    name = Pavan Kataria
    email = [email protected]

[includeIf "gitdir:~/work/"]
    path = ~/work/.gitconfig

And then your work specific config ~/work/.gitconfig would look like this:

[user]
    email = [email protected]

Thank you @alexg for informing me of this in the comments.

Display exact matches only with grep

Try the below command, because it works perfectly:

grep -ow "yourstring"

crosscheck:-

Remove the instance of word from file, then re-execute this command and it should display empty result.

SQL changing a value to upper or lower case

SQL SERVER 2005:

print upper('hello');
print lower('HELLO');

xml.LoadData - Data at the root level is invalid. Line 1, position 1

I Think that the problem is about encoding. That's why removing first line(with encoding byte) might solve the problem.

My solution for Data at the root level is invalid. Line 1, position 1. in XDocument.Parse(xmlString) was replacing it with XDocument.Load( new MemoryStream( xmlContentInBytes ) );

I've noticed that my xml string looked ok:

<?xml version="1.0" encoding="utf-8"?>

but in different text editor encoding it looked like this:

?<?xml version="1.0" encoding="utf-8"?>

At the end i did not need the xml string but xml byte[]. If you need to use the string you should look for "invisible" bytes in your string and play with encodings to adjust the xml content for parsing or loading.

Hope it will help

Deleting Row in SQLite in Android

To delete rows from a table, you need to provide selection criteria that identify the rows to the delete() method. The mechanism works the same as the selection arguments to the query() method. It divides the selection specification into a selection clause(where clause) and selection arguments.

    SQLiteDatabase db  = this.getWritableDatabase();
     // Define 'where' part of query.
    String selection = Contract.COLUMN_COMPANY_ID + " =?  and "
                       + Contract.CLOUMN_TYPE +" =? ";
   // Specify arguments in placeholder order.
    String[] selectionArgs = { cid,mode };
    // Issue SQL statement.
    int deletedRows = db.delete(Contract.TABLE_NAME, 
                       selection, selectionArgs);
    return deletedRows;// no.of rows deleted.

The return value for the delete() method indicates the number of rows that were deleted from the database.

NLTK and Stopwords Fail #lookuperror

import nltk
nltk.download('stopwords')
from nltk.corpus import stopwords
STOPWORDS = set(stopwords.words('english'))

How can I specify working directory for popen

subprocess.Popen takes a cwd argument to set the Current Working Directory; you'll also want to escape your backslashes ('d:\\test\\local'), or use r'd:\test\local' so that the backslashes aren't interpreted as escape sequences by Python. The way you have it written, the \t part will be translated to a tab.

So, your new line should look like:

subprocess.Popen(r'c:\mytool\tool.exe', cwd=r'd:\test\local')

To use your Python script path as cwd, import os and define cwd using this:

os.path.dirname(os.path.realpath(__file__)) 

How can we store into an NSDictionary? What is the difference between NSDictionary and NSMutableDictionary?

The key difference: NSMutableDictionary can be modified in place, NSDictionary cannot. This is true for all the other NSMutable* classes in Cocoa. NSMutableDictionary is a subclass of NSDictionary, so everything you can do with NSDictionary you can do with both. However, NSMutableDictionary also adds complementary methods to modify things in place, such as the method setObject:forKey:.

You can convert between the two like this:

NSMutableDictionary *mutable = [[dict mutableCopy] autorelease];
NSDictionary *dict = [[mutable copy] autorelease]; 

Presumably you want to store data by writing it to a file. NSDictionary has a method to do this (which also works with NSMutableDictionary):

BOOL success = [dict writeToFile:@"/file/path" atomically:YES];

To read a dictionary from a file, there's a corresponding method:

NSDictionary *dict = [NSDictionary dictionaryWithContentsOfFile:@"/file/path"];

If you want to read the file as an NSMutableDictionary, simply use:

NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithContentsOfFile:@"/file/path"];

Adding custom radio buttons in android

Best way to add custom drawable is:

<RadioButton
    android:id="@+id/radiocar"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:background="@android:color/transparent"
    android:button="@drawable/yourbuttonbackground"
    android:checked="true"
    android:drawableRight="@mipmap/car"
    android:paddingLeft="5dp"
    android:paddingRight="5dp"
    android:text="yourtexthere"/>

Shadow overlay by custom drawable is removed here.

Iterate over values of object

No, there's no direct method to do that with objects.

The Map type does have a values() method that returns an iterator for the values

Gulp command not found after install

I realize that this is an old thread, but for Future-Me, and posterity, I figured I should add my two-cents around the "running npm as sudo" discussion. Disclaimer: I do not use Windows. These steps have only been proven on non-windows machines, both virtual and physical.

You can avoid the need to use sudo by changing the permission to npm's default directory.


How to: change permissions in order to run npm without sudo

Step 1: Find out where npm's default directory is.

  • To do this, open your terminal and run:
    npm config get prefix

Step 2: Proceed, based on the output of that command:

  • Scenario One: npm's default directory is /usr/local
    For most users, your output will show that npm's default directory is /usr/local, in which case you can skip to step 4 to update the permissions for the directory.
  • Scenario Two: npm's default directory is /usr or /Users/YOURUSERNAME/node_modules or /Something/Else/FishyLooking
    If you find that npm's default directory is not /usr/local, but is instead something you can't explain or looks fishy, you should go to step 3 to change the default directory for npm, or you risk messing up your permissions on a much larger scale.

Step 3: Change npm's default directory:

  • There are a couple of ways to go about this, including creating a directory specifically for global installations and then adding that directory to your $PATH, but since /usr/local is probably already in your path, I think it's simpler to just change npm's default directory to that. Like so: npm config set prefix /usr/local
    • For more info on the other approaches I mentioned, see the npm docs here.

Step 4: Update the permissions on npm's default directory:

  • Once you've verified that npm's default directory is in a sensible location, you can update the permissions on it using the command:
    sudo chown -R $(whoami) $(npm config get prefix)/{lib/node_modules,bin,share}

Now you should be able to run npm <whatever> without sudo. Note: You may need to restart your terminal in order for these changes to take effect.

Plot bar graph from Pandas DataFrame

To plot just a selection of your columns you can select the columns of interest by passing a list to the subscript operator:

ax = df[['V1','V2']].plot(kind='bar', title ="V comp", figsize=(15, 10), legend=True, fontsize=12)

What you tried was df['V1','V2'] this will raise a KeyError as correctly no column exists with that label, although it looks funny at first you have to consider that your are passing a list hence the double square brackets [[]].

import matplotlib.pyplot as plt
ax = df[['V1','V2']].plot(kind='bar', title ="V comp", figsize=(15, 10), legend=True, fontsize=12)
ax.set_xlabel("Hour", fontsize=12)
ax.set_ylabel("V", fontsize=12)
plt.show()

enter image description here

Capturing "Delete" Keypress with jQuery

$('html').keyup(function(e){
    if(e.keyCode == 46) {
        alert('Delete key released');
    }
});

Source: javascript char codes key codes from www.cambiaresearch.com

HTTP GET Request in Node.js Express

Check out httpreq: it's a node library I created because I was frustrated there was no simple http GET or POST module out there ;-)

How do you make Vim unhighlight what you searched for?

/lkjasdf has always been faster than :noh for me.

Create a new workspace in Eclipse

You can create multiple workspaces in Eclipse. You have to just specify the path of the workspace during Eclipse startup. You can even switch workspaces via File?Switch workspace.

You can then import project to your workspace, copy paste project to your new workspace folder, then

File?Import?Existing project in to workspace?select project.

PHP returning JSON to JQUERY AJAX CALL

You can return json in PHP this way:

header('Content-Type: application/json');
echo json_encode(array('foo' => 'bar'));
exit;

Java output formatting for Strings

To answer your updated question you can do

String[] lines = ("Name =              Bob\n" +
        "Age =               27\n" +
        "Occupation =        Student\n" +
        "Status =            Single").split("\n");

for (String line : lines) {
    String[] parts = line.split(" = +");
    System.out.printf("%-19s %s%n", parts[0] + " =", parts[1]);
}

prints

Name =              Bob
Age =               27
Occupation =        Student
Status =            Single

How to terminate a Python script

from sys import exit
exit()

As a parameter you can pass an exit code, which will be returned to OS. Default is 0.

Android Failed to install HelloWorld.apk on device (null) Error

I had imported an existing project and started running... i too was facing the same problem (WARNING: Application does not specify an API Device API version is 11 (Android 3.0) ). After all my attempts to resolve that failed,I just created new project under other package to maintain the same names and copied all the file contents of the previously imporetd projects manually and again started running...to my surprise it successfully executed in my first attempt...i think the problem was due to the lack of compatibilty of versions when imported...i hope it may help few...

Disable vertical scroll bar on div overflow: auto

If you want to accomplish the same in Gecko (NS6+, Mozilla, etc) and IE4+ simultaneously, I believe this should do the trick:V

body {
overflow: -moz-scrollbars-vertical;
overflow-x: hidden;
overflow-y: auto;
}

This will be applied to entire body tag, please update it to your relevant css and apply this properties.

Matplotlib - Move X-Axis label downwards, but not X-Axis Ticks

If the variable ax.xaxis._autolabelpos = True, matplotlib sets the label position in function _update_label_position in axis.py according to (some excerpts):

    bboxes, bboxes2 = self._get_tick_bboxes(ticks_to_draw, renderer)
    bbox = mtransforms.Bbox.union(bboxes)
    bottom = bbox.y0
    x, y = self.label.get_position()
    self.label.set_position((x, bottom - self.labelpad * self.figure.dpi / 72.0))

You can set the label position independently of the ticks by using:

    ax.xaxis.set_label_coords(x0, y0)

that sets _autolabelpos to False or as mentioned above by changing the labelpad parameter.

Is ConfigurationManager.AppSettings available in .NET Core 2.0?

I know it's a bit too late, but maybe someone is looking for easy way to access appsettings in .net core app. in API constructor add the following:

public class TargetClassController : ControllerBase
{
    private readonly IConfiguration _config;

    public TargetClassController(IConfiguration config)
    {
        _config = config;
    }

    [HttpGet("{id:int}")]
    public async Task<ActionResult<DTOResponse>> Get(int id)
    {
        var config = _config["YourKeySection:key"];
    }
}

How to change font of UIButton with Swift

Dot-notation is awesome (swift 4.2)

btn.titleLabel?.font = .systemFont(ofSize: 12)

How to display multiple notifications in android

Replace your line with this.

notificationManager.notify((int) ((new Date().getTime() / 1000L) % Integer.MAX_VALUE), notification);

Absolute and Flexbox in React Native

This solution worked for me:

tabBarOptions: {
      showIcon: true,
      showLabel: false,
      style: {
        backgroundColor: '#000',
        borderTopLeftRadius: 40,
        borderTopRightRadius: 40,
        position: 'relative',
        zIndex: 2,
        marginTop: -48
      }
  }

download and install visual studio 2008

For Microsoft Visual C++ 2008, not the general Visual Studio (go.microsoft.com/?linkid=7729279?)

Google Visual Studio 2008 Express instead of just Visual Studio 2008. Click to the first link that appears which is a download link from Microsoft mentioned above.

Changing default shell in Linux

You can change the passwd file directly for the particular user or use the below command

chsh -s /usr/local/bin/bash username

Then log out and log in

What's the best way to generate a UML diagram from Python source code?

You may have heard of Pylint that helps statically checking Python code. Few people know that it comes with a tool named Pyreverse that draws UML diagrams from the python code it reads. Pyreverse uses graphviz as a backend.

It is used like this:

pyreverse -o png -p yourpackage .

where the . can also be a single file.

Center div on the middle of screen

2018: CSS3

div{
    position: absolute;
    top: 50%;
    left: 50%;
    margin-right: -50%;
    transform: translate(-50%, -50%);
}

This is even shorter. For more information see this: CSS: Centering Things

Best Regular Expression for Email Validation in C#

This C# function uses a regular expression to evaluate whether the passed email address is syntactically valid or not.

public static bool isValidEmail(string inputEmail)
{
   string strRegex = @"^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}" +
         @"\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\" + 
         @".)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$";
   Regex re = new Regex(strRegex);
   if (re.IsMatch(inputEmail))
    return (true);
   else
    return (false);
}

Python list subtraction operation

if duplicate and ordering items are problem :

[i for i in a if not i in b or b.remove(i)]

a = [1,2,3,3,3,3,4]
b = [1,3]
result: [2, 3, 3, 3, 4]

Difference between the 'controller', 'link' and 'compile' functions when defining a directive

  1. running code before Compilation : use controller
  2. running code after Compilation : use Link

Angular convention : write business logic in controller and DOM manipulation in link.

Apart from this you can call one controller function from link function of another directive.For example you have 3 custom directives

<animal>
<panther>
<leopard></leopard>
</panther> 
</animal>

and you want to access animal from inside of "leopard" directive.

http://egghead.io/lessons/angularjs-directive-communication will be helpful to know about inter-directive communication

Do you (really) write exception safe code?

Some of us have been using exception for over 20 years. PL/I has them, for example. The premise that they are a new and dangerous technology seems questionable to me.

The entitlements specified...profile. (0xE8008016). Error iOS 4.2

If you're using react-native, make sure that the Test target has the same provisioning profile as the main one.

What's the difference between Html.Label, Html.LabelFor and Html.LabelForModel

Html.Label gives you a label for an input whose name matches the specified input text (more specifically, for the model property matching the string expression):

// Model
public string Test { get; set; }

// View
@Html.Label("Test")

// Output
<label for="Test">Test</label>

Html.LabelFor gives you a label for the property represented by the provided expression (typically a model property):

// Model
public class MyModel
{
    [DisplayName("A property")]
    public string Test { get; set; }
}

// View
@model MyModel
@Html.LabelFor(m => m.Test)

// Output
<label for="Test">A property</label>

Html.LabelForModel is a bit trickier. It returns a label whose for value is that of the parameter represented by the model object. This is useful, in particular, for custom editor templates. For example:

// Model
public class MyModel
{
    [DisplayName("A property")]
    public string Test { get; set; }
}

// Main view
@Html.EditorFor(m => m.Test)

// Inside editor template
@Html.LabelForModel()

// Output
<label for="Test">A property</label>

How do I convert a Python 3 byte-string variable into a regular string?

You had it nearly right in the last line. You want

str(bytes_string, 'utf-8')

because the type of bytes_string is bytes, the same as the type of b'abc'.

What is a "method" in Python?

http://docs.python.org/2/tutorial/classes.html#method-objects

Usually, a method is called right after it is bound:

x.f()

In the MyClass example, this will return the string 'hello world'. However, it is not necessary to call a method right away: x.f is a method object, and can be stored away and called at a later time. For example:

xf = x.f
while True:
    print xf()

will continue to print hello world until the end of time.

What exactly happens when a method is called? You may have noticed that x.f() was called without an argument above, even though the function definition for f() specified an argument. What happened to the argument? Surely Python raises an exception when a function that requires an argument is called without any — even if the argument isn’t actually used...

Actually, you may have guessed the answer: the special thing about methods is that the object is passed as the first argument of the function. In our example, the call x.f() is exactly equivalent to MyClass.f(x). In general, calling a method with a list of n arguments is equivalent to calling the corresponding function with an argument list that is created by inserting the method’s object before the first argument.

If you still don’t understand how methods work, a look at the implementation can perhaps clarify matters. When an instance attribute is referenced that isn’t a data attribute, its class is searched. If the name denotes a valid class attribute that is a function object, a method object is created by packing (pointers to) the instance object and the function object just found together in an abstract object: this is the method object. When the method object is called with an argument list, a new argument list is constructed from the instance object and the argument list, and the function object is called with this new argument list.

How to convert a Hibernate proxy to a real entity object

Thank you for the suggested solutions! Unfortunately, none of them worked for my case: receiving a list of CLOB objects from Oracle database through JPA - Hibernate, using a native query.

All of the proposed approaches gave me either a ClassCastException or just returned java Proxy object (which deeply inside contained the desired Clob).

So my solution is the following (based on several above approaches):

Query sqlQuery = manager.createNativeQuery(queryStr);
List resultList = sqlQuery.getResultList();
for ( Object resultProxy : resultList ) {
    String unproxiedClob = unproxyClob(resultProxy);
    if ( unproxiedClob != null ) {
       resultCollection.add(unproxiedClob);
    }
}

private String unproxyClob(Object proxy) {
    try {
        BeanInfo beanInfo = Introspector.getBeanInfo(proxy.getClass());
        for (PropertyDescriptor property : beanInfo.getPropertyDescriptors()) {
            Method readMethod = property.getReadMethod();
            if ( readMethod.getName().contains("getWrappedClob") ) {
                Object result = readMethod.invoke(proxy);
                return clobToString((Clob) result);
            }
        }
    }
    catch (InvocationTargetException | IntrospectionException | IllegalAccessException | SQLException | IOException e) {
        LOG.error("Unable to unproxy CLOB value.", e);
    }
    return null;
}

private String clobToString(Clob data) throws SQLException, IOException {
    StringBuilder sb = new StringBuilder();
    Reader reader = data.getCharacterStream();
    BufferedReader br = new BufferedReader(reader);

    String line;
    while( null != (line = br.readLine()) ) {
        sb.append(line);
    }
    br.close();

    return sb.toString();
}

Hope this will help somebody!

Can you issue pull requests from the command line on GitHub?

I've created a tool recently that does exactly what you want:

https://github.com/jd/git-pull-request

It automates everything in a single command, forking the repo, pushing the PR etc. It also supports updating the PR if you need to edit/fix it!

Get generic type of class at runtime

As others mentioned, it's only possible via reflection in certain circumstances.

If you really need the type, this is the usual (type-safe) workaround pattern:

public class GenericClass<T> {

     private final Class<T> type;

     public GenericClass(Class<T> type) {
          this.type = type;
     }

     public Class<T> getMyType() {
         return this.type;
     }
}

Importing Excel spreadsheet data into another Excel spreadsheet containing VBA

This should get you started: Using VBA in your own Excel workbook, have it prompt the user for the filename of their data file, then just copy that fixed range into your target workbook (that could be either the same workbook as your macro enabled one, or a third workbook). Here's a quick vba example of how that works:

' Get customer workbook...
Dim customerBook As Workbook
Dim filter As String
Dim caption As String
Dim customerFilename As String
Dim customerWorkbook As Workbook
Dim targetWorkbook As Workbook

' make weak assumption that active workbook is the target
Set targetWorkbook = Application.ActiveWorkbook

' get the customer workbook
filter = "Text files (*.xlsx),*.xlsx"
caption = "Please Select an input file "
customerFilename = Application.GetOpenFilename(filter, , caption)

Set customerWorkbook = Application.Workbooks.Open(customerFilename)

' assume range is A1 - C10 in sheet1
' copy data from customer to target workbook
Dim targetSheet As Worksheet
Set targetSheet = targetWorkbook.Worksheets(1)
Dim sourceSheet As Worksheet
Set sourceSheet = customerWorkbook.Worksheets(1)

targetSheet.Range("A1", "C10").Value = sourceSheet.Range("A1", "C10").Value

' Close customer workbook
customerWorkbook.Close

Is it possible to listen to a "style change" event?

I had the same problem, so I wrote this. It works rather well. Looks great if you mix it with some CSS transitions.

function toggle_visibility(id) {
   var e = document.getElementById("mjwelcome");
   if(e.style.height == '')
      e.style.height = '0px';
   else
      e.style.height = '';
}

method in class cannot be applied to given types

generateNumbers() expects a parameter and you aren't passing one in!

generateNumbers() also returns after it has set the first random number - seems to be some confusion about what it is trying to do.

How can I pass selected row to commandLink inside dataTable or ui:repeat?

As to the cause, the <f:attribute> is specific to the component itself (populated during view build time), not to the iterated row (populated during view render time).

There are several ways to achieve the requirement.

  1. If your servletcontainer supports a minimum of Servlet 3.0 / EL 2.2, then just pass it as an argument of action/listener method of UICommand component or AjaxBehavior tag. E.g.

     <h:commandLink action="#{bean.insert(item.id)}" value="insert" />
    

    In combination with:

     public void insert(Long id) {
         // ...
     }
    

    This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.

    You can even pass the entire item object:

     <h:commandLink action="#{bean.insert(item)}" value="insert" />
    

    with:

     public void insert(Item item) {
         // ...
     }
    

    On Servlet 2.5 containers, this is also possible if you supply an EL implementation which supports this, like as JBoss EL. For configuration detail, see this answer.


  2. Use <f:param> in UICommand component. It adds a request parameter.

     <h:commandLink action="#{bean.insert}" value="insert">
         <f:param name="id" value="#{item.id}" />
     </h:commandLink>
    

    If your bean is request scoped, let JSF set it by @ManagedProperty

     @ManagedProperty(value="#{param.id}")
     private Long id; // +setter
    

    Or if your bean has a broader scope or if you want more fine grained validation/conversion, use <f:viewParam> on the target view, see also f:viewParam vs @ManagedProperty:

     <f:viewParam name="id" value="#{bean.id}" required="true" />
    

    Either way, this has the advantage that the datamodel doesn't necessarily need to be preserved for the form submit (for the case that your bean is request scoped).


  3. Use <f:setPropertyActionListener> in UICommand component. The advantage is that this removes the need for accessing the request parameter map when the bean has a broader scope than the request scope.

     <h:commandLink action="#{bean.insert}" value="insert">
         <f:setPropertyActionListener target="#{bean.id}" value="#{item.id}" />
     </h:commandLink>
    

    In combination with

     private Long id; // +setter
    

    It'll be just available by property id in action method. This only requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.


  4. Bind the datatable value to DataModel<E> instead which in turn wraps the items.

     <h:dataTable value="#{bean.model}" var="item">
    

    with

     private transient DataModel<Item> model;
    
     public DataModel<Item> getModel() {
         if (model == null) {
             model = new ListDataModel<Item>(items);
         }
         return model;
     }
    

    (making it transient and lazily instantiating it in the getter is mandatory when you're using this on a view or session scoped bean since DataModel doesn't implement Serializable)

    Then you'll be able to access the current row by DataModel#getRowData() without passing anything around (JSF determines the row based on the request parameter name of the clicked command link/button).

     public void insert() {
         Item item = model.getRowData();
         Long id = item.getId();
         // ...
     }
    

    This also requires that the datamodel is preserved for the form submit request. Best is to put the bean in the view scope by @ViewScoped.


  5. Use Application#evaluateExpressionGet() to programmatically evaluate the current #{item}.

     public void insert() {
         FacesContext context = FacesContext.getCurrentInstance();
         Item item = context.getApplication().evaluateExpressionGet(context, "#{item}", Item.class);
         Long id = item.getId();
         // ...
     }
    

Which way to choose depends on the functional requirements and whether the one or the other offers more advantages for other purposes. I personally would go ahead with #1 or, when you'd like to support servlet 2.5 containers as well, with #2.

SmtpException: Unable to read data from the transport connection: net_io_connectionclosed

For anyone who stumbles across this post looking for a solution and you've set up SMTP sendgrid via Azure.

The username is not the username you set up when you've created the sendgrid object in azure. To find your username;

  • Click on your sendgrid object in azure and click manage. You will be redirected to the SendGrid site.
  • Confirm your email and then copy down the username displayed there.. it's an automatically generated username.
  • Add the username from SendGrid into your SMTP settings in the web.config file.

Hope this helps!

What is the difference between HTTP_HOST and SERVER_NAME in PHP?

As balusC said SERVER_NAME is not reliable and can be changed in apache config , server name config of server and firewall that can be between you and server.

Following function always return real host (user typed host) without port and it's almost reliable:

function getRealHost(){
   list($realHost,)=explode(':',$_SERVER['HTTP_HOST']);
   return $realHost;
}

How do you specifically order ggplot2 x axis instead of alphabetical order?

The accepted answer offers a solution which requires changing of the underlying data frame. This is not necessary. One can also simply factorise within the aes() call directly or create a vector for that instead.

This is certainly not much different than user Drew Steen's answer, but with the important difference of not changing the original data frame.

level_order <- c('virginica', 'versicolor', 'setosa') #this vector might be useful for other plots/analyses

ggplot(iris, aes(x = factor(Species, level = level_order), y = Petal.Width)) + geom_col()

or

level_order <- factor(iris$Species, level = c('virginica', 'versicolor', 'setosa'))

ggplot(iris, aes(x = level_order, y = Petal.Width)) + geom_col()

or
directly in the aes() call without a pre-created vector:

ggplot(iris, aes(x = factor(Species, level = c('virginica', 'versicolor', 'setosa')), y = Petal.Width)) + geom_col()

that's for the first version

How to parse JSON array in jQuery?

You can download a JSON parser from a link on the JSON.org website which works great, you can also stringify you JSON to view the contents.

Also, if you're using EVAL and it's a JSON array then you'll need to use the following synrax:

eval('([' + jsonData + '])');

How to remove duplicate white spaces in string using Java?

Try this - You have to import java.util.regex.*;

    Pattern pattern = Pattern.compile("\\s+");
    Matcher matcher = pattern.matcher(string);
    boolean check = matcher.find();
    String str = matcher.replaceAll(" ");

Where string is your string on which you need to remove duplicate white spaces

How to skip over an element in .map()?

Here's a fun solution:

/**
 * Filter-map. Like map, but skips undefined values.
 *
 * @param callback
 */
function fmap(callback) {
    return this.reduce((accum, ...args) => {
        let x = callback(...args);
        if(x !== undefined) {
            accum.push(x);
        }
        return accum;
    }, []);
}

Use with the bind operator:

[1,2,-1,3]::fmap(x => x > 0 ? x * 2 : undefined); // [2,4,6]

Large WCF web service request failing with (400) HTTP Bad Request

I was also getting this issue also however none of the above worked for me as I was using a custom binding (for BinaryXML) after an long time digging I found the answer here :-

Sending large XML from Silverlight to WCF

As am using a customBinding, the maxReceivedMessageSize has to be set on the httpTransport element under the binding element in the web.config:

<httpsTransport maxReceivedMessageSize="4194304" /> 

How to empty a Heroku database

Best solution for you issue will be

heroku pg:reset -r heroku  --confirm your_heroku_app_name

--confirm your_heroku_app_name

is not required, but terminal always ask me do that command.

After that command you will be have pure db, without structure and stuff, after that you can run

heroku run rake db:schema:load -r heroku

or

heroku run rake db:migrate -r heroku

How to revert the last migration?

there is a good library to use its called djagno-nomad, although not directly related to the question asked, thought of sharing this,

scenario: most of the time when switching to project, we feel like it should revert our changes that we did on this current branch, that's what exactly this library does, checkout below

https://pypi.org/project/django-nomad/

asp.net Button OnClick event not firing

In my case I put required="required" inside CKEditor control.
Removing this attribute fixed the issue.
Before

<CKEditor:CKEditorControl ID="txtDescription" BasePath="/ckeditor/" runat="server" required="required"></CKEditor:CKEditorControl>

After

<CKEditor:CKEditorControl ID="txtDescription" BasePath="/ckeditor/" runat="server"></CKEditor:CKEditorControl>

IE Driver download location Link for Selenium

You can download IE Driver (both 32 and 64-bit) from Selenium official site: http://docs.seleniumhq.org/download/

32 bit Windows IE

64 bit Windows IE

IE Driver is also available in the following site:

http://selenium-release.storage.googleapis.com/index.html

Using JSON POST Request

Modern browsers do not currently implement JSONRequest (as far as I know) since it is only a draft right now. I have found someone who has implemented it as a library that you can include in your page: http://devpro.it/JSON/files/JSONRequest-js.html (please note that it has a few dependencies).

Otherwise, you might want to go with another JS library like jQuery or Mootools.

Apply CSS Style to child elements

Here is some code that I recently wrote. I think that it provides a basic explanation of combining class/ID names with pseudoclasses.

_x000D_
_x000D_
.content {_x000D_
  width: 800px;_x000D_
  border: 1px solid black;_x000D_
  border-radius: 10px;_x000D_
  box-shadow: 0 0 5px 2px grey;_x000D_
  margin: 30px auto 20px auto;_x000D_
  /*height:200px;*/_x000D_
_x000D_
}_x000D_
p.red {_x000D_
  color: red;_x000D_
}_x000D_
p.blue {_x000D_
  color: blue;_x000D_
}_x000D_
p#orange {_x000D_
  color: orange;_x000D_
}_x000D_
p#green {_x000D_
  color: green;_x000D_
}
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
_x000D_
<head>_x000D_
  <title>Class practice</title>_x000D_
  <link href="wrench_favicon.ico" rel="icon" type="image/x-icon" />_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
  <div class="content">_x000D_
    <p id="orange">orange</p>_x000D_
    <p id="green">green</p>_x000D_
    <p class="red">red</p>_x000D_
    <p class="blue">blue</p>_x000D_
  </div>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_

sql ORDER BY multiple values in specific order?

you can use position(text in text) in order by for ordering the sequence

What is the difference between `sorted(list)` vs `list.sort()`?

Note: Simplest difference between sort() and sorted() is: sort() doesn't return any value while, sorted() returns an iterable list.

sort() doesn't return any value.

The sort() method just sorts the elements of a given list in a specific order - Ascending or Descending without returning any value.

The syntax of sort() method is:

list.sort(key=..., reverse=...)

Alternatively, you can also use Python's in-built function sorted() for the same purpose. sorted function return sorted list

 list=sorted(list, key=..., reverse=...)

editing PATH variable on mac

Edit /etc/paths. Then close the terminal and reopen it.

$ sudo vi /etc/paths

Note: each entry is seperated by line breaks.

/usr/local/bin
/usr/bin
/bin
/usr/sbin
/sbin

OSError [Errno 22] invalid argument when use open() in Python

for folder, subs, files in os.walk(unicode(docs_dir, 'utf-8')):
    for filename in files:
        if not filename.startswith('.'):
            file_path = os.path.join(folder, filename)

Ruby on Rails: Where to define global constants?

According your condition, you can also define some environmental variables, and fetch it via ENV['some-var'] in ruby code, this solution may not fit for you, but I hope it may help others.

Example: you can create different files .development_env, .production_env, .test_env and load it according your application environments, check this gen dotenv-rails which automate this for your.

How to create a new file in unix?

The command is lowercase: touch filename.

Keep in mind that touch will only create a new file if it does not exist! Here's some docs for good measure: http://unixhelp.ed.ac.uk/CGI/man-cgi?touch

If you always want an empty file, one way to do so would be to use:

echo "" > filename

How to search in a List of Java object

Using Java 8

With Java 8 you can simply convert your list to a stream allowing you to write:

import java.util.List;
import java.util.stream.Collectors;

List<Sample> list = new ArrayList<Sample>();
List<Sample> result = list.stream()
    .filter(a -> Objects.equals(a.value3, "three"))
    .collect(Collectors.toList());

Note that

  • a -> Objects.equals(a.value3, "three") is a lambda expression
  • result is a List with a Sample type
  • It's very fast, no cast at every iteration
  • If your filter logic gets heavier, you can do list.parallelStream() instead of list.stream() (read this)


Apache Commons

If you can't use Java 8, you can use Apache Commons library and write:

import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.Predicate;

Collection result = CollectionUtils.select(list, new Predicate() {
     public boolean evaluate(Object a) {
         return Objects.equals(((Sample) a).value3, "three");
     }
 });

// If you need the results as a typed array:
Sample[] resultTyped = (Sample[]) result.toArray(new Sample[result.size()]);

Note that:

  • There is a cast from Object to Sample at each iteration
  • If you need your results to be typed as Sample[], you need extra code (as shown in my sample)



Bonus: A nice blog article talking about how to find element in list.

Thin Black Border for a Table

Style the td and th instead

td, th {
    border: 1px solid black;
}

And also to make it so there is no spacing between cells use:

table {
    border-collapse: collapse;
}

(also note, you have border-style: none; which should be border-style: solid;)

See an example here: http://jsfiddle.net/KbjNr/

how to print float value upto 2 decimal place without rounding off

i'd suggest shorter and faster approach:

printf("%.2f", ((signed long)(fVal * 100) * 0.01f));

this way you won't overflow int, plus multiplication by 100 shouldn't influence the significand/mantissa itself, because the only thing that really is changing is exponent.

Loop through checkboxes and count each one checked or unchecked

Using Selectors

You can get all checked checkboxes like this:

var boxes = $(":checkbox:checked");

And all non-checked like this:

var nboxes = $(":checkbox:not(:checked)");

You could merely cycle through either one of these collections, and store those names. If anything is absent, you know it either was or wasn't checked. In PHP, if you had an array of names which were checked, you could simply do an in_array() request to know whether or not any particular box should be checked at a later date.

Serialize

jQuery also has a serialize method that will maintain the state of your form controls. For instance, the example provided on jQuery's website follows:

single=Single2&multiple=Multiple&multiple=Multiple3&check=check2&radio=radio2

This will enable you to keep the information for which elements were checked as well.

How to select from subquery using Laravel Query Builder?

Correct way described in this answer: https://stackoverflow.com/a/52772444/2519714 Most popular answer at current moment is not totally correct.

This way https://stackoverflow.com/a/24838367/2519714 is not correct in some cases like: sub select has where bindings, then joining table to sub select, then other wheres added to all query. For example query: select * from (select * from t1 where col1 = ?) join t2 on col1 = col2 and col3 = ? where t2.col4 = ? To make this query you will write code like:

$subQuery = DB::query()->from('t1')->where('t1.col1', 'val1');
$query = DB::query()->from(DB::raw('('. $subQuery->toSql() . ') AS subquery'))
    ->mergeBindings($subQuery->getBindings());
$query->join('t2', function(JoinClause $join) {
    $join->on('subquery.col1', 't2.col2');
    $join->where('t2.col3', 'val3');
})->where('t2.col4', 'val4');

During executing this query, his method $query->getBindings() will return bindings in incorrect order like ['val3', 'val1', 'val4'] in this case instead correct ['val1', 'val3', 'val4'] for raw sql described above.

One more time correct way to do this:

$subQuery = DB::query()->from('t1')->where('t1.col1', 'val1');
$query = DB::query()->fromSub($subQuery, 'subquery');
$query->join('t2', function(JoinClause $join) {
    $join->on('subquery.col1', 't2.col2');
    $join->where('t2.col3', 'val3');
})->where('t2.col4', 'val4');

Also bindings will be automatically and correctly merged to new query.

os.path.dirname(__file__) returns empty

can be used also like that:

dirname(dirname(abspath(__file__)))

Importing CSV with line breaks in Excel 2007

just create a new sheet with cells with linebreak, save it to csv then open it with an editor that can show the end of line characters (like notepad++). By doing that you will notice that a linebreak in a cell is coded with LF while a "real" end of line is code with CR LF. Voilà, now you know how to generate a "correct" csv file for excel.

Passing an Array as Arguments, not an Array, in PHP

As has been mentioned, as of PHP 5.6+ you can (should!) use the ... token (aka "splat operator", part of the variadic functions functionality) to easily call a function with an array of arguments:

<?php
function variadic($arg1, $arg2)
{
    // Do stuff
    echo $arg1.' '.$arg2;
}

$array = ['Hello', 'World'];

// 'Splat' the $array in the function call
variadic(...$array);

// 'Hello World'

Note: array items are mapped to arguments by their position in the array, not their keys.

As per CarlosCarucce's comment, this form of argument unpacking is the fastest method by far in all cases. In some comparisons, it's over 5x faster than call_user_func_array.

Aside

Because I think this is really useful (though not directly related to the question): you can type-hint the splat operator parameter in your function definition to make sure all of the passed values match a specific type.

(Just remember that doing this it MUST be the last parameter you define and that it bundles all parameters passed to the function into the array.)

This is great for making sure an array contains items of a specific type:

<?php

// Define the function...

function variadic($var, SomeClass ...$items)
{
    // $items will be an array of objects of type `SomeClass`
}

// Then you can call...

variadic('Hello', new SomeClass, new SomeClass);

// or even splat both ways

$items = [
    new SomeClass,
    new SomeClass,
];

variadic('Hello', ...$items);

How do I initialize a byte array in Java?

You can use the Java UUID class to store these values, instead of byte arrays:

UUID

public UUID(long mostSigBits,
            long leastSigBits)

Constructs a new UUID using the specified data. mostSigBits is used for the most significant 64 bits of the UUID and leastSigBits becomes the least significant 64 bits of the UUID.

REST API using POST instead of GET

Think about it. When your client makes a GET request to an URI X, what it's saying to the server is: "I want a representation of the resource located at X, and this operation shouldn't change anything on the server." A PUT request is saying: "I want you to replace whatever is the resource located at X with the new entity I'm giving you on the body of this request". A DELETE request is saying: "I want you to delete whatever is the resource located at X". A PATCH is saying "I'm giving you this diff, and you should try to apply it to the resource at X and tell me if it succeeds." But a POST is saying: "I'm sending you this data subordinated to the resource at X, and we have a previous agreement on what you should do with it."

If you don't have it documented somewhere that the resource expects a POST and does something with it, it doesn't make sense to send a POST to it expecting it to act like a GET.

REST relies on the standardized behavior of the underlying protocol, and POST is precisely the method used for an action that isn't standardized. The result of a GET, PUT and DELETE requests are clearly defined in the standard, but POST isn't. The result of a POST is subordinated to the server, so if it's not documented that you can use POST to do something, you have to assume that you can't.

How to instantiate, initialize and populate an array in TypeScript?

There isn't a field initialization syntax like that for objects in JavaScript or TypeScript.

Option 1:

class bar {
    // Makes a public field called 'length'
    constructor(public length: number) { }
}

bars = [ new bar(1) ];

Option 2:

interface bar {
    length: number;
}

bars = [ {length: 1} ];

Mocking a class: Mock() or patch()?

I've got a YouTube video on this.

Short answer: Use mock when you're passing in the thing that you want mocked, and patch if you're not. Of the two, mock is strongly preferred because it means you're writing code with proper dependency injection.

Silly example:

# Use a mock to test this.
my_custom_tweeter(twitter_api, sentence):
    sentence.replace('cks','x')   # We're cool and hip.
    twitter_api.send(sentence)

# Use a patch to mock out twitter_api. You have to patch the Twitter() module/class 
# and have it return a mock. Much uglier, but sometimes necessary.
my_badly_written_tweeter(sentence):
    twitter_api = Twitter(user="XXX", password="YYY")
    sentence.replace('cks','x') 
    twitter_api.send(sentence)

What do the python file extensions, .pyc .pyd .pyo stand for?

  1. .py: This is normally the input source code that you've written.
  2. .pyc: This is the compiled bytecode. If you import a module, python will build a *.pyc file that contains the bytecode to make importing it again later easier (and faster).
  3. .pyo: This was a file format used before Python 3.5 for *.pyc files that were created with optimizations (-O) flag. (see the note below)
  4. .pyd: This is basically a windows dll file. http://docs.python.org/faq/windows.html#is-a-pyd-file-the-same-as-a-dll

Also for some further discussion on .pyc vs .pyo, take a look at: http://www.network-theory.co.uk/docs/pytut/CompiledPythonfiles.html (I've copied the important part below)

  • When the Python interpreter is invoked with the -O flag, optimized code is generated and stored in ‘.pyo’ files. The optimizer currently doesn't help much; it only removes assert statements. When -O is used, all bytecode is optimized; .pyc files are ignored and .py files are compiled to optimized bytecode.
  • Passing two -O flags to the Python interpreter (-OO) will cause the bytecode compiler to perform optimizations that could in some rare cases result in malfunctioning programs. Currently only __doc__ strings are removed from the bytecode, resulting in more compact ‘.pyo’ files. Since some programs may rely on having these available, you should only use this option if you know what you're doing.
  • A program doesn't run any faster when it is read from a ‘.pyc’ or ‘.pyo’ file than when it is read from a ‘.py’ file; the only thing that's faster about ‘.pyc’ or ‘.pyo’ files is the speed with which they are loaded.
  • When a script is run by giving its name on the command line, the bytecode for the script is never written to a ‘.pyc’ or ‘.pyo’ file. Thus, the startup time of a script may be reduced by moving most of its code to a module and having a small bootstrap script that imports that module. It is also possible to name a ‘.pyc’ or ‘.pyo’ file directly on the command line.

Note:

On 2015-09-15 the Python 3.5 release implemented PEP-488 and eliminated .pyo files. This means that .pyc files represent both unoptimized and optimized bytecode.

How to create dispatch queue in Swift 3

DispatchQueue.main.async(execute: {
   // code
})

Try catch statements in C

Perhaps not a major language (unfortunately), but in APL, theres the ?EA operation (stand for Execute Alternate).

Usage: 'Y' ?EA 'X' where X and Y are either code snippets supplied as strings or function names.

If X runs into an error, Y (usually error-handling) will be executed instead.

How to convert a string to character array in c (or) how to extract a single char form string?

In this simple way

char str [10] = "IAmCute";
printf ("%c",str[4]);

How to fix syntax error, unexpected T_IF error in php?

PHP parser errors take some getting used to; if it complains about an unexpected 'something' at line X, look at line X-1 first. In this case it will not tell you that you forgot a semi-colon at the end of the previous line , instead it will complain about the if that comes next.

You'll get used to it :)

Tomcat 8 Maven Plugin for Java 8

groupId and Mojo name change Since version 2.0-beta-1 tomcat mojos has been renamed to tomcat6 and tomcat7 with the same goals.

You must configure your pom to use this new groupId:

<pluginManagement>
  <plugins>
    <plugin>
      <groupId>org.apache.tomcat.maven</groupId>
      <artifactId>tomcat6-maven-plugin</artifactId>
      <version>2.3-SNAPSHOT</version>
    </plugin>
    <plugin>
      <groupId>org.apache.tomcat.maven</groupId>
      <artifactId>tomcat7-maven-plugin</artifactId>
      <version>2.3-SNAPSHOT</version>
    </plugin>
  </plugins>
</pluginManagement>

Or add the groupId in your settings.xml

.... org.apache.tomcat.maven ....

oracle sql: update if exists else insert

You could use the SQL%ROWCOUNT Oracle variable:

UPDATE table1
  SET field2 = value2, 
      field3 = value3 
WHERE field1 = value1; 

IF (SQL%ROWCOUNT = 0) THEN 

  INSERT INTO table (field1, field2, field3)
  VALUES (value1, value2, value3);

END IF; 

It would be easier just to determine if your primary key (i.e. field1) has a value and then perform an insert or update accordingly. That is, if you use said values as parameters for a stored procedure.

How can I edit a .jar file?

Here's what I did:

  • Extracted the files using WinRAR
  • Made my changes to the extracted files
  • Opened the original JAR file with WinRAR
  • Used the ADD button to replace the files that I modified

That's it. I have tested it with my Nokia and it's working for me.

What is the difference between JOIN and JOIN FETCH when using JPA and Hibernate

in this link i mentioned before on the comment, read this part :

A "fetch" join allows associations or collections of values to be initialized along with their parent objects using a single select. This is particularly useful in the case of a collection. It effectively overrides the outer join and lazy declarations of the mapping file for associations and collections.

this "JOIN FETCH" will have it's effect if you have (fetch = FetchType.LAZY) property for a collection inside entity(example bellow).

And it is only effect the method of "when the query should happen". And you must also know this:

hibernate have two orthogonal notions : when is the association fetched and how is it fetched. It is important that you do not confuse them. We use fetch to tune performance. We can use lazy to define a contract for what data is always available in any detached instance of a particular class.

when is the association fetched --> your "FETCH" type

how is it fetched --> Join/select/Subselect/Batch

In your case, FETCH will only have it's effect if you have department as a set inside Employee, something like this in the entity:

@OneToMany(fetch = FetchType.LAZY)
private Set<Department> department;

when you use

FROM Employee emp
JOIN FETCH emp.department dep

you will get emp and emp.dep. when you didnt use fetch you can still get emp.dep but hibernate will processing another select to the database to get that set of department.

so its just a matter of performance tuning, about you want to get all result(you need it or not) in a single query(eager fetching), or you want to query it latter when you need it(lazy fetching).

Use eager fetching when you need to get small data with one select(one big query). Or use lazy fetching to query what you need latter(many smaller query).

use fetch when :

  • no large unneeded collection/set inside that entity you about to get

  • communication from application server to database server too far and need long time

  • you may need that collection latter when you don't have the access to it(outside of the transactional method/class)

C# - Making a Process.Start wait until the process has start-up

Like others have already said, it's not immediately obvious what you're asking. I'm going to assume that you want to start a process and then perform another action when the process "is ready".

Of course, the "is ready" is the tricky bit. Depending on what you're needs are, you may find that simply waiting is sufficient. However, if you need a more robust solution, you can consider using a named Mutex to control the control flow between your two processes.

For example, in your main process, you might create a named mutex and start a thread or task which will wait. Then, you can start the 2nd process. When that process decides that "it is ready", it can open the named mutex (you have to use the same name, of course) and signal to the first process.

Nginx serves .php files as downloads, instead of executing them

This workded for me.

1) MyApp file

vi /etc/nginx/sites-available/myApp

server {
  listen 80;
  listen [::]:80;

  root /var/www/myApp;
  index index.php index.html index.htm;

  location ~ \.php$ {
      try_files $uri =404;
      fastcgi_split_path_info ^(.+\.php)(/.+)$;
      fastcgi_pass unix:/run/php/php7.0-fpm.sock;
      fastcgi_index index.php;
      fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
          include fastcgi_params;
      }
}

PHP5 users

Change

fastcgi_pass unix:/run/php/php7.0-fpm.sock;

to

fastcgi_pass unix:/var/run/php5-fpm.sock;

2) Configure cgi.fix_pathinfo

Set cgi.fix_pathinfo to 0

Location:

PHP5 /etc/php5/fpm/php.ini

PHP7 /etc/php/7.0/fpm/php.ini


3) Restart services

FPM

php5 sudo service php5-fpm restart

php7 sudo service php7.0-fpm restart

NGINX

sudo service nginx restart

How can I export a GridView.DataSource to a datatable or dataset?

You should convert first DataSource in BindingSource, look example

BindingSource bs = (BindingSource)dgrid.DataSource; // Se convierte el DataSource 
DataTable tCxC = (DataTable) bs.DataSource;

With the data of tCxC you can do anything.

Injecting Mockito mocks into a Spring bean

Update: There are now better, cleaner solutions to this problem. Please consider the other answers first.

I eventually found an answer to this by ronen on his blog. The problem I was having is due to the method Mockito.mock(Class c) declaring a return type of Object. Consequently Spring is unable to infer the bean type from the factory method return type.

Ronen's solution is to create a FactoryBean implementation that returns mocks. The FactoryBean interface allows Spring to query the type of objects created by the factory bean.

My mocked bean definition now looks like:

<bean id="mockDaoFactory" name="dao" class="com.package.test.MocksFactory">
    <property name="type" value="com.package.Dao" />
</bean>

How to use python numpy.savetxt to write strings and float number to an ASCII file?

The currently accepted answer does not actually address the question, which asks how to save lists that contain both strings and float numbers. For completeness I provide a fully working example, which is based, with some modifications, on the link given in @joris comment.

import numpy as np

names  = np.array(['NAME_1', 'NAME_2', 'NAME_3'])
floats = np.array([ 0.1234 ,  0.5678 ,  0.9123 ])

ab = np.zeros(names.size, dtype=[('var1', 'U6'), ('var2', float)])
ab['var1'] = names
ab['var2'] = floats

np.savetxt('test.txt', ab, fmt="%10s %10.3f")

Update: This example also works properly in Python 3 by using the 'U6' Unicode string dtype, when creating the ab structured array, instead of the 'S6' byte string. The latter dtype would work in Python 2.7, but would write strings like b'NAME_1' in Python 3.

how to compare the Java Byte[] array?

I looked for an array wrapper which makes it comparable to use with guava TreeRangeMap. The class doesn't accept comparator.

After some research I realized that ByteBuffer from JDK has this feature and it doesn't copy original array which is good. More over you can compare faster with ByteBuffer::asLongBuffer 8 bytes at time (also doesn't copy). By default ByteBuffer::wrap(byte[]) use BigEndian so order relation is the same as comparing individual bytes.

.

SyntaxError: JSON.parse: unexpected character at line 1 column 1 of the JSON data

JSON.parse() doesn't recognize That data as string. For example {objAskGrant:"Yes",objPass:"asdfasdf",objNameSurname:"asdfasdf adfasdf",objEmail:"[email protected]",objGsm:3241234123,objAdres:"asdfasdf",objTerms:"CheckIsValid"}

Which is like this: JSON.parse({objAskGrant:"Yes",objPass:"asdfasdf",objNameSurname:"asdfasdf adfasdf",objEmail:"[email protected]",objGsm:3241234123,objAdres:"asdfasdf",objTerms:"CheckIsValid"}); That will output SyntaxError: missing " ' " instead of "{" on line...

So correctly wrap all data like this: '{"objAskGrant":"Yes","objPass":"asdfasdf","objNameSurname":"asdfasdf adfasdf","objEmail":"[email protected]","objGsm":3241234123,"objAdres":"asdfasdf","objTerms":"CheckIsValid"}' Which works perfectly well for me.

And not like this: "{"objAskGrant":"Yes","objPass":"asdfasdf","objNameSurname":"asdfasdf adfasdf","objEmail":"[email protected]","objGsm":3241234123,"objAdres":"asdfasdf","objTerms":"CheckIsValid"}" Which give the present error you are experiencing.

What is the best way to conditionally apply a class?

We can make a function to manage return class with condition

enter image description here

<script>
    angular.module('myapp', [])
            .controller('ExampleController', ['$scope', function ($scope) {
                $scope.MyColors = ['It is Red', 'It is Yellow', 'It is Blue', 'It is Green', 'It is Gray'];
                $scope.getClass = function (strValue) {
                    switch(strValue) {
                        case "It is Red":return "Red";break;
                        case "It is Yellow":return "Yellow";break;
                        case "It is Blue":return "Blue";break;
                        case "It is Green":return "Green";break;
                        case "It is Gray":return "Gray";break;
                    }
                }
        }]);
</script>

And then

<body ng-app="myapp" ng-controller="ExampleController">

<h2>AngularJS ng-class if example</h2>
<ul >
    <li ng-repeat="icolor in MyColors" >
        <p ng-class="[getClass(icolor), 'b']">{{icolor}}</p>
    </li>
</ul>
<hr/>
<p>Other way using : ng-class="{'class1' : expression1, 'class2' : expression2,'class3':expression2,...}"</p>
<ul>
    <li ng-repeat="icolor in MyColors">
        <p ng-class="{'Red':icolor=='It is Red','Yellow':icolor=='It is Yellow','Blue':icolor=='It is Blue','Green':icolor=='It is Green','Gray':icolor=='It is Gray'}" class="b">{{icolor}}</p>
    </li>
</ul>

You can refer to full code page at ng-class if example

How to make PopUp window in java

The same answer : JOptionpane with an example :)

package experiments;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class CreateDialogFromOptionPane {

    public static void main(final String[] args) {
        final JFrame parent = new JFrame();
        JButton button = new JButton();

        button.setText("Click me to show dialog!");
        parent.add(button);
        parent.pack();
        parent.setVisible(true);

        button.addActionListener(new java.awt.event.ActionListener() {
            @Override
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                String name = JOptionPane.showInputDialog(parent,
                        "What is your name?", null);
            }
        });
    }
}

enter image description here

How to implement HorizontalScrollView like Gallery?

Here is my layout:

    <HorizontalScrollView
        android:id="@+id/horizontalScrollView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:paddingTop="@dimen/padding" >

       <LinearLayout
        android:id="@+id/shapeLayout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp" >
        </LinearLayout>
    </HorizontalScrollView>

And I populate it in the code with dynamic check-boxes.

Reload nginx configuration

If your system has systemctl

sudo systemctl reload nginx

If your system supports service (using debian/ubuntu) try this

sudo service nginx reload

If not (using centos/fedora/etc) you can try the init script

sudo /etc/init.d/nginx reload

Error: select command denied to user '<userid>'@'<ip-address>' for table '<table-name>'

For me, I accidentally included my local database name inside the SQL query, hence the access denied issue came up when I deployed.

I removed the database name from the SQL query and it got fixed.

Android Canvas: drawing too large bitmap

If you don't want your image to be pre-scaled you can move it to the res/drawable-nodpi/ folder.

More info: https://developer.android.com/training/multiscreen/screendensities#DensityConsiderations

View google chrome's cached pictures

You can make a bookmark with this as the url:

javascript:
var cached_anchors = $$('a');
for (var i in cached_anchors) {
    var ca = cached_anchors[i];
    if(ca.href.search('sprite') < 0 && ca.href.search('.png') > -1 || ca.href.search('.gif') > -1 || ca.href.search('.jpg') > -1) {
        var a = document.createElement('a');
        a.href = ca.innerHTML;
        a.target = '_blank';

        var img = document.createElement('img');
        img.src = ca.innerHTML;
        img.style.maxHeight = '100px';

        a.appendChild(img);
        document.getElementsByTagName('body')[0].appendChild(a);
    }
}
document.getElementsByTagName('body')[0].removeChild(document.getElementsByTagName('table')[0]);
void(0);

Then just go to chrome://cache and then click your bookmark and it'll show you all the images.

Load and execution sequence of a web page?

Open your page in Firefox and get the HTTPFox addon. It will tell you all that you need.

Found this on archivist.incuito:

http://archivist.incutio.com/viewlist/css-discuss/76444

When you first request a page, your browser sends a GET request to the server, which returns the HTML to the browser. The browser then starts parsing the page (possibly before all of it has been returned).

When it finds a reference to an external entity such as a CSS file, an image file, a script file, a Flash file, or anything else external to the page (either on the same server/domain or not), it prepares to make a further GET request for that resource.

However the HTTP standard specifies that the browser should not make more than two concurrent requests to the same domain. So it puts each request to a particular domain in a queue, and as each entity is returned it starts the next one in the queue for that domain.

The time it takes for an entity to be returned depends on its size, the load the server is currently experiencing, and the activity of every single machine between the machine running the browser and the server. The list of these machines can in principle be different for every request, to the extent that one image might travel from the USA to me in the UK over the Atlantic, while another from the same server comes out via the Pacific, Asia and Europe, which takes longer. So you might get a sequence like the following, where a page has (in this order) references to three script files, and five image files, all of differing sizes:

  1. GET script1 and script2; queue request for script3 and images1-5.
  2. script2 arrives (it's smaller than script1): GET script3, queue images1-5.
  3. script1 arrives; GET image1, queue images2-5.
  4. image1 arrives, GET image2, queue images3-5.
  5. script3 fails to arrive due to a network problem - GET script3 again (automatic retry).
  6. image2 arrives, script3 still not here; GET image3, queue images4-5.
  7. image 3 arrives; GET image4, queue image5, script3 still on the way.
  8. image4 arrives, GET image5;
  9. image5 arrives.
  10. script3 arrives.

In short: any old order, depending on what the server is doing, what the rest of the Internet is doing, and whether or not anything has errors and has to be re-fetched. This may seem like a weird way of doing things, but it would quite literally be impossible for the Internet (not just the WWW) to work with any degree of reliability if it wasn't done this way.

Also, the browser's internal queue might not fetch entities in the order they appear in the page - it's not required to by any standard.

(Oh, and don't forget caching, both in the browser and in caching proxies used by ISPs to ease the load on the network.)

Error in strings.xml file in Android

post your complete string. Though, my guess is there is an apostrophe (') character in your string. replace it with (\') and it will fix the issue. for example,

//strings.xml
<string name="terms">
Hey Mr. Android, are you stuck?  Here, I\'ll clear a path for you.  
</string>

Ref:

http://www.mrexcel.com/forum/showthread.php?t=195353

https://code.google.com/archive/p/replicaisland/issues/48

How to display Woocommerce Category image?

To prevent full size category images slowing page down, you can use smaller images with wp_get_attachment_image_src():

<?php 

$thumbnail_id = get_woocommerce_term_meta( $term->term_id, 'thumbnail_id', true );

// get the medium-sized image url
$image = wp_get_attachment_image_src( $thumbnail_id, 'medium' );

// Output in img tag
echo '<img src="' . $image[0] . '" alt="" />'; 

// Or as a background for a div
echo '<div class="image" style="background-image: url("' . $image[0] .'")"></div>';

?>

EDIT: Fixed variable name and missing quote

How to rearrange Pandas column sequence?

You can do the following:

df =DataFrame({'a':[1,2,3,4],'b':[2,4,6,8]})

df['x']=df.a + df.b
df['y']=df.a - df.b

create column title whatever order you want in this way:

column_titles = ['x','y','a','b']

df.reindex(columns=column_titles)

This will give you desired output

Best way to alphanumeric check in JavaScript

The asker's original inclination to use str.charCodeAt(i) appears to be faster than the regular expression alternative. In my test on jsPerf the RegExp option performs 66% slower in Chrome 36 (and slightly slower in Firefox 31).

Here's a cleaned-up version of the original validation code that receives a string and returns true or false:

function isAlphaNumeric(str) {
  var code, i, len;

  for (i = 0, len = str.length; i < len; i++) {
    code = str.charCodeAt(i);
    if (!(code > 47 && code < 58) && // numeric (0-9)
        !(code > 64 && code < 91) && // upper alpha (A-Z)
        !(code > 96 && code < 123)) { // lower alpha (a-z)
      return false;
    }
  }
  return true;
};

Of course, there may be other considerations, such as readability. A one-line regular expression is definitely prettier to look at. But if you're strictly concerned with speed, you may want to consider this alternative.

Vertically align text next to an image?

It can be confusing, I agree. Try utilizing table features. I use this simple CSS trick to position modals at the center of the webpage. It has large browser support:

<div class="table">
    <div class="cell">
        <img src="..." alt="..." />
        <span>It works now</span>
    </div>
</div>

and CSS part:

.table { display: table; }
.cell { display: table-cell; vertical-align: middle; }

Note that you have to style and adjust the size of image and table container to make it work as you desire. Enjoy.

Error: Jump to case label

The problem is that variables declared in one case are still visible in the subsequent cases unless an explicit { } block is used, but they will not be initialized because the initialization code belongs to another case.

In the following code, if foo equals 1, everything is ok, but if it equals 2, we'll accidentally use the i variable which does exist but probably contains garbage.

switch(foo) {
  case 1:
    int i = 42; // i exists all the way to the end of the switch
    dostuff(i);
    break;
  case 2:
    dostuff(i*2); // i is *also* in scope here, but is not initialized!
}

Wrapping the case in an explicit block solves the problem:

switch(foo) {
  case 1:
    {
        int i = 42; // i only exists within the { }
        dostuff(i);
        break;
    }
  case 2:
    dostuff(123); // Now you cannot use i accidentally
}

Edit

To further elaborate, switch statements are just a particularly fancy kind of a goto. Here's an analoguous piece of code exhibiting the same issue but using a goto instead of a switch:

int main() {
    if(rand() % 2) // Toss a coin
        goto end;

    int i = 42;

  end:
    // We either skipped the declaration of i or not,
    // but either way the variable i exists here, because
    // variable scopes are resolved at compile time.
    // Whether the *initialization* code was run, though,
    // depends on whether rand returned 0 or 1.
    std::cout << i;
}

How do I create a GUI for a windows application using C++?

I strongly prefer simply using Microsoft Visual Studio and writing a native Win32 app.

For a GUI as simple as the one that you describe, you could simply create a Dialog Box and use it as your main application window. The default application created by the Win32 Project wizard in Visual Studio actually pops a window, so you can replace that window with your Dialog Box and replace the WndProc with a similar (but simpler) DialogProc.

The question, then, is one of tools and cost. The Express Edition of Visual C++ does everything you want except actually create the Dialog Template resource. For this, you could either code it in the RC file by hand or in memory by hand. Related SO question: Windows API Dialogs without using resource files.

Or you could try one of the free resource editors that others have recommended.

Finally, the Visual Studio 2008 Standard Edition is a costlier option but gives you an integrated resource editor.

Custom Date Format for Bootstrap-DatePicker

I'm sure you are using a old version. You must use the last version available at master branch:

https://github.com/eternicode/bootstrap-datepicker

Should I use "camel case" or underscores in python?

for everything related to Python's style guide: i'd recommend you read PEP8.

To answer your question:

Function names should be lowercase, with words separated by underscores as necessary to improve readability.

Why am I getting this error: No mapping specified for the following EntitySet/AssociationSet - Entity1?

For those who are using Database First approach all you have to do after inserting a new entity is to Generate Database From Model again by right click on your .edmx file and select Generate Database From Model...

For loop in multidimensional javascript array

var cubes = [["string", "string"], ["string", "string"]];

for(var i = 0; i < cubes.length; i++) {
    for(var j = 0; j < cubes[i].length; j++) {
        console.log(cubes[i][j]);
    }
}

Split string into list in jinja?

After coming back to my own question after 5 year and seeing so many people found this useful, a little update.

A string variable can be split into a list by using the split function (it can contain similar values, set is for the assignment) . I haven't found this function in the official documentation but it works similar to normal Python. The items can be called via an index, used in a loop or like Dave suggested if you know the values, it can set variables like a tuple.

{% set list1 = variable1.split(';') %}
The grass is {{ list1[0] }} and the boat is {{ list1[1] }}

or

{% set list1 = variable1.split(';') %}
{% for item in list1 %}
    <p>{{ item }}<p/>
{% endfor %} 

or

{% set item1, item2 = variable1.split(';') %}
The grass is {{ item1 }} and the boat is {{ item2 }}

how to get current datetime in SQL?

try this

SELECT CURTIME(); return 23:12:58

SELECT CURDATE(); return 2020-11-12

SELECT NOW(); return 2020-11-12 23:19:26

SELECT DAY(now()); return 12

SELECT DAYNAME(now()); return Thursday

Hope this would be helpful for you.

Use Font Awesome Icon in Placeholder

I know this question it is very old. But I didn't see any simple answer like I used to use.

You just need to add the fas class to the input and put a valid hex in this case &#xf002 for Font-Awesome's glyph as here <input type="text" class="fas" placeholder="&#xf002" />

You can find the unicode of each glyph in the official web here.

This is a simple example you don't need css or javascript.

_x000D_
_x000D_
input {_x000D_
  padding: 5px;_x000D_
}
_x000D_
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.6.3/css/all.css" integrity="sha384-UHRtZLI+pbxtHCWp1t77Bi1L4ZtiqrqD80Kn4Z8NTSRyMA2Fd33n5dQ8lWUE00s/" crossorigin="anonymous">_x000D_
<form role="form">_x000D_
  <div class="form-group">_x000D_
    <input type="text" class="fas" placeholder="&#xf002" />_x000D_
  </div>_x000D_
</form>
_x000D_
_x000D_
_x000D_

JAX-RS / Jersey how to customize error handling?

Just as an extension to @Steven Lavine answer in case you want to open the browser login window. I found it hard to properly return the Response (MDN HTTP Authentication) from the Filter in case that the user wasn't authenticated yet

This helped me to build the Response to force browser login, note the additional modification of the headers. This will set the status code to 401 and set the header that causes the browser to open the username/password dialog.

// The extended Exception class
public class NotLoggedInException extends WebApplicationException {
  public NotLoggedInException(String message) {
    super(Response.status(Response.Status.UNAUTHORIZED)
      .entity(message)
      .type(MediaType.TEXT_PLAIN)
      .header("WWW-Authenticate", "Basic realm=SecuredApp").build()); 
  }
}

// Usage in the Filter
if(headers.get("Authorization") == null) { throw new NotLoggedInException("Not logged in"); }

How to compare data between two table in different databases using Sql Server 2008?

In order to compare two databases, I've written the procedures bellow. If you want to compare two tables you can use procedure 'CompareTables'. Example :

EXEC master.dbo.CompareTables 'DB1', 'dbo', 'table1', 'DB2', 'dbo', 'table2'

If you want to compare two databases, use the procedure 'CompareDatabases'. Example :

EXEC master.dbo.CompareDatabases 'DB1', 'DB2'

Note : - I tried to make the procedures secure, but anyway, those procedures are only for testing and debugging. - If you want a complete solution for comparison use third party like (Visual Studio, ...)

USE [master]
GO

create proc [dbo].[CompareDatabases]
    @FirstDatabaseName nvarchar(50),
    @SecondDatabaseName nvarchar(50)
    as
begin
    -- Check that databases exist
    if not exists(SELECT name FROM sys.databases WHERE name=@FirstDatabaseName)
        return 0
    if not exists(SELECT name FROM sys.databases WHERE name=@SecondDatabaseName)
        return 0

    declare @result table (TABLE_NAME nvarchar(256))
    SET NOCOUNT ON
    insert into @result EXEC('(Select distinct TABLE_NAME from ' + @FirstDatabaseName  + '.INFORMATION_SCHEMA.COLUMNS '
                                    +'Where TABLE_SCHEMA=''dbo'')'
                            + 'intersect'
                            + '(Select distinct TABLE_NAME from ' + @SecondDatabaseName  + '.INFORMATION_SCHEMA.COLUMNS '
                                    +'Where TABLE_SCHEMA=''dbo'')')

    DECLARE @TABLE_NAME nvarchar(256)
    DECLARE curseur CURSOR FOR
        SELECT TABLE_NAME FROM @result
    OPEN curseur
    FETCH curseur INTO @TABLE_NAME
        WHILE @@FETCH_STATUS = 0
            BEGIN
                print 'TABLE : ' + @TABLE_NAME
                EXEC master.dbo.CompareTables @FirstDatabaseName, 'dbo', @TABLE_NAME, @SecondDatabaseName, 'dbo', @TABLE_NAME
                FETCH curseur INTO @TABLE_NAME
            END
        CLOSE curseur
    DEALLOCATE curseur
    SET NOCOUNT OFF
end
GO

.

USE [master]
GO

CREATE PROC [dbo].[CompareTables]
    @FirstTABLE_CATALOG nvarchar(256),
    @FirstTABLE_SCHEMA nvarchar(256),
    @FirstTABLE_NAME nvarchar(256),
    @SecondTABLE_CATALOG nvarchar(256),
    @SecondTABLE_SCHEMA nvarchar(256),
    @SecondTABLE_NAME nvarchar(256)
    AS
BEGIN
    -- Verify if first table exist
    DECLARE @table1 nvarchar(256) = @FirstTABLE_CATALOG + '.' + @FirstTABLE_SCHEMA + '.' + @FirstTABLE_NAME
    DECLARE @return_status int
    EXEC @return_status = master.dbo.TableExist @FirstTABLE_CATALOG, @FirstTABLE_SCHEMA, @FirstTABLE_NAME
    IF @return_status = 0
        BEGIN
            PRINT @table1 + ' : Table Not FOUND'
            RETURN 0
        END



    -- Verify if second table exist
    DECLARE @table2 nvarchar(256) = @SecondTABLE_CATALOG + '.' + @SecondTABLE_SCHEMA + '.' + @SecondTABLE_NAME
    EXEC @return_status = master.dbo.TableExist @SecondTABLE_CATALOG, @SecondTABLE_SCHEMA, @SecondTABLE_NAME
    IF @return_status = 0
        BEGIN
            PRINT @table2 + ' : Table Not FOUND'
            RETURN 0
        END

    -- Compare the two tables
    DECLARE @sql AS NVARCHAR(MAX)
    SELECT @sql = '('
                + '(SELECT ''' + @table1 + ''' as _Table, * FROM ' + @FirstTABLE_CATALOG + '.' + @FirstTABLE_SCHEMA + '.' + @FirstTABLE_NAME + ')'
                + 'EXCEPT'
                + '(SELECT ''' + @table1 + ''' as _Table, * FROM ' + @SecondTABLE_CATALOG + '.' + @SecondTABLE_SCHEMA + '.' + @SecondTABLE_NAME + ')'
                + ')'
                + 'UNION'
                + '('
                + '(SELECT ''' + @table2 + ''' as _Table, * FROM ' + @SecondTABLE_CATALOG + '.' + @SecondTABLE_SCHEMA + '.' + @SecondTABLE_NAME + ')'
                + 'EXCEPT'
                + '(SELECT ''' + @table2 + ''' as _Table, * FROM ' + @FirstTABLE_CATALOG + '.' + @FirstTABLE_SCHEMA + '.' + @FirstTABLE_NAME + ')'
                + ')'
    DECLARE @wrapper AS NVARCHAR(MAX) = 'if exists (' + @sql + ')' + char(10) + '    (' + @sql + ')ORDER BY 2'
    Exec(@wrapper)
END
GO

.

USE [master]
GO

CREATE PROC [dbo].[TableExist]
    @TABLE_CATALOG nvarchar(256),
    @TABLE_SCHEMA nvarchar(256),
    @TABLE_NAME nvarchar(256)
    AS
BEGIN
    IF NOT EXISTS(SELECT name FROM sys.databases WHERE name=@TABLE_CATALOG)
        RETURN 0

    declare @result table (TABLE_SCHEMA nvarchar(256), TABLE_NAME nvarchar(256))
    SET NOCOUNT ON
    insert into @result EXEC('Select TABLE_SCHEMA, TABLE_NAME from ' + @TABLE_CATALOG  + '.INFORMATION_SCHEMA.COLUMNS')
    SET NOCOUNT OFF

    IF EXISTS(SELECT TABLE_SCHEMA, TABLE_NAME FROM @result
                WHERE TABLE_SCHEMA=@TABLE_SCHEMA AND TABLE_NAME=@TABLE_NAME)
        RETURN 1

    RETURN 0
END

GO

Converting between datetime, Timestamp and datetime64

If you want to convert an entire pandas series of datetimes to regular python datetimes, you can also use .to_pydatetime().

pd.date_range('20110101','20110102',freq='H').to_pydatetime()

> [datetime.datetime(2011, 1, 1, 0, 0) datetime.datetime(2011, 1, 1, 1, 0)
   datetime.datetime(2011, 1, 1, 2, 0) datetime.datetime(2011, 1, 1, 3, 0)
   ....

It also supports timezones:

pd.date_range('20110101','20110102',freq='H').tz_localize('UTC').tz_convert('Australia/Sydney').to_pydatetime()

[ datetime.datetime(2011, 1, 1, 11, 0, tzinfo=<DstTzInfo 'Australia/Sydney' EST+11:00:00 DST>)
 datetime.datetime(2011, 1, 1, 12, 0, tzinfo=<DstTzInfo 'Australia/Sydney' EST+11:00:00 DST>)
....

NOTE: If you are operating on a Pandas Series you cannot call to_pydatetime() on the entire series. You will need to call .to_pydatetime() on each individual datetime64 using a list comprehension or something similar:

datetimes = [val.to_pydatetime() for val in df.problem_datetime_column]

How can I see an the output of my C programs using Dev-C++?

Use #include conio.h

Then add getch(); before return 0;

How do I set path while saving a cookie value in JavaScript?

See https://developer.mozilla.org/en/DOM/document.cookie for more documentation:

 setItem: function (sKey, sValue, vEnd, sPath, sDomain, bSecure) {  
     if (!sKey || /^(?:expires|max\-age|path|domain|secure)$/.test(sKey)) { return; }  
     var sExpires = "";  
     if (vEnd) {  
       switch (typeof vEnd) {  
         case "number": sExpires = "; max-age=" + vEnd; break;  
         case "string": sExpires = "; expires=" + vEnd; break;  
         case "object": if (vEnd.hasOwnProperty("toGMTString")) { sExpires = "; expires=" + vEnd.toGMTString(); } break;  
       }  
     }  
     document.cookie = escape(sKey) + "=" + escape(sValue) + sExpires + (sDomain ? "; domain=" + sDomain : "") + (sPath ? "; path=" + sPath : "") + (bSecure ? "; secure" : "");  
   }

Add context path to Spring Boot application

server.contextPath=/mainstay

works for me if i had one war file in JBOSS. Among multiple war files where each contain jboss-web.xml it didn't work. I had to put jboss-web.xml inside WEB-INF directory with content

<?xml version="1.0" encoding="UTF-8"?>
<jboss-web xmlns="http://www.jboss.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://www.jboss.com/xml/ns/javaee http://www.jboss.org/j2ee/schema/jboss-web_5_1.xsd">
    <context-root>mainstay</context-root>
</jboss-web>

How to fix "Headers already sent" error in PHP

No output before sending headers!

Functions that send/modify HTTP headers must be invoked before any output is made. summary ? Otherwise the call fails:

Warning: Cannot modify header information - headers already sent (output started at script:line)

Some functions modifying the HTTP header are:

Output can be:

  • Unintentional:

    • Whitespace before <?php or after ?>
    • The UTF-8 Byte Order Mark specifically
    • Previous error messages or notices
  • Intentional:

    • print, echo and other functions producing output
    • Raw <html> sections prior <?php code.

Why does it happen?

To understand why headers must be sent before output it's necessary to look at a typical HTTP response. PHP scripts mainly generate HTML content, but also pass a set of HTTP/CGI headers to the webserver:

HTTP/1.1 200 OK
Powered-By: PHP/5.3.7
Vary: Accept-Encoding
Content-Type: text/html; charset=utf-8

<html><head><title>PHP page output page</title></head>
<body><h1>Content</h1> <p>Some more output follows...</p>
and <a href="/"> <img src=internal-icon-delayed> </a>

The page/output always follows the headers. PHP has to pass the headers to the webserver first. It can only do that once. After the double linebreak it can nevermore amend them.

When PHP receives the first output (print, echo, <html>) it will flush all collected headers. Afterwards it can send all the output it wants. But sending further HTTP headers is impossible then.

How can you find out where the premature output occured?

The header() warning contains all relevant information to locate the problem cause:

Warning: Cannot modify header information - headers already sent by (output started at /www/usr2345/htdocs/auth.php:52) in /www/usr2345/htdocs/index.php on line 100

Here "line 100" refers to the script where the header() invocation failed.

The "output started at" note within the parenthesis is more significant. It denominates the source of previous output. In this example it's auth.php and line 52. That's where you had to look for premature output.

Typical causes:

  1. Print, echo

    Intentional output from print and echo statements will terminate the opportunity to send HTTP headers. The application flow must be restructured to avoid that. Use functions and templating schemes. Ensure header() calls occur before messages are written out.

    Functions that produce output include

    • print, echo, printf, vprintf
    • trigger_error, ob_flush, ob_end_flush, var_dump, print_r
    • readfile, passthru, flush, imagepng, imagejpeg


    among others and user-defined functions.

  2. Raw HTML areas

    Unparsed HTML sections in a .php file are direct output as well. Script conditions that will trigger a header() call must be noted before any raw <html> blocks.

    <!DOCTYPE html>
    <?php
        // Too late for headers already.
    

    Use a templating scheme to separate processing from output logic.

    • Place form processing code atop scripts.
    • Use temporary string variables to defer messages.
    • The actual output logic and intermixed HTML output should follow last.

  3. Whitespace before <?php for "script.php line 1" warnings

    If the warning refers to output in line 1, then it's mostly leading whitespace, text or HTML before the opening <?php token.

     <?php
    # There's a SINGLE space/newline before <? - Which already seals it.
    

    Similarly it can occur for appended scripts or script sections:

    ?>
    
    <?php
    

    PHP actually eats up a single linebreak after close tags. But it won't compensate multiple newlines or tabs or spaces shifted into such gaps.

  4. UTF-8 BOM

    Linebreaks and spaces alone can be a problem. But there are also "invisible" character sequences which can cause this. Most famously the UTF-8 BOM (Byte-Order-Mark) which isn't displayed by most text editors. It's the byte sequence EF BB BF, which is optional and redundant for UTF-8 encoded documents. PHP however has to treat it as raw output. It may show up as the characters  in the output (if the client interprets the document as Latin-1) or similar "garbage".

    In particular graphical editors and Java based IDEs are oblivious to its presence. They don't visualize it (obliged by the Unicode standard). Most programmer and console editors however do:

    joes editor showing UTF-8 BOM placeholder, and MC editor a dot

    There it's easy to recognize the problem early on. Other editors may identify its presence in a file/settings menu (Notepad++ on Windows can identify and remedy the problem), Another option to inspect the BOMs presence is resorting to an hexeditor. On *nix systems hexdump is usually available, if not a graphical variant which simplifies auditing these and other issues:

    beav hexeditor showing utf-8 bom

    An easy fix is to set the text editor to save files as "UTF-8 (no BOM)" or similar such nomenclature. Often newcomers otherwise resort to creating new files and just copy&pasting the previous code back in.

    Correction utilities

    There are also automated tools to examine and rewrite text files (sed/awk or recode). For PHP specifically there's the phptags tag tidier. It rewrites close and open tags into long and short forms, but also easily fixes leading and trailing whitespace, Unicode and UTF-x BOM issues:

    phptags  --whitespace  *.php
    

    It's sane to use on a whole include or project directory.

  5. Whitespace after ?>

    If the error source is mentioned as behind the closing ?> then this is where some whitespace or raw text got written out. The PHP end marker does not terminate script executation at this point. Any text/space characters after it will be written out as page content still.

    It's commonly advised, in particular to newcomers, that trailing ?> PHP close tags should be omitted. This eschews a small portion of these cases. (Quite commonly include()d scripts are the culprit.)

  6. Error source mentioned as "Unknown on line 0"

    It's typically a PHP extension or php.ini setting if no error source is concretized.

    • It's occasionally the gzip stream encoding setting or the ob_gzhandler.
    • But it could also be any doubly loaded extension= module generating an implicit PHP startup/warning message.

  7. Preceding error messages

    If another PHP statement or expression causes a warning message or notice being printeded out, that also counts as premature output.

    In this case you need to eschew the error, delay the statement execution, or suppress the message with e.g. isset() or @() - when either doesn't obstruct debugging later on.

No error message

If you have error_reporting or display_errors disabled per php.ini, then no warning will show up. But ignoring errors won't make the problem go away. Headers still can't be sent after premature output.

So when header("Location: ...") redirects silently fail it's very advisable to probe for warnings. Reenable them with two simple commands atop the invocation script:

error_reporting(E_ALL);
ini_set("display_errors", 1);

Or set_error_handler("var_dump"); if all else fails.

Speaking of redirect headers, you should often use an idiom like this for final code paths:

exit(header("Location: /finished.html"));

Preferrably even a utility function, which prints a user message in case of header() failures.

Output buffering as workaround

PHPs output buffering is a workaround to alleviate this issue. It often works reliably, but shouldn't substitute for proper application structuring and separating output from control logic. Its actual purpose is minimizing chunked transfers to the webserver.

  1. The output_buffering= setting nevertheless can help. Configure it in the php.ini or via .htaccess or even .user.ini on modern FPM/FastCGI setups.
    Enabling it will allow PHP to buffer output instead of passing it to the webserver instantly. PHP thus can aggregate HTTP headers.

  2. It can likewise be engaged with a call to ob_start(); atop the invocation script. Which however is less reliable for multiple reasons:

    • Even if <?php ob_start(); ?> starts the first script, whitespace or a BOM might get shuffled before, rendering it ineffective.

    • It can conceal whitespace for HTML output. But as soon as the application logic attempts to send binary content (a generated image for example), the buffered extraneous output becomes a problem. (Necessitating ob_clean() as furher workaround.)

    • The buffer is limited in size, and can easily overrun when left to defaults. And that's not a rare occurence either, difficult to track down when it happens.

Both approaches therefore may become unreliable - in particular when switching between development setups and/or production servers. Which is why output buffering is widely considered just a crutch / strictly a workaround.

See also the basic usage example in the manual, and for more pros and cons:

But it worked on the other server!?

If you didn't get the headers warning before, then the output buffering php.ini setting has changed. It's likely unconfigured on the current/new server.

Checking with headers_sent()

You can always use headers_sent() to probe if it's still possible to... send headers. Which is useful to conditionally print an info or apply other fallback logic.

if (headers_sent()) {
    die("Redirect failed. Please click on this link: <a href=...>");
}
else{
    exit(header("Location: /user.php"));
}

Useful fallback workarounds are:

  • HTML <meta> tag

    If your application is structurally hard to fix, then an easy (but somewhat unprofessional) way to allow redirects is injecting a HTML <meta> tag. A redirect can be achieved with:

     <meta http-equiv="Location" content="http://example.com/">
    

    Or with a short delay:

     <meta http-equiv="Refresh" content="2; url=../target.html">
    

    This leads to non-valid HTML when utilized past the <head> section. Most browsers still accept it.

  • JavaScript redirect

    As alternative a JavaScript redirect can be used for page redirects:

     <script> location.replace("target.html"); </script>
    

    While this is often more HTML compliant than the <meta> workaround, it incurs a reliance on JavaScript-capable clients.

Both approaches however make acceptable fallbacks when genuine HTTP header() calls fail. Ideally you'd always combine this with a user-friendly message and clickable link as last resort. (Which for instance is what the http_redirect() PECL extension does.)

Why setcookie() and session_start() are also affected

Both setcookie() and session_start() need to send a Set-Cookie: HTTP header. The same conditions therefore apply, and similar error messages will be generated for premature output situations.

(Of course they're furthermore affected by disabled cookies in the browser, or even proxy issues. The session functionality obviously also depends on free disk space and other php.ini settings, etc.)

Further links

Python Pandas: How to read only first n rows of CSV files in?

If you only want to read the first 999,999 (non-header) rows:

read_csv(..., nrows=999999)

If you only want to read rows 1,000,000 ... 1,999,999

read_csv(..., skiprows=1000000, nrows=999999)

nrows : int, default None Number of rows of file to read. Useful for reading pieces of large files*

skiprows : list-like or integer Row numbers to skip (0-indexed) or number of rows to skip (int) at the start of the file

and for large files, you'll probably also want to use chunksize:

chunksize : int, default None Return TextFileReader object for iteration

pandas.io.parsers.read_csv documentation

How to edit the legend entry of a chart in Excel?

Left Click on chart. «PivotTable Field List» will appear on right. On the right down quarter of PivotTable Field List (S Values), you see the names of the legends. Left Click on the legend name. Left Click on the «Value field settings». At the top there is «Source Name». You can’t change it. Below there is «Custom Name». Change the Custom Name as you wish. Now the legend name on the chart has the new name you gave.

'uint32_t' does not name a type

I had tha same problem trying to compile a lib I download from the internet. In my case, there was already a #include <cstdint> in the code. I solved it adding a:

using std::uint32_t;

Python "\n" tag extra line

The print function in python adds itself \n

You could use

import sys
sys.stdout.write(a)

instead