Replace specific text with a redacted version using Python
You can do it using named-entity recognition (NER). It's fairly simple and there are out-of-the-shelf tools out there to do it, such as spaCy.
NER is an NLP task where a neural network (or other method) is trained to detect certain entities, such as names, places, dates and organizations.
Example:
Sponge Bob went to South beach, he payed a ticket of $200!
I know, Michael is a good person, he goes to McDonalds, but donates to charity at St. Louis street.
Returns:
![NER with spacy](https://i.stack.imgur.com/CCG3k.png)
Just be aware that this is not 100%!
Here are a little snippet for you to try out:
import spacy
phrases = ['Sponge Bob went to South beach, he payed a ticket of $200!', 'I know, Michael is a good person, he goes to McDonalds, but donates to charity at St. Louis street.']
nlp = spacy.load('en')
for phrase in phrases:
doc = nlp(phrase)
replaced = ""
for token in doc:
if token in doc.ents:
replaced+="XXXX "
else:
replaced+=token.text+" "
Read more here: https://spacy.io/usage/linguistic-features#named-entities
You could, instead of replacing with XXXX, replace based on the entity type, like:
if ent.label_ == "PERSON":
replaced += "<PERSON> "
Then:
import re, random
personames = ["Jack", "Mike", "Bob", "Dylan"]
phrase = re.replace("<PERSON>", random.choice(personames), phrase)
MultipartException: Current request is not a multipart request
in ARC (advanced rest client) - specify as below to make it work
Content-Type multipart/form-data
(this is header name and header value)
this allows you to add form data as key and values
you can specify you field name now as per your REST specification and select your file to upload from file selector.
Synchronous XMLHttpRequest warning and <script>
Browsers now warn for the use of synchronous XHR. MDN says this was implemented recently:
Starting with Gecko 30.0 (Firefox 30.0 / Thunderbird 30.0 / SeaMonkey 2.27)
https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/Synchronous_and_Asynchronous_Requests#Synchronous_request
Here's how the change got implemented in Firefox and Chromium:
As for Chrome people report this started happening somewhere around version 39. I'm not sure how to link a revision/changeset to a particular version of Chrome.
Yes, it happens when jQuery appends markup to the page including script tags that load external js files. You can reproduce it with something like this:
$('body').append('<script src="foo.js"></script>');
I guess jQuery will fix this in some future version. Until then we can either ignore it or use A. Wolff's suggestion above.
PDF Blob - Pop up window not showing content
I ended up just downloading my pdf using below code
function downloadPdfDocument(fileName){
var req = new XMLHttpRequest();
req.open("POST", "/pdf/" + fileName, true);
req.responseType = "blob";
fileName += "_" + new Date() + ".pdf";
req.onload = function (event) {
var blob = req.response;
//for IE
if (window.navigator && window.navigator.msSaveOrOpenBlob) {
window.navigator.msSaveOrOpenBlob(blob, fileName);
} else {
var link = document.createElement('a');
link.href = window.URL.createObjectURL(blob);
link.download = fileName;
link.click();
}
};
req.send();
}
VBA using ubound on a multidimensional array
In addition to the already excellent answers, also consider this function to retrieve both the number of dimensions and their bounds, which is similar to John's answer, but works and looks a little differently:
Function sizeOfArray(arr As Variant) As String
Dim str As String
Dim numDim As Integer
numDim = NumberOfArrayDimensions(arr)
str = "Array"
For i = 1 To numDim
str = str & "(" & LBound(arr, i) & " To " & UBound(arr, i)
If Not i = numDim Then
str = str & ", "
Else
str = str & ")"
End If
Next i
sizeOfArray = str
End Function
Private Function NumberOfArrayDimensions(arr As Variant) As Integer
' By Chip Pearson
' http://www.cpearson.com/excel/vbaarrays.htm
Dim Ndx As Integer
Dim Res As Integer
On Error Resume Next
' Loop, increasing the dimension index Ndx, until an error occurs.
' An error will occur when Ndx exceeds the number of dimension
' in the array. Return Ndx - 1.
Do
Ndx = Ndx + 1
Res = UBound(arr, Ndx)
Loop Until Err.Number <> 0
NumberOfArrayDimensions = Ndx - 1
End Function
Example usage:
Sub arrSizeTester()
Dim arr(1 To 2, 3 To 22, 2 To 9, 12 To 18) As Variant
Debug.Print sizeOfArray(arr())
End Sub
And its output:
Array(1 To 2, 3 To 22, 2 To 9, 12 To 18)
MySQL maximum memory usage
If you are looking for optimizing your docker mysql container then the below command may help. I was able to run mysql docker container from a default 480mb to mere 100 mbs
docker run -d -p 3306:3306 -e MYSQL_DATABASE=test -e MYSQL_ROOT_PASSWORD=tooor -e MYSQL_USER=test -e MYSQL_PASSWORD=test -v /mysql:/var/lib/mysql --name mysqldb mysql --table_definition_cache=100 --performance_schema=0 --default-authentication-plugin=mysql_native_password
Bootstrap 3 panel header with buttons wrong position
You should apply a "clearfix" to clear the parent element. Next thing, the h4 for the header title, extend all the way across the header, so after you apply clearfix, it will push down the child element causing the header div to have a larger height.
Here is a fix, just replace it with your code.
<div class="panel-heading clearfix">
<b>Panel header</b>
<div class="btn-group pull-right">
<a href="#" class="btn btn-default btn-sm">## Lock</a>
<a href="#" class="btn btn-default btn-sm">## Delete</a>
<a href="#" class="btn btn-default btn-sm">## Move</a>
</div>
</div>
Editted on 12/22/2015 - added .clearfix to heading div
Creating a new user and password with Ansible
Neither of the solutions worked directly on my Mac controlling Ubuntu. So for others' sake, combining Mxx and JoelB answers, here is the current Python 3 solution:
pip3 install passlib
python3 -c 'from passlib.hash import md5_crypt; \
print(md5_crypt.encrypt("This is my Password", salt="SomeSalt"))'
The result will be $1$SomeSalt$UqddPX3r4kH3UL5jq5/ZI.
, as in Mxx' answer.
Better still, use SHA512 instead of MD5:
python3 -c 'from passlib.hash import sha512_crypt; \
print(sha512_crypt.encrypt("This is my Password", salt="SomeSalt"))'
Result:
$6$rounds=656000$SomeSalt$oYpmnpZahIsvn5FK8g4bDFEAmGpEN114Fe6Ko4HvinzFaz5Rq2UXQxoJZ9ZQyQoi9zaBo3gBH/FEAov3FHv48
PostgreSQL Error: Relation already exists
There should be no single quotes here 'A'
. Single quotes are for string literals: 'some value'
.
Either use double quotes to preserve the upper case spelling of "A":
CREATE TABLE "A" ...
Or don't use quotes at all:
CREATE TABLE A ...
which is identical to
CREATE TABLE a ...
because all unquoted identifiers are folded to lower case automatically in PostgreSQL.
You could avoid problems with the index name completely by using simpler syntax:
CREATE TABLE csd_relationship (
csd_relationship_id serial PRIMARY KEY,
type_id integer NOT NULL,
object_id integer NOT NULL
);
Does the same as your original query, only it avoids naming conflicts automatically. It picks the next free identifier automatically. More about the serial type in the manual.
form_for with nested resources
Travis R is correct. (I wish I could upvote ya.) I just got this working myself. With these routes:
resources :articles do
resources :comments
end
You get paths like:
/articles/42
/articles/42/comments/99
routed to controllers at
app/controllers/articles_controller.rb
app/controllers/comments_controller.rb
just as it says at http://guides.rubyonrails.org/routing.html#nested-resources, with no special namespaces.
But partials and forms become tricky. Note the square brackets:
<%= form_for [@article, @comment] do |f| %>
Most important, if you want a URI, you may need something like this:
article_comment_path(@article, @comment)
Alternatively:
[@article, @comment]
as described at http://edgeguides.rubyonrails.org/routing.html#creating-paths-and-urls-from-objects
For example, inside a collections partial with comment_item
supplied for iteration,
<%= link_to "delete", article_comment_path(@article, comment_item),
:method => :delete, :confirm => "Really?" %>
What jamuraa says may work in the context of Article, but it did not work for me in various other ways.
There is a lot of discussion related to nested resources, e.g. http://weblog.jamisbuck.org/2007/2/5/nesting-resources
Interestingly, I just learned that most people's unit-tests are not actually testing all paths. When people follow jamisbuck's suggestion, they end up with two ways to get at nested resources. Their unit-tests will generally get/post to the simplest:
# POST /comments
post :create, :comment => {:article_id=>42, ...}
In order to test the route that they may prefer, they need to do it this way:
# POST /articles/42/comments
post :create, :article_id => 42, :comment => {...}
I learned this because my unit-tests started failing when I switched from this:
resources :comments
resources :articles do
resources :comments
end
to this:
resources :comments, :only => [:destroy, :show, :edit, :update]
resources :articles do
resources :comments, :only => [:create, :index, :new]
end
I guess it's ok to have duplicate routes, and to miss a few unit-tests. (Why test? Because even if the user never sees the duplicates, your forms may refer to them, either implicitly or via named routes.) Still, to minimize needless duplication, I recommend this:
resources :comments
resources :articles do
resources :comments, :only => [:create, :index, :new]
end
Sorry for the long answer. Not many people are aware of the subtleties, I think.
How to find a hash key containing a matching value
Another approach I would try is by using #map
clients.map{ |key, _| key if clients[key] == {"client_id"=>"2180"} }.compact
#=> ["orange"]
This will return all occurences of given value. The underscore means that we don't need key's value to be carried around so that way it's not being assigned to a variable. The array will contain nils if the values doesn't match - that's why I put #compact
at the end.
How to Delete node_modules - Deep Nested Folder in Windows
Please save yourself the need to read most of these answers and just use npx rather than trying to install rimraf globally. You can run a single command and always have the most recent version with none of the issues seen here.
npx rimraf ./**/node_modules
jQuery: get parent tr for selected radio button
Try this.
You don't need to prefix attribute name by @
in jQuery selector. Use closest()
method to get the closest parent element matching the selector.
$("#MwDataList input[name=selectRadioGroup]:checked").closest('tr');
You can simplify your method like this
function getSelectedRowGuid() {
return GetRowGuid(
$("#MwDataList > input:radio[@name=selectRadioGroup]:checked :parent tr"));
}
closest()
- Gets the first element that matches the selector, beginning at the current element and progressing up through the DOM tree.
As a side note, the ids of the elements should be unique on the page so try to avoid having same ids for radio buttons which I can see in your markup. If you are not going to use the ids then just remove it from the markup.
how do I join two lists using linq or lambda expressions
The way to do this using the Extention Methods, instead of the linq query syntax would be like this:
var results = workOrders.Join(plans,
wo => wo.WorkOrderNumber,
p => p.WorkOrderNumber,
(order,plan) => new {order.WorkOrderNumber, order.WorkDescription, plan.ScheduledDate}
);
Round integers to the nearest 10
About the round(..)
function returning a float
That float (double-precision in Python) is always a perfect representation of an integer, as long as it's in the range [-253..253]. (Pedants pay attention: it's not two's complement in doubles, so the range is symmetric about zero.)
See the discussion here for details.
How to reduce the image file size using PIL
The main image manager in PIL
is PIL
's Image
module.
from PIL import Image
import math
foo = Image.open("path\\to\\image.jpg")
x, y = foo.size
x2, y2 = math.floor(x-50), math.floor(y-20)
foo = foo.resize((x2,y2),Image.ANTIALIAS)
foo.save("path\\to\\save\\image_scaled.jpg",quality=95)
You can add optimize=True
to the arguments of you want to decrease the size even more, but optimize only works for JPEG's and PNG's.
For other image extensions, you could decrease the quality of the new saved image.
You could change the size of the new image by just deleting a bit of code and defining the image size and you can only figure out how to do this if you look at the code carefully.
I defined this size:
x, y = foo.size
x2, y2 = math.floor(x-50), math.floor(y-20)
just to show you what is (almost) normally done with horizontal images.
For vertical images you might do:
x, y = foo.size
x2, y2 = math.floor(x-20), math.floor(y-50)
. Remember, you can still delete that bit of code and define a new size.
How do you add input from user into list in Python
shopList = []
maxLengthList = 6
while len(shopList) < maxLengthList:
item = input("Enter your Item to the List: ")
shopList.append(item)
print shopList
print "That's your Shopping List"
print shopList
adb shell command to make Android package uninstall dialog appear
While the above answers work but in case you have multiple devices connected to your computer then the following command can be used to remove the app from one of them:
adb -s <device-serial> shell pm uninstall <app-package-name>
If you want to find out the device serial then use the following command:
adb devices -l
This will give you a list of devices attached. The left column shows the device serials.
How to add include path in Qt Creator?
If you are using qmake, the standard Qt build system, just add a line to the .pro
file as documented in the qmake Variable Reference:
INCLUDEPATH += <your path>
If you are using your own build system, you create a project by selecting "Import of Makefile-based project". This will create some files in your project directory including a file named <your project name>.includes
. In that file, simply list the paths you want to include, one per line. Really all this does is tell Qt Creator where to look for files to index for auto completion. Your own build system will have to handle the include paths in its own way.
As explained in the Qt Creator Manual, <your path>
must be an absolute path, but you can avoid OS-, host- or user-specific entries in your .pro
file by using $$PWD
which refers to the folder that contains your .pro
file, e.g.
INCLUDEPATH += $$PWD/code/include
Concatenating variables in Bash
Try doing this, there's no special character to concatenate in bash :
mystring="${arg1}12${arg2}endoffile"
explanations
If you don't put brackets, you will ask bash to concatenate $arg112 + $argendoffile
(I guess that's not what you asked) like in the following example :
mystring="$arg112$arg2endoffile"
The brackets are delimiters for the variables when needed. When not needed, you can use it or not.
another solution
(less portable : require
bash
> 3.1)
$ arg1=foo
$ arg2=bar
$ mystring="$arg1"
$ mystring+="12"
$ mystring+="$arg2"
$ mystring+="endoffile"
$ echo "$mystring"
foo12barendoffile
See http://mywiki.wooledge.org/BashFAQ/013
SQLAlchemy IN clause
Just an addition to the answers above.
If you want to execute a SQL with an "IN" statement you could do this:
ids_list = [1,2,3]
query = "SELECT id, name FROM user WHERE id IN %s"
args = [(ids_list,)] # Don't forget the "comma", to force the tuple
conn.execute(query, args)
Two points:
- There is no need for Parenthesis for the IN statement(like "... IN(%s) "), just put "...IN %s"
- Force the list of your ids to be one element of a tuple. Don't forget the " , " : (ids_list,)
EDIT
Watch out that if the length of list is one or zero this will raise an error!
Create a function with optional call variables
Powershell provides a lot of built-in support for common parameter scenarios, including mandatory parameters, optional parameters, "switch" (aka flag) parameters, and "parameter sets."
By default, all parameters are optional. The most basic approach is to simply check each one for $null
, then implement whatever logic you want from there. This is basically what you have already shown in your sample code.
If you want to learn about all of the special support that Powershell can give you, check out these links:
about_Functions
about_Functions_Advanced
about_Functions_Advanced_Parameters
Iterating through populated rows
For the benefit of anyone searching for similar, see worksheet .UsedRange
,
e.g. ? ActiveSheet.UsedRange.Rows.Count
and loops such as
For Each loopRow in Sheets(1).UsedRange.Rows: Print loopRow.Row: Next
Getting the class name from a static method in Java
I have used these two approach for both static
and non static
scenario:
Main class:
//For non static approach
public AndroidLogger(Object classObject) {
mClassName = classObject.getClass().getSimpleName();
}
//For static approach
public AndroidLogger(String className) {
mClassName = className;
}
How to provide class name:
non static way:
private AndroidLogger mLogger = new AndroidLogger(this);
Static way:
private static AndroidLogger mLogger = new AndroidLogger(Myclass.class.getSimpleName());
How do I use a third-party DLL file in Visual Studio C++?
You only need to use LoadLibrary if you want to late bind and only resolve the imported functions at runtime. The easiest way to use a third party dll is to link against a .lib.
In reply to your edit:
Yes, the third party API should consist of a dll and/or a lib that contain the implementation and header files that declares the required types. You need to know the type definitions whichever method you use - for LoadLibrary you'll need to define function pointers, so you could just as easily write your own header file instead. Basically, you only need to use LoadLibrary if you want late binding. One valid reason for this would be if you aren't sure if the dll will be available on the target PC.
Testing if a list of integer is odd or even
#region even and odd numbers
for (int x = 0; x <= 50; x = x + 2)
{
int y = 1;
y = y + x;
if (y < 50)
{
Console.WriteLine("Odd number is #{" + x + "} : even number is #{" + y + "} order by Asc");
Console.ReadKey();
}
else
{
Console.WriteLine("Odd number is #{" + x + "} : even number is #{0} order by Asc");
Console.ReadKey();
}
}
//order by desc
for (int z = 50; z >= 0; z = z - 2)
{
int w = z;
w = w - 1;
if (w > 0)
{
Console.WriteLine("odd number is {" + z + "} : even number is {" + w + "} order by desc");
Console.ReadKey();
}
else
{
Console.WriteLine("odd number is {" + z + "} : even number is {0} order by desc");
Console.ReadKey();
}
}
jQuery scroll to ID from different page
I've written something that detects if the page contains the anchor that was clicked on, and if not, goes to the normal page, otherwise it scrolls to the specific section:
$('a[href*=\\#]').on('click',function(e) {
var target = this.hash;
var $target = $(target);
console.log(targetname);
var targetname = target.slice(1, target.length);
if(document.getElementById(targetname) != null) {
e.preventDefault();
}
$('html, body').stop().animate({
'scrollTop': $target.offset().top-120 //or the height of your fixed navigation
}, 900, 'swing', function () {
window.location.hash = target;
});
});
How do I "shake" an Android device within the Android emulator to bring up the dev menu to debug my React Native app
If you're using the new emulator that comes with Android Studio 2.0, the keyboard shortcut for the menu key is now Cmd+M, just like in Genymotion.
Alternatively, you can always send a menu button press using adb
in a terminal:
adb shell input keyevent KEYCODE_MENU
Also note that the menu button shortcut isn't a strict requirement, it's just the default behavior provided by the ReactActivity
Java class (which is used by default if you created your project with react-native init
). Here's the relevant code from onKeyUp
in ReactActivity.java
:
if (keyCode == KeyEvent.KEYCODE_MENU) {
mReactInstanceManager.showDevOptionsDialog();
return true;
}
If you're adding React Native to an existing app (documentation here) and you aren't using ReactActivity
, you'll need to hook the menu button up in a similar way. You can also call ReactInstanceManager.showDevOptionsDialog
through any other mechanism. For example, in an app I'm working on, I added a dev-only Action Bar menu item that brings up the menu, since I find that more convenient than shaking the device when working on a physical device.
Adding a slide effect to bootstrap dropdown
Here is a nice simple solution using jQuery
that works nicely:
$('.dropdown-toggle').click(function () {
$(this).next('.dropdown-menu').slideToggle(300);
});
$('.dropdown-toggle').focusout(function () {
$(this).next('.dropdown-menu').slideUp(300);
})
The slide animation toggle occurs on clicking and it always slides back up on losing focus.
Alter the 300
value to anything you want, the lower the number the faster the animation.
Edit:
This solution will only work for desktop views. It will need some further modification in order to display nicely for mobile.
Property 'map' does not exist on type 'Observable<Response>'
for all those linux users that are having this problem, check if the rxjs-compat folder is locked. I had this exact same issue and I went in terminal, used the sudo su to give permission to the whole rxjs-compat folder and it was fixed. Thats assuming you imported
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';
in the project.ts file where the original .map error occurred.
make iframe height dynamic based on content inside- JQUERY/Javascript
Sample using PHP htmlspecialchars() + check if height exists and is > 0:
$my_html_markup = ''; // Insert here HTML markup with CSS, JS... '<html><head></head><body>...</body></html>'
$iframe = '<iframe onload="if(this.contentWindow.document.body.scrollHeight) {this.height = this.contentWindow.document.body.scrollHeight;}" width="100%" src="javascript: \''. htmlspecialchars($my_html_markup) . '\'"></iframe>';
Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.6 or one of its dependencies could not be resolved
Step1: Delete all instances of java from you machine
Step2: Delete all the environment variables related to java/jdk/jre
Step3: Check in programm files and program files(X86) folder, there should not be java folder.
Step4: Install java again.
Step5: Go to cmd and type "java -version"
Result: it will display the java version which is installed in your machine.
Step6: now delete all the files which are in C:/User/AdminOrUserNameofYourMachine/.m2 folder
Step6: go to cmd and run "mvn -v"
Result: It will display the Apache maven version installed on your machine
Step7: Now Rebuild your project.
This worked for me.
Type datetime for input parameter in procedure
In this part of your SP:
IF @DateFirst <> '' and @DateLast <> ''
set @FinalSQL = @FinalSQL
+ ' or convert (Date,DateLog) >= ''' + @DateFirst
+ ' and convert (Date,DateLog) <=''' + @DateLast
you are trying to concatenate strings and datetimes.
As the datetime
type has higher priority than varchar
/nvarchar
, the +
operator, when it happens between a string and a datetime, is interpreted as addition, not as concatenation, and the engine then tries to convert your string parts (' or convert (Date,DateLog) >= '''
and others) to datetime or numeric values. And fails.
That doesn't happen if you omit the last two parameters when invoking the procedure, because the condition evaluates to false and the offending statement isn't executed.
To amend the situation, you need to add explicit casting of your datetime variables to strings:
set @FinalSQL = @FinalSQL
+ ' or convert (Date,DateLog) >= ''' + convert(date, @DateFirst)
+ ' and convert (Date,DateLog) <=''' + convert(date, @DateLast)
You'll also need to add closing single quotes:
set @FinalSQL = @FinalSQL
+ ' or convert (Date,DateLog) >= ''' + convert(date, @DateFirst) + ''''
+ ' and convert (Date,DateLog) <=''' + convert(date, @DateLast) + ''''
printf with std::string?
The main reason is probably that a C++ string is a struct that includes a current-length value, not just the address of a sequence of chars terminated by a 0 byte. Printf and its relatives expect to find such a sequence, not a struct, and therefore get confused by C++ strings.
Speaking for myself, I believe that printf has a place that can't easily be filled by C++ syntactic features, just as table structures in html have a place that can't easily be filled by divs. As Dykstra wrote later about the goto, he didn't intend to start a religion and was really only arguing against using it as a kludge to make up for poorly-designed code.
It would be quite nice if the GNU project would add the printf family to their g++ extensions.
DLL Load Library - Error Code 126
Windows dll error 126 can have many root causes.
The most useful methods I have found to debug this are:
- Use dependency walker to look for any obvious problems (which you
have already done)
- Use the sysinternals utility Process Monitor http://technet.microsoft.com/en-us/sysinternals/bb896645 from Microsoft to trace all file access while your dll is trying to load. With this utility, you will see everything that that dll is trying to pull in and usually the problem can be determined from there.
How to run a shell script at startup
- Add your script to /etc/init.d/ directory
- Update your rc run-levels:
$ update-rc.d myScript.sh defaults NN
where NN is the order in which it should be executed. 99 for example will mean it would be run after 98 and before 100.
Cannot read property 'addEventListener' of null
I encountered the same problem and checked for null but it did not help. Because the script was loading before page load. So just by placing the script before the end body tag solved the problem.
Map HTML to JSON
I had a similar issue where I wanted to represent HTML as JSON in the following way:
- For HTML text nodes, use a
string
- For HTML elements, use an array with:
- The (tag) name of the element
- An object, mapping attribute keys to attribute values
- The (inlined) list of children nodes
Example:
<div>
<span>text</span>Text2
</div>
becomes
[
'div',
{},
['span', {}, 'text'],
'Text2'
]
I wrote a function which handles transforming a DOM Element into this kind of JS structure. You can find this function at the end of this answer. The function is written in Typescript. You can use the Typescript playground to convert it to clean JavaScript.
Furthermore, if you need to parse an html string into DOM, assign to .innerHtml
:
let element = document.createElement('div')
element.innerHtml = htmlString
Also, this one is common knowledge but if you need a JSON string output, use JSON.stringify
.
/**
* A NodeDescriptor stands for either an (HTML) Element, or for a text node
*/
export type NodeDescriptor = ElementDescriptor | string
/**
* Array representing an HTML Element. It consists of:
*
* - The (tag) name of the element
* - An object, mapping attribute keys to attribute values
* - The (inlined) list of children nodes
*/
export type ElementDescriptor = [
string,
Record<string, string>,
...NodeDescriptor[]
]
export let htmlToJs = (element: Element, trim = true): ElementDescriptor => {
let convertElement = (element: Element): ElementDescriptor => {
let attributeObject: Record<string, string> = {}
for (let { name, value } of element.attributes) {
attributeObject[name] = value
}
let childArray: NodeDescriptor[] = []
for (let node of element.childNodes) {
let converter = htmlToJsDispatch[node.nodeType]
if (converter) {
let descriptor = converter(node as any)
let skip = false
if (trim && typeof descriptor === 'string') {
descriptor = descriptor.trim()
if (descriptor === '') skip = true
}
if (!skip) childArray.push(descriptor)
}
}
return [element.tagName.toLowerCase(), attributeObject, ...childArray]
}
let htmlToJsDispatch = {
[element.ELEMENT_NODE]: convertElement,
[element.TEXT_NODE]: (node: Text): string => node.data,
}
return convertElement(element)
}
c# dictionary one key many values
Dictionary<int, string[]> dictionaty = new Dictionary<int, string[]>() {
{1, new string[]{"a","b","c"} },
{2, new string[]{"222","str"} }
};
php string to int
If you want to leave only numbers - use preg_replace like: (int)preg_replace("/[^\d]+/","",$b).
Should you commit .gitignore into the Git repos?
Normally yes, .gitignore
is useful for everyone who wants to work with the repository. On occasion you'll want to ignore more private things (maybe you often create LOG
or something. In those cases you probably don't want to force that on anyone else.
How to set null to a GUID property
extrac Guid values from database functions:
#region GUID
public static Guid GGuid(SqlDataReader reader, string field)
{
try
{
return reader[field] == DBNull.Value ? Guid.Empty : (Guid)reader[field];
}
catch { return Guid.Empty; }
}
public static Guid GGuid(SqlDataReader reader, int ordinal = 0)
{
try
{
return reader[ordinal] == DBNull.Value ? Guid.Empty : (Guid)reader[ordinal];
}
catch { return Guid.Empty; }
}
public static Guid? NGuid(SqlDataReader reader, string field)
{
try
{
if (reader[field] == DBNull.Value) return (Guid?)null; else return (Guid)reader[field];
}
catch { return (Guid?)null; }
}
public static Guid? NGuid(SqlDataReader reader, int ordinal = 0)
{
try
{
if (reader[ordinal] == DBNull.Value) return (Guid?)null; else return (Guid)reader[ordinal];
}
catch { return (Guid?)null; }
}
#endregion
Better way to find control in ASP.NET
I decided to just build controls dictionaries. Harder to maintain, might run faster than the recursive FindControl().
protected void Page_Load(object sender, EventArgs e)
{
this.BuildControlDics();
}
private void BuildControlDics()
{
_Divs = new Dictionary<MyEnum, HtmlContainerControl>();
_Divs.Add(MyEnum.One, this.divOne);
_Divs.Add(MyEnum.Two, this.divTwo);
_Divs.Add(MyEnum.Three, this.divThree);
}
And before I get down-thumbs for not answering the OP's question...
Q: Now, my question is that is there any other way/solution to find the nested control in ASP.NET?
A: Yes, avoid the need to search for them in the first place. Why search for things you already know are there? Better to build a system allowing reference of known objects.
insert/delete/update trigger in SQL server
Not possible, per MSDN:
You can have the same code execute for multiple trigger types, but the syntax does not allow for multiple code blocks in one trigger:
Trigger on an INSERT, UPDATE, or DELETE statement to a table or view (DML Trigger)
CREATE TRIGGER [ schema_name . ]trigger_name
ON { table | view }
[ WITH <dml_trigger_option> [ ,...n ] ]
{ FOR | AFTER | INSTEAD OF }
{ [ INSERT ] [ , ] [ UPDATE ] [ , ] [ DELETE ] }
[ NOT FOR REPLICATION ]
AS { sql_statement [ ; ] [ ,...n ] | EXTERNAL NAME <method specifier [ ; ] > }
How to customize listview using baseadapter
public class ListElementAdapter extends BaseAdapter{
String[] data;
Context context;
LayoutInflater layoutInflater;
public ListElementAdapter(String[] data, Context context) {
super();
this.data = data;
this.context = context;
layoutInflater = LayoutInflater.from(context);
}
@Override
public int getCount() {
return data.length;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
convertView= layoutInflater.inflate(R.layout.item, null);
TextView txt=(TextView)convertView.findViewById(R.id.text);
txt.setText(data[position]);
return convertView;
}
}
Just call ListElementAdapter in your Main Activity and set Adapter to ListView.
How do I add a ToolTip to a control?
- Add a ToolTip component to your form
- Select one of the controls that you want a tool tip for
- Open the property grid (F4), in the list you will find a property called "ToolTip on toolTip1" (or something similar). Set the desired tooltip text on that property.
- Repeat 2-3 for the other controls
- Done.
The trick here is that the ToolTip control is an extender control, which means that it will extend the set of properties for other controls on the form. Behind the scenes this is achieved by generating code like in Svetlozar's answer. There are other controls working in the same manner (such as the HelpProvider
).
How to get all files under a specific directory in MATLAB?
This answer does not directly answer the question but may be a good solution outside of the box.
I upvoted gnovice's solution, but want to offer another solution: Use the system dependent command of your operating system:
tic
asdfList = getAllFiles('../TIMIT_FULL/train');
toc
% Elapsed time is 19.066170 seconds.
tic
[status,cmdout] = system('find ../TIMIT_FULL/train/ -iname "*.wav"');
C = strsplit(strtrim(cmdout));
toc
% Elapsed time is 0.603163 seconds.
Positive:
- Very fast (in my case for a database of 18000 files on linux).
- You can use well tested solutions.
- You do not need to learn or reinvent a new syntax to select i.e.
*.wav
files.
Negative:
- You are not system independent.
- You rely on a single string which may be hard to parse.
cancelling a handler.postdelayed process
In case you do have multiple inner/anonymous runnables passed to same handler, and you want to cancel all at same event use
handler.removeCallbacksAndMessages(null);
As per documentation,
Remove any pending posts of callbacks and sent messages whose obj is
token. If token is null, all callbacks and messages will be removed.
MySQL: What's the difference between float and double?
They both represent floating point numbers. A FLOAT
is for single-precision, while a DOUBLE
is for double-precision numbers.
MySQL uses four bytes for single-precision values and eight bytes for double-precision values.
There is a big difference from floating point numbers and decimal (numeric) numbers, which you can use with the DECIMAL
data type. This is used to store exact numeric data values, unlike floating point numbers, where it is important to preserve exact precision, for example with monetary data.
Ctrl+click doesn't work in Eclipse Juno
I can confirm that Ctrl + click works fine with the following :
Eclipse Java EE IDE for Web Developers.
Version: Juno Release
Build id: 20120606-2254
Operating System : Windows 7, 64 Bit
What do you have for the following preference ?
On Window -> Preferences -> General -> Editors -> Text Editors -> Hyperlinking -> Open Declaration
Here is what I had for a new workspace in Juno :
![enter image description here](https://i.stack.imgur.com/wABdJ.png)
Update
I have not experienced this in the recent past, but I vaguely remember encountering this problem in previous Eclipse releases (Galileo and earlier).
All of what follows is worth doing only if we are sure that it's a problem with the Eclipse workspace. A quick way of checking this is to restart eclipse with a new workspace (Do this by going to File -> Switch Workspace -> Other... and choosing the path to a folder which is preferably empty and different than the current workspace folder).
If things worked in the new workspace, my fix then was one of the following, in increasing order extremeness :
- Re-start eclipse (Yup, sometimes that is all it took)
- Re-start eclipse with the
-clean
parameter to clean out the workspace ( See this). This might specially be worth doing if you used a workspace from an older version of eclipse.
- When the above failed, and I just had to use my existing workspace, I backed up my workspace folder and restarted Eclipse after deleting
WORKSPACE_FOLDER/.metadata/.plugins/org.eclipse.jdt.core
How to convert An NSInteger to an int?
Commonly used in UIsegmentedControl, "error" appear when compiling in 64bits instead of 32bits, easy way for not pass it to a new variable is to use this tips, add (int):
[_monChiffre setUnite:(int)[_valUnites selectedSegmentIndex]];
instead of :
[_monChiffre setUnite:[_valUnites selectedSegmentIndex]];
How to use SVG markers in Google Maps API v3
OK! I done this soon in my web,I try two ways to create the custom google map marker, this run code use canvg.js is the best compatibility for browser.the Commented-Out Code is not support IE11 urrently.
_x000D_
_x000D_
var marker;_x000D_
var CustomShapeCoords = [16, 1.14, 21, 2.1, 25, 4.2, 28, 7.4, 30, 11.3, 30.6, 15.74, 25.85, 26.49, 21.02, 31.89, 15.92, 43.86, 10.92, 31.89, 5.9, 26.26, 1.4, 15.74, 2.1, 11.3, 4, 7.4, 7.1, 4.2, 11, 2.1, 16, 1.14];_x000D_
_x000D_
function initMap() {_x000D_
var map = new google.maps.Map(document.getElementById('map'), {_x000D_
zoom: 13,_x000D_
center: {_x000D_
lat: 59.325,_x000D_
lng: 18.070_x000D_
}_x000D_
});_x000D_
var markerOption = {_x000D_
latitude: 59.327,_x000D_
longitude: 18.067,_x000D_
color: "#" + "000",_x000D_
text: "ha"_x000D_
};_x000D_
marker = createMarker(markerOption);_x000D_
marker.setMap(map);_x000D_
marker.addListener('click', changeColorAndText);_x000D_
};_x000D_
_x000D_
function changeColorAndText() {_x000D_
var iconTmpObj = createSvgIcon( "#c00", "ok" );_x000D_
marker.setOptions( {_x000D_
icon: iconTmpObj_x000D_
} );_x000D_
};_x000D_
_x000D_
function createMarker(options) {_x000D_
//IE MarkerShape has problem_x000D_
var markerObj = new google.maps.Marker({_x000D_
icon: createSvgIcon(options.color, options.text),_x000D_
position: {_x000D_
lat: parseFloat(options.latitude),_x000D_
lng: parseFloat(options.longitude)_x000D_
},_x000D_
draggable: false,_x000D_
visible: true,_x000D_
zIndex: 10,_x000D_
shape: {_x000D_
coords: CustomShapeCoords,_x000D_
type: 'poly'_x000D_
}_x000D_
});_x000D_
_x000D_
return markerObj;_x000D_
};_x000D_
_x000D_
function createSvgIcon(color, text) {_x000D_
var div = $("<div></div>");_x000D_
_x000D_
var svg = $(_x000D_
'<svg width="32px" height="43px" viewBox="0 0 32 43" xmlns="http://www.w3.org/2000/svg">' +_x000D_
'<path style="fill:#FFFFFF;stroke:#020202;stroke-width:1;stroke-miterlimit:10;" d="M30.6,15.737c0-8.075-6.55-14.6-14.6-14.6c-8.075,0-14.601,6.55-14.601,14.6c0,4.149,1.726,7.875,4.5,10.524c1.8,1.801,4.175,4.301,5.025,5.625c1.75,2.726,5,11.976,5,11.976s3.325-9.25,5.1-11.976c0.825-1.274,3.05-3.6,4.825-5.399C28.774,23.813,30.6,20.012,30.6,15.737z"/>' +_x000D_
'<circle style="fill:' + color + ';" cx="16" cy="16" r="11"/>' +_x000D_
'<text x="16" y="20" text-anchor="middle" style="font-size:10px;fill:#FFFFFF;">' + text + '</text>' +_x000D_
'</svg>'_x000D_
);_x000D_
div.append(svg);_x000D_
_x000D_
var dd = $("<canvas height='50px' width='50px'></cancas>");_x000D_
_x000D_
var svgHtml = div[0].innerHTML;_x000D_
_x000D_
canvg(dd[0], svgHtml);_x000D_
_x000D_
var imgSrc = dd[0].toDataURL("image/png");_x000D_
//"scaledSize" and "optimized: false" together seems did the tricky ---IE11 && viewBox influent IE scaledSize_x000D_
//var svg = '<svg width="32px" height="43px" viewBox="0 0 32 43" xmlns="http://www.w3.org/2000/svg">'_x000D_
// + '<path style="fill:#FFFFFF;stroke:#020202;stroke-width:1;stroke-miterlimit:10;" d="M30.6,15.737c0-8.075-6.55-14.6-14.6-14.6c-8.075,0-14.601,6.55-14.601,14.6c0,4.149,1.726,7.875,4.5,10.524c1.8,1.801,4.175,4.301,5.025,5.625c1.75,2.726,5,11.976,5,11.976s3.325-9.25,5.1-11.976c0.825-1.274,3.05-3.6,4.825-5.399C28.774,23.813,30.6,20.012,30.6,15.737z"/>'_x000D_
// + '<circle style="fill:' + color + ';" cx="16" cy="16" r="11"/>'_x000D_
// + '<text x="16" y="20" text-anchor="middle" style="font-size:10px;fill:#FFFFFF;">' + text + '</text>'_x000D_
// + '</svg>';_x000D_
//var imgSrc = 'data:image/svg+xml;charset=UTF-8,' + encodeURIComponent(svg);_x000D_
_x000D_
var iconObj = {_x000D_
size: new google.maps.Size(32, 43),_x000D_
url: imgSrc,_x000D_
scaledSize: new google.maps.Size(32, 43)_x000D_
};_x000D_
_x000D_
return iconObj;_x000D_
};
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
_x000D_
<head>_x000D_
<meta charset="utf-8">_x000D_
<title>Your Custom Marker </title>_x000D_
<style>_x000D_
/* Always set the map height explicitly to define the size of the div_x000D_
* element that contains the map. */_x000D_
#map {_x000D_
height: 100%;_x000D_
}_x000D_
/* Optional: Makes the sample page fill the window. */_x000D_
html,_x000D_
body {_x000D_
height: 100%;_x000D_
margin: 0;_x000D_
padding: 0;_x000D_
}_x000D_
</style>_x000D_
</head>_x000D_
_x000D_
<body>_x000D_
<div id="map"></div>_x000D_
<script src="https://canvg.github.io/canvg/canvg.js"></script>_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>_x000D_
<script async defer src="https://maps.googleapis.com/maps/api/js?callback=initMap"></script>_x000D_
</body>_x000D_
_x000D_
</html>
_x000D_
_x000D_
_x000D_
ERROR 1067 (42000): Invalid default value for 'created_at'
You can do it like this:
CREATE TABLE `ttt` (
`id` INT(11) UNSIGNED NOT NULL AUTO_INCREMENT,
`t1` TIMESTAMP NULL DEFAULT '0000-00-00 00:00:00',
`t2` TIMESTAMP NULL DEFAULT '0000-00-00 00:00:00',
`t3` TIMESTAMP NULL DEFAULT '0000-00-00 00:00:00',
`t4` TIMESTAMP NULL DEFAULT 0,
PRIMARY KEY (`id`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;
- Because the TIMESTAMP value is stored as Epoch Seconds, the timestamp value '1970-01-01 00:00:00' (UTC) is reserved since the second #0 is used to represent '0000-00-00 00:00:00'.
- In MariaDB 5.5 and before there could only be one TIMESTAMP column per table that had CURRENT_TIMESTAMP defined as its default value. This limit has no longer applied since MariaDB 10.0.
see: https://mariadb.com/kb/en/mariadb/timestamp/
sample
MariaDB []> insert into ttt (id) VALUES (1),(2),(3);
Query OK, 3 rows affected (0.01 sec)
Records: 3 Duplicates: 0 Warnings: 0
MariaDB []> select * from ttt;
+----+---------------------+---------------------+---------------------+---------------------+
| id | t1 | t2 | t3 | t4 |
+----+---------------------+---------------------+---------------------+---------------------+
| 1 | 0000-00-00 00:00:00 | 2000-01-01 12:01:02 | 0000-00-00 00:00:00 | 0000-00-00 00:00:00 |
| 2 | 0000-00-00 00:00:00 | 2000-01-01 12:01:02 | 0000-00-00 00:00:00 | 0000-00-00 00:00:00 |
| 3 | 0000-00-00 00:00:00 | 2000-01-01 12:01:02 | 0000-00-00 00:00:00 | 0000-00-00 00:00:00 |
+----+---------------------+---------------------+---------------------+---------------------+
3 rows in set (0.00 sec)
MariaDB []>
Reading specific columns from a text file in python
It may help:
import csv
with open('csv_file','r') as f:
# Printing Specific Part of CSV_file
# Printing last line of second column
lines = list(csv.reader(f, delimiter = ' ', skipinitialspace = True))
print(lines[-1][1])
# For printing a range of rows except 10 last rows of second column
for i in range(len(lines)-10):
print(lines[i][1])
How can you search Google Programmatically Java API
Some facts:
Google offers a public search webservice API which returns JSON: http://ajax.googleapis.com/ajax/services/search/web. Documentation here
Java offers java.net.URL
and java.net.URLConnection
to fire and handle HTTP requests.
JSON can in Java be converted to a fullworthy Javabean object using an arbitrary Java JSON API. One of the best is Google Gson.
Now do the math:
public static void main(String[] args) throws Exception {
String google = "http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=";
String search = "stackoverflow";
String charset = "UTF-8";
URL url = new URL(google + URLEncoder.encode(search, charset));
Reader reader = new InputStreamReader(url.openStream(), charset);
GoogleResults results = new Gson().fromJson(reader, GoogleResults.class);
// Show title and URL of 1st result.
System.out.println(results.getResponseData().getResults().get(0).getTitle());
System.out.println(results.getResponseData().getResults().get(0).getUrl());
}
With this Javabean class representing the most important JSON data as returned by Google (it actually returns more data, but it's left up to you as an exercise to expand this Javabean code accordingly):
public class GoogleResults {
private ResponseData responseData;
public ResponseData getResponseData() { return responseData; }
public void setResponseData(ResponseData responseData) { this.responseData = responseData; }
public String toString() { return "ResponseData[" + responseData + "]"; }
static class ResponseData {
private List<Result> results;
public List<Result> getResults() { return results; }
public void setResults(List<Result> results) { this.results = results; }
public String toString() { return "Results[" + results + "]"; }
}
static class Result {
private String url;
private String title;
public String getUrl() { return url; }
public String getTitle() { return title; }
public void setUrl(String url) { this.url = url; }
public void setTitle(String title) { this.title = title; }
public String toString() { return "Result[url:" + url +",title:" + title + "]"; }
}
}
###See also:
Update since November 2010 (2 months after the above answer), the public search webservice has become deprecated (and the last day on which the service was offered was September 29, 2014). Your best bet is now querying http://www.google.com/search directly along with a honest user agent and then parse the result using a HTML parser. If you omit the user agent, then you get a 403 back. If you're lying in the user agent and simulate a web browser (e.g. Chrome or Firefox), then you get a way much larger HTML response back which is a waste of bandwidth and performance.
Here's a kickoff example using Jsoup as HTML parser:
String google = "http://www.google.com/search?q=";
String search = "stackoverflow";
String charset = "UTF-8";
String userAgent = "ExampleBot 1.0 (+http://example.com/bot)"; // Change this to your company's name and bot homepage!
Elements links = Jsoup.connect(google + URLEncoder.encode(search, charset)).userAgent(userAgent).get().select(".g>.r>a");
for (Element link : links) {
String title = link.text();
String url = link.absUrl("href"); // Google returns URLs in format "http://www.google.com/url?q=<url>&sa=U&ei=<someKey>".
url = URLDecoder.decode(url.substring(url.indexOf('=') + 1, url.indexOf('&')), "UTF-8");
if (!url.startsWith("http")) {
continue; // Ads/news/etc.
}
System.out.println("Title: " + title);
System.out.println("URL: " + url);
}
How to prevent page scrolling when scrolling a DIV element?
here a simple solution without jQuery which does not destroy the browser native scroll (this is: no artificial/ugly scrolling):
var scrollable = document.querySelector('.scrollable');
scrollable.addEventListener('wheel', function(event) {
var deltaY = event.deltaY;
var contentHeight = scrollable.scrollHeight;
var visibleHeight = scrollable.offsetHeight;
var scrollTop = scrollable.scrollTop;
if (scrollTop === 0 && deltaY < 0)
event.preventDefault();
else if (visibleHeight + scrollTop === contentHeight && deltaY > 0)
event.preventDefault();
});
Live demo: http://jsfiddle.net/ibcaliax/bwmzfmq7/4/
How to copy file from HDFS to the local file system
In order to copy files from HDFS to the local file system the following command could be run:
hadoop dfs -copyToLocal <input> <output>
<input>
: the HDFS directory path (e.g /mydata) that you want to copy
<output>
: the destination directory path (e.g. ~/Documents)
Passing parameters to a Bash function
If you prefer named parameters, it's possible (with a few tricks) to actually pass named parameters to functions (also makes it possible to pass arrays and references).
The method I developed allows you to define named parameters passed to a function like this:
function example { args : string firstName , string lastName , integer age } {
echo "My name is ${firstName} ${lastName} and I am ${age} years old."
}
You can also annotate arguments as @required or @readonly, create ...rest arguments, create arrays from sequential arguments (using e.g. string[4]
) and optionally list the arguments in multiple lines:
function example {
args
: @required string firstName
: string lastName
: integer age
: string[] ...favoriteHobbies
echo "My name is ${firstName} ${lastName} and I am ${age} years old."
echo "My favorite hobbies include: ${favoriteHobbies[*]}"
}
In other words, not only you can call your parameters by their names (which makes up for a more readable core), you can actually pass arrays (and references to variables - this feature works only in Bash 4.3 though)! Plus, the mapped variables are all in the local scope, just as $1
(and others).
The code that makes this work is pretty light and works both in Bash 3 and Bash 4 (these are the only versions I've tested it with). If you're interested in more tricks like this that make developing with bash much nicer and easier, you can take a look at my Bash Infinity Framework, the code below is available as one of its functionalities.
shopt -s expand_aliases
function assignTrap {
local evalString
local -i paramIndex=${__paramIndex-0}
local initialCommand="${1-}"
if [[ "$initialCommand" != ":" ]]
then
echo "trap - DEBUG; eval \"${__previousTrap}\"; unset __previousTrap; unset __paramIndex;"
return
fi
while [[ "${1-}" == "," || "${1-}" == "${initialCommand}" ]] || [[ "${#@}" -gt 0 && "$paramIndex" -eq 0 ]]
do
shift # First colon ":" or next parameter's comma ","
paramIndex+=1
local -a decorators=()
while [[ "${1-}" == "@"* ]]
do
decorators+=( "$1" )
shift
done
local declaration=
local wrapLeft='"'
local wrapRight='"'
local nextType="$1"
local length=1
case ${nextType} in
string | boolean) declaration="local " ;;
integer) declaration="local -i" ;;
reference) declaration="local -n" ;;
arrayDeclaration) declaration="local -a"; wrapLeft= ; wrapRight= ;;
assocDeclaration) declaration="local -A"; wrapLeft= ; wrapRight= ;;
"string["*"]") declaration="local -a"; length="${nextType//[a-z\[\]]}" ;;
"integer["*"]") declaration="local -ai"; length="${nextType//[a-z\[\]]}" ;;
esac
if [[ "${declaration}" != "" ]]
then
shift
local nextName="$1"
for decorator in "${decorators[@]}"
do
case ${decorator} in
@readonly) declaration+="r" ;;
@required) evalString+="[[ ! -z \$${paramIndex} ]] || echo \"Parameter '$nextName' ($nextType) is marked as required by '${FUNCNAME[1]}' function.\"; " >&2 ;;
@global) declaration+="g" ;;
esac
done
local paramRange="$paramIndex"
if [[ -z "$length" ]]
then
# ...rest
paramRange="{@:$paramIndex}"
# trim leading ...
nextName="${nextName//\./}"
if [[ "${#@}" -gt 1 ]]
then
echo "Unexpected arguments after a rest array ($nextName) in '${FUNCNAME[1]}' function." >&2
fi
elif [[ "$length" -gt 1 ]]
then
paramRange="{@:$paramIndex:$length}"
paramIndex+=$((length - 1))
fi
evalString+="${declaration} ${nextName}=${wrapLeft}\$${paramRange}${wrapRight}; "
# Continue to the next parameter:
shift
fi
done
echo "${evalString} local -i __paramIndex=${paramIndex};"
}
alias args='local __previousTrap=$(trap -p DEBUG); trap "eval \"\$(assignTrap \$BASH_COMMAND)\";" DEBUG;'
How to set breakpoints in inline Javascript in Google Chrome?
If you cannot see the "Scripts" tab, make sure you are launching Chrome with the right arguments. I had this problem when I launched Chrome for debugging server-side JavaScript with the argument --remote-shell-port=9222
. I have no problem if I launch Chrome with no argument.
How to generate access token using refresh token through google drive API?
Just posting my answer in case it helps anyone as I spent an hour to figure it out :)
First of all two very helpful link related to google api and fetching data from any of google services:
https://developers.google.com/analytics/devguides/config/mgmt/v3/quickstart/web-php
https://developers.google.com/identity/protocols/OAuth2WebServer
Furthermore, when using the following method:
$client->setAccessToken($token)
The $token
needs to be the full object returned by the google when making authorization request, not the only access_token
which you get inside the object so if you get the object lets say:
{"access_token":"xyz","token_type":"Bearer","expires_in":3600,"refresh_token":"mno","created":1532363626}
then you need to give:
$client->setAccessToken('{"access_token":"xyz","token_type":"Bearer","expires_in":3600,"refresh_token":"mno","created":1532363626}')
Not
$client->setAccessToken('xyz')
And then even if your access_token
is expired, google will refresh it itself by using the refresh_token
in the access_token
object.
Convert one date format into another in PHP
The Basics
The simplist way to convert one date format into another is to use strtotime()
with date()
. strtotime()
will convert the date into a Unix Timestamp. That Unix Timestamp can then be passed to date()
to convert it to the new format.
$timestamp = strtotime('2008-07-01T22:35:17.02');
$new_date_format = date('Y-m-d H:i:s', $timestamp);
Or as a one-liner:
$new_date_format = date('Y-m-d H:i:s', strtotime('2008-07-01T22:35:17.02'));
Keep in mind that strtotime()
requires the date to be in a valid format. Failure to provide a valid format will result in strtotime()
returning false which will cause your date to be 1969-12-31.
Using DateTime()
As of PHP 5.2, PHP offered the DateTime()
class which offers us more powerful tools for working with dates (and time). We can rewrite the above code using DateTime()
as so:
$date = new DateTime('2008-07-01T22:35:17.02');
$new_date_format = $date->format('Y-m-d H:i:s');
Working with Unix timestamps
date()
takes a Unix timeatamp as its second parameter and returns a formatted date for you:
$new_date_format = date('Y-m-d H:i:s', '1234567890');
DateTime() works with Unix timestamps by adding an @
before the timestamp:
$date = new DateTime('@1234567890');
$new_date_format = $date->format('Y-m-d H:i:s');
If the timestamp you have is in milliseconds (it may end in 000
and/or the timestamp is thirteen characters long) you will need to convert it to seconds before you can can convert it to another format. There's two ways to do this:
- Trim the last three digits off using
substr()
Trimming the last three digits can be acheived several ways, but using substr()
is the easiest:
$timestamp = substr('1234567899000', -3);
- Divide the substr by 1000
You can also convert the timestamp into seconds by dividing by 1000. Because the timestamp is too large for 32 bit systems to do math on you will need to use the BCMath library to do the math as strings:
$timestamp = bcdiv('1234567899000', '1000');
To get a Unix Timestamp you can use strtotime()
which returns a Unix Timestamp:
$timestamp = strtotime('1973-04-18');
With DateTime() you can use DateTime::getTimestamp()
$date = new DateTime('2008-07-01T22:35:17.02');
$timestamp = $date->getTimestamp();
If you're running PHP 5.2 you can use the U
formatting option instead:
$date = new DateTime('2008-07-01T22:35:17.02');
$timestamp = $date->format('U');
Working with non-standard and ambiguous date formats
Unfortunately not all dates that a developer has to work with are in a standard format. Fortunately PHP 5.3 provided us with a solution for that. DateTime::createFromFormat()
allows us to tell PHP what format a date string is in so it can be successfully parsed into a DateTime object for further manipulation.
$date = DateTime::createFromFormat('F-d-Y h:i A', 'April-18-1973 9:48 AM');
$new_date_format = $date->format('Y-m-d H:i:s');
In PHP 5.4 we gained the ability to do class member access on instantiation has been added which allows us to turn our DateTime()
code into a one-liner:
$new_date_format = (new DateTime('2008-07-01T22:35:17.02'))->format('Y-m-d H:i:s');
$new_date_format = DateTime::createFromFormat('F-d-Y h:i A', 'April-18-1973 9:48 AM')->format('Y-m-d H:i:s');
How do I specify the JDK for a GlassFish domain?
In Linux file system , Edit below file as this steps
Path - /opt/glassfish3/glassfish/config
File Name - asenv.conf
Add the JAVA HOME path as below to the end of file.
AS_JAVA=/opt/jdk1.8.0_201
Now start the glassfish server.
Passing command line arguments from Maven as properties in pom.xml
Inside pom.xml
<project>
.....
<profiles>
<profile>
<id>linux64</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<properties>
<build_os>linux</build_os>
<build_ws>gtk</build_ws>
<build_arch>x86_64</build_arch>
</properties>
</profile>
<profile>
<id>win64</id>
<activation>
<property>
<name>env</name>
<value>win64</value>
</property>
</activation>
<properties>
<build_os>win32</build_os>
<build_ws>win32</build_ws>
<build_arch>x86_64</build_arch>
</properties>
</profile>
</profiles>
.....
<plugin>
<groupId>org.eclipse.tycho</groupId>
<artifactId>target-platform-configuration</artifactId>
<version>${tycho.version}</version>
<configuration>
<environments>
<environment>
<os>${build_os}</os>
<ws>${build_ws}</ws>
<arch>${build_arch}</arch>
</environment>
</environments>
</configuration>
</plugin>
.....
In this example when you run the pom without any argument mvn clean install
default profile will execute.
When executed with mvn -Denv=win64 clean install
win64 profile will executed.
Please refer http://maven.apache.org/guides/introduction/introduction-to-profiles.html
Get current URL from IFRAME
I had an issue with blob url hrefs. So, with a reference to the iframe, I just produced an url from the iframe's src attribute:
const iframeReference = document.getElementById("iframe_id");
const iframeUrl = iframeReference ? new URL(iframeReference.src) : undefined;
if (iframeUrl) {
console.log("Voila: " + iframeUrl);
} else {
console.warn("iframe with id iframe_id not found");
}
bash: Bad Substitution
Your script syntax is valid bash and good.
Possible causes for the failure:
Your bash
is not really bash but ksh
or some other shell which doesn't understand bash's parameter substitution. Because your script looks fine and works with bash.
Do ls -l /bin/bash
and check it's really bash and not sym-linked to some other shell.
If you do have bash on your system, then you may be executing your script the wrong way like: ksh script.sh
or sh script.sh
(and your default shell is not bash). Since you have proper shebang, if you have bash ./script.sh
or bash ./script.sh
should be fine.
Returning a boolean value in a JavaScript function
You could simplify this a lot:
- Check whether one is not empty
- Check whether they are equal
This will result in this, which will always return a boolean. Your function also should always return a boolean, but you can see it does a little better if you simplify your code:
function validatePassword()
{
var password = document.getElementById("password");
var confirm_password = document.getElementById("password_confirm");
return password.value !== "" && password.value === confirm_password.value;
// not empty and equal
}
Selecting a Record With MAX Value
What do you mean costs too much? Too much what?
SELECT MAX(Balance) AS MaxBalance, CustomerID FROM CUSTOMERS GROUP BY CustomerID
If your table is properly indexed (Balance) and there has got to be an index on the PK than I am not sure what you mean about costs too much or seems unreliable? There is nothing unreliable about an aggregate that you are using and telling it to do. In this case, MAX()
does exactly what you tell it to do - there's nothing magical about it.
Take a look at MAX()
and if you want to filter it use the HAVING
clause.
Deleting array elements in JavaScript - delete vs splice
Array.remove() Method
John Resig, creator of jQuery created a very handy Array.remove
method that I always use it in my projects.
// Array Remove - By John Resig (MIT Licensed)
Array.prototype.remove = function(from, to) {
var rest = this.slice((to || from) + 1 || this.length);
this.length = from < 0 ? this.length + from : from;
return this.push.apply(this, rest);
};
and here's some examples of how it could be used:
// Remove the second item from the array
array.remove(1);
// Remove the second-to-last item from the array
array.remove(-2);
// Remove the second and third items from the array
array.remove(1,2);
// Remove the last and second-to-last items from the array
array.remove(-2,-1);
John's website
Heap space out of memory
If you are using a lot of memory and facing memory leaks, then you might want to check if you are using a large number of ArrayList
s or HashMap
s with many elements each.
An ArrayList
is implemented as a dynamic array. The source code from Sun/Oracle shows that when a new element is inserted into a full ArrayList
, a new array of 1.5 times the size of the original array is created, and the elements copied over. What this means is that you could be wasting up to 50% of the space in each ArrayList
you use, unless you call its trimToSize
method. Or better still, if you know the number of elements you are going to insert before hand, then call the constructor with the initial capacity as its argument.
I did not examine the source code for HashMap
very carefully, but at a first glance it appears that the array length in each HashMap
must be a power of two, making it another implementation of a dynamic array. Note that HashSet
is essentially a wrapper around HashMap
.
Resize UIImage and change the size of UIImageView
If you have the size of the image, why don't you set the frame.size
of the image view to be of this size?
EDIT----
Ok, so seeing your comment I propose this:
UIImageView *imageView;
//so let's say you're image view size is set to the maximum size you want
CGFloat maxWidth = imageView.frame.size.width;
CGFloat maxHeight = imageView.frame.size.height;
CGFloat viewRatio = maxWidth / maxHeight;
CGFloat imageRatio = image.size.height / image.size.width;
if (imageRatio > viewRatio) {
CGFloat imageViewHeight = round(maxWidth * imageRatio);
imageView.frame = CGRectMake(0, ceil((self.bounds.size.height - imageViewHeight) / 2.f), maxWidth, imageViewHeight);
}
else if (imageRatio < viewRatio) {
CGFloat imageViewWidth = roundf(maxHeight / imageRatio);
imageView.frame = CGRectMake(ceil((maxWidth - imageViewWidth) / 2.f), 0, imageViewWidth, maxHeight);
} else {
//your image view is already at the good size
}
This code will resize your image view to its image ratio, and also position the image view to the same centre as your "default" position.
PS: I hope you're setting imageView.layer.shouldRasterise = YES
and imageView.layer.rasterizationScale = [UIScreen mainScreen].scale;
if you're using CALayer shadow effect ;) It will greatly improve the performance of your UI.
Check for false
Checking if something isn't false... So it's true, just if you're doing something that is quantum physics.
if(!(borrar() === false))
or
if(borrar() === true)
How to get disk capacity and free space of remote computer
Another way is casting a string to a WMI object:
$size = ([wmi]"\\remotecomputer\root\cimv2:Win32_logicalDisk.DeviceID='c:'").Size
$free = ([wmi]"\\remotecomputer\root\cimv2:Win32_logicalDisk.DeviceID='c:'").FreeSpace
Also you can divide the results by 1GB or 1MB if you want different units:
$disk = ([wmi]"\\remotecomputer\root\cimv2:Win32_logicalDisk.DeviceID='c:'")
"Remotecomputer C: has {0:#.0} GB free of {1:#.0} GB Total" -f ($disk.FreeSpace/1GB),($disk.Size/1GB) | write-output
Output is: Remotecomputer C: has 252.7 GB free of 298.0 GB Total
Read text file into string array (and write)
As of Go1.1 release, there is a bufio.Scanner API that can easily read lines from a file. Consider the following example from above, rewritten with Scanner:
package main
import (
"bufio"
"fmt"
"log"
"os"
)
// readLines reads a whole file into memory
// and returns a slice of its lines.
func readLines(path string) ([]string, error) {
file, err := os.Open(path)
if err != nil {
return nil, err
}
defer file.Close()
var lines []string
scanner := bufio.NewScanner(file)
for scanner.Scan() {
lines = append(lines, scanner.Text())
}
return lines, scanner.Err()
}
// writeLines writes the lines to the given file.
func writeLines(lines []string, path string) error {
file, err := os.Create(path)
if err != nil {
return err
}
defer file.Close()
w := bufio.NewWriter(file)
for _, line := range lines {
fmt.Fprintln(w, line)
}
return w.Flush()
}
func main() {
lines, err := readLines("foo.in.txt")
if err != nil {
log.Fatalf("readLines: %s", err)
}
for i, line := range lines {
fmt.Println(i, line)
}
if err := writeLines(lines, "foo.out.txt"); err != nil {
log.Fatalf("writeLines: %s", err)
}
}
Regex - Does not contain certain Characters
^[^<>]+$
The caret in the character class ([^
) means match anything but, so this means, beginning of string, then one or more of anything except <
and >
, then the end of the string.
What is a NullPointerException, and how do I fix it?
A null pointer exception is an indicator that you are using an object without initializing it.
For example, below is a student class which will use it in our code.
public class Student {
private int id;
public int getId() {
return this.id;
}
public setId(int newId) {
this.id = newId;
}
}
The below code gives you a null pointer exception.
public class School {
Student student;
public School() {
try {
student.getId();
}
catch(Exception e) {
System.out.println("Null pointer exception");
}
}
}
Because you are using student
, but you forgot to initialize it like in the
correct code shown below:
public class School {
Student student;
public School() {
try {
student = new Student();
student.setId(12);
student.getId();
}
catch(Exception e) {
System.out.println("Null pointer exception");
}
}
}
How to sort a HashSet?
Java 8 way to sort it would be:
fooHashSet.stream()
.sorted(Comparator.comparing(Foo::getSize)) //comparator - how you want to sort it
.collect(Collectors.toList()); //collector - what you want to collect it to
*Foo::getSize
it's an example how to sort the HashSet of YourItem's naturally by size.
*Collectors.toList()
is going to collect the result of sorting into a List the you will need to capture it with List<Foo> sortedListOfFoo =
In C# check that filename is *possibly* valid (not that it exists)
I've had luck using regular expressions as others have shown.
One thing to keep in mind is that Windows at least prohibits some filenames that otherwise containlegal characters. A few come to mind: com, nul, prn.
I don't have it with me now, but I have a regex that takes these filename into consideration. If you want I can post it, otherwise I'm sure you can find it the same way I did: Google.
-Jay
Removing object from array in Swift 3
This is what I've used (Swift 5)...
extension Array where Element:Equatable
{
@discardableResult
mutating func removeFirst(_ item:Any ) -> Any? {
for index in 0..<self.count {
if(item as? Element == self[index]) {
return self.remove(at: index)
}
}
return nil
}
@discardableResult
mutating func removeLast(_ item:Any ) -> Any? {
var index = self.count-1
while index >= 0 {
if(item as? Element == self[index]) {
return self.remove(at: index)
}
index -= 1
}
return nil
}
}
var arrContacts:[String] = ["A","B","D","C","B","D"]
var contacts: [Any] = ["B","D"]
print(arrContacts)
var index = 1
arrContacts.removeFirst(contacts[index])
print(arrContacts)
index = 0
arrContacts.removeLast(contacts[index])
print(arrContacts)
Results:
["A", "B", "D", "C", "B", "D"]
["A", "B", "C", "B", "D"]
["A", "B", "C", "D"]
Important: The array from which you remove items must contain Equatable elements (such as objects, strings, number, etc.)
How can I use threading in Python?
I would like to contribute with a simple example and the explanations I've found useful when I had to tackle this problem myself.
In this answer you will find some information about Python's GIL (global interpreter lock) and a simple day-to-day example written using multiprocessing.dummy plus some simple benchmarks.
Global Interpreter Lock (GIL)
Python doesn't allow multi-threading in the truest sense of the word. It has a multi-threading package, but if you want to multi-thread to speed your code up, then it's usually not a good idea to use it.
Python has a construct called the global interpreter lock (GIL).
The GIL makes sure that only one of your 'threads' can execute at any one time. A thread acquires the GIL, does a little work, then passes the GIL onto the next thread.
This happens very quickly so to the human eye it may seem like your threads are executing in parallel, but they are really just taking turns using the same CPU core.
All this GIL passing adds overhead to execution. This means that if you want to make your code run faster then using the threading
package often isn't a good idea.
There are reasons to use Python's threading package. If you want to run some things simultaneously, and efficiency is not a concern,
then it's totally fine and convenient. Or if you are running code that needs to wait for something (like some I/O) then it could make a lot of sense. But the threading library won't let you use extra CPU cores.
Multi-threading can be outsourced to the operating system (by doing multi-processing), and some external application that calls your Python code (for example, Spark or Hadoop), or some code that your Python code calls (for example: you could have your Python code call a C function that does the expensive multi-threaded stuff).
Why This Matters
Because lots of people spend a lot of time trying to find bottlenecks in their fancy Python multi-threaded code before they learn what the GIL is.
Once this information is clear, here's my code:
#!/bin/python
from multiprocessing.dummy import Pool
from subprocess import PIPE,Popen
import time
import os
# In the variable pool_size we define the "parallelness".
# For CPU-bound tasks, it doesn't make sense to create more Pool processes
# than you have cores to run them on.
#
# On the other hand, if you are using I/O-bound tasks, it may make sense
# to create a quite a few more Pool processes than cores, since the processes
# will probably spend most their time blocked (waiting for I/O to complete).
pool_size = 8
def do_ping(ip):
if os.name == 'nt':
print ("Using Windows Ping to " + ip)
proc = Popen(['ping', ip], stdout=PIPE)
return proc.communicate()[0]
else:
print ("Using Linux / Unix Ping to " + ip)
proc = Popen(['ping', ip, '-c', '4'], stdout=PIPE)
return proc.communicate()[0]
os.system('cls' if os.name=='nt' else 'clear')
print ("Running using threads\n")
start_time = time.time()
pool = Pool(pool_size)
website_names = ["www.google.com","www.facebook.com","www.pinterest.com","www.microsoft.com"]
result = {}
for website_name in website_names:
result[website_name] = pool.apply_async(do_ping, args=(website_name,))
pool.close()
pool.join()
print ("\n--- Execution took {} seconds ---".format((time.time() - start_time)))
# Now we do the same without threading, just to compare time
print ("\nRunning NOT using threads\n")
start_time = time.time()
for website_name in website_names:
do_ping(website_name)
print ("\n--- Execution took {} seconds ---".format((time.time() - start_time)))
# Here's one way to print the final output from the threads
output = {}
for key, value in result.items():
output[key] = value.get()
print ("\nOutput aggregated in a Dictionary:")
print (output)
print ("\n")
print ("\nPretty printed output: ")
for key, value in output.items():
print (key + "\n")
print (value)
Rounding integer division (instead of truncating)
From Linux kernel (GPLv2):
/*
* Divide positive or negative dividend by positive divisor and round
* to closest integer. Result is undefined for negative divisors and
* for negative dividends if the divisor variable type is unsigned.
*/
#define DIV_ROUND_CLOSEST(x, divisor)( \
{ \
typeof(x) __x = x; \
typeof(divisor) __d = divisor; \
(((typeof(x))-1) > 0 || \
((typeof(divisor))-1) > 0 || (__x) > 0) ? \
(((__x) + ((__d) / 2)) / (__d)) : \
(((__x) - ((__d) / 2)) / (__d)); \
} \
)
How do you create a REST client for Java?
As I mentioned in this thread I tend to use Jersey which implements JAX-RS and comes with a nice REST client. The nice thing is if you implement your RESTful resources using JAX-RS then the Jersey client can reuse the entity providers such as for JAXB/XML/JSON/Atom and so forth - so you can reuse the same objects on the server side as you use on the client side unit test.
For example here is a unit test case from the Apache Camel project which looks up XML payloads from a RESTful resource (using the JAXB object Endpoints). The resource(uri) method is defined in this base class which just uses the Jersey client API.
e.g.
clientConfig = new DefaultClientConfig();
client = Client.create(clientConfig);
resource = client.resource("http://localhost:8080");
// lets get the XML as a String
String text = resource("foo").accept("application/xml").get(String.class);
BTW I hope that future version of JAX-RS add a nice client side API along the lines of the one in Jersey
Any way (or shortcut) to auto import the classes in IntelliJ IDEA like in Eclipse?
IntelliJ IDEA does not have an action to add imports. Rather it has the ability to do such as you type. If you enable the "Add unambiguous imports on the fly" in Settings > Editor > General > Auto Import, IntelliJ IDEA will add them as you type without the need for any shortcuts. You can also add classes and packages to exclude from auto importing to make a class you use heavily, that clashes with other classes of the same name, unambiguous.
For classes that are ambiguous (or is you prefer to have the "Add unambiguous imports on the fly" option turned off), just type the name of the class (just the name is OK, no need to fully qualify). Use code completion and select the particular class you want:
Notice the fully qualified names to the right. When I select the one I want and hit enter, IDEA will automatically add the import statement. This works the same if I was typing the name of a constructor. For static methods, you can even just keep typing the method you want. In the following screenshot, no "StringUtils" class is imported yet.
![enter image description here](https://i.stack.imgur.com/Z8Gft.png)
Alternatively, type the class name and then hit Alt+Enter or ?+Enter to "Show intention actions and quick-fixes" and then select the import option.
Although I've never used it, I think the Eclipse Code Formatter third party plug-in will do what you want. It lists "emulates Eclipse's imports optimizing" as a feature. See its instructions for more information. But in the end, I suspect you'll find the built in IDEA features work fine once you get use to their paradigm. In general, IDEA uses a "develop by intentions" concept. So rather than interrupting my development work to add an import statement, I just type the class I want (my intention) and IDEA automatically adds the import statement for the class for me.
What's the difference between @JoinColumn and mappedBy when using a JPA @OneToMany association
The annotation mappedBy ideally should always be used in the Parent side (Company class) of the bi directional relationship, in this case it should be in Company class pointing to the member variable 'company' of the Child class (Branch class)
The annotation @JoinColumn is used to specify a mapped column for joining an entity association, this annotation can be used in any class (Parent or Child) but it should ideally be used only in one side (either in parent class or in Child class not in both) here in this case i used it in the Child side (Branch class) of the bi directional relationship indicating the foreign key in the Branch class.
below is the working example :
parent class , Company
@Entity
public class Company {
private int companyId;
private String companyName;
private List<Branch> branches;
@Id
@GeneratedValue
@Column(name="COMPANY_ID")
public int getCompanyId() {
return companyId;
}
public void setCompanyId(int companyId) {
this.companyId = companyId;
}
@Column(name="COMPANY_NAME")
public String getCompanyName() {
return companyName;
}
public void setCompanyName(String companyName) {
this.companyName = companyName;
}
@OneToMany(fetch=FetchType.LAZY,cascade=CascadeType.ALL,mappedBy="company")
public List<Branch> getBranches() {
return branches;
}
public void setBranches(List<Branch> branches) {
this.branches = branches;
}
}
child class, Branch
@Entity
public class Branch {
private int branchId;
private String branchName;
private Company company;
@Id
@GeneratedValue
@Column(name="BRANCH_ID")
public int getBranchId() {
return branchId;
}
public void setBranchId(int branchId) {
this.branchId = branchId;
}
@Column(name="BRANCH_NAME")
public String getBranchName() {
return branchName;
}
public void setBranchName(String branchName) {
this.branchName = branchName;
}
@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name="COMPANY_ID")
public Company getCompany() {
return company;
}
public void setCompany(Company company) {
this.company = company;
}
}
jQuery serialize does not register checkboxes
sometimes unchecked means other values, for instance checked could mean yes unchecked no or 0,1 etc it depends on the meaning you want to give.. so could be another state besides "unchecked means it's not in the querystring at all"
"It would make it a lot easier to store information in DB. Because then the number of fields from Serialize would equal the number of fields in table. Now I have to contrll which ones are missing", youre right this is my problem too... so it appears i have to check for this nonexisting value....
but maybe this could be a solution?
http://tdanemar.wordpress.com/2010/08/24/jquery-serialize-method-and-checkboxes/
Java and SQLite
There is a new project SQLJet that is a pure Java implementation of SQLite. It doesn't support all of the SQLite features yet, but may be a very good option for some of the Java projects that work with SQLite databases.
AngularJS ng-class if-else expression
I had a situation where I needed two 'if' statements that could both go true and an 'else' or default if neither were true, not sure if this is an improvement on Jossef's answer but it seemed cleaner to me:
ng-class="{'class-one' : value.one , 'class-two' : value.two}" class="else-class"
Where value.one and value.two are true, they take precedent over the .else-class
Replace whole line containing a string using Sed
You can use the change command to replace the entire line, and the -i
flag to make the changes in-place. For example, using GNU sed:
sed -i '/TEXT_TO_BE_REPLACED/c\This line is removed by the admin.' /tmp/foo
How can one grab a stack trace in C?
There's backtrace()
, and backtrace_symbols()
:
From the man page:
#include <execinfo.h>
#include <stdio.h>
...
void* callstack[128];
int i, frames = backtrace(callstack, 128);
char** strs = backtrace_symbols(callstack, frames);
for (i = 0; i < frames; ++i) {
printf("%s\n", strs[i]);
}
free(strs);
...
One way to use this in a more convenient/OOP way is to save the result of backtrace_symbols()
in an exception class constructor. Thus, whenever you throw that type of exception you have the stack trace. Then, just provide a function for printing it out. For example:
class MyException : public std::exception {
char ** strs;
MyException( const std::string & message ) {
int i, frames = backtrace(callstack, 128);
strs = backtrace_symbols(callstack, frames);
}
void printStackTrace() {
for (i = 0; i < frames; ++i) {
printf("%s\n", strs[i]);
}
free(strs);
}
};
...
try {
throw MyException("Oops!");
} catch ( MyException e ) {
e.printStackTrace();
}
Ta da!
Note: enabling optimization flags may make the resulting stack trace inaccurate. Ideally, one would use this capability with debug flags on and optimization flags off.
Animate scroll to ID on page load
try with following code. make elements with class name page-scroll and keep id name to href
of corresponding links
$('a.page-scroll').bind('click', function(event) {
var $anchor = $(this);
$('html, body').stop().animate({
scrollTop: ($($anchor.attr('href')).offset().top - 50)
}, 1250, 'easeInOutExpo');
event.preventDefault();
});
Can local storage ever be considered secure?
This is a really interesting article here. I'm considering implementing JS encryption for offering security when using local storage. It's absolutely clear that this will only offer protection if the device is stolen (and is implemented correctly). It won't offer protection against keyloggers etc. However this is not a JS issue as the keylogger threat is a problem of all applications, regardless of their execution platform (browser, native). As to the article "JavaScript Crypto Considered Harmful" referenced in the first answer, I have one criticism; it states "You could use SSL/TLS to solve this problem, but that's expensive and complicated". I think this is a very ambitious claim (and possibly rather biased). Yes, SSL has a cost, but if you look at the cost of developing native applications for multiple OS, rather than web-based due to this issue alone, the cost of SSL becomes insignificant.
My conclusion - There is a place for client-side encryption code, however as with all applications the developers must recognise it's limitations and implement if suitable for their needs, and ensuring there are ways of mitigating it's risks.
Running AMP (apache mysql php) on Android
There are no PHP interpreters that I know of for Android or IOS (or WebOS or BlackBerryOS).
If you want to run a web site as an app on a mobile device or tablet as a native application, all functionality needs to be in Javascript and wrapped with a library like PhoneGap or Titanium. Android and IOS web apps are both able to use local storage databases where data can be kept until a network connection is made. Any server-side logic would require a call out to your web server and an active internet connection on the device.
Java regex to extract text between tags
A generic,simpler and a bit primitive approach to find tag, attribute and value
Pattern pattern = Pattern.compile("<(\\w+)( +.+)*>((.*))</\\1>");
System.out.println(pattern.matcher("<asd> TEST</asd>").find());
System.out.println(pattern.matcher("<asd TEST</asd>").find());
System.out.println(pattern.matcher("<asd attr='3'> TEST</asd>").find());
System.out.println(pattern.matcher("<asd> <x>TEST<x>asd>").find());
System.out.println("-------");
Matcher matcher = pattern.matcher("<as x> TEST</as>");
if (matcher.find()) {
for (int i = 0; i <= matcher.groupCount(); i++) {
System.out.println(i + ":" + matcher.group(i));
}
}
Send data from javascript to a mysql database
The other posters are correct you cannot connect to MySQL directly from javascript.
This is because JavaScript is at client side & mysql is server side.
So your best bet is to use ajax to call a handler as quoted above if you can let us know what language your project is in we can better help you ie php/java/.net
If you project is using php then the example from Merlyn is a good place to start, I would personally use jquery.ajax() to cut down you code and have a better chance of less cross browser issues.
http://api.jquery.com/jQuery.ajax/
Convert byte[] to char[]
You must know the source encoding.
string someText = "The quick brown fox jumps over the lazy dog.";
byte[] bytes = Encoding.Unicode.GetBytes(someText);
char[] chars = Encoding.Unicode.GetChars(bytes);
MATLAB - multiple return values from a function?
Use the following in the function you will call and it will work just fine.
[a b c] = yourfunction(optional)
%your code
a = 5;
b = 7;
c = 10;
return
end
This is a way to call the function both from another function and from the command terminal
[aa bb cc] = yourfunction(optional);
The variables aa, bb and cc now hold the return variables.
Change icon on click (toggle)
If your icon is based on the text in the block (ligatures) rather the class of the block then the following will work. This example uses the Google Material Icons '+' and '-' icons as part of MaterializeCSS.
<a class="btn-class"><i class="material-icons">add</i></a>
$('.btn-class').on('click',function(){
if ($(this).find('i').text() == 'add'){
$(this).find('i').text('remove');
} else {
$(this).find('i').text('add');
}
});
Edit: Added missing );
needed for this to function properly.
It also works for JQuery post 1.9 where toggling of functions was deprecated.
Redirecting to authentication dialog - "An error occurred. Please try again later"
I faced the same problem and reason was that my app was not live
and publicly available.
I added my email id in contact email under setting tabs and make my app live(which previously was disabled to make live).
After making my app live its showing sharing dialogue with proper image, title and description with my app name in bottom.
PowerShell - Start-Process and Cmdline Switches
Warning
If you run PowerShell from a cmd.exe window created by Powershell, the 2nd instance no longer waits for jobs to complete.
cmd> PowerShell
PS> Start-Process cmd.exe -Wait
Now from the new cmd window, run PowerShell again and within it start a 2nd cmd window:
cmd2> PowerShell
PS> Start-Process cmd.exe -Wait
PS>
The 2nd instance of PowerShell no longer honors the -Wait request and ALL background process/jobs return 'Completed' status even thou they are still running !
I discovered this when my C# Explorer program is used to open a cmd.exe window and PS is run from that window, it also ignores the -Wait request.
It appears that any PowerShell which is a 'win32 job' of cmd.exe fails to honor the wait request.
I ran into this with PowerShell version 3.0 on windows 7/x64
What does ** (double star/asterisk) and * (star/asterisk) do for parameters?
A good example of using both in a function is:
>>> def foo(*arg,**kwargs):
... print arg
... print kwargs
>>>
>>> a = (1, 2, 3)
>>> b = {'aa': 11, 'bb': 22}
>>>
>>>
>>> foo(*a,**b)
(1, 2, 3)
{'aa': 11, 'bb': 22}
>>>
>>>
>>> foo(a,**b)
((1, 2, 3),)
{'aa': 11, 'bb': 22}
>>>
>>>
>>> foo(a,b)
((1, 2, 3), {'aa': 11, 'bb': 22})
{}
>>>
>>>
>>> foo(a,*b)
((1, 2, 3), 'aa', 'bb')
{}
How do you use script variables in psql?
I've posted a new solution for this on another thread.
It uses a table to store variables, and can be updated at any time. A static immutable getter function is dynamically created (by another function), triggered by update to your table. You get nice table storage, plus the blazing fast speeds of an immutable getter.
Android Pop-up message
Use This And Call This In OnCreate Method In Which Activity You Want
public void popupMessage(){
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
alertDialogBuilder.setMessage("No Internet Connection. Check Your Wifi Or enter code hereMobile Data.");
alertDialogBuilder.setIcon(R.drawable.ic_no_internet);
alertDialogBuilder.setTitle("Connection Failed");
alertDialogBuilder.setNegativeButton("ok", new DialogInterface.OnClickListener(){
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Log.d("internet","Ok btn pressed");
finishAffinity();
System.exit(0);
}
});
AlertDialog alertDialog = alertDialogBuilder.create();
alertDialog.show();
}
How do I ignore files in a directory in Git?
If you want to put a .gitignore file at the top level and make it work for any folder below it use /**/
.
E.g. to ignore all *.map
files in a /src/main/
folder and sub-folders use:
/src/main/**/*.map
Generate fixed length Strings filled with whitespaces
For right pad you need String.format("%0$-15s", str)
i.e. -
sign will "right" pad and no -
sign will "left" pad
See my example:
import java.util.Scanner;
public class Solution {
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.println("================================");
for(int i=0;i<3;i++)
{
String s1=sc.nextLine();
Scanner line = new Scanner( s1);
line=line.useDelimiter(" ");
String language = line.next();
int mark = line.nextInt();;
System.out.printf("%s%03d\n",String.format("%0$-15s", language),mark);
}
System.out.println("================================");
}
}
The input must be a string and a number
example input : Google 1
Scikit-learn train_test_split with indices
If you are using pandas you can access the index by calling .index of whatever array you wish to mimic. The train_test_split carries over the pandas indices to the new dataframes.
In your code you simply use
x1.index
and the returned array is the indexes relating to the original positions in x.
Whitespace Matching Regex - Java
For your purpose you can use this snnippet:
import org.apache.commons.lang3.StringUtils;
StringUtils.normalizeSpace(string);
This will normalize the spacing to single and will strip off the starting and trailing whitespaces as well.
String sampleString = "Hello world!";
sampleString.replaceAll("\\s{2}", " "); // replaces exactly two consecutive spaces
sampleString.replaceAll("\\s{2,}", " "); // replaces two or more consecutive white spaces
SELECT CASE WHEN THEN (SELECT)
For a start the first select has 6 columns and the second has 4 columns. Perhaps make both have the same number of columns (adding nulls?).
Accessing AppDelegate from framework?
If you're creating a framework the whole idea is to make it portable. Tying a framework to the app delegate defeats the purpose of building a framework. What is it you need the app delegate for?
Multiple cases in switch statement
gcc implements an extension to the C language to support sequential ranges:
switch (value)
{
case 1...3:
//Do Something
break;
case 4...6:
//Do Something
break;
default:
//Do the Default
break;
}
Edit: Just noticed the C# tag on the question, so presumably a gcc answer doesn't help.
How to increase scrollback buffer size in tmux?
The history limit is a pane attribute that is fixed at the time of pane creation and cannot be changed for existing panes. The value is taken from the history-limit
session option (the default value is 2000).
To create a pane with a different value you will need to set the appropriate history-limit
option before creating the pane.
To establish a different default, you can put a line like the following in your .tmux.conf
file:
set-option -g history-limit 3000
Note: Be careful setting a very large default value, it can easily consume lots of RAM if you create many panes.
For a new pane (or the initial pane in a new window) in an existing session, you can set that session’s history-limit
. You might use a command like this (from a shell):
tmux set-option history-limit 5000 \; new-window
For (the initial pane of the initial window in) a new session you will need to set the “global” history-limit
before creating the session:
tmux set-option -g history-limit 5000 \; new-session
Note: If you do not re-set the history-limit
value, then the new value will be also used for other panes/windows/sessions created in the future; there is currently no direct way to create a single new pane/window/session with its own specific limit without (at least temporarily) changing history-limit
(though show-option
(especially in 1.7 and later) can help with retrieving the current value so that you restore it later).
How to pass a form input value into a JavaScript function
There are several ways to approach this. Personally, I would avoid in-line scripting. Since you've tagged jQuery, let's use that.
HTML:
<form>
<input type="text" id="formValueId" name="valueId"/>
<input type="button" id="myButton" />
</form>
JavaScript:
$(document).ready(function() {
$('#myButton').click(function() {
foo($('#formValueId').val());
});
});
Python vs. Java performance (runtime speed)
There is no good answer as Python and Java are both specifications for which there are many different implementations. For example, CPython, IronPython, Jython, and PyPy are just a handful of Python implementations out there. For Java, there is the HotSpot VM, the Mac OS X Java VM, OpenJRE, etc. Jython generates Java bytecode, and so it would be using more-or-less the same underlying Java. CPython implements quite a handful of things directly in C, so it is very fast, but then again Java VMs also implement many functions in C. You would probably have to measure on a function-by-function basis and across a variety of interpreters and VMs in order to make any reasonable statement.
How to display image from URL on Android
You can directly show image from web without downloading it. Please check the below function . It will show the images from the web into your image view.
public static Drawable LoadImageFromWebOperations(String url) {
try {
InputStream is = (InputStream) new URL(url).getContent();
Drawable d = Drawable.createFromStream(is, "src name");
return d;
} catch (Exception e) {
return null;
}
}
then set image to imageview using code in your activity.
iOS8 Beta Ad-Hoc App Download (itms-services)
I was struggling with this, my app was installing but not complete (almost 60% I can say) in iOS8, but in iOS7.1 it was working as expected. The error message popped was:
"Cannot install at this time".
Finally Zillan's link helped me to get apple documentation. So, check:
- make sure the internet reachability in your device as you will be in local network/ intranet.
- Also make sure the address
ax.init.itunes.apple.com
is not getting blocked by your firewall/proxy (Just type this address in safari, a blank page must load).
As soon as I changed the proxy it installed completely. Hope it will help someone.
Difference between return 1, return 0, return -1 and exit?
To indicate execution status.
status 0 means the program succeeded.
status different from 0 means the program exited due to error or anomaly.
return n; from your main entry function will terminate your process and report to the parent process (the one that executed your process) the result of your process. 0 means SUCCESS. Other codes usually indicates a failure and its meaning.
How to find all occurrences of an element in a list
Here is a time performance comparison between using np.where
vs list_comprehension
. Seems like np.where
is faster on average.
# np.where
start_times = []
end_times = []
for i in range(10000):
start = time.time()
start_times.append(start)
temp_list = np.array([1,2,3,3,5])
ixs = np.where(temp_list==3)[0].tolist()
end = time.time()
end_times.append(end)
print("Took on average {} seconds".format(
np.mean(end_times)-np.mean(start_times)))
Took on average 3.81469726562e-06 seconds
# list_comprehension
start_times = []
end_times = []
for i in range(10000):
start = time.time()
start_times.append(start)
temp_list = np.array([1,2,3,3,5])
ixs = [i for i in range(len(temp_list)) if temp_list[i]==3]
end = time.time()
end_times.append(end)
print("Took on average {} seconds".format(
np.mean(end_times)-np.mean(start_times)))
Took on average 4.05311584473e-06 seconds
How can I set the max-width of a table cell using percentages?
the percent should be relative to an absolute size,
try this :
_x000D_
_x000D_
table {
width:200px;
}
td {
width:65%;
border:1px solid black;
}
_x000D_
<table>
<tr>
<td>Testasdas 3123 1 dasd as da</td>
<td>A long string blah blah blah</td>
</tr>
</table>
_x000D_
_x000D_
_x000D_
How do I check if a property exists on a dynamic anonymous type in c#?
Merging and fixing answers from Serj-TM and user3359453 so that it works with both ExpandoObject and DynamicJsonObject. This works for me.
public static bool HasPropertyExist(dynamic settings, string name)
{
if (settings is System.Dynamic.ExpandoObject)
return ((IDictionary<string, object>)settings).ContainsKey(name);
if (settings is System.Web.Helpers.DynamicJsonObject)
try
{
return settings[name] != null;
}
catch (KeyNotFoundException)
{
return false;
}
return settings.GetType().GetProperty(name) != null;
}
What does numpy.random.seed(0) do?
numpy.random.seed(0)
numpy.random.randint(10, size=5)
This produces the following output:
array([5, 0, 3, 3, 7])
Again,if we run the same code we will get the same result.
Now if we change the seed value 0 to 1 or others:
numpy.random.seed(1)
numpy.random.randint(10, size=5)
This produces the following output: array([5 8 9 5 0])
but now the output not the same like above.
How to embed image or picture in jupyter notebook, either from a local machine or from a web resource?
There are several ways to post an image in Jupyter notebooks:
via HTML:
from IPython.display import Image
from IPython.core.display import HTML
Image(url= "http://my_site.com/my_picture.jpg")
You retain the ability to use HTML tags to resize, etc...
Image(url= "http://my_site.com/my_picture.jpg", width=100, height=100)
You can also display images stored locally, either via relative or absolute path.
PATH = "/Users/reblochonMasque/Documents/Drawings/"
Image(filename = PATH + "My_picture.jpg", width=100, height=100)
if the image it wider than the display settings: thanks
use unconfined=True
to disable max-width confinement of the image
from IPython.core.display import Image, display
display(Image('https://i.ytimg.com/vi/j22DmsZEv30/maxresdefault.jpg', width=1900, unconfined=True))
or via markdown:
- make sure the cell is a markdown cell, and not a code cell, thanks @??? in the comments)
- Please note that on some systems, the markdown does not allow white space in the filenames. Thanks to @CoffeeTableEspresso and @zebralamy in the comments)
(On macos, as long as you are on a markdown cell you would do like this: ![title](../image 1.png)
, and not worry about the white space).
for a web image:
![Image of Yaktocat](https://octodex.github.com/images/yaktocat.png)
as shown by @cristianmtr
Paying attention not to use either these quotes ""
or those ''
around the url.
or a local one:
![title](img/picture.png)
demonstrated by @Sebastian
How to convert integer to char in C?
To convert integer to char only 0 to 9 will be converted. As we know 0's ASCII value is 48 so we have to add its value to the integer value to convert in into the desired character
hence
int i=5;
char c = i+'0';
change Oracle user account status from EXPIRE(GRACE) to OPEN
In case you know the password of that user, or you would like to guess it, do the following:
If this command connects successufully, you will see the message "connected", otherwise you'd see an error message. If you are then successufull logging, that means that you know the password.
In that case, just do:
alter user NAME_OF_THE_USER identified by OLD_PASSWORD;
and this will reset the password to the same password as before and also reset the account_status for that user.
Responsive table handling in Twitter Bootstrap
There are many different things you can do when dealing with responsive tables.
I personally like this approach by Chris Coyier:
You can find many other alternatives here:
If you can leverage Bootstrap and get something quickly, you can simply use the class names ".hidden-phone" and ".hidden-tablet" to hide some rows but this approach might to be the best in many cases. More info (see "Responsive utility classes"):
How do I pass data to Angular routed components?
By default i won't use a guard for this one for me it is more can i enter the route or can i leave it. It is not to share data betweenn them.
If you want to load data before we entered a route just add an resolver to this one this is also part of the Router.
As very basic example:
Resolver
import { Resolve, ActivatedRoute } from "@angular/router";
import { Observable } from "rxjs";
import { Injectable } from "@angular/core";
import { take } from "rxjs/operators";
@Injectable()
export class UserResolver implements Resolve<User> {
constructor(
private userService: UserService,
private route: ActivatedRoute
) {}
resolve(): Observable<firebase.User> {
return this.route.params.pipe(
switchMap((params) => this.userService.fetchUser(params.user_id)),
take(1)
);
}
}
put to the router:
RouterModule.forChild([
{
path: "user/:user_id",
component: MyUserDetailPage,
resolve: {
user: UserResolver
}
}
}]
get the data in our component
ngOnInit() {
const user: firebase.User = this.activatedRoute.snapshot.data.user;
}
The downside on this approach is, he will enter the route first if he get the user data not before, this ensures the data for the user has been loaded and is ready on start of the component, but you will stay on the old page as long the data has been loaded (Loading Animation)
Multi-dimensional arrays in Bash
I am posting the following because it is a very simple and clear way to mimic (at least to some extent) the behavior of a two-dimensional array in Bash. It uses a here-file (see the Bash manual) and read
(a Bash builtin command):
## Store the "two-dimensional data" in a file ($$ is just the process ID of the shell, to make sure the filename is unique)
cat > physicists.$$ <<EOF
Wolfgang Pauli 1900
Werner Heisenberg 1901
Albert Einstein 1879
Niels Bohr 1885
EOF
nbPhysicists=$(wc -l physicists.$$ | cut -sf 1 -d ' ') # Number of lines of the here-file specifying the physicists.
## Extract the needed data
declare -a person # Create an indexed array (necessary for the read command).
while read -ra person; do
firstName=${person[0]}
familyName=${person[1]}
birthYear=${person[2]}
echo "Physicist ${firstName} ${familyName} was born in ${birthYear}"
# Do whatever you need with data
done < physicists.$$
## Remove the temporary file
rm physicists.$$
Output:
Physicist Wolfgang Pauli was born in 1900 Physicist Werner Heisenberg was born in 1901 Physicist Albert Einstein was born in 1879 Physicist Niels Bohr was born in 1885
The way it works:
- The lines in the temporary file created play the role of one-dimensional vectors, where the blank spaces (or whatever separation character you choose; see the description of the
read
command in the Bash manual) separate the elements of these vectors.
- Then, using the
read
command with its -a
option, we loop over each line of the file (until we reach end of file). For each line, we can assign the desired fields (= words) to an array, which we declared just before the loop. The -r
option to the read
command prevents backslashes from acting as escape characters, in case we typed backslashes in the here-document physicists.$$
.
In conclusion a file is created as a 2D-array, and its elements are extracted using a loop over each line, and using the ability of the read
command to assign words to the elements of an (indexed) array.
Slight improvement:
In the above code, the file physicists.$$
is given as input to the while
loop, so that it is in fact passed to the read
command. However, I found that this causes problems when I have another command asking for input inside the while
loop. For example, the select
command waits for standard input, and if placed inside the while
loop, it will take input from physicists.$$
, instead of prompting in the command-line for user input.
To correct this, I use the -u
option of read
, which allows to read from a file descriptor. We only have to create a file descriptor (with the exec
command) corresponding to physicists.$$
and to give it to the -u
option of read, as in the following code:
## Store the "two-dimensional data" in a file ($$ is just the process ID of the shell, to make sure the filename is unique)
cat > physicists.$$ <<EOF
Wolfgang Pauli 1900
Werner Heisenberg 1901
Albert Einstein 1879
Niels Bohr 1885
EOF
nbPhysicists=$(wc -l physicists.$$ | cut -sf 1 -d ' ') # Number of lines of the here-file specifying the physicists.
exec {id_file}<./physicists.$$ # Create a file descriptor stored in 'id_file'.
## Extract the needed data
declare -a person # Create an indexed array (necessary for the read command).
while read -ra person -u "${id_file}"; do
firstName=${person[0]}
familyName=${person[1]}
birthYear=${person[2]}
echo "Physicist ${firstName} ${familyName} was born in ${birthYear}"
# Do whatever you need with data
done
## Close the file descriptor
exec {id_file}<&-
## Remove the temporary file
rm physicists.$$
Notice that the file descriptor is closed at the end.
What is the difference between ApplicationContext and WebApplicationContext in Spring MVC?
ApplicationContext (Root Application Context) :
Every Spring MVC web application has an applicationContext.xml file which is configured as the root of context configuration. Spring loads this file and creates an applicationContext for the entire application.
This file is loaded by the ContextLoaderListener which is configured as a context param in web.xml file. And there will be only one applicationContext per web application.
WebApplicationContext :
WebApplicationContext is a web aware application context i.e. it has servlet context information.
A single web application can have multiple WebApplicationContext and each Dispatcher servlet (which is the front controller of Spring MVC architecture) is associated with a WebApplicationContext. The webApplicationContext configuration file *-servlet.xml is specific to a DispatcherServlet.
And since a web application can have more than one dispatcher servlet configured to serve multiple requests, there can be more than one webApplicationContext file per web application.
How to return a value from try, catch, and finally?
To return a value when using try/catch
you can use a temporary variable, e.g.
public static double add(String[] values) {
double sum = 0.0;
try {
int length = values.length;
double arrayValues[] = new double[length];
for(int i = 0; i < length; i++) {
arrayValues[i] = Double.parseDouble(values[i]);
sum += arrayValues[i];
}
} catch(NumberFormatException e) {
e.printStackTrace();
} catch(RangeException e) {
throw e;
} finally {
System.out.println("Thank you for using the program!");
}
return sum;
}
Else you need to have a return in every execution path (try block or catch block) that has no throw
.
How to split a line into words separated by one or more spaces in bash?
It depends upon what you mean by split. If you want to iterate over words in a line, which is in a variable, you can just iterate. For example, let's say the variable line
is this is a line
. Then you can do this:
for word in $line; do echo $word; done
This will print:
this
is
a
line
for .. in $var
splits $var
using the values in $IFS
, the default value of which means "split blanks and newlines".
If you want to read lines from user or a file, you can do something like:
cat $filename | while read line
do
echo "Processing new line" >/dev/tty
for word in $line
do
echo $word
done
done
For anything else, you need to be more explicit and define your question in more detail.
Note: Edited to remove bashism, but I still kept cat $filename | ...
because I like it more than redirection.
Pure CSS collapse/expand div
@gbtimmon's answer is great, but way, way too complicated. I've simplified his code as much as I could.
_x000D_
_x000D_
#answer,
#show,
#hide:target {
display: none;
}
#hide:target + #show,
#hide:target ~ #answer {
display: inherit;
}
_x000D_
<a href="#hide" id="hide">Show</a>
<a href="#/" id="show">Hide</a>
<div id="answer"><p>Answer</p></div>
_x000D_
_x000D_
_x000D_
How can I escape a double quote inside double quotes?
A simple example of escaping quotes in the shell:
$ echo 'abc'\''abc'
abc'abc
$ echo "abc"\""abc"
abc"abc
It's done by finishing an already-opened one ('
), placing the escaped one (\'
), and then opening another one ('
).
Alternatively:
$ echo 'abc'"'"'abc'
abc'abc
$ echo "abc"'"'"abc"
abc"abc
It's done by finishing already opened one ('
), placing a quote in another quote ("'"
), and then opening another one ('
).
More examples: Escaping single-quotes within single-quoted strings
Return multiple fields as a record in PostgreSQL with PL/pgSQL
Don't use CREATE TYPE to return a polymorphic result. Use and abuse the RECORD type instead. Check it out:
CREATE FUNCTION test_ret(a TEXT, b TEXT) RETURNS RECORD AS $$
DECLARE
ret RECORD;
BEGIN
-- Arbitrary expression to change the first parameter
IF LENGTH(a) < LENGTH(b) THEN
SELECT TRUE, a || b, 'a shorter than b' INTO ret;
ELSE
SELECT FALSE, b || a INTO ret;
END IF;
RETURN ret;
END;$$ LANGUAGE plpgsql;
Pay attention to the fact that it can optionally return two or three columns depending on the input.
test=> SELECT test_ret('foo','barbaz');
test_ret
----------------------------------
(t,foobarbaz,"a shorter than b")
(1 row)
test=> SELECT test_ret('barbaz','foo');
test_ret
----------------------------------
(f,foobarbaz)
(1 row)
This does wreak havoc on code, so do use a consistent number of columns, but it's ridiculously handy for returning optional error messages with the first parameter returning the success of the operation. Rewritten using a consistent number of columns:
CREATE FUNCTION test_ret(a TEXT, b TEXT) RETURNS RECORD AS $$
DECLARE
ret RECORD;
BEGIN
-- Note the CASTING being done for the 2nd and 3rd elements of the RECORD
IF LENGTH(a) < LENGTH(b) THEN
ret := (TRUE, (a || b)::TEXT, 'a shorter than b'::TEXT);
ELSE
ret := (FALSE, (b || a)::TEXT, NULL::TEXT);
END IF;
RETURN ret;
END;$$ LANGUAGE plpgsql;
Almost to epic hotness:
test=> SELECT test_ret('foobar','bar');
test_ret
----------------
(f,barfoobar,)
(1 row)
test=> SELECT test_ret('foo','barbaz');
test_ret
----------------------------------
(t,foobarbaz,"a shorter than b")
(1 row)
But how do you split that out in to multiple rows so that your ORM layer of choice can convert the values in to your language of choice's native data types? The hotness:
test=> SELECT a, b, c FROM test_ret('foo','barbaz') AS (a BOOL, b TEXT, c TEXT);
a | b | c
---+-----------+------------------
t | foobarbaz | a shorter than b
(1 row)
test=> SELECT a, b, c FROM test_ret('foobar','bar') AS (a BOOL, b TEXT, c TEXT);
a | b | c
---+-----------+---
f | barfoobar |
(1 row)
This is one of the coolest and most underused features in PostgreSQL. Please spread the word.
Static variables in C++
A static variable declared in a header file outside of the class would be file-scoped
in every .c file which includes the header. That means separate copy of a variable with same name is accessible in each of the .c files where you include the header file.
A static class variable on the other hand is class-scoped
and the same static variable is available to every compilation unit that includes the header containing the class with static variable.
Conditional Replace Pandas
Try this:
df.my_channel = df.my_channel.where(df.my_channel <= 20000, other= 0)
or
df.my_channel = df.my_channel.mask(df.my_channel > 20000, other= 0)
jQuery or JavaScript auto click
You are trying to make a popup work maybe? I don't know how to emulate click, maybe you can try to fire click event somehow, but I don't know if it is possible. More than likely such functionality is not implemented, because of security and privacy concerns.
You can use div with position:absolute to emulate popup at the same page. If you insist creating another page, I cannot help you. Maybe somebody else with more experience will add his 15 cents.
Could not resolve all dependencies for configuration ':classpath'
6 years later here, but for them who are stil facing this issue, I solved it as following.
It happened when my module had a different gradle version than the main project. I had gradle version 3.5.3
in project and an older version in module. So, I Just updated that version. The file is here:
./node-modules/[module-name]/android/build.gradle
Use of ~ (tilde) in R programming Language
The thing on the right of <-
is a formula
object. It is often used to denote a statistical model, where the thing on the left of the ~
is the response and the things on the right of the ~
are the explanatory variables. So in English you'd say something like "Species depends on Sepal Length, Sepal Width, Petal Length and Petal Width".
The myFormula <-
part of that line stores the formula in an object called myFormula
so you can use it in other parts of your R code.
Other common uses of formula objects in R
The lattice
package uses them to specify the variables to plot.
The ggplot2
package uses them to specify panels for plotting.
The dplyr
package uses them for non-standard evaulation.
ListView with OnItemClickListener
lv.setOnItemClickListener( new OnItemClickListener() {
@Override
public void onItemClick(AdapterView < ? > parent, View view,
int position, long id) {
// TODO Auto-generated method stub
}
} );
How to declare a constant in Java
- You can use an
enum
type in Java 5 and onwards for the purpose you have described. It is type safe.
- A is an instance variable. (If it has the static modifier, then it becomes a static variable.) Constants just means the value doesn't change.
- Instance variables are data members belonging to the object and not the class. Instance variable = Instance field.
If you are talking about the difference between instance variable and class variable, instance variable exist per object created. While class variable has only one copy per class loader regardless of the number of objects created.
Java 5 and up enum
type
public enum Color{
RED("Red"), GREEN("Green");
private Color(String color){
this.color = color;
}
private String color;
public String getColor(){
return this.color;
}
public String toString(){
return this.color;
}
}
If you wish to change the value of the enum you have created, provide a mutator method.
public enum Color{
RED("Red"), GREEN("Green");
private Color(String color){
this.color = color;
}
private String color;
public String getColor(){
return this.color;
}
public void setColor(String color){
this.color = color;
}
public String toString(){
return this.color;
}
}
Example of accessing:
public static void main(String args[]){
System.out.println(Color.RED.getColor());
// or
System.out.println(Color.GREEN);
}
What's an easy way to read random line from a file in Unix command line?
Here is what I discovery since my Mac OS doesn't use all the easy answers. I used the jot command to generate a number since the $RANDOM variable solutions seems not to be very random in my test. When testing my solution I had a wide variance in the solutions provided in the output.
RANDOM1=`jot -r 1 1 235886`
#range of jot ( 1 235886 ) found from earlier wc -w /usr/share/dict/web2
echo $RANDOM1
head -n $RANDOM1 /usr/share/dict/web2 | tail -n 1
The echo of the variable is to get a visual of the generated random number.
Regex pattern including all special characters
Please don't do that... little Unicode BABY ANGEL
s like this one are dying! ??? (? these are not images) (nor is the arrow!)
?
And you are killing 20 years of DOS :-) (the last smiley is called WHITE SMILING FACE
... Now it's at 263A
... But in ancient times it was ALT-1
)
and his friend
?
BLACK SMILING FACE
... Now it's at 263B
... But in ancient times it was ALT-2
Try a negative match:
Pattern regex = Pattern.compile("[^A-Za-z0-9]");
(this will ok only A-Z
"standard" letters and "standard" 0-9
digits.)