Programs & Examples On #Flir

How do you add an action to a button programmatically in xcode

 UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button addTarget:self 
       action:@selector(aMethod1:)
forControlEvents:UIControlEventTouchUpInside];
[button setTitle:@"Show View" forState:UIControlStateNormal];
button.frame = CGRectMake(80.0, 210.0, 160.0, 40.0);
[view addSubview:button];   

How to have the cp command create any necessary folders for copying a file to a destination

For those that are on Mac OSX, perhaps the easiest way to work around this is to use ditto (only on the mac, AFAIK, though). It will create the directory structure that is missing in the destination.

For instance, I did this

ditto 6.3.2/6.3.2/macosx/bin/mybinary ~/work/binaries/macosx/6.3.2/

where ~/work did not contain the binaries directory before I ran the command.

I thought rsync should work similarly, but it seems it only works for one level of missing directories. That is,

rsync 6.3.3/6.3.3/macosx/bin/mybinary ~/work/binaries/macosx/6.3.3/

worked, because ~/work/binaries/macosx existed but not ~/work/binaries/macosx/6.3.2/

Unity 2d jumping script

The answer above is now obsolete with Unity 5 or newer. Use this instead!

GetComponent<Rigidbody2D>().AddForce(new Vector2(0,10), ForceMode2D.Impulse);

I also want to add that this leaves the jump height super private and only editable in the script, so this is what I did...

    public float playerSpeed;  //allows us to be able to change speed in Unity
public Vector2 jumpHeight;

// Use this for initialization
void Start () {

}
// Update is called once per frame
void Update ()
{
    transform.Translate(playerSpeed * Time.deltaTime, 0f, 0f);  //makes player run

    if (Input.GetMouseButtonDown(0) || Input.GetKeyDown(KeyCode.Space))  //makes player jump
    {
        GetComponent<Rigidbody2D>().AddForce(jumpHeight, ForceMode2D.Impulse);

This makes it to where you can edit the jump height in Unity itself without having to go back to the script.

Side note - I wanted to comment on the answer above, but I can't because I'm new here. :)

Python datetime to string without microsecond component

Since not all datetime.datetime instances have a microsecond component (i.e. when it is zero), you can partition the string on a "." and take only the first item, which will always work:

unicode(datetime.datetime.now()).partition('.')[0]

How can I open a link in a new window?

this solution also considered the case that url is empty and disabled(gray) the empty link.

_x000D_
_x000D_
$(function() {_x000D_
  changeAnchor();_x000D_
});_x000D_
_x000D_
function changeAnchor() {_x000D_
  $("a[name$='aWebsiteUrl']").each(function() { // you can write your selector here_x000D_
    $(this).css("background", "none");_x000D_
    $(this).css("font-weight", "normal");_x000D_
_x000D_
    var url = $(this).attr('href').trim();_x000D_
    if (url == " " || url == "") { //disable empty link_x000D_
      $(this).attr("class", "disabled");_x000D_
      $(this).attr("href", "javascript:void(0)");_x000D_
    } else {_x000D_
      $(this).attr("target", "_blank");// HERE set the non-empty links, open in new window_x000D_
    }_x000D_
  });_x000D_
}
_x000D_
a.disabled {_x000D_
  text-decoration: none;_x000D_
  pointer-events: none;_x000D_
  cursor: default;_x000D_
  color: grey;_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>_x000D_
<a name="aWebsiteUrl" href="http://www.baidu.com" class='#'>[website]</a>_x000D_
<a name="aWebsiteUrl" href=" " class='#'>[website]</a>_x000D_
<a name="aWebsiteUrl" href="http://www.alibaba.com" class='#'>[website]</a>_x000D_
<a name="aWebsiteUrl" href="http://www.qq.com" class='#'>[website]</a>
_x000D_
_x000D_
_x000D_

Add and remove attribute with jquery

If you want to do this, you need to save it in a variable first. So you don't need to use id to query this element every time.

var el = $("#page_navigation1");

$("#add").click(function(){
  el.attr("id","page_navigation1");
});     

$("#remove").click(function(){
  el.removeAttr("id");
});     

How to destroy Fragment?

If you are in the fragment itself, you need to call this. Your fragment needs to be the fragment that is being called. Enter code:

getFragmentManager().beginTransaction().remove(yourFragment).commitAllowingStateLoss();

or if you are using supportLib, then you need to call:

getSupportFragmentManager().beginTransaction().remove(yourFragment).commitAllowingStateLoss();

What is the difference between ports 465 and 587?

Port 465: IANA has reassigned a new service to this port, and it should no longer be used for SMTP communications.

However, because it was once recognized by IANA as valid, there may be legacy systems that are only capable of using this connection method. Typically, you will use this port only if your application demands it. A quick Google search, and you'll find many consumer ISP articles that suggest port 465 as the recommended setup. Hopefully this ends soon! It is not RFC compliant.

Port 587: This is the default mail submission port. When a mail client or server is submitting an email to be routed by a proper mail server, it should always use this port.

Everyone should consider using this port as default, unless you're explicitly blocked by your upstream network or hosting provider. This port, coupled with TLS encryption, will ensure that email is submitted securely and following the guidelines set out by the IETF.

Port 25: This port continues to be used primarily for SMTP relaying. SMTP relaying is the transmittal of email from email server to email server.

In most cases, modern SMTP clients (Outlook, Mail, Thunderbird, etc) shouldn't use this port. It is traditionally blocked, by residential ISPs and Cloud Hosting Providers, to curb the amount of spam that is relayed from compromised computers or servers. Unless you're specifically managing a mail server, you should have no traffic traversing this port on your computer or server.

Php $_POST method to get textarea value

Make sure your escaping the HTML characters

E.g.

// Always check an input variable is set before you use it
if (isset($_POST['contact_list'])) {
    // Escape any html characters
    echo htmlentities($_POST['contact_list']);
}

This would occur because of the angle brackets and the browser thinking they are tags.

See: http://php.net/manual/en/function.htmlentities.php

How do I show a console output/window in a forms application?

Building on Chaz's answer, in .NET 5 there is a breaking change, so two modifications are required in the project file, i.e. changing OutputType and adding DisableWinExeOutputInference. Example:

<PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net5.0-windows10.0.17763.0</TargetFramework>
    <UseWindowsForms>true</UseWindowsForms>
    <DisableWinExeOutputInference>true</DisableWinExeOutputInference>
    <Platforms>AnyCPU;x64;x86</Platforms>
</PropertyGroup>

How to run cron job every 2 hours

0 */1 * * * “At minute 0 past every hour.”

0 */2 * * * “At minute 0 past every 2nd hour.”

This is the proper way to set cronjobs for every hr.

Set a path variable with spaces in the path in a Windows .cmd file or batch file

I use

set "VAR_NAME=<String With Spaces>"

when updating path:

set "PATH=%UTIL_DIR%;%PATH%"

JavaScript: set dropdown selected item based on option text

This works in latest Chrome, FireFox and Edge, but not IE11:

document.evaluate('//option[text()="Yahoo"]', document).iterateNext().selected = 'selected';

And if you want to ignore spaces around the title:

document.evaluate('//option[normalize-space(text())="Yahoo"]', document).iterateNext().selected = 'selected'

"application blocked by security settings" prevent applets running using oracle SE 7 update 51 on firefox on Linux mint

As an alternative answer, there's a command line to invoke directly the Control Panel, which is javaws -viewer, should work for both openJDK and Oracle's JDK (thanks @Nasser for checking the availability in Oracle's JDK)

Same caution to run as the user you need to access permissions with applies.

adb server version doesn't match this client

System: Windows 7, Android Studio.

This error occurred when I ran adb devices from Windows Commandline.

The root cause was that the adb I was running from commandline was not the same adb running from Android Studio.

Solution:

  1. First kill all running adb processes on the machine.

    taskkill /F /IM adb.exe

  2. Run your app from Android Studio.

  3. Locate the exact File Location of adb.exe either from Windows Task Manager, OR by running the command below

    wmic process where "name='adb.exe'" get ProcessID, ExecutablePath

  4. On Windows Command prompt, run where adb to locate the adb that runs from command prompt. This path would be different from the one in Step 3 above.

  5. Edit Windows system variable PATH. Delete the base path found in Step 4 from it.

  6. After you have edited PATH, you can see the current contents of this variable by typing below command in a NEW command prompt (don't use old prompt.)

    echo %PATH%

Now, run adb from command prompt. It should NOT show any "server out of date error"!

AttributeError: 'str' object has no attribute 'append'

Why myList[1] is considered a 'str' object?

Because it is a string. What else is 'from form', if not a string? (Actually, strings are sequences too, i.e. they can be indexed, sliced, iterated, etc. as well - but that's part of the str class and doesn't make it a list or something).

mList[1] returns the first item in the list 'from form'

If you mean that myList is 'from form', no it's not!!! The second (indexing starts at 0) element is 'from form'. That's a BIG difference. It's the difference between a house and a person.

Also, myList doesn't have to be a list from your short code sample - it could be anything that accepts 1 as index - a dict with 1 as index, a list, a tuple, most other sequences, etc. But that's irrelevant.

but I cannot append to item 1 in the list myList

Of course not, because it's a string and you can't append to string. String are immutable. You can concatenate (as in, "there's a new object that consists of these two") strings. But you cannot append (as in, "this specific object now has this at the end") to them.

How to check if BigDecimal variable == 0 in java?

There is a constant that you can check against:

someBigDecimal.compareTo(BigDecimal.ZERO) == 0

Extract XML Value in bash script

I agree with Charles Duffy that a proper XML parser is the right way to go.

But as to what's wrong with your sed command (or did you do it on purpose?).

  • $data was not quoted, so $data is subject to shell's word splitting, filename expansion among other things. One of the consequences being that the spacing in the XML snippet is not preserved.

So given your specific XML structure, this modified sed command should work

title=$(sed -ne '/title/{s/.*<title>\(.*\)<\/title>.*/\1/p;q;}' <<< "$data")

Basically for the line that contains title, extract the text between the tags, then quit (so you don't extract the 2nd <title>)

How do you create vectors with specific intervals in R?

Use the code

x = seq(0,100,5) #this means (starting number, ending number, interval)

the output will be

[1]   0   5  10  15  20  25  30  35  40  45  50  55  60  65  70  75
[17]  80  85  90  95 100

download csv file from web api in angular js

I think the best way to download any file generated by REST call is to use window.location example :

_x000D_
_x000D_
    $http({_x000D_
        url: url,_x000D_
        method: 'GET'_x000D_
    })_x000D_
    .then(function scb(response) {_x000D_
        var dataResponse = response.data;_x000D_
        //if response.data for example is : localhost/export/data.csv_x000D_
        _x000D_
        //the following will download the file without changing the current page location_x000D_
        window.location = 'http://'+ response.data_x000D_
    }, function(response) {_x000D_
      showWarningNotification($filter('translate')("global.errorGetDataServer"));_x000D_
    });
_x000D_
_x000D_
_x000D_

Convert from java.util.date to JodaTime

java.util.Date date = ...
DateTime dateTime = new DateTime(date);

Make sure date isn't null, though, otherwise it acts like new DateTime() - I really don't like that.

How to get POSTed JSON in Flask?

The following codes can be used:

@app.route('/api/add_message/<uuid>', methods=['GET', 'POST'])
def add_message(uuid):
  content = request.json['text']
  print content
  return uuid

Here is a screenshot of me getting the json data:

enter image description here

You can see that what is returned is a dictionary type of data.

How do I create a comma delimited string from an ArrayList?

The solutions so far are all quite complicated. The idiomatic solution should doubtless be:

String.Join(",", x.Cast(Of String)().ToArray())

There's no need for fancy acrobatics in new framework versions. Supposing a not-so-modern version, the following would be easiest:

Console.WriteLine(String.Join(",", CType(x.ToArray(GetType(String)), String())))

mspmsp's second solution is a nice approach as well but it's not working because it misses the AddressOf keyword. Also, Convert.ToString is rather inefficient (lots of unnecessary internal evaluations) and the Convert class is generally not very cleanly designed. I tend to avoid it, especially since it's completely redundant.

What underlies this JavaScript idiom: var self = this?

function Person(firstname, lastname) {
  this.firstname = firstname;

  this.lastname = lastname;
  this.getfullname = function () {
    return `${this.firstname}   ${this.lastname}`;
  };

  let that = this;
  this.sayHi = function() {
    console.log(`i am this , ${this.firstname}`);
    console.log(`i am that , ${that.firstname}`);
  };
}

let thisss = new Person('thatbetty', 'thatzhao');

let thatt = {firstname: 'thisbetty', lastname: 'thiszhao'};

thisss.sayHi.call(thatt);

Check synchronously if file/directory exists in Node.js

The answer to this question has changed over the years. The current answer is here at the top, followed by the various answers over the years in chronological order:

Current Answer

You can use fs.existsSync():

const fs = require("fs"); // Or `import fs from "fs";` with ESM
if (fs.existsSync(path)) {
    // Do something
}

It was deprecated for several years, but no longer is. From the docs:

Note that fs.exists() is deprecated, but fs.existsSync() is not. (The callback parameter to fs.exists() accepts parameters that are inconsistent with other Node.js callbacks. fs.existsSync() does not use a callback.)

You've specifically asked for a synchronous check, but if you can use an asynchronous check instead (usually best with I/O), use fs.promises.access if you're using async functions or fs.access (since exists is deprecated) if not:

In an async function:

try {
    await fs.promises.access("somefile");
    // The check succeeded
} catch (error) {
    // The check failed
}

Or with a callback:

fs.access("somefile", error => {
    if (!error) {
        // The check succeeded
    } else {
        // The check failed
    }
});

Historical Answers

Here are the historical answers in chronological order:

  • Original answer from 2010
    (stat/statSync or lstat/lstatSync)
  • Update September 2012
    (exists/existsSync)
  • Update February 2015
    (Noting impending deprecation of exists/existsSync, so we're probably back to stat/statSync or lstat/lstatSync)
  • Update December 2015
    (There's also fs.access(path, fs.F_OK, function(){}) / fs.accessSync(path, fs.F_OK), but note that if the file/directory doesn't exist, it's an error; docs for fs.stat recommend using fs.access if you need to check for existence without opening)
  • Update December 2016
    fs.exists() is still deprecated but fs.existsSync() is no longer deprecated. So you can safely use it now.

Original answer from 2010:

You can use statSync or lstatSync (docs link), which give you an fs.Stats object. In general, if a synchronous version of a function is available, it will have the same name as the async version with Sync at the end. So statSync is the synchronous version of stat; lstatSync is the synchronous version of lstat, etc.

lstatSync tells you both whether something exists, and if so, whether it's a file or a directory (or in some file systems, a symbolic link, block device, character device, etc.), e.g. if you need to know if it exists and is a directory:

var fs = require('fs');
try {
    // Query the entry
    stats = fs.lstatSync('/the/path');

    // Is it a directory?
    if (stats.isDirectory()) {
        // Yes it is
    }
}
catch (e) {
    // ...
}

...and similarly, if it's a file, there's isFile; if it's a block device, there's isBlockDevice, etc., etc. Note the try/catch; it throws an error if the entry doesn't exist at all.

If you don't care what the entry is and only want to know whether it exists, you can use path.existsSync (or with latest, fs.existsSync) as noted by user618408:

var path = require('path');
if (path.existsSync("/the/path")) { // or fs.existsSync
    // ...
}

It doesn't require a try/catch but gives you no information about what the thing is, just that it's there. path.existsSync was deprecated long ago.


Side note: You've expressly asked how to check synchronously, so I've used the xyzSync versions of the functions above. But wherever possible, with I/O, it really is best to avoid synchronous calls. Calls into the I/O subsystem take significant time from a CPU's point of view. Note how easy it is to call lstat rather than lstatSync:

// Is it a directory?
lstat('/the/path', function(err, stats) {
    if (!err && stats.isDirectory()) {
        // Yes it is
    }
});

But if you need the synchronous version, it's there.

Update September 2012

The below answer from a couple of years ago is now a bit out of date. The current way is to use fs.existsSync to do a synchronous check for file/directory existence (or of course fs.exists for an asynchronous check), rather than the path versions below.

Example:

var fs = require('fs');

if (fs.existsSync(path)) {
    // Do something
}

// Or

fs.exists(path, function(exists) {
    if (exists) {
        // Do something
    }
});

Update February 2015

And here we are in 2015 and the Node docs now say that fs.existsSync (and fs.exists) "will be deprecated". (Because the Node folks think it's dumb to check whether something exists before opening it, which it is; but that's not the only reason for checking whether something exists!)

So we're probably back to the various stat methods... Until/unless this changes yet again, of course.

Update December 2015

Don't know how long it's been there, but there's also fs.access(path, fs.F_OK, ...) / fs.accessSync(path, fs.F_OK). And at least as of October 2016, the fs.stat documentation recommends using fs.access to do existence checks ("To check if a file exists without manipulating it afterwards, fs.access() is recommended."). But note that the access not being available is considered an error, so this would probably be best if you're expecting the file to be accessible:

var fs = require('fs');

try {
    fs.accessSync(path, fs.F_OK);
    // Do something
} catch (e) {
    // It isn't accessible
}

// Or

fs.access(path, fs.F_OK, function(err) {
    if (!err) {
        // Do something
    } else {
        // It isn't accessible
    }
});

Update December 2016

You can use fs.existsSync():

if (fs.existsSync(path)) {
    // Do something
}

It was deprecated for several years, but no longer is. From the docs:

Note that fs.exists() is deprecated, but fs.existsSync() is not. (The callback parameter to fs.exists() accepts parameters that are inconsistent with other Node.js callbacks. fs.existsSync() does not use a callback.)

What is the difference between resource and endpoint?

Consider a server which has the information of users, missions and their reward points.

  1. Users and Reward Points are the resources
  2. An end point can relate to more than one resource
  3. Endpoints can be described using either a description or a full or partial URL

enter image description here

Source: API Endpoints vs Resources

Dynamic SELECT TOP @var In SQL Server

Its also possible to use dynamic SQL and execute it with the exec command:

declare @sql  nvarchar(200), @count int
set @count = 10
set @sql = N'select top ' + cast(@count as nvarchar(4)) + ' * from table'
exec (@sql)

How to convert NSNumber to NSString

//An example of implementation :
// we set the score of one player to a value
[Game getCurrent].scorePlayer1 = [NSNumber numberWithInteger:1];
// We copy the value in a NSNumber
NSNumber *aNumber = [Game getCurrent].scorePlayer1;
// Conversion of the NSNumber aNumber to a String with stringValue
NSString *StringScorePlayer1 = [aNumber stringValue];

How to do the Recursive SELECT query in MySQL?

If you want to be able to have a SELECT without problems of the parent id having to be lower than child id, a function could be used. It supports also multiple children (as a tree should do) and the tree can have multiple heads. It also ensure to break if a loop exists in the data.

I wanted to use dynamic SQL to be able to pass the table/columns names, but functions in MySQL don't support this.

DELIMITER $$

CREATE FUNCTION `isSubElement`(pParentId INT, pId INT) RETURNS int(11)
DETERMINISTIC    
READS SQL DATA
BEGIN
DECLARE isChild,curId,curParent,lastParent int;
SET isChild = 0;
SET curId = pId;
SET curParent = -1;
SET lastParent = -2;

WHILE lastParent <> curParent AND curParent <> 0 AND curId <> -1 AND curParent <> pId AND isChild = 0 DO
    SET lastParent = curParent;
    SELECT ParentId from `test` where id=curId limit 1 into curParent;

    IF curParent = pParentId THEN
        SET isChild = 1;
    END IF;
    SET curId = curParent;
END WHILE;

RETURN isChild;
END$$

Here, the table test has to be modified to the real table name and the columns (ParentId,Id) may have to be adjusted for your real names.

Usage :

SET @wantedSubTreeId = 3;
SELECT * FROM test WHERE isSubElement(@wantedSubTreeId,id) = 1 OR ID = @wantedSubTreeId;

Result :

3   7   k
5   3   d
9   3   f
1   5   a

SQL for test creation :

CREATE TABLE IF NOT EXISTS `test` (
  `Id` int(11) NOT NULL,
  `ParentId` int(11) DEFAULT NULL,
  `Name` varchar(300) NOT NULL,
  PRIMARY KEY (`Id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1;

insert into test (id, parentid, name) values(3,7,'k');
insert into test (id, parentid, name) values(5,3,'d');
insert into test (id, parentid, name) values(9,3,'f');
insert into test (id, parentid, name) values(1,5,'a');
insert into test (id, parentid, name) values(6,2,'o');
insert into test (id, parentid, name) values(2,8,'c');

EDIT : Here is a fiddle to test it yourself. It forced me to change the delimiter using the predefined one, but it works.

Convert ASCII number to ASCII Character in C

You can assign int to char directly.

int a = 65;
char c = a;
printf("%c", c);

In fact this will also work.

printf("%c", a);  // assuming a is in valid range

EnterKey to press button in VBA Userform

Use the TextBox's Exit event handler:

Private Sub TextBox1_Exit(ByVal Cancel As MSForms.ReturnBoolean)
    Logincode_Click  
End Sub

How do I serialize a C# anonymous type to a JSON string?

Assuming you are using this for a web service, you can just apply the following attribute to the class:

[System.Web.Script.Services.ScriptService]

Then the following attribute to each method that should return Json:

[ScriptMethod(ResponseFormat = ResponseFormat.Json)]

And set the return type for the methods to be "object"

Decoding base64 in batch

Here's a batch file, called base64encode.bat, that encodes base64.

@echo off
if not "%1" == "" goto :arg1exists
echo usage: base64encode input-file [output-file]
goto :eof
:arg1exists
set base64out=%2
if "%base64out%" == "" set base64out=con 
(
  set base64tmp=base64.tmp
  certutil -encode "%1" %base64tmp% > nul
  findstr /v /c:- %base64tmp%
  erase %base64tmp%
) > %base64out%

Changing upload_max_filesize on PHP

This solution can be applied only if the issue is on a WordPress installation!

If you don't have FTP access or too lazy to edit files,

You can use Increase Maximum Upload File Size plugin to increase the maximum upload file size.

Go to "next" iteration in JavaScript forEach loop

You can simply return if you want to skip the current iteration.

Since you're in a function, if you return before doing anything else, then you have effectively skipped execution of the code below the return statement.

Stretch horizontal ul to fit width of div

inelegant (but effective) way: use percentages

#horizontal-style {
    width: 100%;
}

li {
    width: 20%;
}

This only works with the 5 <li> example. For more or less, modify your percentage accordingly. If you have other <li>s on your page, you can always assign these particular ones a class of "menu-li" so that only they are affected.

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

READ AT LEAST THE FIRST PARA HERE!

I know this is 3 years too late, but Matt's (accepted) answer is incomplete and will eventually get you into trouble. The key here is that, if you choose to use multipart/form-data, the boundary must not appear in the file data that the server eventually receives.

This is not a problem for application/x-www-form-urlencoded, because there is no boundary. x-www-form-urlencoded can also always handle binary data, by the simple expedient of turning one arbitrary byte into three 7BIT bytes. Inefficient, but it works (and note that the comment about not being able to send filenames as well as binary data is incorrect; you just send it as another key/value pair).

The problem with multipart/form-data is that the boundary separator must not be present in the file data (see RFC 2388; section 5.2 also includes a rather lame excuse for not having a proper aggregate MIME type that avoids this problem).

So, at first sight, multipart/form-data is of no value whatsoever in any file upload, binary or otherwise. If you don't choose your boundary correctly, then you will eventually have a problem, whether you're sending plain text or raw binary - the server will find a boundary in the wrong place, and your file will be truncated, or the POST will fail.

The key is to choose an encoding and a boundary such that your selected boundary characters cannot appear in the encoded output. One simple solution is to use base64 (do not use raw binary). In base64 3 arbitrary bytes are encoded into four 7-bit characters, where the output character set is [A-Za-z0-9+/=] (i.e. alphanumerics, '+', '/' or '='). = is a special case, and may only appear at the end of the encoded output, as a single = or a double ==. Now, choose your boundary as a 7-bit ASCII string which cannot appear in base64 output. Many choices you see on the net fail this test - the MDN forms docs, for example, use "blob" as a boundary when sending binary data - not good. However, something like "!blob!" will never appear in base64 output.

Validate email with a regex in jQuery

You probably want to use a regex like the one described here to check the format. When the form's submitted, run the following test on each field:

var userinput = $(this).val();
var pattern = /^\b[A-Z0-9._%-]+@[A-Z0-9.-]+\.[A-Z]{2,4}\b$/i

if(!pattern.test(userinput))
{
  alert('not a valid e-mail address');
}?

Image vs zImage vs uImage

What is the difference between them?

Image: the generic Linux kernel binary image file.

zImage: a compressed version of the Linux kernel image that is self-extracting.

uImage: an image file that has a U-Boot wrapper (installed by the mkimage utility) that includes the OS type and loader information.
A very common practice (e.g. the typical Linux kernel Makefile) is to use a zImage file. Since a zImage file is self-extracting (i.e. needs no external decompressors), the wrapper would indicate that this kernel is "not compressed" even though it actually is.


Note that the author/maintainer of U-Boot considers the (widespread) use of using a zImage inside a uImage questionable:

Actually it's pretty stupid to use a zImage inside an uImage. It is much better to use normal (uncompressed) kernel image, compress it using just gzip, and use this as poayload for mkimage. This way U-Boot does the uncompresiong instead of including yet another uncompressor with each kernel image.

(quoted from https://lists.yoctoproject.org/pipermail/yocto/2013-October/016778.html)


Which type of kernel image do I have to use?

You could choose whatever you want to program for.
For economy of storage, you should probably chose a compressed image over the uncompressed one.
Beware that executing the kernel (presumably the Linux kernel) involves more than just loading the kernel image into memory. Depending on the architecture (e.g. ARM) and the Linux kernel version (e.g. with or without DTB), there are registers and memory buffers that may have to be prepared for the kernel. In one instance there was also hardware initialization that U-Boot performed that had to be replicated.

ADDENDUM

I know that u-boot needs a kernel in uImage format.

That is accurate for all versions of U-Boot which only have the bootm command.
But more recent versions of U-Boot could also have the bootz command that can boot a zImage.

JUNIT testing void methods

If your method is void and you want to check for an exception, you could use expected: https://weblogs.java.net/blog/johnsmart/archive/2009/09/27/testing-exceptions-junit-47

javascript: get a function's variable's value within another function

nameContent only exists within the first() function, as you defined it within the first() function.

To make its scope broader, define it outside of the functions:

var nameContent;

function first(){
    nameContent=document.getElementById('full_name').value;
}

function second() {
    first();
    y=nameContent; alert(y);
}
second();

A slightly better approach would be to return the value, as global variables get messy very quickly:

function getFullName() {
  return document.getElementById('full_name').value;
}

function doStuff() {
  var name = getFullName();

  alert(name);
}

doStuff();

Dynamically load a JavaScript file

all the major javascript libraries like jscript, prototype, YUI have support for loading script files. For example, in YUI, after loading the core you can do the following to load the calendar control

var loader = new YAHOO.util.YUILoader({

    require: ['calendar'], // what components?

    base: '../../build/',//where do they live?

    //filter: "DEBUG",  //use debug versions (or apply some
                        //some other filter?

    //loadOptional: true, //load all optional dependencies?

    //onSuccess is the function that YUI Loader
    //should call when all components are successfully loaded.
    onSuccess: function() {
        //Once the YUI Calendar Control and dependencies are on
        //the page, we'll verify that our target container is 
        //available in the DOM and then instantiate a default
        //calendar into it:
        YAHOO.util.Event.onAvailable("calendar_container", function() {
            var myCal = new YAHOO.widget.Calendar("mycal_id", "calendar_container");
            myCal.render();
        })
     },

    // should a failure occur, the onFailure function will be executed
    onFailure: function(o) {
        alert("error: " + YAHOO.lang.dump(o));
    }

 });

// Calculate the dependency and insert the required scripts and css resources
// into the document
loader.insert();

Convert Java string to Time, NOT Date

You might consider Joda Time or Java 8, which has a type called LocalTime specifically for a time of day without a date component.

Example code in Joda-Time 2.7/Java 8.

LocalTime t = LocalTime.parse( "17:40" ) ;

What is the easiest way to ignore a JPA field during persistence?

This answer comes a little late, but it completes the response.

In order to avoid a field from an entity to be persisted in DB one can use one of the two mechanisms:

@Transient - the JPA annotation marking a field as not persistable

transient keyword in java. Beware - using this keyword, will prevent the field to be used with any serialization mechanism from java. So, if the field must be serialized you'd better use just the @Transient annotation.

How can I get a JavaScript stack trace when I throw an exception?

I don't think there's anything built in that you can use however I did find lots of examples of people rolling their own.

No Title Bar Android Theme

 this.requestWindowFeature(getWindow().FEATURE_NO_TITLE);

Java ResultSet how to check if there are any results

You would usually do something like this:

while ( resultSet.next() ) { 
   // Read the next item
   resultSet.getString("columnName");
}

If you want to report an empty set, add a variable counting the items read. If you only need to read a single item, then your code is adequate.

Should composer.lock be committed to version control?

If you’re concerned about your code breaking, you should commit the composer.lock to your version control system to ensure all your project collaborators are using the same version of the code. Without a lock file, you will get new third-party code being pulled down each time.

The exception is when you use a meta apps, libraries where the dependencies should be updated on install (like the Zend Framework 2 Skeleton App). So the aim is to grab the latest dependencies each time when you want to start developing.

Source: Composer: It’s All About the Lock File

See also: What are the differences between composer update and composer install?

Getting "Cannot call a class as a function" in my React Project

I had it when I did so :

function foo() (...) export default foo

correctly:

export default  () =>(...);

or

const foo = ...
export default foo

Scrolling an iframe with JavaScript?

Inspired by Nelson's and Chris' comments, I've found a way to workaround the same origin policy with a div and an iframe:

HTML:

<div id='div_iframe'><iframe id='frame' src='...'></iframe></div>

CSS:

#div_iframe {
  border-style: inset;
  border-color: grey;
  overflow: scroll;
  height: 500px;
  width: 90%
}

#frame {
  width: 100%;
  height: 1000%;   /* 10x the div height to embrace the whole page */
}

Now suppose I want to skip the first 438 (vertical) pixels of the iframe page, by scrolling to that position.

JS solution:

document.getElementById('div_iframe').scrollTop = 438

JQuery solution:

$('#div_iframe').scrollTop(438)

CSS solution:

#frame { margin-top: -438px }

(Each solution alone is enough, and the effect of the CSS one is a little different since you can't scroll up to see the top of the iframed page.)

How do I get the n-th level parent of an element in jQuery?

You could give the target parent an id or class (e.g. myParent) and reference is with $('#element').parents(".myParent")

.gitignore after commit

However, will it automatically remove these committed files from the repository?

No.

The 'best' recipe to do this is using git filter-branch as written about here:

The man page for git-filter-branch contains comprehensive examples.

Note You'll be re-writing history. If you had published any revisions containing the accidentally added files, this could create trouble for users of those public branches. Inform them, or perhaps think about how badly you need to remove the files.

Note In the presence of tags, always use the --tag-name-filter cat option to git filter-branch. It never hurts and will save you the head-ache when you realize later taht you needed it

Javascript geocoding from address to latitude and longitude numbers not working

You're accessing the latitude and longitude incorrectly.

Try

<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">

var geocoder = new google.maps.Geocoder();
var address = "new york";

geocoder.geocode( { 'address': address}, function(results, status) {

  if (status == google.maps.GeocoderStatus.OK) {
    var latitude = results[0].geometry.location.lat();
    var longitude = results[0].geometry.location.lng();
    alert(latitude);
  } 
}); 
</script>

How to send string from one activity to another?

In order to insert the text from activity2 to activity1, you first need to create a visit function in activity2.

public void visitactivity1()
{
    Intent i = new Intent(this, activity1.class);
    i.putExtra("key", message);
    startActivity(i);
}

After creating this function, you need to call it from your onCreate() function of activity2:

visitactivity1();

Next, go on to the activity1 Java file. In its onCreate() function, create a Bundle object, fetch the earlier message via its key through this object, and store it in a String.

    Bundle b = getIntent().getExtras();
    String message = b.getString("key", ""); // the blank String in the second parameter is the default value of this variable. In case the value from previous activity fails to be obtained, the app won't crash: instead, it'll go with the default value of an empty string

Now put this element in a TextView or EditText, or whichever layout element you prefer using the setText() function.

Sending GET request with Authentication headers using restTemplate

All of these answers appear to be incomplete and/or kludges. Looking at the RestTemplate interface, it sure looks like it is intended to have a ClientHttpRequestFactory injected into it, and then that requestFactory will be used to create the request, including any customizations of headers, body, and request params.

You either need a universal ClientHttpRequestFactory to inject into a single shared RestTemplate or else you need to get a new template instance via new RestTemplate(myHttpRequestFactory).

Unfortunately, it looks somewhat non-trivial to create such a factory, even when you just want to set a single Authorization header, which is pretty frustrating considering what a common requirement that likely is, but at least it allows easy use if, for example, your Authorization header can be created from data contained in a Spring-Security Authorization object, then you can create a factory that sets the outgoing AuthorizationHeader on every request by doing SecurityContextHolder.getContext().getAuthorization() and then populating the header, with null checks as appropriate. Now all outbound rest calls made with that RestTemplate will have the correct Authorization header.

Without more emphasis placed on the HttpClientFactory mechanism, providing simple-to-overload base classes for common cases like adding a single header to requests, most of the nice convenience methods of RestTemplate end up being a waste of time, since they can only rarely be used.

I'd like to see something simple like this made available

@Configuration
public class MyConfig {
  @Bean
  public RestTemplate getRestTemplate() {
    return new RestTemplate(new AbstractHeaderRewritingHttpClientFactory() {
        @Override
        public HttpHeaders modifyHeaders(HttpHeaders headers) {
          headers.addHeader("Authorization", computeAuthString());
          return headers;
        }
        public String computeAuthString() {
          // do something better than this, but you get the idea
          return SecurityContextHolder.getContext().getAuthorization().getCredential();
        }
    });
  }
}

At the moment, the interface of the available ClientHttpRequestFactory's are harder to interact with than that. Even better would be an abstract wrapper for existing factory implementations which makes them look like a simpler object like AbstractHeaderRewritingRequestFactory for the purposes of replacing just that one piece of functionality. Right now, they are very general purpose such that even writing those wrappers is a complex piece of research.

Global variable Python classes

What you have is correct, though you will not call it global, it is a class attribute and can be accessed via class e.g Shape.lolwut or via an instance e.g. shape.lolwut but be careful while setting it as it will set an instance level attribute not class attribute

class Shape(object):
    lolwut = 1

shape = Shape()

print Shape.lolwut,  # 1
print shape.lolwut,  # 1

# setting shape.lolwut would not change class attribute lolwut 
# but will create it in the instance
shape.lolwut = 2

print Shape.lolwut,  # 1
print shape.lolwut,  # 2

# to change class attribute access it via class
Shape.lolwut = 3

print Shape.lolwut,  # 3
print shape.lolwut   # 2 

output:

1 1 1 2 3 2

Somebody may expect output to be 1 1 2 2 3 3 but it would be incorrect

What is the difference between a deep copy and a shallow copy?

In object oriented programming, a type includes a collection of member fields. These fields may be stored either by value or by reference (i.e., a pointer to a value).

In a shallow copy, a new instance of the type is created and the values are copied into the new instance. The reference pointers are also copied just like the values. Therefore, the references are pointing to the original objects. Any changes to the members that are stored by reference appear in both the original and the copy, since no copy was made of the referenced object.

In a deep copy, the fields that are stored by value are copied as before, but the pointers to objects stored by reference are not copied. Instead, a deep copy is made of the referenced object, and a pointer to the new object is stored. Any changes that are made to those referenced objects will not affect other copies of the object.

In C#, can a class inherit from another class and an interface?

Yes. Try:

class USBDevice : GenericDevice, IOurDevice

Note: The base class should come before the list of interface names.

Of course, you'll still need to implement all the members that the interfaces define. However, if the base class contains a member that matches an interface member, the base class member can work as the implementation of the interface member and you are not required to manually implement it again.

How to synchronize a static variable among threads running different instances of a class in Java?

We can also use ReentrantLock to achieve the synchronization for static variables.

public class Test {

    private static int count = 0;
    private static final ReentrantLock reentrantLock = new ReentrantLock(); 
    public void foo() {  
        reentrantLock.lock();
        count = count + 1;
        reentrantLock.unlock();
    }  
}

How to create a new text file using Python

    file = open("path/of/file/(optional)/filename.txt", "w") #a=append,w=write,r=read
    any_string = "Hello\nWorld"
    file.write(any_string)
    file.close()

“tag already exists in the remote" error after recreating the git tag

Some good answers here. Especially the one by @torek. I thought I'd add this work-around with a little explanation for those in a rush.

To summarize, what happens is that when you move a tag locally, it changes the tag from a non-Null commit value to a different value. However, because git (as a default behavior) doesn't allow changing non-Null remote tags, you can't push the change.

The work-around is to delete the tag (and tick remove all remotes). Then create the same tag and push.

How to search for string in an array

Completing remark to Jimmy Pena's accepted answer

As SeanC points out, this must be a 1-D array.

The following example call demonstrates that the IsInArray() function cannot be called only for 1-dim arrays, but also for "flat" 2-dim arrays:

Sub TestIsInArray()
    Const SearchItem As String = "ghi"
    Debug.Print "SearchItem = '" & SearchItem & "'"
    '----
    'a) Test 1-dim array
    Dim Arr As Variant
    Arr = Split("abc,def,ghi,jkl", ",")
    Debug.Print "a) 1-dim array " & vbNewLine & "   " & Join(Arr, "|") & " ~~> " & IsInArray(SearchItem, Arr)
    '----
    
        '//quick tool to create a 2-dim 1-based array
        Dim v As Variant, vals As Variant                                       
        v = Array(Array("abc", "def", "dummy", "jkl", 5), _
                  Array("mno", "pqr", "stu", "ghi", "vwx"))
        v = Application.Index(v, 0, 0)  ' create 2-dim array (2 rows, 5 cols)
    
    'b) Test "flat" 2-dim arrays
    Debug.Print "b) ""flat"" 2-dim arrays "
    Dim i As Long
    For i = LBound(v) To UBound(v)
        'slice "flat" 2-dim arrays of one row each
        vals = Application.Index(v, i, 0)
        'check for findings
        Debug.Print Format(i, "   0"), Join(vals, "|") & " ~~> " & IsInArray(SearchItem, vals)
    Next i
End Sub
Function IsInArray(stringToBeFound As String, Arr As Variant) As Boolean
'Site: https://stackoverflow.com/questions/10951687/how-to-search-for-string-in-an-array/10952705
'Note: needs a "flat" array, not necessarily a 1-dimensioned array
  IsInArray = (UBound(Filter(Arr, stringToBeFound)) > -1)
End Function

Results in VB Editor's immediate window

SearchItem = 'ghi'
a) 1-dim array 
   abc|def|ghi|jkl ~~> Wahr
b) "flat" 2-dim arrays 
   1          abc|def|dummy|jkl|5         False
   2          mno|pqr|stu|ghi|vwx         True

How to read a Parquet file into Pandas DataFrame?

Update: since the time I answered this there has been a lot of work on this look at Apache Arrow for a better read and write of parquet. Also: http://wesmckinney.com/blog/python-parquet-multithreading/

There is a python parquet reader that works relatively well: https://github.com/jcrobak/parquet-python

It will create python objects and then you will have to move them to a Pandas DataFrame so the process will be slower than pd.read_csv for example.

Difference between two numpy arrays in python

You can also use numpy.subtract

It has the advantage over the difference operator, -, that you do not have to transform the sequences (list or tuples) into a numpy arrays — you save the two commands:

array1 = np.array([1.1, 2.2, 3.3])
array2 = np.array([1, 2, 3])

Example: (Python 3.5)

import numpy as np
result = np.subtract([1.1, 2.2, 3.3], [1, 2, 3])
print ('the difference =', result)

which gives you

the difference = [ 0.1  0.2  0.3]

Remember, however, that if you try to subtract sequences (lists or tuples) with the - operator you will get an error. In this case, you need the above commands to transform the sequences in numpy arrays

Wrong Code:

print([1.1, 2.2, 3.3] - [1, 2, 3])

How to get data from database in javascript based on the value passed to the function

'SELECT * FROM Employ where number = ' + parseInt(val, 10) + ';'

For example, if val is "10" then this will end up building the string:

"SELECT * FROM Employ where number = 10;"

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

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

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

  2. On remote server, load image into docker:

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

jQuery UI Dialog - missing close icon

  just add in css
 .ui-icon-closethick{
 margin-top: -8px!important;
margin-left: -8px!important;

}

Make body have 100% of the browser height

Try setting the height of the html element to 100% as well.

html, 
body {
    height: 100%;
}

Body looks to its parent (HTML) for how to scale the dynamic property, so the HTML element needs to have its height set as well.

However the content of body will probably need to change dynamically. Setting min-height to 100% will accomplish this goal.

html {
  height: 100%;
}
body {
  min-height: 100%;
}

Selecting a Linux I/O Scheduler

You can set this at boot by adding the "elevator" parameter to the kernel cmdline (such as in grub.cfg)

Example:

elevator=deadline

This will make "deadline" the default I/O scheduler for all block devices.

If you'd like to query or change the scheduler after the system has booted, or would like to use a different scheduler for a specific block device, I recommend installing and use the tool ioschedset to make this easy.

https://github.com/kata198/ioschedset

If you're on Archlinux it's available in aur:

https://aur.archlinux.org/packages/ioschedset

Some example usage:

# Get i/o scheduler for all block devices
[username@hostname ~]$ io-get-sched
sda:    bfq
sr0:    bfq

# Query available I/O schedulers
[username@hostname ~]$ io-set-sched --list
mq-deadline kyber bfq none

# Set sda to use "kyber"
[username@hostname ~]$ io-set-sched kyber /dev/sda
Must be root to set IO Scheduler. Rerunning under sudo...

[sudo] password for username:
+ Successfully set sda to 'kyber'!

# Get i/o scheduler for all block devices to assert change
[username@hostname ~]$ io-get-sched
sda:    kyber
sr0:    bfq

# Set all block devices to use 'deadline' i/o scheduler
[username@hostname ~]$ io-set-sched deadline
Must be root to set IO Scheduler. Rerunning under sudo...

+ Successfully set sda to 'deadline'!
+ Successfully set sr0 to 'deadline'!

# Get the current block scheduler just for sda
[username@hostname ~]$ io-get-sched sda
sda:    mq-deadline

Usage should be self-explanatory. The tools are standalone and only require bash.

Hope this helps!

EDIT: Disclaimer, these are scripts I wrote.

Change Git repository directory location.

A more Git based approach would be to make the changes to your local copy using cd or copy and pasting and then pushing these changes from local to remote repository.

If you try checking status of your local repo, it may show "untracked changes" which are actually the relocated files. To push these changes forcefully, you need to stage these files/directories by using

$ git add -A
#And commiting them
$ git commit -m "Relocating image demo files"
#And finally, push
$ git push -u local_repo -f HEAD:master

Hope it helps.

How do I request and process JSON with python?

For anything with requests to URLs you might want to check out requests. For JSON in particular:

>>> import requests
>>> r = requests.get('https://github.com/timeline.json')
>>> r.json()
[{u'repository': {u'open_issues': 0, u'url': 'https://github.com/...

How to grep for two words existing on the same line?

Prescription

One simple rewrite of the command in the question is:

grep "word1" logs | grep "word2"

The first grep finds lines with 'word1' from the file 'logs' and then feeds those into the second grep which looks for lines containing 'word2'.

However, it isn't necessary to use two commands like that. You could use extended grep (grep -E or egrep):

grep -E 'word1.*word2|word2.*word1' logs

If you know that 'word1' will precede 'word2' on the line, you don't even need the alternatives and regular grep would do:

grep 'word1.*word2' logs

The 'one command' variants have the advantage that there is only one process running, and so the lines containing 'word1' do not have to be passed via a pipe to the second process. How much this matters depends on how big the data file is and how many lines match 'word1'. If the file is small, performance isn't likely to be an issue and running two commands is fine. If the file is big but only a few lines contain 'word1', there isn't going to be much data passed on the pipe and using two command is fine. However, if the file is huge and 'word1' occurs frequently, then you may be passing significant data down the pipe where a single command avoids that overhead. Against that, the regex is more complex; you might need to benchmark it to find out what's best — but only if performance really matters. If you run two commands, you should aim to select the less frequently occurring word in the first grep to minimize the amount of data processed by the second.

Diagnosis

The initial script is:

grep -c "word1" | grep -r "word2" logs

This is an odd command sequence. The first grep is going to count the number of occurrences of 'word1' on its standard input, and print that number on its standard output. Until you indicate EOF (e.g. by typing Control-D), it will sit there, waiting for you to type something. The second grep does a recursive search for 'word2' in the files underneath directory logs (or, if it is a file, in the file logs). Or, in my case, it will fail since there's neither a file nor a directory called logs where I'm running the pipeline. Note that the second grep doesn't read its standard input at all, so the pipe is superfluous.

With Bash, the parent shell waits until all the processes in the pipeline have exited, so it sits around waiting for the grep -c to finish, which it won't do until you indicate EOF. Hence, your code seems to get stuck. With Heirloom Shell, the second grep completes and exits, and the shell prompts again. Now you have two processes running, the first grep and the shell, and they are both trying to read from the keyboard, and it is not determinate which one gets any given line of input (or any given EOF indication).

Note that even if you typed data as input to the first grep, you would only get any lines that contain 'word2' shown on the output.


Footnote:

At one time, the answer used:

grep -E 'word1.*word2|word2.*word1' "$@"
grep 'word1.*word2' "$@"

This triggered the comments below.

How to access model hasMany Relation with where condition?

I think that this is the correct way:

class Game extends Eloquent {
    // many more stuff here

    // relation without any constraints ...works fine 
    public function videos() {
        return $this->hasMany('Video');
    }

    // results in a "problem", se examples below
    public function available_videos() {
        return $this->videos()->where('available','=', 1);
    }
}

And then you'll have to

$game = Game::find(1);
var_dump( $game->available_videos()->get() );

Error Importing SSL certificate : Not an X.509 Certificate

This seems like an old thread, but I'll add my experience here. I tried to install a cert as well and got that error. I then opened the cer file with a txt editor, and noticed that there is an extra space (character) at the end of each line. Removing those lines allowed me to import the cert.

Hope this is worth something to someone else.

Visual Studio popup: "the operation could not be completed"

I think StyleCop is the reason of the this issue. So,

  1. Close VS.
  2. I removed all StyleCop.Settings and StyleCop.Cache files in all solution projects.
  3. I removed also all projects *.csproj.user file.
  4. Restart VS.

How to get pip to work behind a proxy server

The pip's proxy parameter is, according to pip --help, in the form scheme://[user:passwd@]proxy.server:port

You should use the following:

pip install --proxy http://user:password@proxyserver:port TwitterApi

Also, the HTTP_PROXY env var should be respected.

Note that in earlier versions (couldn't track down the change in the code, sorry, but the doc was updated here), you had to leave the scheme:// part out for it to work, i.e. pip install --proxy user:password@proxyserver:port

How to check size of a file using Bash?

alternative solution with awk and double parenthesis:

FILENAME=file.txt
SIZE=$(du -sb $FILENAME | awk '{ print $1 }')

if ((SIZE<90000)) ; then 
    echo "less"; 
else 
    echo "not less"; 
fi

Remove last characters from a string in C#. An elegant way?

Use:

public static class StringExtensions
{
    /// <summary>
    /// Cut End. "12".SubstringFromEnd(1) -> "1"
    /// </summary>
    public static string SubstringFromEnd(this string value, int startindex)
    {
        if (string.IsNullOrEmpty(value)) return value;
        return value.Substring(0, value.Length - startindex);
    }
}

I prefer an extension method here for two reasons:

  1. I can chain it with Substring. Example: f1.Substring(directorypathLength).SubstringFromEnd(1)
  2. Speed.

Page scroll when soft keyboard popped up

put this inside your Manifest like this in No fullscreen Mode

android:windowSoftInputMode="stateVisible|adjustPan" 

in your manifest

<activity
    android:windowSoftInputMode="stateVisible|adjustPan"
    android:name="com.example.patronusgps.MainActivity"
    android:label="@string/app_name" >
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />

        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

How do I test if a string is empty in Objective-C?

I put this:

@implementation NSObject (AdditionalMethod)
-(BOOL) isNotEmpty
{
    return !(self == nil
    || [self isKindOfClass:[NSNull class]]
    || ([self respondsToSelector:@selector(length)]
        && [(NSData *)self length] == 0)
    || ([self respondsToSelector:@selector(count)]
        && [(NSArray *)self count] == 0));

};
@end

The problem is that if self is nil, this function is never called. It'll return false, which is desired.

OpenSSL and error in reading openssl.conf file

If you are seeing an error something like

error on line -1 c:apacheconfopenssl.cnf

try changing from back slash to front slash in the -config.

How to state in requirements.txt a direct github source

Normally your requirements.txt file would look something like this:

package-one==1.9.4
package-two==3.7.1
package-three==1.0.1
...

To specify a Github repo, you do not need the package-name== convention.

The examples below update package-two using a GitHub repo. The text between @ and # denotes the specifics of the package.

Specify commit hash (41b95ec in the context of updated requirements.txt):

package-one==1.9.4
git+git://github.com/path/to/package-two@41b95ec#egg=package-two
package-three==1.0.1

Specify branch name (master):

git+git://github.com/path/to/package-two@master#egg=package-two

Specify tag (0.1):

git+git://github.com/path/to/[email protected]#egg=package-two

Specify release (3.7.1):

git+git://github.com/path/to/package-two@releases/tag/v3.7.1#egg=package-two

Note that #egg=package-two is not a comment here, it is to explicitly state the package name

This blog post has some more discussion on the topic.

Can I use tcpdump to get HTTP requests, response header and response body?

I would recommend using Wireshark, which has a "Follow TCP Stream" option that makes it very easy to see the full requests and responses for a particular TCP connection. If you would prefer to use the command line, you can try tcpflow, a tool dedicated to capturing and reconstructing the contents of TCP streams.

Other options would be using an HTTP debugging proxy, like Charles or Fiddler as EricLaw suggests. These have the advantage of having specific support for HTTP to make it easier to deal with various sorts of encodings, and other features like saving requests to replay them or editing requests.

You could also use a tool like Firebug (Firefox), Web Inspector (Safari, Chrome, and other WebKit-based browsers), or Opera Dragonfly, all of which provide some ability to view the request and response headers and bodies (though most of them don't allow you to see the exact byte stream, but instead how the browsers parsed the requests).

And finally, you can always construct requests by hand, using something like telnet, netcat, or socat to connect to port 80 and type the request in manually, or a tool like htty to help easily construct a request and inspect the response.

how to set radio button checked in edit mode in MVC razor view

You have written like

@Html.RadioButtonFor(model => model.gender, "Male", new { @checked = true }) and
@Html.RadioButtonFor(model => model.gender, "Female", new { @checked = true })

Here you have taken gender as a Enum type and you have written the value for the radio button as a string type- change "Male" to 0 and "Female" to 1.

How to view the SQL queries issued by JPA?

With Spring Boot simply add: spring.jpa.show-sql=true to application.properties. This will show the query but without the actual parameters (you will see ? instead of each parameter).

How to specify legend position in matplotlib in graph coordinates

The loc parameter specifies in which corner of the bounding box the legend is placed. The default for loc is loc="best" which gives unpredictable results when the bbox_to_anchor argument is used.
Therefore, when specifying bbox_to_anchor, always specify loc as well.

The default for bbox_to_anchor is (0,0,1,1), which is a bounding box over the complete axes. If a different bounding box is specified, is is usually sufficient to use the first two values, which give (x0, y0) of the bounding box.

Below is an example where the bounding box is set to position (0.6,0.5) (green dot) and different loc parameters are tested. Because the legend extents outside the bounding box, the loc parameter may be interpreted as "which corner of the legend shall be placed at position given by the 2-tuple bbox_to_anchor argument".

enter image description here

import matplotlib.pyplot as plt
plt.rcParams["figure.figsize"] = 6, 3
fig, axes = plt.subplots(ncols=3)
locs = ["upper left", "lower left", "center right"]
for l, ax in zip(locs, axes.flatten()):
    ax.set_title(l)
    ax.plot([1,2,3],[2,3,1], "b-", label="blue")
    ax.plot([1,2,3],[1,2,1], "r-", label="red")
    ax.legend(loc=l, bbox_to_anchor=(0.6,0.5))
    ax.scatter((0.6),(0.5), s=81, c="limegreen", transform=ax.transAxes)

plt.tight_layout()    
plt.show()

See especially this answer for a detailed explanation and the question What does a 4-element tuple argument for 'bbox_to_anchor' mean in matplotlib? .


If you want to specify the legend position in other coordinates than axes coordinates, you can do so by using the bbox_transform argument. If may make sense to use figure coordinates

ax.legend(bbox_to_anchor=(1,0), loc="lower right",  bbox_transform=fig.transFigure)

It may not make too much sense to use data coordinates, but since you asked for it this would be done via bbox_transform=ax.transData.

How do you replace all the occurrences of a certain character in a string?

You really should have multiple input, e.g. one for firstname, middle names, lastname and another one for age. If you want to have some fun though you could try:

>>> input_given="join smith 25"
>>> chars="".join([i for i in input_given if not i.isdigit()])
>>> age=input_given.translate(None,chars)
>>> age
'25'
>>> name=input_given.replace(age,"").strip()
>>> name
'join smith'

This would of course fail if there is multiple numbers in the input. a quick check would be:

assert(age in input_given)

and also:

assert(len(name)<len(input_given))

How to install the current version of Go in Ubuntu Precise

I used following commands from GoLang official repository, it installed GoLang version 1.6 on my Ubuntu 14.04

sudo add-apt-repository ppa:ubuntu-lxc/lxd-stable
sudo apt-get update
sudo apt-get install golang

Reference official GoLang Repo https://github.com/golang/go/wiki/Ubuntu it seems this ppa will always be updated in future.

How to combine two vectors into a data frame

x <-c(1,2,3)
y <-c(100,200,300)
x_name <- "cond"
y_name <- "rating"

require(reshape2)
df <- melt(data.frame(x,y))
colnames(df) <- c(x_name, y_name)
print(df)

UPDATE (2017-02-07): As an answer to @cdaringe comment - there are multiple solutions possible, one of them is below.

library(dplyr)
library(magrittr)

x <- c(1, 2, 3)
y <- c(100, 200, 300)
z <- c(1, 2, 3, 4, 5)
x_name <- "cond"
y_name <- "rating"

# Helper function to create data.frame for the chunk of the data
prepare <- function(name, value, xname = x_name, yname = y_name) {
  data_frame(rep(name, length(value)), value) %>%
    set_colnames(c(xname, yname))
}

bind_rows(
  prepare("x", x),
  prepare("y", y),
  prepare("z", z)
)

How do I get the XML root node with C#?

I got the same question here. If the document is huge, it is not a good idea to use XmlDocument. The fact is that the first element is the root element, based on which XmlReader can be used to get the root element. Using XmlReader will be much more efficient than using XmlDocument as it doesn't require load the whole document into memory.

  using (XmlReader reader = XmlReader.Create(<your_xml_file>)) {
    while (reader.Read()) {
      // first element is the root element
      if (reader.NodeType == XmlNodeType.Element) {
        System.Console.WriteLine(reader.Name);
        break;
      }
    }
  }

Batch file: Find if substring is in string (not in a file)

The solutions that search a file for a substring can also search a string, eg. find or findstr.
In your case, the easy solution would be to pipe a string into the command instead of supplying a filename eg.

case-sensitive string:
echo "abcdefg" | find "bcd"

ignore case of string:
echo "abcdefg" | find /I "bcd"

IF no match found, you will get a blank line response on CMD and %ERRORLEVEL% set to 1

using href links inside <option> tag

(I don't have enough reputation to comment on toscho's answer.)

I have no experience with screen readers and I'm sure your points are valid.

However as far as using a keyboard to manipulate selects, it is trivial to select any option by using the keyboard:

TAB to the control

SPACE to open the select list

UP or DOWN arrows to scroll to the desired list item

ENTER to select the desired item

Only on ENTER does the onchange or (JQuery .change()) event fire.

While I personally would not use a form control for simple menus, there are many web applications that use form controls to change the presentation of the page (eg., sort order.) These can be implemented either by AJAX to load new content into the page, or, in older implementations, by triggering new page loads, which is essentially a page link.

IMHO these are valid uses of a form control.

Default keystore file does not exist?

go to ~/.android if there is no debug.keystore copy it from your project and paste it here then run command again.

How to check if "Radiobutton" is checked?

You can use switch like this:

XML Layout

<RadioGroup
            android:id="@+id/RG"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <RadioButton
                android:id="@+id/R1"
                android:layout_width="wrap_contnet"
                android:layout_height="wrap_content"
                android:text="R1" />

            <RadioButton
                android:id="@+id/R2"
                android:layout_width="wrap_contnet"
                android:layout_height="wrap_content"
                android:text="R2" />
</RadioGroup>

And JAVA Activity

switch (RG.getCheckedRadioButtonId()) {
        case R.id.R1:
            regAuxiliar = ultimoRegistro;
        case R.id.R2:
            regAuxiliar = objRegistro;
        default:
            regAuxiliar = null; // none selected
    }

You will also need to implement an onClick function with button or setOnCheckedChangeListener function to get required functionality.

Maven 3 Archetype for Project With Spring, Spring MVC, Hibernate, JPA

A great Spring MVC quickstart archetype is available on GitHub, courtesy of kolorobot. Good instructions are provided on how to install it to your local Maven repo and use it to create a new Spring MVC project. He’s even helpfully included the Tomcat 7 Maven plugin in the archetypical project so that the newly created Spring MVC can be run from the command line without having to manually deploy it to an application server.

Kolorobot’s example application includes the following:

  • No-xml Spring MVC 3.2 web application for Servlet 3.0 environment
  • Apache Tiles with configuration in place,
  • Bootstrap
  • JPA 2.0 (Hibernate/HSQLDB)
  • JUnit/Mockito
  • Spring Security 3.1

What is the difference between YAML and JSON?

I find both YAML and JSON to be very effective. The only two things that really dictate when one is used over the other for me is one, what the language is used most popularly with. For example, if I'm using Java, Javascript, I'll use JSON. For Java, I'll use their own objects, which are pretty much JSON but lacking in some features, and convert it to JSON if I need to or make it in JSON in the first place. I do that because that's a common thing in Java and makes it easier for other Java developers to modify my code. The second thing is whether I'm using it for the program to remember attributes, or if the program is receiving instructions in the form of a config file, in this case I'll use YAML, because it's very easily human read, has nice looking syntax, and is very easy to modify, even if you have no idea how YAML works. Then, the program will read it and convert it to JSON, or whatever is preferred for that language.

In the end, it honestly doesn't matter. Both JSON and YAML are easily read by any experienced programmer.

Open another page in php

<?php
    header("Location: index.html");
?>

Just make sure nothing is actually written to the page prior to this code, or it won't work.

SVN: Is there a way to mark a file as "do not commit"?

I don't believe there is a way to ignore a file in the repository. We often run into this with web.config and other configuration files.

Although not perfect, the solution I most often see and use is to have .default file and an nant task to create local copies.

For example, in the repo is a file called web.config.default that has default values. Then create a nant task that will rename all the web.config.default files to web.config that can then be customized to local values. This task should be called when a new working copy is retrieved or a build is run.

You'll also need to ignore the web.config file that is created so that it isn't committed to the repository.

How to simulate "Press any key to continue?"

You could use the Microsoft-specific function _getch:

#include <iostream>
#include <conio.h>
// ...
// ...
// ...
cout << "Press any key to continue..." << endl;
_getch();
cout << "Something" << endl;

How to list all tags along with the full message in git?

It's far from pretty, but you could create a script or an alias that does something like this:

for c in $(git for-each-ref refs/tags/ --format='%(refname)'); do echo $c; git show --quiet "$c"; echo; done

How to insert a row in an HTML table body in JavaScript

If you want to add a row into the tbody, get a reference to it and call its insertRow method.

_x000D_
_x000D_
var tbodyRef = document.getElementById('myTable').getElementsByTagName('tbody')[0];

// Insert a row at the end of table
var newRow = tbodyRef.insertRow();

// Insert a cell at the end of the row
var newCell = newRow.insertCell();

// Append a text node to the cell
var newText = document.createTextNode('new row');
newCell.appendChild(newText);
_x000D_
<table id="myTable">
  <thead>
    <tr>
      <th>My Header</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>initial row</td>
    </tr>
  </tbody>
  <tfoot>
    <tr>
      <td>My Footer</td>
    </tr>
  </tfoot>
</table>
_x000D_
_x000D_
_x000D_

(old demo on JSFiddle)

PowerShell script to return members of multiple security groups

This will give you a list of a single group, and the members of each group.

param
(   
    [Parameter(Mandatory=$true,position=0)]
    [String]$GroupName
)

import-module activedirectory

# optional, add a wild card..
# $groups = $groups + "*"

$Groups = Get-ADGroup -filter {Name -like $GroupName} | Select-Object Name

ForEach ($Group in $Groups)
   {write-host " "
    write-host "$($group.name)"
    write-host "----------------------------"

    Get-ADGroupMember -identity $($groupname) -recursive | Select-Object samaccountname

 }
write-host "Export Complete"

If you want the friendly name, or other details, add them to the end of the select-object query.

How to get the children of the $(this) selector?

You can find all img element of parent div like below

$(this).find('img') or $(this).children('img')

If you want specific img element you can write like this

$(this).children('img:nth(n)')  
// where n is the child place in parent list start from 0 onwards

Your div contain only one img element. So for this below is right

 $(this).find("img").attr("alt")
                  OR
  $(this).children("img").attr("alt")

But if your div contain more img element like below

<div class="mydiv">
    <img src="test.png" alt="3">
    <img src="test.png" alt="4">
</div>

then you can't use upper code to find alt value of second img element. So you can try this:

 $(this).find("img:last-child").attr("alt")
                   OR
 $(this).children("img:last-child").attr("alt")

This example shows a general idea that how you can find actual object within parent object. You can use classes to differentiate your child object. That is easy and fun. i.e.

<div class="mydiv">
    <img class='first' src="test.png" alt="3">
    <img class='second' src="test.png" alt="4">
</div>

You can do this as below :

 $(this).find(".first").attr("alt")

and more specific as:

 $(this).find("img.first").attr("alt")

You can use find or children as above code. For more visit Children http://api.jquery.com/children/ and Find http://api.jquery.com/find/. See example http://jsfiddle.net/lalitjs/Nx8a6/

Display JSON as HTML

Your best bet is going to be using your back-end language's tools for this. What language are you using? For Ruby, try json_printer.

Using the "start" command with parameters passed to the started program

The answer in "peculiarity" is correct and directly answers the question. As TimF answered, since the first parameter is in quotes, it is treated as a window title.

Also note that the Virtual PC options are being treated as options to the 'start' command itself, and are not valid for 'start'. This is true for all versions of Windows that have the 'start' command.

This problem with 'start' treating the quoted parameter as a title is even more annoying that just the posted problem. If you run this:

start "some valid command with spaces"

You get a new command prompt window, with the obvious result for a window title. Even more annoying, this new window doesn't inherit customized font, colors or window size, it's just the default for cmd.exe.

Using jquery to get all checked checkboxes with a certain class name

Obligatory .map example:

var checkedVals = $('.theClass:checkbox:checked').map(function() {
    return this.value;
}).get();
alert(checkedVals.join(","));

What's the best practice for putting multiple projects in a git repository?

While most people will tell you to just use multiple repositories, I feel it's worth mentioning there are other solutions.

Solution 1

A single repository can contain multiple independent branches, called orphan branches. Orphan branches are completely separate from each other; they do not share histories.

git checkout --orphan BRANCHNAME

This creates a new branch, unrelated to your current branch. Each project should be in its own orphaned branch.

Now for whatever reason, git needs a bit of cleanup after an orphan checkout.

rm .git/index
rm -r *

Make sure everything is committed before deleting

Once the orphan branch is clean, you can use it normally.

Solution 2

Avoid all the hassle of orphan branches. Create two independent repositories, and push them to the same remote. Just use different branch names for each repo.

# repo 1
git push origin master:master-1

# repo 2
git push origin master:master-2

Apache POI Excel - how to configure columns to be expanded?

Tip : To make Auto size work , the call to sheet.autoSizeColumn(columnNumber) should be made after populating the data into the excel.

Calling the method before populating the data, will have no effect.

How to refresh or show immediately in datagridview after inserting?

Use LoadPatientRecords() after a successful insertion.

Try the below code

private void btnSubmit_Click(object sender, EventArgs e)
{
        if (btnSubmit.Text == "Clear")
        {
            btnSubmit.Text = "Submit";

            txtpFirstName.Focus();
        }
        else
        {
           btnSubmit.Text = "Clear";
           int result = AddPatientRecord();
           if (result > 0)
           {
               MessageBox.Show("Insert Successful");

               LoadPatientRecords();
           }
           else
               MessageBox.Show("Insert Fail");
         }
}

PostgreSQL CASE ... END with multiple conditions

This kind of code perhaps should work for You

SELECT
 *,
 CASE
  WHEN (pvc IS NULL OR pvc = '') AND (datepose < 1980) THEN '01'
  WHEN (pvc IS NULL OR pvc = '') AND (datepose >= 1980) THEN '02'
  WHEN (pvc IS NULL OR pvc = '') AND (datepose IS NULL OR datepose = 0) THEN '03'
  ELSE '00'
 END AS modifiedpvc
FROM my_table;


 gid | datepose | pvc | modifiedpvc 
-----+----------+-----+-------------
   1 |     1961 | 01  | 00
   2 |     1949 |     | 01
   3 |     1990 | 02  | 00
   1 |     1981 |     | 02
   1 |          | 03  | 00
   1 |          |     | 03
(6 rows)

Getting a list of associative array keys

for (var key in dictionary) {
  // Do something with key
}

It's the for..in statement.

CSS div 100% height

try setting the body style to:

body { position:relative;}

it worked for me

What is the difference between readonly="true" & readonly="readonly"?

I'm not sure how they're functionally different. My current batch of OS X browsers don't show any difference.

I would assume they are all functionally the same due to legacy HTML attribute handling. Back in the day, any flag (Boolean) attribute need only be present, sans value, eg

<input readonly>
<option selected>

When XHTML came along, this syntax wasn't valid and values were required. Whilst the W3 specified using the attribute name as the value, I'm guessing most browser vendors decided to simply check for attribute existence.

Java Currency Number format

If you want work on currencies, you have to use BigDecimal class. The problem is, there's no way to store some float numbers in memory (eg. you can store 5.3456, but not 5.3455), which can effects in bad calculations.

There's an nice article how to cooperate with BigDecimal and currencies:

http://www.javaworld.com/javaworld/jw-06-2001/jw-0601-cents.html

Python 'If not' syntax

Yes, if bar is not None is more explicit, and thus better, assuming it is indeed what you want. That's not always the case, there are subtle differences: if not bar: will execute if bar is any kind of zero or empty container, or False. Many people do use not bar where they really do mean bar is not None.

Convert utf8-characters to iso-88591 and back in PHP

It is much better to use

$value = mb_convert_encode($value,'HTML-ENTITIES','UTF-8');

Specially when you are using AJAX call for submitting 'ISO-8859-1' characters. It works for Chinese, Japanese, Czech, German and many more languages.

Moving Panel in Visual Studio Code to right side

As sample as this from the GUI. View->Appearance->Move Side Bar Right

enter image description here

How to reference a .css file on a razor view?

I prefer to use the razor html helper from Client Dependency dll

Html.RequireCss("yourfile", 9999); // 9999 is loading priority 

How to restore a SQL Server 2012 database to SQL Server 2008 R2?

You won't be able to restore from 2012 to 2008. You will be able to use a tool like red-gate SQL compare to copy the schema etc (provided nothing 2012 specific is used). If you have data to copy across too, you can use their Data Compare tool, and I think you get a 14 day free trial.

how to permit an array with strong parameters

when you want to permit multiple array fields you will have to list array fields at last while permitting ,as given -

params.require(:questions).permit(:question, :user_id, answers: [], selected_answer: [] )

(this works)

Resolving javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed Error?

This seems as good a place as any to document another possible reason for the infamous PKIX error message. After spending far too long looking at the keystore and truststore contents and various java installation configs I realised that my issue was down to... a typo.

The typo meant that I was also using the keystore as the truststore. As my companies Root CA was not defined as a standalone cert in the keystore but only as part of a cert chain, and was not defined anywhere else (i.e. cacerts) I kept getting the PKIX error.

After a failed release (this is prod config, it was ok elsewhere) and two days of head scratching I finally saw the typo, and now all is good.

Hope this helps someone.

How to find my php-fpm.sock?

Solved in my case, i look at

sudo tail -f /var/log/nginx/error.log

and error is php5-fpm.sock not found

I look at sudo ls -lah /var/run/

there was no php5-fpm.sock

I edit the www.conf  

sudo vim /etc/php5/fpm/pool.d/www.conf

change

listen = 127.0.0.1:9000

for

listen = /var/run/php5-fpm.sock

and reboot

How to Convert the value in DataTable into a string array in c#

 
            string[] result = new string[table.Columns.Count];
            DataRow dr = table.Rows[0];
            for (int i = 0; i < dr.ItemArray.Length; i++)
            {
                result[i] = dr[i].ToString();
            }
            foreach (string str in result)
                Console.WriteLine(str);

How to insert selected columns from a CSV file to a MySQL database using LOAD DATA INFILE

For those who have the following error:

Error Code: 1290. The MySQL server is running with the --secure-file-priv option so it cannot execute this statement

You can simply run this command to see which folder can load files from:

SHOW VARIABLES LIKE "secure_file_priv";

After that, you have to copy the files in that folder and run the query with LOAD DATA LOCAL INFILE instead of LOAD DATA INFILE.

What is the difference between "JPG" / "JPEG" / "PNG" / "BMP" / "GIF" / "TIFF" Image?

PNG supports alphachannel transparency.

TIFF can have extended options I.e. Geo referencing for GIS applications.

I recommend only ever using JPEG for photographs, never for images like clip art, logos, text, diagrams, line art.

Favor PNG.

Reset push notification settings for app

Doing it programmatically seems to work for me everytime. I have a build with the following line uncommented:

 [[UIApplication sharedApplication] unregisterForRemoteNotifications];

I run it every time I want to unregister from PN. You might have to end the app explicitly from the recents list and play around with the Notification Center in Settings app to get it right.

Also, the UI prompt asking the user to register for PN may not show up. Not sure if has been disabled in any of the recent iOS versions.

Is it possible to use "return" in stored procedure?

In Stored procedure, you return the values using OUT parameter ONLY. As you have defined two variables in your example:

   outstaticip OUT VARCHAR2, outcount OUT NUMBER

Just assign the return values to the out parameters i.e. outstaticip and outcount and access them back from calling location. What I mean here is: when you call the stored procedure, you will be passing those two variables as well. After the stored procedure call, the variables will be populated with return values.

If you want to have RETURN value as return from the PL/SQL call, then use FUNCTION. Please note that in case, you would be able to return only one variable as return variable.

how to make div click-able?

I suggest to use jQuery:

$('#mydiv')
  .css('cursor', 'pointer')
  .click(
    function(){
     alert('Click event is fired');
    }
  )
  .hover(
    function(){
      $(this).css('background', '#ff00ff');
    },
    function(){
      $(this).css('background', '');
    }
  );

Get column index from label in a data frame

This seems to be an efficient way to list vars with column number:

cbind(names(df)) 

Output:

     [,1]
[1,] "A" 
[2,] "B" 
[3,] "C" 

Sometimes I like to copy variables with position into my code so I use this function:

varnums<- function(x) {w=as.data.frame(c(1:length(colnames(x))),
          paste0('# ',colnames(x)))
names(w)= c("# Var/Pos")
w}
varnums(df)

Output:

# Var/Pos
# A         1
# B         2
# C         3

How do I send an HTML Form in an Email .. not just MAILTO

> 2020 Answer = The Easy Way using Google Apps Script (5 Mins)

We had a similar challenge to solve yesterday, and we solved it using a Google Apps Script!

Send Email From an HTML Form Without a Backend (Server) via Google!

The solution takes 5 mins to implement and I've documented with step-by-step instructions: https://github.com/nelsonic/html-form-send-email-via-google-script-without-server

Brief Overview

A. Using the sample script, deploy a Google App Script

Deploy the sample script as a Google Spreadsheet APP Script: google-script-just-email.js

3-script-editor-showing-script

remember to set the TO_ADDRESS in the script to where ever you want the emails to be sent.
and copy the APP URL so you can use it in the next step when you publish the script.

B. Create your HTML Form and Set the action to the App URL

Using the sample html file: index.html create a basic form.

7-html-form

remember to paste your APP URL into the form action in the HTML form.

C. Test the HTML Form in your Browser

Open the HTML Form in your Browser, Input some data & submit it!

html form

Submit the form. You should see a confirmation that it was sent: form sent

Open the inbox for the email address you set (above)

email received

Done.

Everything about this is customisable, you can easily style/theme the form with your favourite CSS Library and Store the submitted data in a Google Spreadsheet for quick analysis.
The complete instructions are available on GitHub:
https://github.com/nelsonic/html-form-send-email-via-google-script-without-server

How do I POST form data with UTF-8 encoding by using curl?

You CAN use UTF-8 in the POST request, all you need is to specify the charset in your request.

You should use this request:

curl -X POST -H "Content-Type: application/x-www-form-urlencoded; charset=utf-8" --data-ascii "content=derinhält&date=asdf" http://myserverurl.com/api/v1/somemethod

Get list of a class' instance methods

TestClass.instance_methods

or without all the inherited methods

TestClass.instance_methods - Object.methods

(Was 'TestClass.methods - Object.methods')

How to make for loops in Java increase by increments other than 1

Change

for(j = 0; j<=90; j+3)

to

for(j = 0; j<=90; j=j+3)

/exclude in xcopy just for a file type

In my case I had to start a list of exclude extensions from the second line because xcopy ignored the first line.

Flatten nested dictionaries, compressing keys

If you do not mind recursive functions, here is a solution. I have also taken the liberty to include an exclusion-parameter in case there are one or more values you wish to maintain.

Code:

def flatten_dict(dictionary, exclude = [], delimiter ='_'):
    flat_dict = dict()
    for key, value in dictionary.items():
        if isinstance(value, dict) and key not in exclude:
            flatten_value_dict = flatten_dict(value, exclude, delimiter)
            for k, v in flatten_value_dict.items():
                flat_dict[f"{key}{delimiter}{k}"] = v
        else:
            flat_dict[key] = value
    return flat_dict

Usage:

d = {'a':1, 'b':[1, 2], 'c':3, 'd':{'a':4, 'b':{'a':7, 'b':8}, 'c':6}, 'e':{'a':1,'b':2}}
flat_d = flatten_dict(dictionary=d, exclude=['e'], delimiter='.')
print(flat_d)

Output:

{'a': 1, 'b': [1, 2], 'c': 3, 'd.a': 4, 'd.b.a': 7, 'd.b.b': 8, 'd.c': 6, 'e': {'a': 1, 'b': 2}}

How to do something before on submit?

Assuming you have a form like this:

<form id="myForm" action="foo.php" method="post">
   <input type="text" value="" />
   <input type="submit" value="submit form" />

</form>

You can attach a onsubmit-event with jQuery like this:

$('#myForm').submit(function() {
  alert('Handler for .submit() called.');
  return false;
});

If you return false the form won't be submitted after the function, if you return true or nothing it will submit as usual.

See the jQuery documentation for more info.

Python os.path.join() on a list

This can be also thought of as a simple map reduce operation if you would like to think of it from a functional programming perspective.

import os
folders = [("home",".vim"),("home","zathura")]
[reduce(lambda x,y: os.path.join(x,y), each, "") for each in folders]

reduce is builtin in Python 2.x. In Python 3.x it has been moved to itertools However the accepted the answer is better.

This has been answered below but answering if you have a list of items that needs to be joined.

Is there a GUI design app for the Tkinter / grid geometry?

The best tool for doing layouts using grid, IMHO, is graph paper and a pencil. I know you're asking for some type of program, but it really does work. I've been doing Tk programming for a couple of decades so layout comes quite easily for me, yet I still break out graph paper when I have a complex GUI.

Another thing to think about is this: The real power of Tkinter geometry managers comes from using them together*. If you set out to use only grid, or only pack, you're doing it wrong. Instead, design your GUI on paper first, then look for patterns that are best solved by one or the other. Pack is the right choice for certain types of layouts, and grid is the right choice for others. For a very small set of problems, place is the right choice. Don't limit your thinking to using only one of the geometry managers.

* The only caveat to using both geometry managers is that you should only use one per container (a container can be any widget, but typically it will be a frame).

Python reading from a file and saving to utf-8

You can also get through it by the code below:

file=open(completefilepath,'r',encoding='utf8',errors="ignore")
file.read()

JComboBox Selection Change Listener?

It should respond to ActionListeners, like this:

combo.addActionListener (new ActionListener () {
    public void actionPerformed(ActionEvent e) {
        doSomething();
    }
});

@John Calsbeek rightly points out that addItemListener() will work, too. You may get 2 ItemEvents, though, one for the deselection of the previously selected item, and another for the selection of the new item. Just don't use both event types!

Adding attribute in jQuery

best solution: from jQuery v1.6 you can use prop() to add a property

$('#someid').prop('disabled', true);

to remove it, use removeProp()

$('#someid').removeProp('disabled');

Reference

Also note that the .removeProp() method should not be used to set these properties to false. Once a native property is removed, it cannot be added again. See .removeProp() for more information.

How to solve error message: "Failed to map the path '/'."

Executing the command iisreset (cmd with elevated rights) fixed this issue for me.

Why does flexbox stretch my image rather than retaining aspect ratio?

It is stretching because align-self default value is stretch. Set align-self to center.

align-self: center;

See documentation here: align-self

Rails ActiveRecord date between

I have been using the 3 dots, instead of 2. Three dots gives you a range that is open at the beginning and closed at the end, so if you do 2 queries for subsequent ranges, you can't get the same row back in both.

2.2.2 :003 > Comment.where(updated_at: 2.days.ago.beginning_of_day..1.day.ago.beginning_of_day)
Comment Load (0.3ms)  SELECT "comments".* FROM "comments" WHERE ("comments"."updated_at" BETWEEN '2015-07-12 00:00:00.000000' AND '2015-07-13 00:00:00.000000')
=> #<ActiveRecord::Relation []> 
2.2.2 :004 > Comment.where(updated_at: 2.days.ago.beginning_of_day...1.day.ago.beginning_of_day)
Comment Load (0.3ms)  SELECT "comments".* FROM "comments" WHERE ("comments"."updated_at" >= '2015-07-12 00:00:00.000000' AND "comments"."updated_at" < '2015-07-13 00:00:00.000000')
=> #<ActiveRecord::Relation []> 

And, yes, always nice to use a scope!

How to loop through a checkboxlist and to find what's checked and not checked?

for (int i = 0; i < clbIncludes.Items.Count; i++)
  if (clbIncludes.GetItemChecked(i))
    // Do selected stuff
  else
    // Do unselected stuff

If the the check is in indeterminate state, this will still return true. You may want to replace

if (clbIncludes.GetItemChecked(i))

with

if (clbIncludes.GetItemCheckState(i) == CheckState.Checked)

if you want to only include actually checked items.

IOS: verify if a point is inside a rect

In objective c you can use CGRectContainsPoint(yourview.frame, touchpoint)

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
UITouch* touch = [touches anyObject];
CGPoint touchpoint = [touch locationInView:self.view];
if( CGRectContainsPoint(yourview.frame, touchpoint) ) {

}else{

}}

In swift 3 yourview.frame.contains(touchpoint)

 override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    let touch:UITouch = touches.first!
    let touchpoint:CGPoint = touch.location(in: self.view)
    if wheel.frame.contains(touchpoint)  {

    }else{

    }

}

github: server certificate verification failed

Another possible cause is that the clock of your machine is not synced (e.g. on Raspberry Pi). Check the current date/time using:

$ date

If the date and/or time is incorrect, try to update using:

$ sudo ntpdate -u time.nist.gov

Disabling enter key for form

Here's a simple way to accomplish this with jQuery that limits it to the appropriate input elements:

//prevent submission of forms when pressing Enter key in a text input
$(document).on('keypress', ':input:not(textarea):not([type=submit])', function (e) {
    if (e.which == 13) e.preventDefault();
});

Thanks to this answer: https://stackoverflow.com/a/1977126/560114.

How to customize message box

MessageBox::Show uses function from user32.dll, and its style is dependent on Windows, so you cannot change it like that, you have to create your own form

HashMap and int as key

Use Integer instead.

HashMap<Integer, MyObject> myMap = new HashMap<Integer, MyObject>();

Java will automatically autobox your int primitive values to Integer objects.

Read more about autoboxing from Oracle Java documentations.

Returning the product of a list

Without using lambda:

from operator import mul
reduce(mul, list, 1)

it is better and faster. With python 2.7.5

from operator import mul
import numpy as np
import numexpr as ne
# from functools import reduce # python3 compatibility

a = range(1, 101)
%timeit reduce(lambda x, y: x * y, a)   # (1)
%timeit reduce(mul, a)                  # (2)
%timeit np.prod(a)                      # (3)
%timeit ne.evaluate("prod(a)")          # (4)

In the following configuration:

a = range(1, 101)  # A
a = np.array(a)    # B
a = np.arange(1, 1e4, dtype=int) #C
a = np.arange(1, 1e5, dtype=float) #D

Results with python 2.7.5


       |     1     |     2     |     3     |     4     |
-------+-----------+-----------+-----------+-----------+
 A       20.8 µs     13.3 µs     22.6 µs     39.6 µs     
 B        106 µs     95.3 µs     5.92 µs     26.1 µs
 C       4.34 ms     3.51 ms     16.7 µs     38.9 µs
 D       46.6 ms     38.5 ms      180 µs      216 µs

Result: np.prod is the fastest one, if you use np.array as data structure (18x for small array, 250x for large array)

with python 3.3.2:


       |     1     |     2     |     3     |     4     |
-------+-----------+-----------+-----------+-----------+
 A       23.6 µs     12.3 µs     68.6 µs     84.9 µs     
 B        133 µs      107 µs     7.42 µs     27.5 µs
 C       4.79 ms     3.74 ms     18.6 µs     40.9 µs
 D       48.4 ms     36.8 ms      187 µs      214 µs

Is python 3 slower?

Casting int to bool in C/C++

There some kind of old school 'Marxismic' way to the cast int -> bool without C4800 warnings of Microsoft's cl compiler - is to use negation of negation.

int  i  = 0;
bool bi = !!i;

int  j  = 1;
bool bj = !!j;

Positive Number to Negative Number in JavaScript?

If you don't feel like using Math.Abs * -1 you can you this simple if statement :P

if (x > 0) {
    x = -x;
}

Of course you could make this a function like this

function makeNegative(number) {
    if (number > 0) {
        number = -number;
    }
}

makeNegative(-3) => -3 makeNegative(5) => -5

Hope this helps! Math.abs will likely work for you but if it doesn't this little

Bootstrap Collapse not Collapsing

Add jQuery and make sure only one link for jQuery cause more than one doesn't work...

onclick or inline script isn't working in extension

As already mentioned, Chrome Extensions don't allow to have inline JavaScript due to security reasons so you can try this workaround as well.

HTML file

<!doctype html>
    <html>
        <head>
            <title>
                Getting Started Extension's Popup
            </title>
            <script src="popup.js"></script>
        </head>
        <body>
            <div id="text-holder">ha</div><br />
            <a class="clickableBtn">
                  hyhy
            </a>
        </body>
    </html>
<!doctype html>

popup.js

window.onclick = function(event) {
    var target = event.target ;
    if(target.matches('.clickableBtn')) {
        var clickedEle = document.activeElement.id ;
        var ele = document.getElementById(clickedEle);
        alert(ele.text);
    }
}

Or if you are having a Jquery file included then

window.onclick = function(event) {
    var target = event.target ;
    if(target.matches('.clickableBtn')) {
        alert($(target).text());
    }
}

What is the minimum I have to do to create an RPM file?

Process of generating RPM from source file:

  1. download source file with.gz extention.
  2. install rpm-build and rpmdevtools from yum install. (rpmbuild folder will be generated...SPECS,SOURCES,RPMS.. folders will should be generated inside the rpmbuild folder).
  3. copy the source code.gz to SOURCES folder.(rpmbuild/SOURCES)
  4. Untar the tar ball by using the following command. go to SOURCES folder :rpmbuild/SOURCES where tar file is present. command: e.g tar -xvzf httpd-2.22.tar.gz httpd-2.22 folder will be generated in the same path.
  5. go to extracted folder and then type below command: ./configure --prefix=/usr/local/apache2 --with-included-apr --enable-proxy --enable-proxy-balancer --with-mpm=worker --enable-mods-static=all (.configure may vary according to source for which RPM has to built-- i have done for apache HTTPD which needs apr and apr-util dependency package).
  6. run below command once the configure is successful: make
  7. after successfull execution od make command run: checkinstall in tha same folder. (if you dont have checkinstall software please download latest version from site) Also checkinstall software has bug which can be solved by following way::::: locate checkinstallrc and then replace TRANSLATE = 1 to TRANSLATE=0 using vim command. Also check for exclude package: EXCLUDE="/selinux"
  8. checkinstall will ask for option (type R if you want tp build rpm for source file)
  9. Done .rpm file will be built in RPMS folder inside rpmbuild/RPMS file... ALL the BEST ....

Passing std::string by Value or Reference

Check this answer for C++11. Basically, if you pass an lvalue the rvalue reference

From this article:

void f1(String s) {
    vector<String> v;
    v.push_back(std::move(s));
}
void f2(const String &s) {
    vector<String> v;
    v.push_back(s);
}

"For lvalue argument, ‘f1’ has one extra copy to pass the argument because it is by-value, while ‘f2’ has one extra copy to call push_back. So no difference; for rvalue argument, the compiler has to create a temporary ‘String(L“”)’ and pass the temporary to ‘f1’ or ‘f2’ anyway. Because ‘f2’ can take advantage of move ctor when the argument is a temporary (which is an rvalue), the costs to pass the argument are the same now for ‘f1’ and ‘f2’."

Continuing: " This means in C++11 we can get better performance by using pass-by-value approach when:

  1. The parameter type supports move semantics - All standard library components do in C++11
  2. The cost of move constructor is much cheaper than the copy constructor (both the time and stack usage).
  3. Inside the function, the parameter type will be passed to another function or operation which supports both copy and move.
  4. It is common to pass a temporary as the argument - You can organize you code to do this more.

"

OTOH, for C++98 it is best to pass by reference - less data gets copied around. Passing const or non const depend of whether you need to change the argument or not.

Is it possible to implement a Python for range loop without an iterator variable?

We have had some fun with the following, interesting to share so:

class RepeatFunction:
    def __init__(self,n=1): self.n = n
    def __call__(self,Func):
        for i in xrange(self.n):
            Func()
        return Func


#----usage
k = 0

@RepeatFunction(7)                       #decorator for repeating function
def Job():
    global k
    print k
    k += 1

print '---------'
Job()

Results:

0
1
2
3
4
5
6
---------
7

Is Xamarin free in Visual Studio 2015?

Xamarin is now owned by Microsoft So it completely free to use on Windows and mac as well.

MySQL - Selecting data from multiple tables all with same structure but different data

It sounds like you'd be happer with a single table. The five having the same schema, and sometimes needing to be presented as if they came from one table point to putting it all in one table.

Add a new column which can be used to distinguish among the five languages (I'm assuming it's language that is different among the tables since you said it was for localization). Don't worry about having 4.5 million records. Any real database can handle that size no problem. Add the correct indexes, and you'll have no trouble dealing with them as a single table.

80-characters / right margin line in Sublime Text 3

Yes, it is possible both in Sublime Text 2 and 3 (which you should really upgrade to if you haven't already). Select View ? Ruler ? 80 (there are several other options there as well). If you like to actually wrap your text at 80 columns, select View ? Word Wrap Column ? 80. Make sure that View ? Word Wrap is selected.

To make your selections permanent (the default for all opened files or views), open Preferences ? Settings—User and use any of the following rules:

{
    // set vertical rulers in specified columns.
    // Use "rulers": [80] for just one ruler
    // default value is []
    "rulers": [80, 100, 120],

    // turn on word wrap for source and text
    // default value is "auto", which means off for source and on for text
    "word_wrap": true,

    // set word wrapping at this column
    // default value is 0, meaning wrapping occurs at window width
    "wrap_width": 80
}

These settings can also be used in a .sublime-project file to set defaults on a per-project basis, or in a syntax-specific .sublime-settings file if you only want them to apply to files written in a certain language (Python.sublime-settings vs. JavaScript.sublime-settings, for example). Access these settings files by opening a file with the desired syntax, then selecting Preferences ? Settings—More ? Syntax Specific—User.

As always, if you have multiple entries in your settings file, separate them with commas , except for after the last one. The entire content should be enclosed in curly braces { }. Basically, make sure it's valid JSON.

If you'd like a key combo to automatically set the ruler at 80 for a particular view/file, or you are interested in learning how to set the value without using the mouse, please see my answer here.

Finally, as mentioned in another answer, you really should be using a monospace font in order for your code to line up correctly. Other types of fonts have variable-width letters, which means one 80-character line may not appear to be the same length as another 80-character line with different content, and your indentations will look all messed up. Sublime has monospace fonts set by default, but you can of course choose any one you want. Personally, I really like Liberation Mono. It has glyphs to support many different languages and Unicode characters, looks good at a variety of different sizes, and (most importantly for a programming font) clearly differentiates between 0 and O (digit zero and capital letter oh) and 1 and l (digit one and lowercase letter ell), which not all monospace fonts do, unfortunately. Version 2.0 and later of the font are licensed under the open-source SIL Open Font License 1.1 (here is the FAQ).

How to click an element in Selenium WebDriver using JavaScript

Another easiest solution is to use Key.RETUEN

Click here for solution in detail

driver.findElement(By.name("q")).sendKeys("Selenium Tutorial", Key.RETURN);

Cannot create cache directory .. or directory is not writable. Proceeding without cache in Laravel

Run this command :

    sudo chown -R yourUser /home/yourUser/.composer

How to "comment-out" (add comment) in a batch/cmd?

Putting comments on the same line with commands: use & :: comment

color C          & :: set red font color
echo IMPORTANT INFORMATION
color            & :: reset the color to default

Explanation:

& separates two commands, so in this case color C is the first command and :: set red font color is the second one.


Important:

This statement with comment looks intuitively correct:

goto error1         :: handling the error

but it is not a valid use of the comment. It works only because goto ignores all arguments past the first one. The proof is easy, this goto will not fail either:

goto error1 handling the error

But similar attempt

color 17            :: grey on blue

fails executing the command due to 4 arguments unknown to the color command: ::, grey, on, blue.

It will only work as:

color 17     &      :: grey on blue

So the ampersand is inevitable.

Remote debugging Tomcat with Eclipse

Modify catalina.bat to add

set JPDA_OPTS="-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n" 

and

CATALINA_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,address=8000,server=y,suspend=n

Optional: Add below line to run the debug mode by default when you run startup.bat

call "%EXECUTABLE%" jpda start %CMD_LINE_ARGS%

Eclipse or STS select debug configuration right click -> new

connection type -> Standard socket Attach
Port -> 8000 (as given in the CATALINA_OPTS)
Host -> localhost or IP address

Selecting all text in HTML text input when clicked

If you are using AngularJS, you can use a custom directive for easy access:

define(['angular'], function () {
    angular.module("selectionHelper", [])
    .directive('selectOnClick', function () {
        return {
            restrict: 'A',
            link: function (scope, element, attrs) {                
                element.on('click', function () {
                    this.select();
                });
            }
        };
    });
});

Now one can just use it like this:

<input type="text" select-on-click ... />

The sample is with requirejs - so the first and the last line can be skipped if using something else.

how to bold words within a paragraph in HTML/CSS?

I know this question is old but I ran across it and I know other people might have the same problem. All these answers are okay but do not give proper detail or actual TRUE advice.

When wanting to style a specific section of a paragraph use the span tag.

<p><span style="font-weight:900">Andy Warhol</span> (August 6, 1928 - February 22, 1987) 

was an American artist who was a leading figure in the visual art movement known as pop 

art.</p>

Andy Warhol (August 6, 1928 - February 22, 1987) was an American artist who was a leading figure in the visual art movement known as pop art.

As the code shows, the span tag styles on the specified words: "Andy Warhol". You can further style a word using any CSS font styling codes.

{font-weight; font-size; text-decoration; font-family; margin; color}, etc. 

Any of these and more can be used to style a word, group of words, or even specified paragraphs without having to add a class to the CSS Style Sheet Doc. I hope this helps someone!

How to kill a while loop with a keystroke?

pyHook might help. http://sourceforge.net/apps/mediawiki/pyhook/index.php?title=PyHook_Tutorial#tocpyHook%5FTutorial4

See keyboard hooks; this is more generalized-- if you want specific keyboard interactions and not just using KeyboardInterrupt.

Also, in general (depending on your use) I think having the Ctrl-C option still available to kill your script makes sense.

See also previous question: Detect in python which keys are pressed

SQL Call Stored Procedure for each Row without using a cursor

I like to do something similar to this (though it is still very similar to using a cursor)

[code]

-- Table variable to hold list of things that need looping
DECLARE @holdStuff TABLE ( 
    id INT IDENTITY(1,1) , 
    isIterated BIT DEFAULT 0 , 
    someInt INT ,
    someBool BIT ,
    otherStuff VARCHAR(200)
)

-- Populate your @holdStuff with... stuff
INSERT INTO @holdStuff ( 
    someInt ,
    someBool ,
    otherStuff
)
SELECT  
    1 , -- someInt - int
    1 , -- someBool - bit
    'I like turtles'  -- otherStuff - varchar(200)
UNION ALL
SELECT  
    42 , -- someInt - int
    0 , -- someBool - bit
    'something profound'  -- otherStuff - varchar(200)

-- Loop tracking variables
DECLARE @tableCount INT
SET     @tableCount = (SELECT COUNT(1) FROM [@holdStuff])

DECLARE @loopCount INT
SET     @loopCount = 1

-- While loop variables
DECLARE @id INT
DECLARE @someInt INT
DECLARE @someBool BIT
DECLARE @otherStuff VARCHAR(200)

-- Loop through item in @holdStuff
WHILE (@loopCount <= @tableCount)
    BEGIN

        -- Increment the loopCount variable
        SET @loopCount = @loopCount + 1

        -- Grab the top unprocessed record
        SELECT  TOP 1 
            @id = id ,
            @someInt = someInt ,
            @someBool = someBool ,
            @otherStuff = otherStuff
        FROM    @holdStuff
        WHERE   isIterated = 0

        -- Update the grabbed record to be iterated
        UPDATE  @holdAccounts
        SET     isIterated = 1
        WHERE   id = @id

        -- Execute your stored procedure
        EXEC someRandomSp @someInt, @someBool, @otherStuff

    END

[/code]

Note that you don't need the identity or the isIterated column on your temp/variable table, i just prefer to do it this way so i don't have to delete the top record from the collection as i iterate through the loop.

Sometimes adding a WCF Service Reference generates an empty reference.cs

When this happens, look in the Errors window and the Output window to see if there are any error messages. If that doesn't help, try running svcutil.exe manually, and see if there are any error messages.

AngularJS does not send hidden field value

Here I would like to share my working code :

_x000D_
_x000D_
<input type="text" name="someData" ng-model="data" ng-init="data=2" style="display: none;"/>_x000D_
OR_x000D_
<input type="hidden" name="someData" ng-model="data" ng-init="data=2"/>_x000D_
OR_x000D_
<input type="hidden" name="someData" ng-init="data=2"/>
_x000D_
_x000D_
_x000D_

html script src="" triggering redirection with button

I was having this problem but i found out that it was a permissions problem I changed my permissions to 0744 and now it works. I don't know if this was your problem but it worked for me.

How to Detect Browser Window /Tab Close Event?

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script>
<script type="text/javascript">
var validNavigation = false;

function wireUpEvents() {
var dont_confirm_leave = 0; //set dont_confirm_leave to 1 when you want the    user to be able to leave withou confirmation
 var leave_message = 'ServerThemes.Net Recommend BEST WEB HOSTING at new tab  window. Good things will come to you'
 function goodbye(e) {
if (!validNavigation) {
window.open("http://serverthemes.net/best-web-hosting-services","_blank");
return leave_message;

}
}
window.onbeforeunload=goodbye;

// Attach the event keypress to exclude the F5 refresh
$(document).bind('keypress', function(e) {
if (e.keyCode == 116){
  validNavigation = true;
 }
 });

// Attach the event click for all links in the page
$("a").bind("click", function() {
validNavigation = true;
});
  // Attach the event submit for all forms in the page
 $("form").bind("submit", function() {
 validNavigation = true;
});

 // Attach the event click for all inputs in the page
  $("input[type=submit]").bind("click", function() {
 validNavigation = true;
 });

 }

  // Wire up the events as soon as the DOM tree is ready
   $(document).ready(function() {
   wireUpEvents();
   });
   </script>

I did answer at Can you use JavaScript to detect whether a user has closed a browser tab? closed a browser? or has left a browser?

Find the paths between two given nodes?

Breadth-first search traverses a graph and in fact finds all paths from a starting node. Usually, BFS doesn't keep all paths, however. Instead, it updates a prededecessor function p to save the shortest path. You can easily modify the algorithm so that p(n) doesn't only store one predecessor but a list of possible predecessors.

Then all possible paths are encoded in this function, and by traversing p recursively you get all possible path combinations.

One good pseudocode which uses this notation can be found in Introduction to Algorithms by Cormen et al. and has subsequently been used in many University scripts on the subject. A Google search for “BFS pseudocode predecessor p” uproots this hit on Stack Exchange.

What is the newline character in the C language: \r or \n?

What is the newline character in the C language: \r or \n?

The new-line may be thought of a some char and it has the value of '\n'. C11 5.2.1

This C new-line comes up in 3 places: C source code, as a single char and as an end-of-line in file I/O when in text mode.

  1. Many compilers will treat source text as ASCII. In that case, codes 10, sometimes 13, and sometimes paired 13,10 as new-line for source code. Had the source code been in another character set, different codes may be used. This new-line typically marks the end of a line of source code (actually a bit more complicated here), // comment, and # directives.

  2. In source code, the 2 characters \ and n represent the char new-line as \n. If ASCII is used, this char would have the value of 10.

  3. In file I/O, in text mode, upon reading the bytes of the input file (and stdin), depending on the environment, when bytes with the value(s) of 10 (Unix), 13,10, (*1) (Windows), 13 (Old Mac??) and other variations are translated in to a '\n'. Upon writing a file (or stdout), the reverse translation occurs.
    Note: File I/O in binary mode makes no translation.

The '\r' in source code is the carriage return char.

(*1) A lone 13 and/or 10 may also translate into \n.

HTML5 phone number validation with pattern

enter image description here

^[789]\d{9,9}$

  • Minimum digits 10
  • Maximum digits 10
  • number starts with 7,8,9

How to connect to remote Oracle DB with PL/SQL Developer?

Username : username
Password : password
Database : //123.45.67.89:1521/TEST
Connect as : Normal

this work for me and (version 13.0.6.1911 64 bit)

Postgres could not connect to server

On Yosemite, if the pid file is blocking Postgres from starting and you have a launchctl daemon trying (and failing) to load the database daemons, then you'll need to unload the plist file:

$ launchctl unload ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

Then remove the pid file

$ rm /usr/local/var/postgres/postmaster.pid

Then reload the launchctl daemon

$ launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

How to create cron job using PHP?

There is a simple way to solve this: you can execute php file by cron every 1 minute, and inside php executable file make "if" statement to execute when time "now" like this

<?/** suppose we have 1 hour and 1 minute inteval 01:01 */

$interval_source = "01:01";
$time_now = strtotime( "now" ) / 60;
$interval = substr($interval_source,0,2) * 60 + substr($interval_source,3,2);


if( $time_now % $interval == 0){
/** do cronjob */
}

Detect if a NumPy array contains at least one non-numeric value?

This should be faster than iterating and will work regardless of shape.

numpy.isnan(myarray).any()

Edit: 30x faster:

import timeit
s = 'import numpy;a = numpy.arange(10000.).reshape((100,100));a[10,10]=numpy.nan'
ms = [
    'numpy.isnan(a).any()',
    'any(numpy.isnan(x) for x in a.flatten())']
for m in ms:
    print "  %.2f s" % timeit.Timer(m, s).timeit(1000), m

Results:

  0.11 s numpy.isnan(a).any()
  3.75 s any(numpy.isnan(x) for x in a.flatten())

Bonus: it works fine for non-array NumPy types:

>>> a = numpy.float64(42.)
>>> numpy.isnan(a).any()
False
>>> a = numpy.float64(numpy.nan)
>>> numpy.isnan(a).any()
True

Defining private module functions in python

Python allows for private class members with the double underscore prefix. This technique doesn't work at a module level so I am thinking this is a mistake in Dive Into Python.

Here is an example of private class functions:

class foo():
    def bar(self): pass
    def __bar(self): pass

f = foo()
f.bar()   # this call succeeds
f.__bar() # this call fails

What is the difference between <p> and <div>?

DIV is a generic block level container that can contain any other block or inline elements, including other DIV elements, whereas P is to wrap paragraphs (text).

Convert file path to a file URI?

The solutions above do not work on Linux.

Using .NET Core, attempting to execute new Uri("/home/foo/README.md") results in an exception:

Unhandled Exception: System.UriFormatException: Invalid URI: The format of the URI could not be determined.
   at System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind)
   at System.Uri..ctor(String uriString)
   ...

You need to give the CLR some hints about what sort of URL you have.

This works:

Uri fileUri = new Uri(new Uri("file://"), "home/foo/README.md");

...and the string returned by fileUri.ToString() is "file:///home/foo/README.md"

This works on Windows, too.

new Uri(new Uri("file://"), @"C:\Users\foo\README.md").ToString()

...emits "file:///C:/Users/foo/README.md"

Calling async method synchronously

You should get the awaiter (GetAwaiter()) and end the wait for the completion of the asynchronous task (GetResult()).

string code = GenerateCodeAsync().GetAwaiter().GetResult();

CSS Input field text color of inputted text

Change your second style to this:

input, select, textarea{
    color: #ff0000;
}

At the moment, you are telling the form to change the text to black once the focus is off. The above remedies that.

Also, it is a good idea to place the normal state styles ahead of the :focus and :hover styles in your stylesheet. That helps prevent this problem. So

input, select, textarea{
    color: #ff0000;
}

textarea:focus, input:focus {
    color: #ff0000;
}

Bootstrap4 adding scrollbar to div

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_x000D_
.Scroll {
  height:600px;
  overflow-y: scroll;
}
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<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
</script>
</head>
<body>

<h1>Smooth Scroll</h1>

<div class="Scroll">
  <div class="main" id="section1">
    <h2>Section 1</h2>
    <p>Click on the link to see the "smooth" scrolling effect.</p>
    <p>Note: Remove the scroll-behavior property to remove smooth scrolling.</p>
  </div>
  <div class="main" id="section2">
    <h2>Section 2</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>
  <div class="main" id="section3">
    <h2>Section 3</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>
  <div class="main" id="section4">
    <h2>Section 4</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>

  <div class="main" id="section5">
    <h2>Section 5</h2>
    <a href="#section1">Click Me to Smooth Scroll to Section 1 Above</a>
  </div>
  <div class="main" id="section6">
    <h2>Section 6</h2>
    <p>Knowing how to write a paragraph is incredibly important. It’s a basic aspect of writing, and it is something that everyone should know how to do. There is a specific structure that you have to follow when you’re writing a paragraph. This structure helps make it easier for the reader to understand what is going on. Through writing good paragraphs, a person can communicate a lot better through their writing.</p>
  </div>
  <div class="main" id="section7">
    <h2>Section 7</h2>
    <a href="#section1">Click Me to Smooth Scroll to Section 1 Above</a>
  </div>
</div>
</body>
</html>
_x000D_
_x000D_
_x000D_

What does request.getParameter return?

Both if (one.length() > 0) {} and if (!"".equals(one)) {} will check against an empty foo parameter, and an empty parameter is what you'd get if the the form is submitted with no value in the foo text field.

If there's any chance you can use the Expression Language to handle the parameter, you could access it with empty param.foo in an expression.

<c:if test='${not empty param.foo}'>
    This page code gets rendered.
</c:if>

List of macOS text editors and code editors

I used BBEdit for years, but recently converted to Panic's Coda.

I love Coda. It does everything that I need and now that I've begun programming plug-ins for it, it's become a far more rich tool. The support team are responsive and the community that is growing around it is fantastic. There is still a lot of room for improvement, but that's the cool thing about being part of the kind of community that surrounds it; you have a say in what that improvement is.

Panic - Coda

How to use log levels in java

The java.util.logging.Level documentation does a good job of defining when to use a log level and the target audience of that log level.

Most of the confusion with java.util.logging is in the tracing methods. It should be in the class level documentation but instead the Level.FINE field provides a good overview:

FINE is a message level providing tracing information. All of FINE, FINER, and FINEST are intended for relatively detailed tracing. The exact meaning of the three levels will vary between subsystems, but in general, FINEST should be used for the most voluminous detailed output, FINER for somewhat less detailed output, and FINE for the lowest volume (and most important) messages. In general the FINE level should be used for information that will be broadly interesting to developers who do not have a specialized interest in the specific subsystem. FINE messages might include things like minor (recoverable) failures. Issues indicating potential performance problems are also worth logging as FINE.

One important thing to understand which is not mentioned in the level documentation is that call-site tracing information is logged at FINER.

  • Logger#entering A LogRecord with message "ENTRY", log level FINER, ...
  • Logger#throwing The logging is done using the FINER level...The LogRecord's message is set to "THROW"
  • Logger#exiting A LogRecord with message "RETURN", log level FINER...

If you log a message as FINE you will be able to configure logging system to see the log output with or without tracing log records surrounding the log message. So use FINE only when tracing log records are not required as context to understand the log message.

FINER indicates a fairly detailed tracing message. By default logging calls for entering, returning, or throwing an exception are traced at this level.

In general, most use of FINER should be left to call of entering, exiting, and throwing. That will for the most part reserve FINER for call-site tracing when verbose logging is turned on. When swallowing an expected exception it makes sense to use FINER in some cases as the alternative to calling trace throwing method since the exception is not actually thrown. This makes it look like a trace when it isn't a throw or an actual error that would be logged at a higher level.

FINEST indicates a highly detailed tracing message.

Use FINEST when the tracing log message you are about to write requires context information about program control flow. You should also use FINEST for tracing messages that produce large amounts of output data.

CONFIG messages are intended to provide a variety of static configuration information, to assist in debugging problems that may be associated with particular configurations. For example, CONFIG message might include the CPU type, the graphics depth, the GUI look-and-feel, etc.

The CONFIG works well for assisting system admins with the items listed above.

Typically INFO messages will be written to the console or its equivalent. So the INFO level should only be used for reasonably significant messages that will make sense to end users and system administrators.

Examples of this are tracing program startup and shutdown.

In general WARNING messages should describe events that will be of interest to end users or system managers, or which indicate potential problems.

An example use case could be exceptions thrown from AutoCloseable.close implementations.

In general SEVERE messages should describe events that are of considerable importance and which will prevent normal program execution. They should be reasonably intelligible to end users and to system administrators.

For example, if you have transaction in your program where if any one of the steps fail then all of the steps voided then SEVERE would be appropriate to use as the log level.

Set markers for individual points on a line in Matplotlib

You can do:

import matplotlib.pyplot as plt
x = [1,2,3,4,5]
y = [2,1,3,6,7]

plt.plot(x, y, style='.-')
plt.show()

This will return a graph with the data points marked with a dot

When to use <span> instead <p>?

The <p> tag is a paragraph, and as such, it is a block element (as is, for instance, h1 and div), whereas span is an inline element (as, for instance, b and a)

Block elements by default create some whitespace above and below themselves, and nothing can be aligned next to them, unless you set a float attribute to them.

Inline elements deal with spans of text inside a paragraph. They typically have no margins, and as such, you cannot, for instance, set a width to it.

MySQL match() against() - order by relevance and column?

I have never done so, but it seems like

MATCH (head, head, body) AGAINST ('some words' IN BOOLEAN MODE)

Should give a double weight to matches found in the head.


Just read this comment on the docs page, Thought it might be of value to you:

Posted by Patrick O'Lone on December 9 2002 6:51am

It should be noted in the documentation that IN BOOLEAN MODE will almost always return a relevance of 1.0. In order to get a relevance that is meaningful, you'll need to:

SELECT MATCH('Content') AGAINST ('keyword1 keyword2') as Relevance 
FROM table 
WHERE MATCH ('Content') AGAINST('+keyword1+keyword2' IN BOOLEAN MODE) 
HAVING Relevance > 0.2 
ORDER BY Relevance DESC 

Notice that you are doing a regular relevance query to obtain relevance factors combined with a WHERE clause that uses BOOLEAN MODE. The BOOLEAN MODE gives you the subset that fulfills the requirements of the BOOLEAN search, the relevance query fulfills the relevance factor, and the HAVING clause (in this case) ensures that the document is relevant to the search (i.e. documents that score less than 0.2 are considered irrelevant). This also allows you to order by relevance.

This may or may not be a bug in the way that IN BOOLEAN MODE operates, although the comments I've read on the mailing list suggest that IN BOOLEAN MODE's relevance ranking is not very complicated, thus lending itself poorly for actually providing relevant documents. BTW - I didn't notice a performance loss for doing this, since it appears MySQL only performs the FULLTEXT search once, even though the two MATCH clauses are different. Use EXPLAIN to prove this.

So it would seem you may not need to worry about calling the fulltext search twice, though you still should "use EXPLAIN to prove this"

How do I print a list of "Build Settings" in Xcode project?

In Xcode 4 and possibly before, in the run script build phase there is an option "Show enviroment variables in build phase". If selected this will show then on a olive green background in the build log.

MySQL Workbench not displaying query results

This was still happening to me on version 6.3.9 on OSX. I downloaded 6.1.7 again to actually see the result grid again.

What a pain in the butt!

Makefile, header dependencies

A slightly modified version of Sophie's answer which allows to output the *.d files to a different folder (I will only paste the interesting part that generates the dependency files):

$(OBJDIR)/%.o: %.cpp
# Generate dependency file
    mkdir -p $(@D:$(OBJDIR)%=$(DEPDIR)%)
    $(CXX) $(CXXFLAGS) $(CPPFLAGS) -MM -MT $@ $< -MF $(@:$(OBJDIR)/%.o=$(DEPDIR)/%.d)
# Generate object file
    mkdir -p $(@D)
    $(CXX) $(CXXFLAGS) $(CPPFLAGS) -c $< -o $@

Note that the parameter

-MT $@

is used to ensure that the targets (i.e. the object file names) in the generated *.d files contain the full path to the *.o files and not just the file name.

I don't know why this parameter is NOT needed when using -MMD in combination with -c (as in Sophie's version). In this combination it seems to write the full path of the *.o files into the *.d files. Without this combination, -MMD also writes only the pure file names without any directory components into the *.d files. Maybe somebody knows why -MMD writes the full path when combined with -c. I have not found any hint in the g++ man page.

Kubernetes how to make Deployment to update image

kubectl rollout restart deployment myapp

This is the current way to trigger a rolling update and leave the old replica sets in place for other operations provided by kubectl rollout like rollbacks.