Programs & Examples On #Bluehost

DO NOT USE THIS TAG! Bluehost is a hosting provider. Use tags specific to your CODING problem. General hosting problems should go to https://serverfault.com

SQL UPDATE all values in a field with appended string CONCAT not working

convert the NULL values with empty string by wrapping it in COALESCE

"UPDATE table SET data = CONCAT(COALESCE(`data`,''), 'a')"

OR

Use CONCAT_WS instead:

"UPDATE table SET data = CONCAT_WS(',',data, 'a')"

Create a folder if it doesn't already exist

Faster way to create folder:

if (!is_dir('path/to/directory')) {
    mkdir('path/to/directory', 0777, true);
}

problem with php mail 'From' header

I solved this by adding email accounts in Cpanel and also adding that same email to the header from field like this

$header = 'From: XXXXXXXX <[email protected]>' . "\r\n";

CSS submit button weird rendering on iPad/iPhone

Add this code into the css file:

input {
-webkit-appearance: none;
-moz-appearance: none;
appearance: none;
}

This will help.

How can I put a ListView into a ScrollView without it collapsing?

Although the suggested setListViewHeightBasedOnChildren() methods work in most of the cases, in some cases, specially with a lot of items, I noticed that the last elements are not displayed. So I decided to mimic a simple version of the ListView behavior in order to reuse any Adapter code, here it's the ListView alternative:

import android.content.Context;
import android.database.DataSetObserver;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.ListAdapter;

public class StretchedListView extends LinearLayout {

private final DataSetObserver dataSetObserver;
private ListAdapter adapter;
private OnItemClickListener onItemClickListener;

public StretchedListView(Context context, AttributeSet attrs) {
    super(context, attrs);
    setOrientation(LinearLayout.VERTICAL);
    this.dataSetObserver = new DataSetObserver() {
        @Override
        public void onChanged() {
            syncDataFromAdapter();
            super.onChanged();
        }

        @Override
        public void onInvalidated() {
            syncDataFromAdapter();
            super.onInvalidated();
        }
    };
}

public void setAdapter(ListAdapter adapter) {
    ensureDataSetObserverIsUnregistered();

    this.adapter = adapter;
    if (this.adapter != null) {
        this.adapter.registerDataSetObserver(dataSetObserver);
    }
    syncDataFromAdapter();
}

protected void ensureDataSetObserverIsUnregistered() {
    if (this.adapter != null) {
        this.adapter.unregisterDataSetObserver(dataSetObserver);
    }
}

public Object getItemAtPosition(int position) {
    return adapter != null ? adapter.getItem(position) : null;
}

public void setSelection(int i) {
    getChildAt(i).setSelected(true);
}

public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
    this.onItemClickListener = onItemClickListener;
}

public ListAdapter getAdapter() {
    return adapter;
}

public int getCount() {
    return adapter != null ? adapter.getCount() : 0;
}

private void syncDataFromAdapter() {
    removeAllViews();
    if (adapter != null) {
        int count = adapter.getCount();
        for (int i = 0; i < count; i++) {
            View view = adapter.getView(i, null, this);
            boolean enabled = adapter.isEnabled(i);
            if (enabled) {
                final int position = i;
                final long id = adapter.getItemId(position);
                view.setOnClickListener(new View.OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        if (onItemClickListener != null) {
                            onItemClickListener.onItemClick(null, v, position, id);
                        }
                    }
                });
            }
            addView(view);

        }
    }
}
}

what is .subscribe in angular?

subscribe() -Invokes an execution of an Observable and registers Observer handlers for notifications it will emit. -Observable- representation of any set of values over any amount of time.

How can I plot separate Pandas DataFrames as subplots?

Here is a working pandas subplot example, where modes is the column names of the dataframe.

    dpi=200
    figure_size=(20, 10)
    fig, ax = plt.subplots(len(modes), 1, sharex="all", sharey="all", dpi=dpi)
    for i in range(len(modes)):
        ax[i] = pivot_df.loc[:, modes[i]].plot.bar(figsize=(figure_size[0], figure_size[1]*len(modes)),
                                                   ax=ax[i], title=modes[i], color=my_colors[i])
        ax[i].legend()
    fig.suptitle(name)

Pandas subplot bar example

Postgres: How to convert a json string to text?

There is no way in PostgreSQL to deconstruct a scalar JSON object. Thus, as you point out,

select  length(to_json('Some "text"'::TEXT) ::TEXT);

is 15,

The trick is to convert the JSON into an array of one JSON element, then extract that element using ->>.

select length( array_to_json(array[to_json('Some "text"'::TEXT)])->>0 );

will return 11.

Detecting touch screen devices with Javascript

In jQuery Mobile you can simply do:

$.support.touch

Don't know why this is so undocumented.. but it is crossbrowser safe (latest 2 versions of current browsers).

What does "<>" mean in Oracle

It means not equal to

Should I use != or <> for not equal in TSQL?

Have a look at the link. It has detailed explanation of what to use for what.

How to add percent sign to NSString

The code for percent sign in NSString format is %%. This is also true for NSLog() and printf() formats.

How to document a method with parameter(s)?

Conventions:

Tools:


Update: Since Python 3.5 you can use type hints which is a compact, machine-readable syntax:

from typing import Dict, Union

def foo(i: int, d: Dict[str, Union[str, int]]) -> int:
    """
    Explanation: this function takes two arguments: `i` and `d`.
    `i` is annotated simply as `int`. `d` is a dictionary with `str` keys
    and values that can be either `str` or `int`.

    The return type is `int`.

    """

The main advantage of this syntax is that it is defined by the language and that it's unambiguous, so tools like PyCharm can easily take advantage from it.

Is there a NumPy function to return the first index of something in an array?

Yes, given an array, array, and a value, item to search for, you can use np.where as:

itemindex = numpy.where(array==item)

The result is a tuple with first all the row indices, then all the column indices.

For example, if an array is two dimensions and it contained your item at two locations then

array[itemindex[0][0]][itemindex[1][0]]

would be equal to your item and so would be:

array[itemindex[0][1]][itemindex[1][1]]

How to convert number of minutes to hh:mm format in TSQL?

In case someone is interested in getting results as 60 becomes 01:00 hours, 120 becomes 02:00 hours, 150 becomes 02:30 hours, this function might help:

    create FUNCTION [dbo].[MinutesToHHMM]
(
    @minutes int 
)
RETURNS varchar(30)
AS

BEGIN
declare @h int
        set @h= @minutes / 60
        declare @mins varchar(2)
        set @mins= iif(@minutes%60<10,concat('0',cast((@minutes % 60) as varchar(2))),cast((@minutes % 60) as varchar(2)))
return iif(@h <10, concat('0', cast(@h as varchar(5)),':',@mins)
        ,concat(cast(@h as varchar(5)),':',@mins))

end

What is the difference between a string and a byte string?

Unicode is an agreed-upon format for the binary representation of characters and various kinds of formatting (e.g. lower case/upper case, new line, carriage return), and other "things" (e.g. emojis). A computer is no less capable of storing a unicode representation (a series of bits), whether in memory or in a file, than it is of storing an ascii representation (a different series of bits), or any other representation (series of bits).

For communication to take place, the parties to the communication must agree on what representation will be used.

Because unicode seeks to represent all the possible characters (and other "things") used in inter-human and inter-computer communication, it requires a greater number of bits for the representation of many characters (or things) than other systems of representation that seek to represent a more limited set of characters/things. To "simplify," and perhaps to accommodate historical usage, unicode representation is almost exclusively converted to some other system of representation (e.g. ascii) for the purpose of storing characters in files.

It is not the case that unicode cannot be used for storing characters in files, or transmitting them through any communications channel, simply that it is not.

The term "string," is not precisely defined. "String," in its common usage, refers to a set of characters/things. In a computer, those characters may be stored in any one of many different bit-by-bit representations. A "byte string" is a set of characters stored using a representation that uses eight bits (eight bits being referred to as a byte). Since, these days, computers use the unicode system (characters represented by a variable number of bytes) to store characters in memory, and byte strings (characters represented by single bytes) to store characters to files, a conversion must be used before characters represented in memory will be moved into storage in files.

Create HTML table using Javascript

In the html file there are three input boxes with userid,username,department respectively.

These inputboxes are used to get the input from the user.

The user can add any number of inputs to the page.

When clicking the button the script will enable the debugger mode.

In javascript, to enable the debugger mode, we have to add the following tag in the javascript.

/************************************************************************\

    Tools->Internet Options-->Advanced-->uncheck
    Disable script debugging(Internet Explorer)
    Disable script debugging(Other)

    <html xmlns="http://www.w3.org/1999/xhtml" >

    <head runat="server">

    <title>Dynamic Table</title>

    <script language="javascript" type="text/javascript">

    // <!CDATA[

    function CmdAdd_onclick() {

    var newTable,startTag,endTag;



    //Creating a new table

    startTag="<TABLE id='mainTable'><TBODY><TR><TD style=\"WIDTH: 120px\">User ID</TD>
    <TD style=\"WIDTH: 120px\">User Name</TD><TD style=\"WIDTH: 120px\">Department</TD></TR>"

    endTag="</TBODY></TABLE>"

    newTable=startTag;

    var trContents;

    //Get the row contents

    trContents=document.body.getElementsByTagName('TR');

    if(trContents.length>1)

    {

    for(i=1;i<trContents.length;i++)

    {

    if(trContents(i).innerHTML)

    {

    // Add previous rows

    newTable+="<TR>";

    newTable+=trContents(i).innerHTML;

    newTable+="</TR>";

    } 

    }

    }

    //Add the Latest row

    newTable+="<TR><TD style=\"WIDTH: 120px\" >" +
        document.getElementById('userid').value +"</TD>";

    newTable+="<TD style=\"WIDTH: 120px\" >" +
        document.getElementById('username').value +"</TD>";

    newTable+="<TD style=\"WIDTH: 120px\" >" +
        document.getElementById('department').value +"</TD><TR>";

    newTable+=endTag;

    //Update the Previous Table With New Table.

    document.getElementById('tableDiv').innerHTML=newTable;

    }

    // ]]>

    </script>

    </head>

    <body>

    <form id="form1" runat="server">

    <div>

    <br />

    <label>UserID</label> 

    <input id="userid" type="text" /><br />

    <label>UserName</label> 

    <input id="username" type="text" /><br />

    <label>Department</label> 

    <input id="department" type="text" />

    <center>

    <input id="CmdAdd" type="button" value="Add" onclick="return CmdAdd_onclick()" />
    </center>



    </div>

    <div id="tableDiv" style="text-align:center" >

    <table id="mainTable">

    <tr style="width:120px " >

    <td >User ID</td>

    <td>User Name</td>

    <td>Department</td>

    </tr>

    </table>

    </div>

    </form>

    </body>

    </html>

How can I detect when an Android application is running in the emulator?

Checking the answers, none of them worked when using LeapDroid, Droid4x or Andy emulators,

What does work for all cases is the following:

 private static String getSystemProperty(String name) throws Exception {
    Class systemPropertyClazz = Class.forName("android.os.SystemProperties");
    return (String) systemPropertyClazz.getMethod("get", new Class[]{String.class}).invoke(systemPropertyClazz, new Object[]{name});
}

public boolean isEmulator() {
    boolean goldfish = getSystemProperty("ro.hardware").contains("goldfish");
    boolean emu = getSystemProperty("ro.kernel.qemu").length() > 0;
    boolean sdk = getSystemProperty("ro.product.model").equals("sdk");
    return goldfish || emu || sdk;
}

Timeout function if it takes too long to finish

The process for timing out an operations is described in the documentation for signal.

The basic idea is to use signal handlers to set an alarm for some time interval and raise an exception once that timer expires.

Note that this will only work on UNIX.

Here's an implementation that creates a decorator (save the following code as timeout.py).

from functools import wraps
import errno
import os
import signal

class TimeoutError(Exception):
    pass

def timeout(seconds=10, error_message=os.strerror(errno.ETIME)):
    def decorator(func):
        def _handle_timeout(signum, frame):
            raise TimeoutError(error_message)

        def wrapper(*args, **kwargs):
            signal.signal(signal.SIGALRM, _handle_timeout)
            signal.alarm(seconds)
            try:
                result = func(*args, **kwargs)
            finally:
                signal.alarm(0)
            return result

        return wraps(func)(wrapper)

    return decorator

This creates a decorator called @timeout that can be applied to any long running functions.

So, in your application code, you can use the decorator like so:

from timeout import timeout

# Timeout a long running function with the default expiry of 10 seconds.
@timeout
def long_running_function1():
    ...

# Timeout after 5 seconds
@timeout(5)
def long_running_function2():
    ...

# Timeout after 30 seconds, with the error "Connection timed out"
@timeout(30, os.strerror(errno.ETIMEDOUT))
def long_running_function3():
    ...

Jackson enum Serializing and DeSerializer

The serializer / deserializer solution pointed out by @xbakesx is an excellent one if you wish to completely decouple your enum class from its JSON representation.

Alternatively, if you prefer a self-contained solution, an implementation based on @JsonCreator and @JsonValue annotations would be more convenient.

So leveraging on the example by @Stanley the following is a complete self-contained solution (Java 6, Jackson 1.9):

public enum DeviceScheduleFormat {

    Weekday,
    EvenOdd,
    Interval;

    private static Map<String, DeviceScheduleFormat> namesMap = new HashMap<String, DeviceScheduleFormat>(3);

    static {
        namesMap.put("weekday", Weekday);
        namesMap.put("even-odd", EvenOdd);
        namesMap.put("interval", Interval);
    }

    @JsonCreator
    public static DeviceScheduleFormat forValue(String value) {
        return namesMap.get(StringUtils.lowerCase(value));
    }

    @JsonValue
    public String toValue() {
        for (Entry<String, DeviceScheduleFormat> entry : namesMap.entrySet()) {
            if (entry.getValue() == this)
                return entry.getKey();
        }

        return null; // or fail
    }
}

What is the purpose of using WHERE 1=1 in SQL statements?

As you said:

if you are adding conditions dynamically you don't have to worry about stripping the initial AND that's the only reason could be, you are right.

How can I sort a std::map first by value, then by key?

std::map will sort its elements by keys. It doesn't care about the values when sorting.

You can use std::vector<std::pair<K,V>> then sort it using std::sort followed by std::stable_sort:

std::vector<std::pair<K,V>> items;

//fill items

//sort by value using std::sort
std::sort(items.begin(), items.end(), value_comparer);

//sort by key using std::stable_sort
std::stable_sort(items.begin(), items.end(), key_comparer);

The first sort should use std::sort since it is nlog(n), and then use std::stable_sort which is n(log(n))^2 in the worst case.

Note that while std::sort is chosen for performance reason, std::stable_sort is needed for correct ordering, as you want the order-by-value to be preserved.


@gsf noted in the comment, you could use only std::sort if you choose a comparer which compares values first, and IF they're equal, sort the keys.

auto cmp = [](std::pair<K,V> const & a, std::pair<K,V> const & b) 
{ 
     return a.second != b.second?  a.second < b.second : a.first < b.first;
};
std::sort(items.begin(), items.end(), cmp);

That should be efficient.

But wait, there is a better approach: store std::pair<V,K> instead of std::pair<K,V> and then you don't need any comparer at all — the standard comparer for std::pair would be enough, as it compares first (which is V) first then second which is K:

std::vector<std::pair<V,K>> items;
//...
std::sort(items.begin(), items.end());

That should work great.

Intellij idea cannot resolve anything in maven

Unfortunately I ran into the same issue and I was head scratching why this is happening. I almost tried everything on this page and but none worked for me.

So , I tried to go the root of this problem; and the problem was (Atleast for me) that I was trying to open a maven project but pom file was not identified. So right clicking on the pom file and choosing "add as maven project" and then right clicking on the project -> Maven -> Reimport did all the magic for me :)

Hopefully this can be helpful for someone.

SQL Error: ORA-01861: literal does not match format string 01861

Try replacing the string literal for date '1989-12-09' with TO_DATE('1989-12-09','YYYY-MM-DD')

Can you center a Button in RelativeLayout?

It's really easy. Try the code below,

<RelativeLayout
    android:id="@+id/second_RL"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_below="@+id/first_RL"
    android:background="@android:color/holo_blue_bright"
    android:gravity="center">

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button" />

</RelativeLayout>

What method in the String class returns only the first N characters?

Whenever I have to do string manipulations in C#, I miss the good old Left and Right functions from Visual Basic, which are much simpler to use than Substring.

So in most of my C# projects, I create extension methods for them:

public static class StringExtensions
{
    public static string Left(this string str, int length)
    {
        return str.Substring(0, Math.Min(length, str.Length));
    }

    public static string Right(this string str, int length)
    {
        return str.Substring(str.Length - Math.Min(length, str.Length));
    }
}

Note:
The Math.Min part is there because Substring throws an ArgumentOutOfRangeException when the input string's length is smaller than the requested length, as already mentioned in some comments under previous answers.

Usage:

string longString = "Long String";

// returns "Long";
string left1 = longString.Left(4);

// returns "Long String";
string left2 = longString.Left(100);

Completely cancel a rebase

If you are "Rebasing", "Already started rebase" which you want to cancel, just comment (#) all commits listed in rebase editor.

As a result you will get a command line message

Nothing to do

Which .NET Dependency Injection frameworks are worth looking into?

I can recommend Ninject. It's incredibly fast and easy to use but only if you don't need XML configuration, else you should use Windsor.

How to debug heap corruption errors?

I'd like to add my experience. In the last few days, I solved an instance of this error in my application. In my particular case, the errors in the code were:

  • Removing elements from an STL collection while iterating over it (I believe there are debug flags in Visual Studio to catch these things; I caught it during code review)
  • This one is more complex, I'll divide it in steps:
    • From a native C++ thread, call back into managed code
    • In managed land, call Control.Invoke and dispose a managed object which wraps the native object to which the callback belongs.
    • Since the object is still alive inside the native thread (it will remain blocked in the callback call until Control.Invoke ends). I should clarify that I use boost::thread, so I use a member function as the thread function.
    • Solution: Use Control.BeginInvoke (my GUI is made with Winforms) instead so that the native thread can end before the object is destroyed (the callback's purpose is precisely notifying that the thread ended and the object can be destroyed).

To compare two elements(string type) in XSLT?

First of all, the provided long code:

    <xsl:choose>
        <xsl:when test="OU_NAME='OU_ADDR1'">   --comparing two elements coming from XML             
            <!--remove if  adrees already contain  operating unit name <xsl:value-of select="OU_NAME"/> <fo:block/>-->
            <xsl:if test="OU_ADDR1 !='' ">
                <xsl:value-of select="OU_ADDR1"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR2 !='' ">
                <xsl:value-of select="OU_ADDR2"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR3 !='' ">
                <xsl:value-of select="OU_ADDR3"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="OU_TOWN_CITY !=''">
                <xsl:value-of select="OU_TOWN_CITY"/>,
                <fo:leader leader-pattern="space" leader-length="2.0pt"/>
            </xsl:if>
            <xsl:value-of select="OU_REGION2"/>
            <fo:leader leader-pattern="space" leader-length="3.0pt"/>
            <xsl:value-of select="OU_POSTALCODE"/>
            <fo:block/>
            <xsl:value-of select="OU_COUNTRY"/>
        </xsl:when>
        <xsl:otherwise>
            <xsl:value-of select="OU_NAME"/>
            <fo:block/>
            <xsl:if test="OU_ADDR1 !='' ">
                <xsl:value-of select="OU_ADDR1"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR2 !='' ">
                <xsl:value-of select="OU_ADDR2"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR3 !='' ">
                <xsl:value-of select="OU_ADDR3"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="OU_TOWN_CITY !=''">
                <xsl:value-of select="OU_TOWN_CITY"/>,
                <fo:leader leader-pattern="space" leader-length="2.0pt"/>
            </xsl:if>
            <xsl:value-of select="OU_REGION2"/>
            <fo:leader leader-pattern="space" leader-length="3.0pt"/>
            <xsl:value-of select="OU_POSTALCODE"/>
            <fo:block/>
            <xsl:value-of select="OU_COUNTRY"/>
        </xsl:otherwise>
    </xsl:choose>

is equivalent to this, much shorter code:

<xsl:if test="not(OU_NAME='OU_ADDR1)'">
              <xsl:value-of select="OU_NAME"/>
        </xsl:if>
            <xsl:if test="OU_ADDR1 !='' ">
                <xsl:value-of select="OU_ADDR1"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR2 !='' ">
                <xsl:value-of select="OU_ADDR2"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="LE_ADDR3 !='' ">
                <xsl:value-of select="OU_ADDR3"/>
                <fo:block/>
            </xsl:if>
            <xsl:if test="OU_TOWN_CITY !=''">
                <xsl:value-of select="OU_TOWN_CITY"/>,
                <fo:leader leader-pattern="space" leader-length="2.0pt"/>
            </xsl:if>
            <xsl:value-of select="OU_REGION2"/>
            <fo:leader leader-pattern="space" leader-length="3.0pt"/>
            <xsl:value-of select="OU_POSTALCODE"/>
            <fo:block/>
            <xsl:value-of select="OU_COUNTRY"/>

Now, to your question:

how to compare two elements coming from xml as string

In Xpath 1.0 strings can be compared only for equality (or inequality), using the operator = and the function not() together with the operator =.

$str1 = $str2

evaluates to true() exactly when the string $str1 is equal to the string $str2.

not($str1 = $str2)

evaluates to true() exactly when the string $str1 is not equal to the string $str2.

There is also the != operator. It generally should be avoided because it has anomalous behavior whenever one of its operands is a node-set.

Now, the rules for comparing two element nodes are similar:

$el1 = $el2

evaluates to true() exactly when the string value of $el1 is equal to the string value of $el2.

not($el1 = $el2)

evaluates to true() exactly when the string value of $el1 is not equal to the string value of $el2.

However, if one of the operands of = is a node-set, then

 $ns = $str

evaluates to true() exactly when there is at least one node in the node-set $ns1, whose string value is equal to the string $str

$ns1 = $ns2

evaluates to true() exactly when there is at least one node in the node-set $ns1, whose string value is equal to the string value of some node from $ns2

Therefore, the expression:

OU_NAME='OU_ADDR1'

evaluates to true() only when there is at least one element child of the current node that is named OU_NAME and whose string value is the string 'OU_ADDR1'.

This is obviously not what you want!

Most probably you want:

OU_NAME=OU_ADDR1

This expression evaluates to true exactly there is at least one OU_NAME child of the current node and one OU_ADDR1 child of the current node with the same string value.

Finally, in XPath 2.0, strings can be compared also using the value comparison operators lt, le, eq, gt, ge and the inherited from XPath 1.0 general comparison operator =.

Trying to evaluate a value comparison operator when one or both of its arguments is a sequence of more than one item results in error.

Reset select2 value and show placeholder

You must define the select2 as

$("#customers_select").select2({
    placeholder: "Select a customer",
    initSelection: function(element, callback) {                   
    }
});

To reset the select2

$("#customers_select").select2("val", "");

JavaScript Adding an ID attribute to another created Element

You set an element's id by setting its corresponding property:

myPara.id = ID;

How to copy a row from one SQL Server table to another

SELECT * INTO < new_table > FROM < existing_table > WHERE < clause >

Is there a developers api for craigslist.org

Craiglist is pretty stingy with their data , they even go out of their way to block scraping. If you use ruby here is a gem I wrote to help scrape craiglist data you can search through multiple cities , calculate average price ect...

How to change the JDK for a Jenkins job?

There is a JDK dropdown in "job name" -> Configure in Jenkins web ui. It will list all JDKs available in Jenkins configuration.

`col-xs-*` not working in Bootstrap 4

In Bootstrap 4.3, col-xs-{value} is replaced by col-{value}

There is no change in sm, md, lg, xl remains the same.

.col-{value}
.col-sm-{value}
.col-md-{value}
.col-lg-{value}
.col-xl-{value}

The term 'ng' is not recognized as the name of a cmdlet

Also you can run following command to resolve, npm install -g @angular/cli

loop through json array jquery

you could also change from the .get() method to the .getJSON() method, jQuery will then parse the string returned as data to a javascript object and/or array that you can then reference like any other javascript object/array.

using your code above, if you changed .get to .getJSON, you should get an alert of [object Object] for each element in the array. If you changed the alert to alert(item.name) you will get the names.

Show constraints on tables command

You can use this:

select
    table_name,column_name,referenced_table_name,referenced_column_name
from
    information_schema.key_column_usage
where
    referenced_table_name is not null
    and table_schema = 'my_database' 
    and table_name = 'my_table'

Or for better formatted output use this:

select
    concat(table_name, '.', column_name) as 'foreign key',  
    concat(referenced_table_name, '.', referenced_column_name) as 'references'
from
    information_schema.key_column_usage
where
    referenced_table_name is not null
    and table_schema = 'my_database' 
    and table_name = 'my_table'

Breaking out of nested loops

You can also refactor your code to use a generator. But this may not be a solution for all types of nested loops.

How to change background color in the Notepad++ text editor?

You may need admin access to do it on your system.

  1. Create a folder 'themes' in the Notepad++ installation folder i.e. C:\Program Files (x86)\Notepad++
  2. Search or visit pages like http://timtrott.co.uk/notepad-colour-schemes/ to download the favourite theme. It will be an SML file.
    • Note: I prefer Neon any day.
  3. Download the themes from the site and drag them to the themes folder.
    • Note: I was unable to copy-paste or create new files in 'themes' folder so I used drag and that worked.
  4. Follow the steps provided by @triforceofcourage to select the new theme in Notepad++ preferences.

How to show SVG file on React Native?

After trying many ways and libraries I decided to create a new font (with Glyphs or this tutorial) and add my SVG files to it, then use "Text" component with my custom font.

Hope this helps anyone that has the same problem with SVG in react-native.

How can I check if a string is a number?

Many datatypes have a TryParse-method that will return true if it managed to successfully convert to that specific type, with the parsed value as an out-parameter.

In your case these might be of interest:

http://msdn.microsoft.com/en-us/library/system.int32.tryparse.aspx

http://msdn.microsoft.com/en-us/library/system.decimal.tryparse.aspx

Detect user scroll down or scroll up in jQuery

To differentiate between scroll up/down in jQuery, you could use:

var mousewheelevt = (/Firefox/i.test(navigator.userAgent)) ? "DOMMouseScroll" : "mousewheel" //FF doesn't recognize mousewheel as of FF3.x
$('#yourDiv').bind(mousewheelevt, function(e){

    var evt = window.event || e //equalize event object     
    evt = evt.originalEvent ? evt.originalEvent : evt; //convert to originalEvent if possible               
    var delta = evt.detail ? evt.detail*(-40) : evt.wheelDelta //check for detail first, because it is used by Opera and FF

    if(delta > 0) {
        //scroll up
    }
    else{
        //scroll down
    }   
});

This method also works in divs that have overflow:hidden.

I successfully tested it in FireFox, IE and Chrome.

Get child node index

I had issue with text nodes, and it was showing wrong index. Here is version to fix it.

function getChildNodeIndex(elem)
{   
    let position = 0;
    while ((elem = elem.previousSibling) != null)
    {
        if(elem.nodeType != Node.TEXT_NODE)
            position++;
    }

    return position;
}

How to show all privileges from a user in oracle?

To show all privileges:

select name from system_privilege_map;

Datetime BETWEEN statement not working in SQL Server

From Sql Server 2008 you have "date" format.

So you can use

SELECT * FROM LOGS WHERE CONVERT(date,[CHECK_IN]) BETWEEN '2013-10-18' AND '2013-10-18'

https://docs.microsoft.com/en-us/sql/t-sql/data-types/date-transact-sql

How to parse a string into a nullable int

Try this:

public static int? ParseNullableInt(this string value)
{
    int intValue;
    if (int.TryParse(value, out intValue))
        return intValue;
    return null;
}

Error: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

Ok - for me the source of the problem was in serialisation/deserialisation. The object that was being sent and received was as follows where the code is submitted and the code and maskedPhoneNumber is returned.

@ApiObject(description = "What the object is for.")
@JsonIgnoreProperties(ignoreUnknown = true)
public class CodeVerification {

    @ApiObjectField(description = "The code which is to be verified.")
    @NotBlank(message = "mandatory")
    private final String code;

    @ApiObjectField(description = "The masked mobile phone number to which the code was verfied against.")
    private final String maskedMobileNumber;

    public codeVerification(@JsonProperty("code") String code, String maskedMobileNumber) {
        this.code = code;
        this.maskedMobileNumber = maskedMobileNumber;
    }

    public String getcode() {
        return code;
    }

    public String getMaskedMobileNumber() {
        return maskedMobileNumber;
    }
}

The problem was that I didn't have a JsonProperty defined for the maskedMobileNumber in the constructor. i.e. Constructor should have been

public codeVerification(@JsonProperty("code") String code, @JsonProperty("maskedMobileNumber") String maskedMobileNumber) {
    this.code = code;
    this.maskedMobileNumber = maskedMobileNumber;
}

Unable instantiate android.gms.maps.MapFragment

Add Google Play Services to Your Project

To make the Google Play services APIs available to your app:

follow the steps present in this link : http://developer.android.com/google/play-services/setup.html#Setup

django MultiValueDictKeyError error, how do I deal with it

For me, this error occurred in my django project because of the following:

  1. I inserted a new hyperlink in my home.html present in templates folder of my project as below:

    _x000D_
    _x000D_
    <input type="button" value="About" onclick="location.href='{% url 'about' %}'">
    _x000D_
    _x000D_
    _x000D_

  2. In views.py, I had the following definitions of count and about:

   def count(request):
           fulltext = request.GET['fulltext']
           wordlist = fulltext.split()
           worddict = {}
           for word in wordlist:
               if word in worddict:
                   worddict[word] += 1
               else:
                   worddict[word] = 1
                   worddict = sorted(worddict.items(), key = operator.itemgetter(1),reverse=True)
           return render(request,'count.html', 'fulltext':fulltext,'count':len(wordlist),'worddict'::worddict})

   def about(request): 
       return render(request,"about.html")
  1. In urls.py, I had the following url patterns:
    urlpatterns = [
        path('admin/', admin.site.urls),
        path('',views.homepage,name="home"),
        path('eggs',views.eggs),
        path('count/',views.count,name="count"),
        path('about/',views.count,name="about"),
    ]

As can be seen in no. 3 above,in the last url pattern, I was incorrectly calling views.count whereas I needed to call views.about. This line fulltext = request.GET['fulltext'] in count function (which was mistakenly called because of wrong entry in urlpatterns) of views.py threw the multivaluedictkeyerror exception.

Then I changed the last url pattern in urls.py to the correct one i.e. path('about/',views.about,name="about"), and everything worked fine.

Apparently, in general a newbie programmer in django can make the mistake I made of wrongly calling another view function for a url, which might be expecting different set of parameters or passing different set of objects in its render call, rather than the intended behavior.

Hope this helps some newbie programmer to django.

What exactly is node.js used for?

Node.js is an open source command line tool built for the server side JavaScript code.

Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications.

Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.

The basic philosophy of node.js is:

Non-blocking I/O - every I/O call must take a callback, whether it is to retrieve information from disk, network or another process. Built-in support for the most important protocols (HTTP, DNS, TLS) Low-level. Do not remove functionality present at the POSIX layer. For example, support half-closed TCP connections. Stream everything; never force the buffering of data.

Credit - Simple Overview About Node.js

Python class returning value

You are describing a function, not a class.

def Myclass():
    return []

bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

Although BeautifulSoup supports the HTML parser by default If you want to use any other third-party Python parsers you need to install that external parser like(lxml).

soup_object= BeautifulSoup(markup,"html.parser") #Python HTML parser

But if you don't specified any parser as parameter you will get an warning that no parser specified.

soup_object= BeautifulSoup(markup) #Warnning

To use any other external parser you need to install it and then need to specify it. like

pip install lxml

soup_object= BeautifulSoup(markup,'lxml') # C dependent parser 

External parser have c and python dependency which may have some advantage and disadvantage.

How to call a method after a delay in Android

For executing something in the UI Thread after 5 seconds:

new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
    @Override
    public void run() {
        //Do something here
    }
}, 5000);

How do I make a branch point at a specific commit?

git branch -f <branchname> <commit>

I go with Mark Longair's solution and comments and recommend anyone reads those before acting, but I'd suggest the emphasis should be on

git branch -f <branchname> <commit>

Here is a scenario where I have needed to do this.

Scenario

Develop on the wrong branch and hence need to reset it.

Start Okay

Cleanly develop and release some software.

So far so good

Develop on wrong branch

Mistake: Accidentally stay on the release branch while developing further.

After a mistake

Realize the mistake

"OH NO! I accidentally developed on the release branch." The workspace is maybe cluttered with half changed files that represent work-in-progress and we really don't want to touch and mess with. We'd just like git to flip a few pointers to keep track of the current state and put that release branch back how it should be.

Create a branch for the development that is up to date holding the work committed so far and switch to it.

git branch development
git checkout development 

Changed to another branch

Correct the branch

Now we are in the problem situation and need its solution! Rectify the mistake (of taking the release branch forward with the development) and put the release branch back how it should be.

Correct the release branch to point back to the last real release.

git branch -f release release2

The release branch is now correct again, like this ...

Corrected

What if I pushed the mistake to a remote?

git push -f <remote> <branch> is well described in another thread, though the word "overwrite" in the title is misleading. Force "git push" to overwrite remote files

Can I have onScrollListener for a ScrollView?

    // --------Start Scroll Bar Slide--------
    final HorizontalScrollView xHorizontalScrollViewHeader = (HorizontalScrollView) findViewById(R.id.HorizontalScrollViewHeader);
    final HorizontalScrollView xHorizontalScrollViewData = (HorizontalScrollView) findViewById(R.id.HorizontalScrollViewData);
    xHorizontalScrollViewData.getViewTreeObserver().addOnScrollChangedListener(new ViewTreeObserver.OnScrollChangedListener() {
        @Override
        public void onScrollChanged() {
            int scrollX; int scrollY;
            scrollX=xHorizontalScrollViewData.getScrollX();
            scrollY=xHorizontalScrollViewData.getScrollY();
            xHorizontalScrollViewHeader.scrollTo(scrollX, scrollY);
        }
    });
    // ---------End Scroll Bar Slide---------

How to perform a real time search and filter on a HTML table

I created these examples.

Simple indexOf search

var $rows = $('#table tr');
$('#search').keyup(function() {
    var val = $.trim($(this).val()).replace(/ +/g, ' ').toLowerCase();

    $rows.show().filter(function() {
        var text = $(this).text().replace(/\s+/g, ' ').toLowerCase();
        return !~text.indexOf(val);
    }).hide();
});

Demo: http://jsfiddle.net/7BUmG/2/

Regular expression search

More advanced functionality using regular expressions will allow you to search words in any order in the row. It will work the same if you type apple green or green apple:

var $rows = $('#table tr');
$('#search').keyup(function() {

    var val = '^(?=.*\\b' + $.trim($(this).val()).split(/\s+/).join('\\b)(?=.*\\b') + ').*$',
        reg = RegExp(val, 'i'),
        text;

    $rows.show().filter(function() {
        text = $(this).text().replace(/\s+/g, ' ');
        return !reg.test(text);
    }).hide();
});

Demo: http://jsfiddle.net/dfsq/7BUmG/1133/

Debounce

When you implement table filtering with search over multiple rows and columns it is very important that you consider performance and search speed/optimisation. Simply saying you should not run search function on every single keystroke, it's not necessary. To prevent filtering to run too often you should debounce it. Above code example will become:

$('#search').keyup(debounce(function() {
    var val = $.trim($(this).val()).replace(/ +/g, ' ').toLowerCase();
    // etc...
}, 300));

You can pick any debounce implementation, for example from Lodash _.debounce, or you can use something very simple like I use in next demos (debounce from here): http://jsfiddle.net/7BUmG/6230/ and http://jsfiddle.net/7BUmG/6231/.

VueJS conditionally add an attribute for an element

Simplest form:

<input :required="test">   // if true
<input :required="!test">  // if false
<input :required="!!test"> // test ? true : false

Keras model.summary() result - Understanding the # of Parameters

Number of parameters is the amount of numbers that can be changed in the model. Mathematically this means number of dimensions of your optimization problem. For you as a programmer, each of this parameters is a floating point number, which typically takes 4 bytes of memory, allowing you to predict the size of this model once saved.

This formula for this number is different for each neural network layer type, but for Dense layer it is simple: each neuron has one bias parameter and one weight per input: N = n_neurons * ( n_inputs + 1).

Get key from a HashMap using the value

if you what to obtain "ONE" by giving in 100 then

initialize hash map by

hashmap = new HashMap<Object,String>();

haspmap.put(100,"one");

and retrieve value by hashMap.get(100)

hope that helps.

What is the significance of #pragma marks? Why do we need #pragma marks?

Just to add the information I was looking for: pragma mark is Xcode specific, so if you deal with a C++ project that you open in different IDEs, it does not have any effect there. In Qt Creator, for example, it does not add categories for methods, nor generate any warnings/errors.

EDIT

#pragma is a preprocessor directive which comes from C programming language. Its purpose is to specify implementation-dependent information to the compiler - that is, each compiler might choose to interpret this directive as it wants. That said, it is rather considered an extension which does not change/influence the code itself. So compilers might as well ignore it.

Xcode is an IDE which takes advantage of #pragma and uses it in its own specific way. The point is, #pragma is not Xcode and even Objective-C specific.

asp.net mvc3 return raw html to view

Give a try to return bootstrap alert message, this worked for me

return Content("<div class='alert alert-success'><a class='close' data-dismiss='alert'>
&times;</a><strong style='width:12px'>Thanks!</strong> updated successfully</div>");

Note: Don't forget to add bootstrap css and js in your view page

hope helps someone.

Pythonic way to print list items

Assuming you are fine with your list being printed [1,2,3], then an easy way in Python3 is:

mylist=[1,2,3,'lorem','ipsum','dolor','sit','amet']

print(f"There are {len(mylist):d} items in this lorem list: {str(mylist):s}")

Running this produces the following output:

There are 8 items in this lorem list: [1, 2, 3, 'lorem', 'ipsum', 'dolor', 'sit', 'amet']

How to create a multiline UITextfield?

A supplement to h4xxr's answer in the above, an easier way to adjust the height of the UITextField is to select square border style in the attribute inspectors->Text Field. (By default, the border style of a UITextfield is ellipse.)

Reference: Answered Brian in here : How to set UITextField height?

HTTP 404 when accessing .svc file in IIS

There are 2 .net framework version are given under the features in add role/ features in server 2012

a. 3.5

b. 4.5

Depending up on used framework you can enable HTTP-Activation under WCF services. :)

Center/Set Zoom of Map to cover all visible Markers?

You need to use the fitBounds() method.

var markers = [];//some array
var bounds = new google.maps.LatLngBounds();
for (var i = 0; i < markers.length; i++) {
 bounds.extend(markers[i]);
}

map.fitBounds(bounds);

Documentation from developers.google.com/maps/documentation/javascript:

fitBounds(bounds[, padding])

Parameters:

`bounds`:  [`LatLngBounds`][1]|[`LatLngBoundsLiteral`][1]
`padding` (optional):  number|[`Padding`][1]

Return Value: None

Sets the viewport to contain the given bounds.
Note: When the map is set to display: none, the fitBounds function reads the map's size as 0x0, and therefore does not do anything. To change the viewport while the map is hidden, set the map to visibility: hidden, thereby ensuring the map div has an actual size.

How to determine total number of open/active connections in ms sql server 2005

This shows the number of connections per each DB:

SELECT 
    DB_NAME(dbid) as DBName, 
    COUNT(dbid) as NumberOfConnections,
    loginame as LoginName
FROM
    sys.sysprocesses
WHERE 
    dbid > 0
GROUP BY 
    dbid, loginame

And this gives the total:

SELECT 
    COUNT(dbid) as TotalConnections
FROM
    sys.sysprocesses
WHERE 
    dbid > 0

If you need more detail, run:

sp_who2 'Active'

Note: The SQL Server account used needs the 'sysadmin' role (otherwise it will just show a single row and a count of 1 as the result)

Create empty file using python

There is no way to create a file without opening it There is os.mknod("newfile.txt") (but it requires root privileges on OSX). The system call to create a file is actually open() with the O_CREAT flag. So no matter how, you'll always open the file.

So the easiest way to simply create a file without truncating it in case it exists is this:

open(x, 'a').close()

Actually you could omit the .close() since the refcounting GC of CPython will close it immediately after the open() statement finished - but it's cleaner to do it explicitely and relying on CPython-specific behaviour is not good either.

In case you want touch's behaviour (i.e. update the mtime in case the file exists):

import os
def touch(path):
    with open(path, 'a'):
        os.utime(path, None)

You could extend this to also create any directories in the path that do not exist:

basedir = os.path.dirname(path)
if not os.path.exists(basedir):
    os.makedirs(basedir)

SQL Server 2008 Row Insert and Update timestamps

try

CREATE TABLE [dbo].[Names]
(
    [Name] [nvarchar](64) NOT NULL,
    [CreateTS] [smalldatetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [smalldatetime] NOT NULL

)

PS I think a smalldatetime is good enough. You may decide differently.

Can you not do this at the "moment of impact" ?

In Sql Server, this is common:

Update dbo.MyTable 
Set 

ColA = @SomeValue , 
UpdateDS = CURRENT_TIMESTAMP
Where...........

Sql Server has a "timestamp" datatype.

But it may not be what you think.

Here is a reference:

http://msdn.microsoft.com/en-us/library/ms182776(v=sql.90).aspx

Here is a little RowVersion (synonym for timestamp) example:

CREATE TABLE [dbo].[Names]
(
    [Name] [nvarchar](64) NOT NULL,
    RowVers rowversion ,
    [CreateTS] [datetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [datetime] NOT NULL

)


INSERT INTO dbo.Names (Name,UpdateTS)
select 'John' , CURRENT_TIMESTAMP
UNION ALL select 'Mary' , CURRENT_TIMESTAMP
UNION ALL select 'Paul' , CURRENT_TIMESTAMP

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Update dbo.Names Set Name = Name

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Maybe a complete working example:

DROP TABLE [dbo].[Names]
GO


CREATE TABLE [dbo].[Names]
(
    [Name] [nvarchar](64) NOT NULL,
    RowVers rowversion ,
    [CreateTS] [datetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [datetime] NOT NULL

)

GO

CREATE TRIGGER dbo.trgKeepUpdateDateInSync_ByeByeBye ON dbo.Names
AFTER INSERT, UPDATE
AS

BEGIN

Update dbo.Names Set UpdateTS = CURRENT_TIMESTAMP from dbo.Names myAlias , inserted triggerInsertedTable where 
triggerInsertedTable.Name = myAlias.Name

END


GO






INSERT INTO dbo.Names (Name,UpdateTS)
select 'John' , CURRENT_TIMESTAMP
UNION ALL select 'Mary' , CURRENT_TIMESTAMP
UNION ALL select 'Paul' , CURRENT_TIMESTAMP

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Update dbo.Names Set Name = Name , UpdateTS = '03/03/2003' /* notice that even though I set it to 2003, the trigger takes over */

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Matching on the "Name" value is probably not wise.

Try this more mainstream example with a SurrogateKey

DROP TABLE [dbo].[Names]
GO


CREATE TABLE [dbo].[Names]
(
    SurrogateKey int not null Primary Key Identity (1001,1),
    [Name] [nvarchar](64) NOT NULL,
    RowVers rowversion ,
    [CreateTS] [datetime] NOT NULL CONSTRAINT CreateTS_DF DEFAULT CURRENT_TIMESTAMP,
    [UpdateTS] [datetime] NOT NULL

)

GO

CREATE TRIGGER dbo.trgKeepUpdateDateInSync_ByeByeBye ON dbo.Names
AFTER UPDATE
AS

BEGIN

   UPDATE dbo.Names
    SET UpdateTS = CURRENT_TIMESTAMP
    From  dbo.Names myAlias
    WHERE exists ( select null from inserted triggerInsertedTable where myAlias.SurrogateKey = triggerInsertedTable.SurrogateKey)

END


GO






INSERT INTO dbo.Names (Name,UpdateTS)
select 'John' , CURRENT_TIMESTAMP
UNION ALL select 'Mary' , CURRENT_TIMESTAMP
UNION ALL select 'Paul' , CURRENT_TIMESTAMP

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Update dbo.Names Set Name = Name , UpdateTS = '03/03/2003' /* notice that even though I set it to 2003, the trigger takes over */

select *  ,  ConvertedRowVers = CONVERT(bigint,RowVers) from [dbo].[Names]

Complex numbers usage in python

In python, you can put ‘j’ or ‘J’ after a number to make it imaginary, so you can write complex literals easily:

>>> 1j
1j
>>> 1J
1j
>>> 1j * 1j
(-1+0j)

The ‘j’ suffix comes from electrical engineering, where the variable ‘i’ is usually used for current. (Reasoning found here.)

The type of a complex number is complex, and you can use the type as a constructor if you prefer:

>>> complex(2,3)
(2+3j)

A complex number has some built-in accessors:

>>> z = 2+3j
>>> z.real
2.0
>>> z.imag
3.0
>>> z.conjugate()
(2-3j)

Several built-in functions support complex numbers:

>>> abs(3 + 4j)
5.0
>>> pow(3 + 4j, 2)
(-7+24j)

The standard module cmath has more functions that handle complex numbers:

>>> import cmath
>>> cmath.sin(2 + 3j)
(9.15449914691143-4.168906959966565j)

How to fix itunes could not connect to the iphone because an invalid response was received from the device?

Try resetting your network settings

Settings -> General -> Reset -> Reset Network Settings

And try deleting the contents of your mac/pc lockdown folder. Here's the link, follow the steps on "Reset the Lockdown folder".

http://support.apple.com/kb/ts2529

This one worked for me.

How do I open a Visual Studio project in design view?

From the Solution Explorer window select your form, right-click, click on View Designer. Voila! The form should display.

I tried posting a couple screenshots, but this is my first post; therefore, I could not post any images.

How do I make a semi transparent background?

Good to know

Some web browsers have difficulty to render text with shadows on top of transparent background. Then you can use a semi transparent 1x1 PNG image as a background.

Note

Remember that IE6 don’t support PNG files.

How do I clone a job in Jenkins?

To copy an existing job, go to http://your-jenkins/newJob and use the "Copy existing job" option. Enter the name of the existing job - Jenkins will verify whether it exists.

The default tab on the front page of Jenkins should list all existing jobs, but maybe your predecessor deleted the tab. You can create a new tab listing all jobs from http://your-jenkins/newView.

search in java ArrayList

You're missing the return statement because if your list size is 0, the for loop will never execute, thus the if will never run, and thus you will never return.

Move the if statement out of the loop.

Insert multiple rows into single column

Another way to do this is with union:

INSERT INTO Data ( Col1 ) 
select 'hello'
union 
select 'world'

maven compilation failure

I had the same issue (even though the project was compiling/working fine in Eclipse), it was not when using the command line build. The reason was that I wasn't using the correct folder structure for mvn: "src/main/java/com" etc. It is looking at these folders by default (I was using "/scr/main/com" etc. which caused issues).

What is it exactly a BLOB in a DBMS context

I think of it as a large array of binary data. The usability of BLOB follows immediately from the limited bandwidth of the DB interface, it is not determined by the DB storage mechanisms. No matter how you store the large piece of data, the only way to store and retrieve is the narrow database interface. The database is a bottleneck of the system. Why to use it as a file server, which can easily be distributed? Normally you do not want to download the BLOB. You just want the DB to store your BLOB urls. Deposite the BLOBs on a separate file server. Then, you reliefe the precious DB connection and provide unlimited bandwidth for large objects. This creates some issue of coherence though.

Extracting jar to specified directory

This worked for me.

I created a folder then changed into the folder using CD option from command prompt.

Then executed the jar from there.

d:\LS\afterchange>jar xvf ..\mywar.war

Order by multiple columns with Doctrine

The orderBy method requires either two strings or an Expr\OrderBy object. If you want to add multiple order declarations, the correct thing is to use addOrderBy method, or instantiate an OrderBy object and populate it accordingly:

   # Inside a Repository method:
   $myResults = $this->createQueryBuilder('a')
       ->addOrderBy('a.column1', 'ASC')
       ->addOrderBy('a.column2', 'ASC')
       ->addOrderBy('a.column3', 'DESC')
   ;

   # Or, using a OrderBy object:
   $orderBy = new OrderBy('a.column1', 'ASC');
   $orderBy->add('a.column2', 'ASC');
   $orderBy->add('a.column3', 'DESC');

   $myResults = $this->createQueryBuilder('a')
       ->orderBy($orderBy)
   ;

Git pull till a particular commit

This works for me:

git pull origin <sha>

e.g.

[dbn src]$ git fetch
[dbn src]$ git status
On branch current_feature
Your branch and 'origin/master' have diverged,
and have 2 and 7 different commits each, respectively.
...
[dbn src]$ git log -3 --pretty=oneline origin/master
f4d10ad2a5eda447bea53fed0b421106dbecea66 CASE-ID1: some descriptive msg
28eb00a42e682e32bdc92e5753a4a9c315f62b42 CASE-ID2: I'm so good at writing commit titles
ff39e46b18a66b21bc1eed81a0974e5c7de6a3e5 CASE-ID2: woooooo
[dbn src]$ git pull origin 28eb00a42e682e32bdc92e5753a4a9c315f62b42
[dbn src]$ git status
On branch current_feature
Your branch and 'origin/master' have diverged,
and have 2 and 1 different commits each, respectively.
...

This pulls 28eb00, ff39e4, and everything before, but doesn't pull f4d10ad. It allows the use of pull --rebase, and honors pull settings in your gitconfig. This works because you're basically treating 28eb00 as a branch.

For the version of git that I'm using, this method requires a full commit hash - no abbreviations or aliases are allowed. You could do something like:

[dbn src]$ git pull origin `git rev-parse origin/master^`

'do...while' vs. 'while'

I am programming about 12 years and only 3 months ago I have met a situation where it was really convenient to use do-while as one iteration was always necessary before checking a condition. So guess your big-time is ahead :).

How to convert a Kotlin source file to a Java source file

As @Vadzim said, in IntelliJ or Android Studio, you just have to do the following to get java code from kotlin:

  1. Menu > Tools > Kotlin > Show Kotlin Bytecode
  2. Click on the Decompile button
  3. Copy the java code

Update:

With a recent version (1.2+) of the Kotlin plugin you also can directly do Menu > Tools > Kotlin -> Decompile Kotlin to Java.

How do you get the current project directory from C# code when creating a custom MSBuild task?

If you want ot know what is the directory where your solution is located, you need to do this:

 var parent = Directory.GetParent(Directory.GetCurrentDirectory()).Parent;
            if (parent != null)
            {
                var directoryInfo = parent.Parent;
                string startDirectory = null;
                if (directoryInfo != null)
                {
                    startDirectory = directoryInfo.FullName;
                }
                if (startDirectory != null)
                { /*Do whatever you want "startDirectory" variable*/}
            }

If you let only with GetCurrrentDirectory() method, you get the build folder no matter if you are debugging or releasing. I hope this help! If you forget about validations it would be like this:

var startDirectory = Directory.GetParent(Directory.GetCurrentDirectory()).Parent.Parent.FullName;

Java method to swap primitives

I might do something like the following. Of course, with the wealth of Collection classes, i can't imagine ever needing to use this in any practical code.

public class Shift {
  public static <T> T[] left (final T... i) {
    if (1 >= i.length) {
      return i;
    }
    final T t = i[0];
    int x = 0;
    for (; x < i.length - 1; x++) {
      i[x] = i[x + 1];
    }
    i[x] = t;
    return i;
  }
}

Called with two arguments, it's a swap.

It can be used as follows:

int x = 1;
int y = 2;
Integer[] yx = Shift.left(x,y);

Alternatively:

Integer[] yx = {x,y};
Shift.left(yx);

Then

x = yx[0];
y = yx[1];

Note: it auto-boxes primitives.

Create PostgreSQL ROLE (user) if it doesn't exist

Here is a generic solution using plpgsql:

CREATE OR REPLACE FUNCTION create_role_if_not_exists(rolename NAME) RETURNS TEXT AS
$$
BEGIN
    IF NOT EXISTS (SELECT * FROM pg_roles WHERE rolname = rolename) THEN
        EXECUTE format('CREATE ROLE %I', rolename);
        RETURN 'CREATE ROLE';
    ELSE
        RETURN format('ROLE ''%I'' ALREADY EXISTS', rolename);
    END IF;
END;
$$
LANGUAGE plpgsql;

Usage:

posgres=# SELECT create_role_if_not_exists('ri');
 create_role_if_not_exists 
---------------------------
 CREATE ROLE
(1 row)
posgres=# SELECT create_role_if_not_exists('ri');
 create_role_if_not_exists 
---------------------------
 ROLE 'ri' ALREADY EXISTS
(1 row)

How to upload files in asp.net core?

Fileservice.cs:

public class FileService : IFileService
{
    private readonly IWebHostEnvironment env;

    public FileService(IWebHostEnvironment env)
    {
        this.env = env;
    }

    public string Upload(IFormFile file)
    {
        var uploadDirecotroy = "uploads/";
        var uploadPath = Path.Combine(env.WebRootPath, uploadDirecotroy);

        if (!Directory.Exists(uploadPath))
            Directory.CreateDirectory(uploadPath);

        var fileName = Guid.NewGuid() + Path.GetExtension(file.FileName);
        var filePath = Path.Combine(uploadPath, fileName);

        using (var strem = File.Create(filePath))
        {
            file.CopyTo(strem);
        }
        return fileName;
    }
}

IFileService:

namespace studentapps.Services
{
    public interface IFileService
    {
        string Upload(IFormFile file);
    }
}

StudentController:

[HttpGet]
public IActionResult Create()
{
    var student = new StudentCreateVM();
    student.Colleges = dbContext.Colleges.ToList();
    return View(student);
}

[HttpPost]
public IActionResult Create([FromForm] StudentCreateVM vm)
{
    Student student = new Student()
    {
        DisplayImage = vm.DisplayImage.FileName,
        Name = vm.Name,
        Roll_no = vm.Roll_no,
        CollegeId = vm.SelectedCollegeId,
    };


    if (ModelState.IsValid)
    {
        var fileName = fileService.Upload(vm.DisplayImage);
        student.DisplayImage = fileName;
        getpath = fileName;

        dbContext.Add(student);
        dbContext.SaveChanges();
        TempData["message"] = "Successfully Added";
    }
    return RedirectToAction("Index");
}

gzip: stdin: not in gzip format tar: Child returned status 1 tar: Error is not recoverable: exiting now

Sometimes the .gz extension is wrongfully appended to the filename.

  • Run file foo.csv.gz to know the actual file type.
  • Rename the file to foo.csv or whatever the actual file type is.

What is the easiest way to clear a database from the CLI with manage.py in Django?

Using Django Extensions, running:

./manage.py reset_db

Will clear the database tables, then running:

./manage.py syncdb

Will recreate them (south may ask you to migrate things).

How can I check the current status of the GPS receiver?

Setting time interval to check for fix is not a good choice.. i noticed that onLocationChanged is not called if you are not moving.. what is understandable since location is not changing :)

Better way would be for example:

  • check interval to last location received (in gpsStatusChanged)
  • if that interval is more than 15s set variable: long_interval = true
  • remove the location listener and add it again, usually then you get updated position if location really is available, if not - you probably lost location
  • in onLocationChanged you just set long_interval to false..

How do I check if a Socket is currently connected in Java?

Assuming you have some level of control over the protocol, I'm a big fan of sending heartbeats to verify that a connection is active. It's proven to be the most fail proof method and will often give you the quickest notification when a connection has been broken.

TCP keepalives will work, but what if the remote host is suddenly powered off? TCP can take a long time to timeout. On the other hand, if you have logic in your app that expects a heartbeat reply every x seconds, the first time you don't get them you know the connection no longer works, either by a network or a server issue on the remote side.

See Do I need to heartbeat to keep a TCP connection open? for more discussion.

How to set border's thickness in percentages?

You can use em for percentage instead of pixels,

Example:

border:10PX dotted #c1a9ff; /* In Pixels */
border:0.75em dotted #c1a9ff; /* Exact same as above in Percentage */

PHP: How to remove all non printable characters in a string?

Many of the other answers here do not take into account unicode characters (e.g. öäüß??îû??????? ). In this case you can use the following:

$string = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F-\x9F]/u', '', $string);

There's a strange class of characters in the range \x80-\x9F (Just above the 7-bit ASCII range of characters) that are technically control characters, but over time have been misused for printable characters. If you don't have any problems with these, then you can use:

$string = preg_replace('/[\x00-\x08\x0B\x0C\x0E-\x1F\x7F]/u', '', $string);

If you wish to also strip line feeds, carriage returns, tabs, non-breaking spaces, and soft-hyphens, you can use:

$string = preg_replace('/[\x00-\x1F\x7F-\xA0\xAD]/u', '', $string);

Note that you must use single quotes for the above examples.

If you wish to strip everything except basic printable ASCII characters (all the example characters above will be stripped) you can use:

$string = preg_replace( '/[^[:print:]]/', '',$string);

For reference see http://www.fileformat.info/info/charset/UTF-8/list.htm

Can I call a function of a shell script from another shell script?

#vi function.sh

#!/bin/bash
f1() {
    echo "Hello $name"
}

f2() {
    echo "Enter your name: "
    read name
    f1
}
f2

#sh function.sh

Here function f2 will call function f1

How do I fix certificate errors when running wget on an HTTPS URL in Cygwin?

If you are using windows just go to control panel, click on automatic updates then click on Windows Update Web Site link. Just follow the step. At least this works for me, no more certificates issue i.e whenever I go to https://www.dropbox.com as before.

Find current directory and file's directory

Current Working Directory: os.getcwd()

And the __file__ attribute can help you find out where the file you are executing is located. This SO post explains everything: How do I get the path of the current executed file in Python?

CSS: Truncate table cells, but fit as much as possible

The problem is the 'table-layout:fixed' which create evenly-spaced-fixed-width columns. But disabling this css-property will kill the text-overflow because the table will become as large as possible (and than there is noting to overflow).

I'm sorry but in this case Fred can't have his cake and eat it to.. unless the landlord gives Celldito less space to work with in the first place, Fred cannot use his..

intelliJ IDEA 13 error: please select Android SDK

I had same problem once. every things seems right. I restart, delete and invalidate cache of Android studio, rebuild, clean and nothings changed. It is finally solved by click on Sync Project with Gradle Files button in android studio 3.0

Sync Project with Gradle Files button

How to get status code from webclient?

You should use

if (e.Status == WebExceptionStatus.ProtocolError)
{
   HttpWebResponse response = (HttpWebResponse)ex.Response;             
   if (response.StatusCode == HttpStatusCode.NotFound)
      System.Diagnostics.Debug.WriteLine("Not found!");
}

Understanding Fragment's setRetainInstance(boolean)

SetRetainInstance(true) allows the fragment sort of survive. Its members will be retained during configuration change like rotation. But it still may be killed when the activity is killed in the background. If the containing activity in the background is killed by the system, it's instanceState should be saved by the system you handled onSaveInstanceState properly. In another word the onSaveInstanceState will always be called. Though onCreateView won't be called if SetRetainInstance is true and fragment/activity is not killed yet, it still will be called if it's killed and being tried to be brought back.

Here are some analysis of the android activity/fragment hope it helps. http://ideaventure.blogspot.com.au/2014/01/android-activityfragment-life-cycle.html

How to customize <input type="file">?

Bootstrap example

<label className="btn btn-info btn-lg">
  Upload
  <input type="file" style="display: none" />
</label>

Easiest way to ignore blank lines when reading a file in Python

If you want you can just put what you had in a list comprehension:

names_list = [line for line in open("names.txt", "r").read().splitlines() if line]

or

all_lines = open("names.txt", "r").read().splitlines()
names_list = [name for name in all_lines if name]

splitlines() has already removed the line endings.

I don't think those are as clear as just looping explicitly though:

names_list = []
with open('names.txt', 'r') as _:
    for line in _:
        line = line.strip()
        if line:
            names_list.append(line)

Edit:

Although, filter looks quite readable and concise:

names_list = filter(None, open("names.txt", "r").read().splitlines())

Calculate percentage saved between two numbers?

100% - discounted price / full price

Purpose of #!/usr/bin/python3 shebang

  1. And this line is how.

  2. It is ignored.

  3. It will fail to run, and should be changed to point to the proper location. Or env should be used.

  4. It will fail to run, and probably fail to run under a different version regardless.

What is the iBeacon Bluetooth Profile

Just to reconcile the difference between sandeepmistry's answer and davidgyoung's answer:

02 01 1a 1a ff 4C 00

Is part of the advertising data format specification [1]

  02 # length of following AD structure
  01 # <<Flags>> AD Structure [2]
  1a # read as b00011010. 
     # In this case, LE General Discoverable,
     # and simultaneous BR/EDR but this may vary by device!

  1a # length of following AD structure
  FF # Manufacturer specific data [3]
4C00 # Apple Inc [4]
0215 # ?? some 2-byte header

Missing from the AD is a Service [5] definition. I think the iBeacon protocol itself has no relationship to the GATT and standard service discovery. If you download RedBearLab's iBeacon program, you'll see that they happen to use the GATT for configuring the advertisement parameters, but this seems to be specific to their implementation, and not part of the spec. The AirLocate program doesn't seem to use the GATT for configuration, for instance, according to LightBlue and or other similar programs I tried.

References:

  1. Core Bluetooth Spec v4, Vol 3, Part C, 11
  2. Vol 3, Part C, 18.1
  3. Vol 3, Part C, 18.11
  4. https://www.bluetooth.org/en-us/specification/assigned-numbers/company-identifiers
  5. Vol 3, Part C, 18.2

How to use PDO to fetch results array in PHP?

$st = $data->prepare("SELECT * FROM exampleWHERE example LIKE :search LIMIT 10"); 

Draw an X in CSS

single element solution:enter image description here

_x000D_
_x000D_
body{_x000D_
    background:blue;_x000D_
}_x000D_
_x000D_
div{_x000D_
    width:40px;_x000D_
    height:40px;_x000D_
    background-color:red;_x000D_
    position:relative;_x000D_
    border-radius:6px;_x000D_
    box-shadow:2px 2px 4px 0 white;_x000D_
}_x000D_
_x000D_
div:before,div:after{_x000D_
    content:'';_x000D_
    position:absolute;_x000D_
    width:36px;_x000D_
    height:4px;_x000D_
    background-color:white;_x000D_
    border-radius:2px;_x000D_
    top:16px;_x000D_
    box-shadow:0 0 2px 0 #ccc;_x000D_
}_x000D_
_x000D_
div:before{_x000D_
    -webkit-transform:rotate(45deg);_x000D_
    -moz-transform:rotate(45deg);_x000D_
    transform:rotate(45deg);_x000D_
    left:2px;_x000D_
}_x000D_
div:after{_x000D_
    -webkit-transform:rotate(-45deg);_x000D_
    -moz-transform:rotate(-45deg);_x000D_
    transform:rotate(-45deg);_x000D_
    right:2px;_x000D_
}
_x000D_
<div></div>
_x000D_
_x000D_
_x000D_

What is the difference between CHARACTER VARYING and VARCHAR in PostgreSQL?

The short answer: there is no difference.

The long answer: CHARACTER VARYING is the official type name from the ANSI SQL standard, which all compliant databases are required to support. VARCHAR is a shorter alias which all modern databases also support. I prefer VARCHAR because it's shorter and because the longer name feels pedantic. However, postgres tools like pg_dump and \d will output character varying.

Why is quicksort better than mergesort?

Consider time and space complexity both. For Merge sort : Time complexity : O(nlogn) , Space complexity : O(nlogn)

For Quick sort : Time complexity : O(n^2) , Space complexity : O(n)

Now, they both win in one scenerio each. But, using a random pivot you can almost always reduce Time complexity of Quick sort to O(nlogn).

Thus, Quick sort is preferred in many applications instead of Merge sort.

Right Align button in horizontal LinearLayout

Real solution for it case:

android:layout_weight="1" for TextView, and your button move to right!

I'm getting favicon.ico error

Also, be careful so your href location isn't faulty. Study case:

My index page was in a temporary sub-folder named LAYOUTS. To reach the favicon.png from inside the IMAGES folder, which was a sibling of the LAYOUTS folder, I had to put a path in my href like this

href="../images/favicon-32x32.png"

Double periods are necessary for folder navigation "upwards", then the forward slash + images string gets you into the images folder (performing a tree branch "jump") and finally you get to reference your file by writing favicon-32x32.png.

This explanation is useful for those that start out from scratch and it would have been useful to have seen it a couple of times since I would forget that I had certain *.php files outside the LAYOUTS folder which needed different tree hrefs on my links, from the HEAD section of each page.

Reference the path to your favicon image accordingly.

How to add a footer to the UITableView?

instead of

self.theTable.tableFooterView = tableFooter;

try

[self.theTable.tableFooterView addSubview:tableFooter];

How do I count unique values inside a list

For ndarray there is a numpy method called unique:

np.unique(array_name)

Examples:

>>> np.unique([1, 1, 2, 2, 3, 3])
array([1, 2, 3])
>>> a = np.array([[1, 1], [2, 3]])
>>> np.unique(a)
array([1, 2, 3])

For a Series there is a function call value_counts():

Series_name.value_counts()

How to restore the menu bar in Visual Studio Code

If you are like me - you did this by inadvertently hitting F11 - toggling fullscreen mode. https://code.visualstudio.com/shortcuts/keyboard-shortcuts-windows.pdf

How to add an item to an ArrayList in Kotlin?

If you have a MUTABLE collection:

val list = mutableListOf(1, 2, 3)
list += 4

If you have an IMMUTABLE collection:

var list = listOf(1, 2, 3)
list += 4

note that I use val for the mutable list to emphasize that the object is always the same, but its content changes.

In case of the immutable list, you have to make it var. A new object is created by the += operator with the additional value.

Adding attribute in jQuery

This could be more helpfull....

$("element").prop("id", "modifiedId");
//for boolean
$("element").prop("disabled", true);
//also you can remove attribute
$('#someid').removeProp('disabled');

how to dynamically add options to an existing select in vanilla javascript

I guess something like this would do the job.

var option = document.createElement("option");
option.text = "Text";
option.value = "myvalue";
var select = document.getElementById("daySelect");
select.appendChild(option);

Deleting Row in SQLite in Android

if you are using SQLiteDatabase then there is a delete method

Definition of Delete

int delete (String table, String whereClause, String[] whereArgs)

Example Implementation

Now we can write a method called delete with argument as name

public void delete(String value) {
    db.delete(DATABASE_TABLE, KEY_NAME + "=?", new String[]{String.valueOf(value)});
}

if you want to delete all records then just pass null to the above method,

public void delete() {
    db.delete(DATABASE_TABLE, null, null);
}

Source Of Information

Regular expression to match URLs in Java

Try the following regex string instead. Your test was probably done in a case-sensitive manner. I have added the lowercase alphas as well as a proper string beginning placeholder.

String regex = "^(https?|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]";

This works too:

String regex = "\\b(https?|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]";

Note:

String regex = "<\\b(https?|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]>"; // matches <http://google.com>

String regex = "<^(https?|ftp|file)://[-a-zA-Z0-9+&@#/%?=~_|!:,.;]*[-a-zA-Z0-9+&@#/%=~_|]>"; // does not match <http://google.com>

Delete last char of string

Removes any trailing commas:

while (strgroupids.EndsWith(","))
    strgroupids = strgroupids.Substring(0, strgroupids.Length - 1);

This is backwards though, you wrote the code that adds the comma in the first place. You should use string.Join(",",g) instead, assuming g is a string[]. Give it a better name than g too !

Convert pyQt UI to python

For pyqt5 you can use

pyuic5 xyz.ui > xyz.py 

or

pyuic5 xyz.ui -o xyz.py

SQL select join: is it possible to prefix all columns as 'prefix.*'?

The only database I know that does this is SQLite, depending on the settings you configure with PRAGMA full_column_names and PRAGMA short_column_names. See http://www.sqlite.org/pragma.html

Otherwise all I can recommend is to fetch columns in a result set by ordinal position rather than by column name, if it's too much trouble for you to type the names of the columns in your query.

This is a good example of why it's bad practice to use SELECT * -- because eventually you'll have a need to type out all the column names anyway.

I understand the need to support columns that may change name or position, but using wildcards makes that harder, not easier.

Prevent line-break of span element

white-space: nowrap is the correct solution but it will prevent any break in a line. If you only want to prevent line breaks between two elements it gets a bit more complicated:

<p>
    <span class="text">Some text</span>
    <span class="icon"></span>
</p>

To prevent breaks between the spans but to allow breaks between "Some" and "text" can be done by:

p {
    white-space: nowrap;
}

.text {
    white-space: normal;
}

That's good enough for Firefox. In Chrome you additionally need to replace the whitespace between the spans with an &nbsp;. (Removing the whitespace doesn't work.)

How do I completely remove root password

Did you try passwd -d root? Most likely, this will do what you want.


You can also manually edit /etc/shadow: (Create a backup copy. Be sure that you can log even if you mess up, for example from a rescue system.) Search for "root". Typically, the root entry looks similar to

root:$X$SK5xfLB1ZW:0:0...

There, delete the second field (everything between the first and second colon):

root::0:0...

Some systems will make you put an asterisk (*) in the password field instead of blank, where a blank field would allow no password (CentOS 8 for example)

root:*:0:0...

Save the file, and try logging in as root. It should skip the password prompt. (Like passwd -d, this is a "no password" solution. If you are really looking for a "blank password", that is "ask for a password, but accept if the user just presses Enter", look at the manpage of mkpasswd, and use mkpasswd to create the second field for the /etc/shadow.)

Upload Image using POST form data in Python-requests

I confronted similar issue when I wanted to post image file to a rest API from Python (Not wechat API though). The solution for me was to use 'data' parameter to post the file in binary data instead of 'files'. Requests API reference

data = open('your_image.png','rb').read()
r = requests.post(your_url,data=data)

Hope this works for your case.

Converting a date in MySQL from string field

This:

STR_TO_DATE(t.datestring, '%d/%m/%Y')

...will convert the string into a datetime datatype. To be sure that it comes out in the format you desire, use DATE_FORMAT:

DATE_FORMAT(STR_TO_DATE(t.datestring, '%d/%m/%Y'), '%Y-%m-%d')

If you can't change the datatype on the original column, I suggest creating a view that uses the STR_TO_DATE call to convert the string to a DateTime data type.

SQL Server 2008- Get table constraints

I tried to edit the answer provided by marc_s however it wasn't accepted for some reason. It formats the sql for easier reading, includes the schema and also names the Default name so that this can easily be pasted into other code.

  SELECT SchemaName = s.Name,
         TableName = t.Name,
         ColumnName = c.Name,
         DefaultName = dc.Name,
         DefaultDefinition = dc.Definition
    FROM sys.schemas                s
    JOIN sys.tables                 t   on  t.schema_id          = s.schema_id
    JOIN sys.default_constraints    dc  on  dc.parent_object_id  = t.object_id 
    JOIN sys.columns                c   on  c.object_id          = dc.parent_object_id
                                        and c.column_id          = dc.parent_column_id
ORDER BY s.Name, t.Name, c.name

Swift convert unix time to date and time

For me: Converting timestamps coming from API to a valid date :

`let date = NSDate.init(fromUnixTimestampNumber: timesTamp /* i.e 1547398524000 */) as Date?`

How To Format A Block of Code Within a Presentation?

http://www.tohtml.com/ created syntax highlighted HTML code for lots of languages. It might be what you're looking for.

How to get process ID of background process?

  • $$ is the current script's pid
  • $! is the pid of the last background process

Here's a sample transcript from a bash session (%1 refers to the ordinal number of background process as seen from jobs):

$ echo $$
3748

$ sleep 100 &
[1] 192

$ echo $!
192

$ kill %1

[1]+  Terminated              sleep 100

How can I add a hint or tooltip to a label in C# Winforms?

yourToolTip = new ToolTip();
//The below are optional, of course,

yourToolTip.ToolTipIcon = ToolTipIcon.Info;
yourToolTip.IsBalloon = true;
yourToolTip.ShowAlways = true;

yourToolTip.SetToolTip(lblYourLabel,"Oooh, you put your mouse over me.");

How to check the exit status using an if statement

Every command that runs has an exit status.

That check is looking at the exit status of the command that finished most recently before that line runs.

If you want your script to exit when that test returns true (the previous command failed) then you put exit 1 (or whatever) inside that if block after the echo.

That being said if you are running the command and wanting to test its output using the following is often more straight-forward.

if some_command; then
    echo command returned true
else
    echo command returned some error
fi

Or to turn that around use ! for negation

if ! some_command; then
    echo command returned some error
else
    echo command returned true
fi

Note though that neither of those cares what the error code is. If you know you only care about a specific error code then you need to check $? manually.

How to use @Nullable and @Nonnull annotations more effectively?

I agree that the annotations "don't propagate very far". However, I see the mistake on the programmer's side.

I understand the Nonnull annotation as documentation. The following method expresses that is requires (as a precondition) a non-null argument x.

    public void directPathToA(@Nonnull Integer x){
        x.toString(); // do stuff to x        
    }

The following code snippet then contains a bug. The method calls directPathToA() without enforcing that y is non-null (that is, it does not guarantee the precondition of the called method). One possibility is to add a Nonnull annotation as well to indirectPathToA() (propagating the precondition). Possibility two is to check for the nullity of y in indirectPathToA() and avoid the call to directPathToA() when y is null.

    public void indirectPathToA(Integer y){
        directPathToA(y);
    }

How to draw a dotted line with css?

For example:

hr {
  border:none;
  border-top:1px dotted #f00;
  color:#fff;
  background-color:#fff;
  height:1px;
  width:50%;
}

See also Styling <hr> with CSS.

How to compile C++ under Ubuntu Linux?

You probably should use g++ rather than gcc.

How do I determine height and scrolling position of window in jQuery?

$(window).height()

$(window).width()

There is also a plugin to jquery to determine element location and offsets

http://plugins.jquery.com/project/dimensions

scrolling offset = offsetHeight property of an element

The OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)"

This is for my reference, as I encountered a variety of SQL error messages while trying to connect with provider. Other answers prescribe "try this, then this, then this". I appreciate the other answers, but I like to pair specific solutions with specific problems


Error

...provider did not give information...Cannot initialize data source object...

Error Numbers

7399, 7303

Error Detail

Msg 7399, Level 16, State 1, Line 2 The OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)" reported an error. 
  The provider did not give any information about the error. 
Msg 7303, Level 16, State 1, Line 2 Cannot initialize the data source object
  of OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)".

Solution

File was open. Close it.

Credit


Error

Access denied...Cannot get the column information...

Error Numbers

7399, 7350

Error Detail

Msg 7399, Level 16, State 1, Line 2 The OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)" reported an error. 
  Access denied.
Msg 7350, Level 16, State 2, Line 2 Cannot get the column information 
  from OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)".

Solution

Give access

Credit


Error

No value given for one or more required parameters....Cannot execute the query ...

Error Numbers

???, 7320

Error Detail

OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)" returned message "No value given for one or more required parameters.".
Msg 7320, Level 16, State 2, Line 2
Cannot execute the query "select [Col A], [Col A] FROM $Sheet" against OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)". 

Solution

Column names might be wrong. Do [Col A] and [Col B] actually exist in your spreadsheet?


Error

"Unspecified error"...Cannot initialize data source object...

Error Numbers

???, 7303

Error Detail

OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)" returned message "Unspecified error".
Msg 7303, Level 16, State 1, Line 2 Cannot initialize the data source object of OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)".

Solution

Run SSMS as admin. See this question.


Other References

Other answers which suggest modifying properties. Not sure how modifying these two properties (checking them or unchecking them) would help.

How can I call a shell command in my Perl script?

From Perl HowTo, the most common ways to execute external commands from Perl are:

  • my $files = `ls -la` — captures the output of the command in $files
  • system "touch ~/foo" — if you don't want to capture the command's output
  • exec "vim ~/foo" — if you don't want to return to the script after executing the command
  • open(my $file, '|-', "grep foo"); print $file "foo\nbar" — if you want to pipe input into the command

React: why child component doesn't update when prop changes

Use the setState function. So you could do

       this.setState({this.state.foo.bar:123}) 

inside the handle event method.

Once, the state is updated, it will trigger changes, and re-render will take place.

How to mark-up phone numbers?

The tel: scheme was used in the late 1990s and documented in early 2000 with RFC 2806 (which was obsoleted by the more-thorough RFC 3966 in 2004) and continues to be improved. Supporting tel: on the iPhone was not an arbitrary decision.

callto:, while supported by Skype, is not a standard and should be avoided unless specifically targeting Skype users.

Me? I'd just start including properly-formed tel: URIs on your pages (without sniffing the user agent) and wait for the rest of the world's phones to catch up :) .

Example:

_x000D_
_x000D_
<a href="tel:+18475555555">1-847-555-5555</a>
_x000D_
_x000D_
_x000D_

Can scrapy be used to scrape dynamic content from websites that are using AJAX?

Here is a simple example of scrapy with an AJAX request. Let see the site rubin-kazan.ru.

All messages are loaded with an AJAX request. My goal is to fetch these messages with all their attributes (author, date, ...):

enter image description here

When I analyze the source code of the page I can't see all these messages because the web page uses AJAX technology. But I can with Firebug from Mozilla Firefox (or an equivalent tool in other browsers) to analyze the HTTP request that generate the messages on the web page:

enter image description here

It doesn't reload the whole page but only the parts of the page that contain messages. For this purpose I click an arbitrary number of page on the bottom:

enter image description here

And I observe the HTTP request that is responsible for message body:

enter image description here

After finish, I analyze the headers of the request (I must quote that this URL I'll extract from source page from var section, see the code below):

enter image description here

And the form data content of the request (the HTTP method is "Post"):

enter image description here

And the content of response, which is a JSON file:

enter image description here

Which presents all the information I'm looking for.

From now, I must implement all this knowledge in scrapy. Let's define the spider for this purpose:

class spider(BaseSpider):
    name = 'RubiGuesst'
    start_urls = ['http://www.rubin-kazan.ru/guestbook.html']

    def parse(self, response):
        url_list_gb_messages = re.search(r'url_list_gb_messages="(.*)"', response.body).group(1)
        yield FormRequest('http://www.rubin-kazan.ru' + url_list_gb_messages, callback=self.RubiGuessItem,
                          formdata={'page': str(page + 1), 'uid': ''})

    def RubiGuessItem(self, response):
        json_file = response.body

In parse function I have the response for first request. In RubiGuessItem I have the JSON file with all information.

Generate a UUID on iOS from Swift

Try this one:

let uuid = NSUUID().uuidString
print(uuid)

Swift 3/4/5

let uuid = UUID().uuidString
print(uuid)

how to get all markers on google-maps-v3

I'm assuming you have multiple markers that you wish to display on a google map.

The solution is two parts, one to create and populate an array containing all the details of the markers, then a second to loop through all entries in the array to create each marker.

Not know what environment you're using, it's a little difficult to provide specific help.

My best advice is to take a look at this article & accepted answer to understand the principals of creating a map with multiple markers: Display multiple markers on a map with their own info windows

How to access array elements in a Django template?

when you render a request tou coctext some information: for exampel:

return render(request, 'path to template',{'username' :username , 'email'.email})

you can acces to it on template like this : for variabels :

{% if username %}{{ username }}{% endif %}

for array :

{% if username %}{{ username.1 }}{% endif %}
{% if username %}{{ username.2 }}{% endif %}

you can also name array objects in views.py and ten use it like:

{% if username %}{{ username.first }}{% endif %}

if there is other problem i wish to help you

Git command to show which specific files are ignored by .gitignore

Notes:


Also interesting (mentioned in qwertymk's answer), you can also use the git check-ignore -v command, at least on Unix (doesn't work in a CMD Windows session)

git check-ignore *
git check-ignore -v *

The second one displays the actual rule of the .gitignore which makes a file to be ignored in your git repo.
On Unix, using "What expands to all files in current directory recursively?" and a bash4+:

git check-ignore **/*

(or a find -exec command)

Note: https://stackoverflow.com/users/351947/Rafi B. suggests in the comments to avoid the (risky) globstar:

git check-ignore -v $(find . -type f -print)

Make sure to exclude the files from the .git/ subfolder though.


Original answer 42009)

git ls-files -i

should work, except its source code indicates:

if (show_ignored && !exc_given) {
                fprintf(stderr, "%s: --ignored needs some exclude pattern\n",
                        argv[0]);

exc_given ?

It turns out it need one more parameter after the -i to actually list anything:

Try:

git ls-files -i --exclude-from=[Path_To_Your_Global].gitignore

(but that would only list your cached (non-ignored) object, with a filter, so that is not quite what you want)


Example:

$ cat .git/ignore
# ignore objects and archives, anywhere in the tree.
*.[oa]
$ cat Documentation/.gitignore
# ignore generated html files,
*.html
# except foo.html which is maintained by hand
!foo.html
$ git ls-files --ignored \
    --exclude='Documentation/*.[0-9]' \
    --exclude-from=.git/ignore \
    --exclude-per-directory=.gitignore

Actually, in my 'gitignore' file (called 'exclude'), I find a command line that could help you:

F:\prog\git\test\.git\info>type exclude
# git ls-files --others --exclude-from=.git/info/exclude
# Lines that start with '#' are comments.
# For a project mostly in C, the following would be a good set of
# exclude patterns (uncomment them if you want to use them):
# *.[oa]
# *~

So....

git ls-files --ignored --exclude-from=.git/info/exclude
git ls-files -i --exclude-from=.git/info/exclude

git ls-files --others --ignored --exclude-standard
git ls-files -o -i --exclude-standard

should do the trick.

(Thanks to honzajde pointing out in the comments that git ls-files -o -i --exclude-from... does not include cached files: only git ls-files -i --exclude-from... (without -o) does.)

As mentioned in the ls-files man page, --others is the important part, in order to show you non-cached, non-committed, normally-ignored files.

--exclude_standard is not just a shortcut, but a way to include all standard "ignored patterns" settings.

exclude-standard
Add the standard git exclusions: .git/info/exclude, .gitignore in each directory, and the user's global exclusion file.

How to start Fragment from an Activity

Another ViewGroup:

A fragment is a ViewGroup which can be shown in an Activity. But it needs a Container. The container can be any Layout (FragmeLayout, LinearLayout, etc. It does not matter).

enter image description here

Step 1:

Define Activity Layout:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="match_parent"
   android:layout_height="match_parent">
   <FrameLayout
       android:id="@+id/fragmentHolder"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
    />
</RelativeLayout>

Step 2:

Define Fragment Layout:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">
    <EditText
       android:id="@+id/user"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"/>
    <EditText
       android:id="@+id/password"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:inputType="textPassword"/>
    <Button
       android:id="@+id/login"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:text="Login"/>
</LinearLayout>

Step 3:

Create Fragment class

public class LoginFragment extends Fragment {


    private Button login;
    private EditText username, password;

    public static LoginFragment getInstance(String username){
       Bundle bundle = new Bundle();
       bundle.putInt("USERNAME", username);
       LoginFragment fragment = new LoginFragment();
       fragment.setArguments(bundle);
       return fragment;
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState){
       View view = inflater.inflate(R.layout.login_fragment, parent, false);
       login = view.findViewById(R.id.login);
       username = view.findViewById(R.id.user);
       password = view.findViewById(R.id.password);
       String name = getArguments().getInt("USERNAME");
       username.setText(username);
       return view;
    }

}

Step 4:

Add fragment in Activity

public class ActivityB extends AppCompatActivity{

   private Fragment currentFragment;

   @Override
   protected void onCreate(Bundle savedInstanceState) {

       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_main);

       currentFragment = LoginFragment.getInstance("Rohit");
       getSupportFragmentManager()
                .beginTransaction()
                .add(R.id.fragmentHolder, currentFragment, "LOGIN_TAG")
                .commit();
   }

}

Demo Project:

This is code is very basic. If you want to learn more advanced topics in Fragment then you can check out these resources:

Woof - Learn the fragment right way
My Android Garage

How can I disable ARC for a single file in a project?

  1. select project -> targets -> build phases -> compiler sources
  2. select file -> compiler flags
  3. add -fno-objc-arc

How do you push just a single Git branch (and no other branches)?

So let's say you have a local branch foo, a remote called origin and a remote branch origin/master.

To push the contents of foo to origin/master, you first need to set its upstream:

git checkout foo
git branch -u origin/master

Then you can push to this branch using:

git push origin HEAD:master

In the last command you can add --force to replace the entire history of origin/master with that of foo.

Insert variable into Header Location PHP

<?php
$variable1 = "foo";
$variable2 = "bar";


header('Location: http://linkhere.com?fieldname1=$variable1&fieldname2=$variable2&fieldname3=$variable3);

?>

This works without any quotations.

How can I recover the return value of a function passed to multiprocessing.Process?

A simple solution:

import multiprocessing

output=[]
data = range(0,10)

def f(x):
    return x**2

def handler():
    p = multiprocessing.Pool(64)
    r=p.map(f, data)
    return r

if __name__ == '__main__':
    output.append(handler())

print(output[0])

Output:

[0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

What is the IntelliJ shortcut key to create a javadoc comment?

Shortcut Alt+Enter shows intention actions where you can choose "Add Javadoc".

Scala: write string to file in one statement

I know it's not one line, but it solves the safety issues as far as I can tell;

// This possibly creates a FileWriter, but maybe not
val writer = Try(new FileWriter(new File("filename")))
// If it did, we use it to write the data and return it again
// If it didn't we skip the map and print the exception and return the original, just in-case it was actually .write() that failed
// Then we close the file
writer.map(w => {w.write("data"); w}).recoverWith{case e => {e.printStackTrace(); writer}}.map(_.close)

If you didn't care about the exception handling then you can write

writer.map(w => {w.writer("data"); w}).recoverWith{case _ => writer}.map(_.close)

How to put a component inside another component in Angular2?

I think in your Angular-2 version directives are not supported in Component decorator, hence you have to register directive same as other component in @NgModule and then import in component as below and also remove directives: [ChildComponent] from decorator.

import {myDirective} from './myDirective';

How to change or add theme to Android Studio?

File - Settings - Appearance & Behavior - Appearance - CHOOSE Darcula in "Theme" - Press Apply.

or

Choose File - Settings - Editor - Colors & Fonts - Then SELECT Darcula in scheme name - Press Apply - restart Studio (sometimes not all elements implement theme)

PreparedStatement IN clause alternatives?

Here's a complete solution in Java to create the prepared statement for you:

/*usage:

Util u = new Util(500); //500 items per bracket. 
String sqlBefore  = "select * from myTable where (";
List<Integer> values = new ArrayList<Integer>(Arrays.asList(1,2,4,5)); 
string sqlAfter = ") and foo = 'bar'"; 

PreparedStatement ps = u.prepareStatements(sqlBefore, values, sqlAfter, connection, "someId");
*/



import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class Util {

    private int numValuesInClause;

    public Util(int numValuesInClause) {
        super();
        this.numValuesInClause = numValuesInClause;
    }

    public int getNumValuesInClause() {
        return numValuesInClause;
    }

    public void setNumValuesInClause(int numValuesInClause) {
        this.numValuesInClause = numValuesInClause;
    }

    /** Split a given list into a list of lists for the given size of numValuesInClause*/
    public List<List<Integer>> splitList(
            List<Integer> values) {


        List<List<Integer>> newList = new ArrayList<List<Integer>>(); 
        while (values.size() > numValuesInClause) {
            List<Integer> sublist = values.subList(0,numValuesInClause);
            List<Integer> values2 = values.subList(numValuesInClause, values.size());   
            values = values2; 

            newList.add( sublist);
        }
        newList.add(values);

        return newList;
    }

    /**
     * Generates a series of split out in clause statements. 
     * @param sqlBefore ""select * from dual where ("
     * @param values [1,2,3,4,5,6,7,8,9,10]
     * @param "sqlAfter ) and id = 5"
     * @return "select * from dual where (id in (1,2,3) or id in (4,5,6) or id in (7,8,9) or id in (10)"
     */
    public String genInClauseSql(String sqlBefore, List<Integer> values,
            String sqlAfter, String identifier) 
    {
        List<List<Integer>> newLists = splitList(values);
        String stmt = sqlBefore;

        /* now generate the in clause for each list */
        int j = 0; /* keep track of list:newLists index */
        for (List<Integer> list : newLists) {
            stmt = stmt + identifier +" in (";
            StringBuilder innerBuilder = new StringBuilder();

            for (int i = 0; i < list.size(); i++) {
                innerBuilder.append("?,");
            }



            String inClause = innerBuilder.deleteCharAt(
                    innerBuilder.length() - 1).toString();

            stmt = stmt + inClause;
            stmt = stmt + ")";


            if (++j < newLists.size()) {
                stmt = stmt + " OR ";
            }

        }

        stmt = stmt + sqlAfter;
        return stmt;
    }

    /**
     * Method to convert your SQL and a list of ID into a safe prepared
     * statements
     * 
     * @throws SQLException
     */
    public PreparedStatement prepareStatements(String sqlBefore,
            ArrayList<Integer> values, String sqlAfter, Connection c, String identifier)
            throws SQLException {

        /* First split our potentially big list into lots of lists */
        String stmt = genInClauseSql(sqlBefore, values, sqlAfter, identifier);
        PreparedStatement ps = c.prepareStatement(stmt);

        int i = 1;
        for (int val : values)
        {

            ps.setInt(i++, val);

        }
        return ps;

    }

}

Subtracting 2 lists in Python

Try this:

list(array([1,2,3])-1)

live output from subprocess command

Similar to previous answers but the following solution worked for for me on windows using Python3 to provide a common method to print and log in realtime (getting-realtime-output-using-python):

def print_and_log(command, logFile):
    with open(logFile, 'wb') as f:
        command = subprocess.Popen(command, stdout=subprocess.PIPE, shell=True)

        while True:
            output = command.stdout.readline()
            if not output and command.poll() is not None:
                f.close()
                break
            if output:
                f.write(output)
                print(str(output.strip(), 'utf-8'), flush=True)
        return command.poll()

How can I return to a parent activity correctly?

I had pretty much the same setup leading to the same unwanted behaviour. For me this worked: adding the following attribute to an activity A in the Manifest.xml of my app:

android:launchMode="singleTask"

See this article for more explanation.

How to check if a table contains an element in Lua?

You can put the values as the table's keys. For example:

function addToSet(set, key)
    set[key] = true
end

function removeFromSet(set, key)
    set[key] = nil
end

function setContains(set, key)
    return set[key] ~= nil
end

There's a more fully-featured example here.

Quick easy way to migrate SQLite3 to MySQL?

Ha... I wish I had found this first! My response was to this post... script to convert mysql dump sql file into format that can be imported into sqlite3 db

Combining the two would be exactly what I needed:


When the sqlite3 database is going to be used with ruby you may want to change:

tinyint([0-9]*) 

to:

sed 's/ tinyint(1*) / boolean/g ' |
sed 's/ tinyint([0|2-9]*) / integer /g' |

alas, this only half works because even though you are inserting 1's and 0's into a field marked boolean, sqlite3 stores them as 1's and 0's so you have to go through and do something like:

Table.find(:all, :conditions => {:column => 1 }).each { |t| t.column = true }.each(&:save)
Table.find(:all, :conditions => {:column => 0 }).each { |t| t.column = false}.each(&:save)

but it was helpful to have the sql file to look at to find all the booleans.

Count the frequency that a value occurs in a dataframe column

@metatoaster has already pointed this out. Go for Counter. It's blazing fast.

import pandas as pd
from collections import Counter
import timeit
import numpy as np

df = pd.DataFrame(np.random.randint(1, 10000, (100, 2)), columns=["NumA", "NumB"])

Timers

%timeit -n 10000 df['NumA'].value_counts()
# 10000 loops, best of 3: 715 µs per loop

%timeit -n 10000 df['NumA'].value_counts().to_dict()
# 10000 loops, best of 3: 796 µs per loop

%timeit -n 10000 Counter(df['NumA'])
# 10000 loops, best of 3: 74 µs per loop

%timeit -n 10000 df.groupby(['NumA']).count()
# 10000 loops, best of 3: 1.29 ms per loop

Cheers!

Sorting 1 million 8-decimal-digit numbers with 1 MB of RAM

Sorting is a secondary problem here. As other said, just storing the integers is hard, and cannot work on all inputs, since 27 bits per number would be necessary.

My take on this is: store only the differences between the consecutive (sorted) integers, as they will be most likely small. Then use a compression scheme, e.g. with 2 additional bits per input number, to encode how many bits the number is stored on. Something like:

00 -> 5 bits
01 -> 11 bits
10 -> 19 bits
11 -> 27 bits

It should be possible to store a fair number of possible input lists within the given memory constraint. The maths of how to pick the compression scheme to have it work on the maximum number of inputs, are beyond me.

I hope you may be able to exploit domain-specific knowledge of your input to find a good enough integer compression scheme based on this.

Oh and then, you do an insertion sort on that sorted list as you receive data.

Java: Find .txt files in specified folder

Try:

List<String> textFiles(String directory) {
  List<String> textFiles = new ArrayList<String>();
  File dir = new File(directory);
  for (File file : dir.listFiles()) {
    if (file.getName().endsWith((".txt"))) {
      textFiles.add(file.getName());
    }
  }
  return textFiles;
}

You want to do a case insensitive search in which case:

    if (file.getName().toLowerCase().endsWith((".txt"))) {

If you want to recursively search for through a directory tree for text files, you should be able to adapt the above as either a recursive function or an iterative function using a stack.

Generate random string/characters in JavaScript

function randomString (strLength, charSet) {
    var result = [];

    strLength = strLength || 5;
    charSet = charSet || 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';

    while (--strLength) {
        result.push(charSet.charAt(Math.floor(Math.random() * charSet.length)));
    }

    return result.join('');
}

This is as clean as it will get. It is fast too, http://jsperf.com/ay-random-string.

Wait for a process to finish

Rauno Palosaari's solution for Timeout in Seconds Darwin, is an excellent workaround for a UNIX-like OS that does not have GNU tail (it is not specific to Darwin). But, depending on the age of the UNIX-like operating system, the command-line offered is more complex than necessary, and can fail:

lsof -p $pid +r 1m%s -t | grep -qm1 $(date -v+${timeout}S +%s 2>/dev/null || echo INF)

On at least one old UNIX, the lsof argument +r 1m%s fails (even for a superuser):

lsof: can't read kernel name list.

The m%s is an output format specification. A simpler post-processor does not require it. For example, the following command waits on PID 5959 for up to five seconds:

lsof -p 5959 +r 1 | awk '/^=/ { if (T++ >= 5) { exit 1 } }'

In this example, if PID 5959 exits of its own accord before the five seconds elapses, ${?} is 0. If not ${?} returns 1 after five seconds.

It may be worth expressly noting that in +r 1, the 1 is the poll interval (in seconds), so it may be changed to suit the situation.

Responsive Images with CSS

the best way i found was to set the image you want to view responsively as a background image and sent a css property for the div as cover.

background-image : url('YOUR URL');
background-size : cover

jQuery click events firing multiple times

In case this works fine

$( "#ok" ).bind( "click", function() {
    console.log("click"); 
});

How to find if an array contains a string

I'm afraid I don't think there's a shortcut to do this - if only someone would write a linq wrapper for VB6!

You could write a function that does it by looping through the array and checking each entry - I don't think you'll get cleaner than that.

There's an example article that provides some details here: http://www.vb6.us/tutorials/searching-arrays-visual-basic-6

How to hide only the Close (x) button?

We can hide close button on form by setting this.ControlBox=false;

Note that this hides all of those sizing buttons. Not just the X. In some cases that may be fine.

Send HTML in email via PHP

I have a this code and it will run perfectly for my site

  public function forgotpassword($pass,$name,$to)
    {
        $body ="<table  width=100% border=0><tr><td>";
        $body .= "<img width=200 src='";
        $body .= $this->imageUrl();
        $body .="'></img></td><td style=position:absolute;left:350;top:60;><h2><font color = #346699>PMS Pvt Ltd.</font><h2></td></tr>";
        $body .='<tr><td colspan=2><br/><br/><br/><strong>Dear '.$name.',</strong></td></tr>';
        $body .= '<tr><td colspan=2><br/><font size=3>As per Your request we send Your Password.</font><br/><br/>Password is : <b>'.$pass.'</b></td></tr>';
        $body .= '<tr><td colspan=2><br/>If you have any questions, please feel free to contact us at:<br/><a href="mailto:[email protected]" target="_blank">[email protected]</a></td></tr>';
        $body .= '<tr><td colspan=2><br/><br/>Best regards,<br>The PMS Team.</td></tr></table>';
        $subject = "Forgot Password";
        $this->sendmail($body,$to,$subject);
    }

mail function

   function sendmail($body,$to,$subject)
        {
            //require_once 'init.php';


            $from='[email protected]';      
            $headersfrom='';
            $headersfrom .= 'MIME-Version: 1.0' . "\r\n";
            $headersfrom .= 'Content-type: text/html; charset=iso-8859-1' . "\r\n";
            $headersfrom .= 'From: '.$from.' '. "\r\n";
            mail($to,$subject,$body,$headersfrom);
        }

image url function is use for if you want to change the image you have change in only one function i have many mail function like forgot password create user there for i am use image url function you can directly set path.

function imageUrl()
    {
        return "http://".$_SERVER['SERVER_NAME'].substr($_SERVER['SCRIPT_NAME'], 0, strrpos($_SERVER['SCRIPT_NAME'], "/")+1)."images/capacity.jpg";
    }

Sequence contains no elements?

This will solve the problem,

var blogPosts = (from p in dc.BlogPosts
             where p.BlogPostID == ID
             select p);
if(blogPosts.Any())
{
  var post = post.Single();
}

How should I do integer division in Perl?

The lexically scoped integer pragma forces Perl to use integer arithmetic in its scope:

print 3.0/2.1 . "\n";    # => 1.42857142857143
{
  use integer;
  print 3.0/2.1 . "\n";  # => 1
}
print 3.0/2.1 . "\n";    # => 1.42857142857143

How do I redirect to another webpage?

You can use:

window.location.replace("http://www.example.com/");

The replace() method does not save the originating page in the session history, so the user can't go back using the back button and again get redirected. NOTE: The browser back button will be deactivated in this case.

However, if you want an effect the same as clicking on a link you should go for:

window.location.href = "http://www.example.com/";

In this case, the browser back button will be active.

How to put a List<class> into a JSONObject and then read that object?

You could use a JSON serializer/deserializer like flexjson to do the conversion for you.

Spring Security exclude url patterns in security annotation configurartion

specifying the "antMatcher" before "authorizeRequests()" like below will restrict the authenticaiton to only those URLs specified in "antMatcher"

http.csrf().disable() .antMatcher("/apiurlneedsauth/**").authorizeRequests().

Inserting records into a MySQL table using Java

this can also be done like this if you don't want to use prepared statements.

String sql = "INSERT INTO course(course_code,course_desc,course_chair)"+"VALUES('"+course_code+"','"+course_desc+"','"+course_chair+"');"

Why it didnt insert value is because you were not providing values, but you were providing names of variables that you have used.

WRONGTYPE Operation against a key holding the wrong kind of value php

This error means that the value indexed by the key "l_messages" is not of type hash, but rather something else. You've probably set it to that other value earlier in your code. Try various other value-getter commands, starting with GET, to see which one works and you'll know what type is actually here.

Sending command line arguments to npm script

As of npm 2.x, you can pass args into run-scripts by separating with --

Terminal

npm run-script start -- --foo=3

Package.json

"start": "node ./index.js"

Index.js

console.log('process.argv', process.argv);

whitespaces in the path of windows filepath

Try putting double quotes in your filepath variable

"\"E:/ABC/SEM 2/testfiles/all.txt\""

Check the permissions of the file or in any case consider renaming the folder to remove the space

How to check if a text field is empty or not in swift

It's too late and its working fine in Xcode 7.3.1

if _txtfield1.text!.isEmpty || _txtfield2.text!.isEmpty {
        //is empty
    }

displayname attribute vs display attribute

DisplayName sets the DisplayName in the model metadata. For example:

[DisplayName("foo")]
public string MyProperty { get; set; }

and if you use in your view the following:

@Html.LabelFor(x => x.MyProperty)

it would generate:

<label for="MyProperty">foo</label>

Display does the same, but also allows you to set other metadata properties such as Name, Description, ...

Brad Wilson has a nice blog post covering those attributes.

Regex to check whether a string contains only numbers

\d will not match the decimal point. Use the following for the decimal.

const re = /^\d*(\.\d+)?$/
'123'.match(re)       // true
'123.3'.match(re)     // true
'123!3'.match(re)     // false

Clear input fields on form submit

You can clear out their values by just setting value to an empty string:

var1.value = '';
var2.value = '';

How to create a popup window (PopupWindow) in Android

are you done with the layout inflating? maybe you can try this!!

View myPoppyView = pw.getContentView();
Button myBelovedButton = (Button)myPoppyView.findViewById(R.id.my_beloved_button);
//do something with my beloved button? :p

Difference between clustered and nonclustered index

A comparison of a non-clustered index with a clustered index with an example

As an example of a non-clustered index, let’s say that we have a non-clustered index on the EmployeeID column. A non-clustered index will store both the value of the

EmployeeID

AND a pointer to the row in the Employee table where that value is actually stored. But a clustered index, on the other hand, will actually store the row data for a particular EmployeeID – so if you are running a query that looks for an EmployeeID of 15, the data from other columns in the table like

EmployeeName, EmployeeAddress, etc

. will all actually be stored in the leaf node of the clustered index itself.

This means that with a non-clustered index extra work is required to follow that pointer to the row in the table to retrieve any other desired values, as opposed to a clustered index which can just access the row directly since it is being stored in the same order as the clustered index itself. So, reading from a clustered index is generally faster than reading from a non-clustered index.

Check if object is a jQuery object

You can check if the object is produced by JQuery with the jquery property:

myObject.jquery // 3.3.1

=> return the number of the JQuery version if the object produced by JQuery. => otherwise, it returns undefined

Destroy or remove a view in Backbone.js

I think this should work

destroyView : function () {
    this.$el.remove();
}

Correct way to import lodash

If you are using webpack 4, the following code is tree shakable.

import { has } from 'lodash-es';

The points to note;

  1. CommonJS modules are not tree shakable so you should definitely use lodash-es, which is the Lodash library exported as ES Modules, rather than lodash (CommonJS).

  2. lodash-es's package.json contains "sideEffects": false, which notifies webpack 4 that all the files inside the package are side effect free (see https://webpack.js.org/guides/tree-shaking/#mark-the-file-as-side-effect-free).

  3. This information is crucial for tree shaking since module bundlers do not tree shake files which possibly contain side effects even if their exported members are not used in anywhere.

Edit

As of version 1.9.0, Parcel also supports "sideEffects": false, threrefore import { has } from 'lodash-es'; is also tree shakable with Parcel. It also supports tree shaking CommonJS modules, though it is likely tree shaking of ES Modules is more efficient than CommonJS according to my experiment.

Java random numbers using a seed

If you're giving the same seed, that's normal. That's an important feature allowing tests.

Check this to understand pseudo random generation and seeds:

Pseudorandom number generator

A pseudorandom number generator (PRNG), also known as a deterministic random bit generator DRBG, is an algorithm for generating a sequence of numbers that approximates the properties of random numbers. The sequence is not truly random in that it is completely determined by a relatively small set of initial values, called the PRNG's state, which includes a truly random seed.

If you want to have different sequences (the usual case when not tuning or debugging the algorithm), you should call the zero argument constructor which uses the nanoTime to try to get a different seed every time. This Random instance should of course be kept outside of your method.

Your code should probably be like this:

private Random generator = new Random();
double randomGenerator() {
    return generator.nextDouble()*0.5;
}

How to stop a thread created by implementing runnable interface?

The simplest way is to interrupt() it, which will cause Thread.currentThread().isInterrupted() to return true, and may also throw an InterruptedException under certain circumstances where the Thread is waiting, for example Thread.sleep(), otherThread.join(), object.wait() etc.

Inside the run() method you would need catch that exception and/or regularly check the Thread.currentThread().isInterrupted() value and do something (for example, break out).

Note: Although Thread.interrupted() seems the same as isInterrupted(), it has a nasty side effect: Calling interrupted() clears the interrupted flag, whereas calling isInterrupted() does not.

Other non-interrupting methods involve the use of "stop" (volatile) flags that the running Thread monitors.

comparing two strings in SQL Server

There is no direct string compare function in SQL Server

CASE
  WHEN str1 = str2 THEN 0
  WHEN str1 < str2 THEN -1
  WHEN str1 > str2 THEN 1
  ELSE NULL --one of the strings is NULL so won't compare (added on edit)
END

Notes

  • you can wraps this via a UDF using CREATE FUNCTION etc
  • you may need NULL handling (in my code above, any NULL will report 1)
  • str1 and str2 will be column names or @variables

Automatic login script for a website on windows machine?

From the term "automatic login" I suppose security (password protection) is not of key importance here.

The guidelines for solution could be to use a JavaScript bookmark (idea borrowed form a nice game published on M&M's DK site).

The idea is to create a javascript file and store it locally. It should do the login data entering depending on current site address. Just an example using jQuery:

// dont forget to include jQuery code
// preferably with .noConflict() in order not to break the site scripts
if (window.location.indexOf("mail.google.com") > -1) {
    // Lets login to Gmail
    jQuery("#Email").val("[email protected]");
    jQuery("#Passwd").val("superSecretPassowrd");
    jQuery("#gaia_loginform").submit();
}

Now save this as say login.js

Then create a bookmark (in any browser) with this (as an) url:

javascript:document.write("<script type='text/javascript' src='file:///path/to/login.js'></script>");

Now when you go to Gmail and click this bookmark you will get automatically logged in by your script.

Multiply the code blocks in your script, to add more sites in the similar manner. You could even combine it with window.open(...) functionality to open more sites, but that may get the script inclusion more complicated.

Note: This only illustrates an idea and needs lots of further work, it's not a complete solution.

Changing image on hover with CSS/HTML

What I would recommend is to use only CSS if possible. My solution would be:

HTML:

<img id="img" class="" src="" />

CSS:

img#img{
    background: url("pictureNumberOne.png");
    background-size: 100px 100px;
    /* Optional transition: */
    transition: background 0.25s ease-in-out;
}
img#img:hover{
    background: url("pictureNumberTwo.png");
    background-size: 100px 100px;
}

That (not defining the src attribute) also ensures that transparent images (or images with transparent parts) are shown correctly (otherwise, if the second pic would be half-transparent, you would also see parts of the first picture).

The background-size attribute is used to set the height and width of a background-image.

If (for any reason) you don't want to change the bg-image of an image, you could also put the image in a div-container as following:

HTML:

<div id="imgContainer" class="">
    <img id="" class="" src="" />
</div>

... and so on.

Determine Pixel Length of String in Javascript/jQuery?

Put it in an absolutely-positioned div then use clientWidth to get the displayed width of the tag. You can even set the visibility to "hidden" to hide the div:

<div id="text" style="position:absolute;visibility:hidden" >This is some text</div>
<input type="button" onclick="getWidth()" value="Go" />
<script type="text/javascript" >
    function getWidth() {
        var width = document.getElementById("text").clientWidth;
        alert(" Width :"+  width);
    }
</script>

Retrofit 2: Get JSON from Response body

use this

response.body().get(0).getUsername().toString();

Rails server says port already used, how to kill that process?

To kill process on a specific port, you can try this

npx kill-port [port-number]

Cannot set property 'innerHTML' of null

The JavaScript part needs to run once the page is loaded, therefore it is advised to place JavaScript script at the end of the body tag.

_x000D_
_x000D_
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Example</title>

</head>
<body>
<div id="hello"></div>
<script type ="text/javascript">
    what();
    function what(){
        document.getElementById('hello').innerHTML = 'hi';
    };
</script>  
</body>
</html>
_x000D_
_x000D_
_x000D_

How do operator.itemgetter() and sort() work?

#sorting first by age then profession,you can change it in function "fun".
a = []

def fun(v):
    return (v[1],v[2])

# create the table (name, age, job)
a.append(["Nick", 30, "Doctor"])
a.append(["John",  8, "Student"])
a.append(["Paul",  8,"Car Dealer"])
a.append(["Mark", 66, "Retired"])

a.sort(key=fun)


print a

PHP not displaying errors even though display_errors = On

You also need to make sure you have your php.ini file include the following set or errors will go only to the log that is set by default or specified in the virtual host's configuration.

display_errors = On

The php.ini file is where base settings for all PHP on your server, however these can easily be overridden and altered any place in the PHP code and effect everything following that change. A good check is to add the display_errors directive to your php.ini file. If you don't see an error, but one is being logged, insert this at the top of the file causing the error:

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

If this works then something earlier in your code is disabling error display.

How to use SQL Order By statement to sort results case insensitive?

You can also do ORDER BY TITLE COLLATE NOCASE.

Edit: If you need to specify ASC or DESC, add this after NOCASE like

ORDER BY TITLE COLLATE NOCASE ASC

or

ORDER BY TITLE COLLATE NOCASE DESC