Programs & Examples On #Builder pattern

What is the difference between Builder Design pattern and Factory Design pattern?

  • Constructing a complex object step by step : builder pattern

  • A simple object is created by using a single method : factory method pattern

  • Creating Object by using multiple factory method : Abstract factory pattern

Builder Pattern in Effective Java

To generate an inner builder in Intellij IDEA, check out this plugin: https://github.com/analytically/innerbuilder

How do you add an ActionListener onto a JButton in Java

Your best bet is to review the Java Swing tutorials, specifically the tutorial on Buttons.

The short code snippet is:

jBtnDrawCircle.addActionListener( /*class that implements ActionListener*/ );

Laravel: Get base url

To just get the app url, that you configured you can use :

Config::get('app.url')

how to find host name from IP with out login to the host

You can do a reverse DNS lookup with host, too. Just give it the IP address as an argument:

$ host 192.168.0.10
server10 has address 192.168.0.10

how to remove the dotted line around the clicked a element in html

Try with !important in css.

a {
  outline:none !important;
}
// it is `very important` that there is `no` `outline` for the `anchor` tag.  Thanks!

Subdomain on different host

sub domain is part of the domain, it's like subletting a room of an apartment. A records has to be setup on the dns for the domain e.g

mydomain.com has IP 123.456.789.999 and hosted with Godaddy. Now to get the sub domain

anothersite.mydomain.com

of which the site is actually on another server then

login to Godaddy and add an A record dnsimple anothersite.mydomain.com and point the IP to the other server 98.22.11.11

And that's it.

How to read attribute value from XmlNode in C#?

You can also use this;

string employeeName = chldNode.Attributes().ElementAt(0).Name

How to query a CLOB column in Oracle

If you are using SQL*Plus try the following...

set long 8000

select ...

If REST applications are supposed to be stateless, how do you manage sessions?

You have to manage client session on the client side. This means that you have to send authentication data with every request, and you probably, but not necessary have an in-memory cache on the server, which pairs auth data to user information like identity, permissions, etc...

This REST statelessness constraint is very important. Without applying this constraint, your server side application won't scale well, because maintaining every single client session will be its Achilles' heel.

Best way to check if MySQL results returned in PHP?

Use the one with mysql_fetch_row because "For SELECT, SHOW, DESCRIBE, EXPLAIN and other statements returning resultset, mysql_query() returns a resource on success, or FALSE on error.

For other type of SQL statements, INSERT, UPDATE, DELETE, DROP, etc, mysql_query() returns TRUE on success or FALSE on error. "

Better way to set distance between flexbox items

This is not a hack. The same technique is also used by bootstrap and its grid, though, instead of margin, bootstrap uses padding for its cols.

.row {
  margin:0 -15px;
}
.col-xx-xx {
  padding:0 15px;
}

How to hide a button programmatically?

Kotlin code is a lot simpler:

if(isVisable) {
    clearButton.visibility = View.INVISIBLE
}
else {
    clearButton.visibility = View.VISIBLE
}

Taking multiple inputs from user in python

Split function will split the input data according to whitespace.

data = input().split()
name=data[0]
id=data[1]
marks = list(map(datatype, data[2:]))

name will get first column, id will contain second column and marks will be a list which will contain data from third column to last column.

What is the difference between == and equals() in Java?

== can be used in many object types but you can use Object.equals for any type , especially Strings and Google Map Markers.

Can you find all classes in a package using reflection?

plain java: FindAllClassesUsingPlainJavaReflectionTest.java

@Slf4j
class FindAllClassesUsingPlainJavaReflectionTest {

  private static final Function<Throwable, RuntimeException> asRuntimeException = throwable -> {
    log.error(throwable.getLocalizedMessage());
    return new RuntimeException(throwable);
  };

  private static final Function<String, Collection<Class<?>>> findAllPackageClasses = basePackageName -> {

    Locale locale = Locale.getDefault();
    Charset charset = StandardCharsets.UTF_8;
    val fileManager = ToolProvider.getSystemJavaCompiler()
                                  .getStandardFileManager(/* diagnosticListener */ null, locale, charset);

    StandardLocation location = StandardLocation.CLASS_PATH;
    JavaFileObject.Kind kind = JavaFileObject.Kind.CLASS;
    Set<JavaFileObject.Kind> kinds = Collections.singleton(kind);
    val javaFileObjects = Try.of(() -> fileManager.list(location, basePackageName, kinds, /* recurse */ true))
                             .getOrElseThrow(asRuntimeException);

    String pathToPackageAndClass = basePackageName.replace(".", File.separator);
    Function<String, String> mapToClassName = s -> {
      String prefix = Arrays.stream(s.split(pathToPackageAndClass))
                            .findFirst()
                            .orElse("");
      return s.replaceFirst(prefix, "")
              .replaceAll(File.separator, ".");
    };

    return StreamSupport.stream(javaFileObjects.spliterator(), /* parallel */ true)
                        .filter(javaFileObject -> javaFileObject.getKind().equals(kind))
                        .map(FileObject::getName)
                        .map(fileObjectName -> fileObjectName.replace(".class", ""))
                        .map(mapToClassName)
                        .map(className -> Try.of(() -> Class.forName(className))
                                             .getOrElseThrow(asRuntimeException))
                        .collect(Collectors.toList());
  };

  @Test
  @DisplayName("should get classes recursively in given package")
  void test() {
    Collection<Class<?>> classes = findAllPackageClasses.apply(getClass().getPackage().getName());
    assertThat(classes).hasSizeGreaterThan(4);
    classes.stream().map(String::valueOf).forEach(log::info);
  }
}

PS: to simplify boilerplates for handling errors, etc, I'm using here vavr and lombok libraries

other implementations could be found in my GitHub daggerok/java-reflection-find-annotated-classes-or-methods repo

Calculate date from week number

One of the biggest problems I found was to convert from weeks to dates, and then from dates to weeks.

The main problem is when trying to get the correct week year from a date that belongs to a week of the previous year. Luckily System.Globalization.ISOWeek.GetYear handles this.

Here is my solution:

public class WeekOfYear
{
    public static (int Year, int Week) DateToWeekOfYear(DateTime date) =>
        (ISOWeek.GetYear(date), ISOWeek.GetWeekOfYear(date));

    public static bool ValidYearAndWeek(int year, int week) =>
           year >= 1 && year <= 9999 && week >= 1 && week <= 53 // bounds of year/week
        && !(year <= 1 && week <= 1) && !(year >= 9999 && week >= 53); // bounds of DateTime

    public int Year { get; }
    public int Week { get; }
    public virtual DateTime StartOfWeek { get; protected set; }
    public virtual DateTime EndOfWeek { get; protected set; }

    public virtual IEnumerable<DateTime> DaysInWeek =>
        Enumerable.Range(1, 10).Select(i => StartOfWeek.AddDays(i));

    public WeekOfYear(int year, int week)
    {
        if (!ValidYearAndWeek(year, week))
            throw new ArgumentException($"DateTime can't represent {week} of year {year}.");

        Year = year;
        Week = week;
        StartOfWeek = ISOWeek.ToDateTime(year, week, DayOfWeek.Monday);
        EndOfWeek = ISOWeek.ToDateTime(year, week, DayOfWeek.Sunday).AddDays(1).AddTicks(-1);
    }

    public WeekOfYear((int Year, int Week) week) : this(week.Year, week.Week) { }
    public WeekOfYear(DateTime date) : this(DateToWeekOfYear(date)) { }
}

The second biggest problem was the preference for weeks starting on Sundays in the US.

The solution I cam up with subclasses WeekOfYear from above, and manages the offset of the in the constructor (which converts week to dates) and DateToWeekOfYear (which converts from date to week).

public class UsWeekOfYear : WeekOfYear
{
    public static new (int Year, int Week) DateToWeekOfYear(DateTime date)
    {
        // if date is a sunday, return the next week
        if (date.DayOfWeek == DayOfWeek.Sunday) date = date.AddDays(1);
        return WeekOfYear.DateToWeekOfYear(date);
    }

    public UsWeekOfYear(int year, int week) : base(year, week)
    {
        StartOfWeek = ISOWeek.ToDateTime(year, week, DayOfWeek.Monday).AddDays(-1);
        EndOfWeek = ISOWeek.ToDateTime(year, week, DayOfWeek.Sunday).AddTicks(-1);
    }

    public UsWeekOfYear((int Year, int Week) week) : this(week.Year, week.Week) { }
    public UsWeekOfYear(DateTime date) : this(DateToWeekOfYear(date)) { }
}

Here is some test code:

public static void Main(string[] args)
{
    Console.WriteLine("== Last Week / First Week");
    Log(new WeekOfYear(2020, 53));
    Log(new UsWeekOfYear(2020, 53));

    Log(new WeekOfYear(2021, 1));
    Log(new UsWeekOfYear(2021, 1));

    Console.WriteLine("\n== Year Crossover (iso)");
    var start = new DateTime(2020, 12, 26);
    var i = 0;
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2020-12-26 - Sat
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2020-12-27 - Sun
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2020-12-28 - Mon
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2020-12-29 - Tue
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2020-12-30 - Wed
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2020-12-30 - Thu
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2021-01-01 - Fri
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2021-01-02 - Sat
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2021-01-03 - Sun
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2021-01-04 - Mon
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2021-01-05 - Tue
    Log(start.AddDays(i), new WeekOfYear(start.AddDays(i++))); // 2021-01-06 - Wed

    Console.WriteLine("\n== Year Crossover (us)");
    i = 0;
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2020-12-26 - Sat
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2020-12-27 - Sun
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2020-12-28 - Mon
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2020-12-29 - Tue
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2020-12-30 - Wed
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2020-12-30 - Thu
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2021-01-01 - Fri
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2021-01-02 - Sat
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2021-01-03 - Sun
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2021-01-04 - Mon
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2021-01-05 - Tue
    Log(start.AddDays(i), new UsWeekOfYear(start.AddDays(i++))); // 2021-01-06 - Wed

    var x = new UsWeekOfYear(2020, 53) as WeekOfYear;
}

public static void Log(WeekOfYear week)
{
    Console.WriteLine($"{week} - {week.StartOfWeek:yyyy-MM-dd} ({week.StartOfWeek:ddd}) - {week.EndOfWeek:yyyy-MM-dd} ({week.EndOfWeek:ddd})");
}

public static void Log(DateTime date, WeekOfYear week)
{
    Console.WriteLine($"{date:yyyy-MM-dd (ddd)} - {week} - {week.StartOfWeek:yyyy-MM-dd (ddd)} - {week.EndOfWeek:yyyy-MM-dd (ddd)}");
}

How to set the text/value/content of an `Entry` widget using a button in tkinter

One way would be to inherit a new class,EntryWithSet, and defining set method that makes use of delete and insert methods of the Entry class objects:

try:                        # In order to be able to import tkinter for
    import tkinter as tk    # either in python 2 or in python 3
except ImportError:
    import Tkinter as tk


class EntryWithSet(tk.Entry):
    """
    A subclass to Entry that has a set method for setting its text to
    a given string, much like a Variable class.
    """

    def __init__(self, master, *args, **kwargs):
        tk.Entry.__init__(self, master, *args, **kwargs)


    def set(self, text_string):
        """
        Sets the object's text to text_string.
        """

        self.delete('0', 'end')
        self.insert('0', text_string)


def on_button_click():
    import random, string
    rand_str = ''.join(random.choice(string.ascii_letters) for _ in range(19))
    entry.set(rand_str)


if __name__ == '__main__':
    root = tk.Tk()
    entry = EntryWithSet(root)
    entry.pack()
    tk.Button(root, text="Set", command=on_button_click).pack()
    tk.mainloop()

Passing bash variable to jq

Posting it here as it might help others. In string it might be necessary to pass the quotes to jq. To do the following with jq:

.items[] | select(.name=="string")

in bash you could do

EMAILID=$1
projectID=$(cat file.json | jq -r '.resource[] | select(.username=='\"$EMAILID\"') | .id')

essentially escaping the quotes and passing it on to jq

Git credential helper - update password

Just cd in the directory where you have installed git-credential-winstore. If you don't know where, just run this in Git Bash:

cat ~/.gitconfig

It should print something looking like:

[credential]
    helper = !'C:\\ProgramFile\\GitCredStore\\git-credential-winstore.exe'

In this case, you repository is C:\ProgramFile\GitCredStore. Once you are inside this folder using Git Bash or the Windows command, just type:

git-credential-winstore.exe erase
host=github.com
protocol=https

Don't forget to press Enter twice after protocol=https.

Why doesn't Python have a sign function?

Try running this, where x is any number

int_sign = bool(x > 0) - bool(x < 0)

The coercion to bool() handles the possibility that the comparison operator doesn't return a boolean.

Removing duplicate elements from an array in Swift

Here's a more flexible way to make a sequence unique with a custom matching function.

extension Sequence where Iterator.Element: Hashable {

    func unique(matching: (Iterator.Element, Iterator.Element) -> Bool) -> [Iterator.Element] {

        var uniqueArray: [Iterator.Element] = []
        forEach { element in
            let isUnique = uniqueArray.reduce(true, { (result, item) -> Bool in
                return result && matching(element, item)
            })
            if isUnique {
                uniqueArray.append(element)
            }
        }
        return uniqueArray
    }
}

anaconda - graphviz - can't import after installation

This command works officially for python:

conda install -c conda-forge python-graphviz

typedef fixed length array

Building off the accepted answer, a multi-dimensional array type, that is a fixed-length array of fixed-length arrays, can't be declared with

typedef char[M] T[N];  // wrong!

instead, the intermediate 1D array type can be declared and used as in the accepted answer:

typedef char T_t[M];
typedef T_t T[N];

or, T can be declared in a single (arguably confusing) statement:

typedef char T[N][M];

which defines a type of N arrays of M chars (be careful about the order, here).

How can I use the MS JDBC driver with MS SQL Server 2008 Express?

Named instances?

URL: jdbc:sqlserver://[serverName][\instanceName][:portNumber][;property=value]

Note: backward slash

WPF - add static items to a combo box

You can also add items in code:

cboWhatever.Items.Add("SomeItem");

Also, to add something where you control display/value, (almost categorically needed in my experience) you can do so. I found a good stackoverflow reference here:

Key Value Pair Combobox in WPF

Sum-up code would be something like this:

ComboBox cboSomething = new ComboBox();
cboSomething.DisplayMemberPath = "Key";
cboSomething.SelectedValuePath = "Value";
cboSomething.Items.Add(new KeyValuePair<string, string>("Something", "WhyNot"));
cboSomething.Items.Add(new KeyValuePair<string, string>("Deus", "Why"));
cboSomething.Items.Add(new KeyValuePair<string, string>("Flirptidee", "Stuff"));
cboSomething.Items.Add(new KeyValuePair<string, string>("Fernum", "Blictor"));

Printing chars and their ASCII-code in C

Try this:

char c = 'a'; // or whatever your character is
printf("%c %d", c, c);

The %c is the format string for a single character, and %d for a digit/integer. By casting the char to an integer, you'll get the ascii value.

curl : (1) Protocol https not supported or disabled in libcurl

Looks like there are so many Answers already but the issue I faced was with double quotes. There is a difference in between:

and

"

Changing the 1 st double quote to the second worked for me, below is the sample curl:

curl -X PUT -u xxx:xxx -T test.txt "https://test.com/test/test.txt"

Could not reliably determine the server's fully qualified domain name

  1. sudo vim /etc/apache2/httpd.conf
  2. Insert the following line at the httpd.conf: ServerName localhost
  3. Just restart the Apache: sudo /etc/init.d/apache2 restart

Explanation of JSONB introduced by PostgreSQL

Peeyush:

The short answer is:

  • If you are doing a lot of JSON manipulation inside PostgreSQL, such as sorting, slicing, splicing, etc., you should use JSONB for speed reasons.
  • If you need indexed lookups for arbitrary key searches on JSON, then you should use JSONB.
  • If you are doing neither of the above, you should probably use JSON.
  • If you need to preserve key ordering, whitespace, and duplicate keys, you should use JSON.

For a longer answer, you'll need to wait for me to do a full "HowTo" writeup closer to the 9.4 release.

"Unable to get the VLookup property of the WorksheetFunction Class" error

I was just having this issue with my own program. I turned out that the value I was searching for was not in my reference table. I fixed my reference table, and then the error went away.

How to change Windows 10 interface language on Single Language version

Worked for me:

  1. Download package (see links below), name it lp.cab and place it to your C: drive

  2. Run the following commands as Administrator:

2.1 installing new language

dism /Online /Add-Package /PackagePath:C:\lp.cab

2.2 get installed packages

dism /Online /Get-Packages

2.3 remove original package

dism /Online /Remove-Package /PackageName:Microsoft-Windows-Client-LanguagePack-Package~31bf3856ad364e35~amd64~ru-RU~10.0.10240.16384

If you don't know which is your original package you can check your installed packages with this line

dism /Online /Get-Packages | findstr /c:"LanguagePack"

  1. Enjoy your new system language

List of MUI for Windows 10:

For LPs for Windows 10 version 1607 build 14393, follow this link.

Windows 10 x64 (Build 10240):

zh-CN: Chinese download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_9949b0581789e2fc205f0eb005606ad1df12745b.cab

hr-HR: Croatian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_c3bde55e2405874ec8eeaf6dc15a295c183b071f.cab

cs-CZ: Czech download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_d0b2a69faa33d1ea1edc0789fdbb581f5a35ce2d.cab

da-DK: Danish download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_15e50641cef50330959c89c2629de30ef8fd2ef6.cab

nl-NL: Dutch download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_8658b909525f49ab9f3ea9386a0914563ffc762d.cab

en-us: English download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_75d67444a5fc444dbef8ace5fed4cfa4fb3602f0.cab

fr-FR: French download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_206d29867210e84c4ea1ff4d2a2c3851b91b7274.cab

de-DE: German download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_3bb20dd5abc8df218b4146db73f21da05678cf44.cab

hi-IN: Hindi download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_e9deaa6a8d8f9dfab3cb90986d320ff24ab7431f.cab

it-IT: Italian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_42c622dc6957875eab4be9d57f25e20e297227d1.cab

ja-JP: Japanese download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_adc2ec900dd1c5e94fc0dbd8e010f9baabae665f.cab

kk-KZ: Kazakh download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_a03ed475983edadd3eb73069c4873966c6b65daf.cab

ko-KR: Korean download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_24411100afa82ede1521337a07485c65d1a14c1d.cab

pt-BR: Portuguese download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_894199ed72fdf98e4564833f117380e45b31d19f.cab

ru-RU: Russian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_d85bb9f00b5ee0b1ea3256b6e05c9ec4029398f0.cab

es-ES: Spanish download.windowsupdate.com/c/msdownload/update/software/updt/2015/07/lp_7b21648a1df6476b39e02476c2319d21fb708c7d.cab

uk-UA: Ukrainian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_131991188afe0ef668d77c8a9a568cb71b57f09f.cab

Windows 10 x86 (Build 10240):

zh-CN: Chinese download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_e7d13432345bcf589877cd3f0b0dad4479785f60.cab

hr-HR: Croatian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_60856d8b4d643835b30d8524f467d4d352395204.cab

cs-CZ: Czech download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_dfa71b93a76b4500578b67fd3bf6b9f10bf5beaa.cab

da-DK: Danish download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_af0ea4318f43d9cb30bcfa5ce7279647f10bc3b3.cab

nl-NL: Dutch download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_cbcdf4818eac2a15cfda81e37595f8ffeb037fd7.cab

en-us: English download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_41877260829bb5f57a52d3310e326c6828d8ce8f.cab

fr-FR: French download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_80fa697f051a3a949258797a0635a4313a448c29.cab

de-DE: German download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_7ea2648033099f99f87642e47e6d959172c6cab8.cab

hi-IN: Hindi download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_78a11997f4e4bf73bbdb1da8011ebfb218bd1bac.cab

it-IT: Italian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_9e62d9a8b141e0eb6434af5a44c4f9468b60a075.cab

ja-JP: Japanese download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_79bd099ac811cb1771e6d9b03d640e5eca636b23.cab

kk-KZ: Kazakh download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_59e690df497799cacb96ab579a706250e5a0c8b6.cab

ko-KR: Korean download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_a88379b0461479ab8b5b47f65c4c3241ef048c04.cab

pt-BR: Portuguese download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_bb9f192068fe42fde8787591197a53c174dce880.cab

ru-RU: Russian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_280bf97bbe34cec1b0da620fa1b2dfe5bdb3ea07.cab

es-ES: Spanish download.windowsupdate.com/c/msdownload/update/software/updt/2015/07/lp_31400c38ffea2f0a44bb2dfbd80086aa3cad54a9.cab

uk-UA: Ukrainian download.windowsupdate.com/d/msdownload/update/software/updt/2015/07/lp_41cd48aa22d21f09fbcedc69197609c1f05f433d.cab

Code signing is required for product type 'Application' in SDK 'iOS5.1'

This error was caused, for me, by different circumstances. A downloaded project tutorial had a default setting of [Project]>Targets>Build Settings>Architectures>Build Active Architecture Only>Release = "Yes." I wasn't intending to build a release, so the solution was to set Release (which presumably requires not just a developer profile but distribution profile) to "No."

How I can delete in VIM all text from current line to end of file?

dG will delete from the current line to the end of file

dCtrl+End will delete from the cursor to the end of the file

But if this file is as large as you say, you may be better off reading the first few lines with head rather than editing and saving the file.

head hugefile > firstlines

(If you are on Windows you can use the Win32 port of head)

Address already in use: JVM_Bind java

I usually come across this when the port which the server (I use JBoss) is already in use

Usual suspects

  1. Apache Http Server => turn down the service if working in windows.
  2. IIS => stop the ISS using
  3. Skype =>yea I got skype attaching itself to port 80

To change the port to which JBoss 4.2.x binds itself go to:

"C:\jboss4.2.2\server\default\deploy\jboss-web.deployer\server.xml"

here default is the instance of the server change the port here :

<Connector port="8080" address="${jboss.bind.address}" >

In the above example the port is bound to 8080

Password encryption/decryption code in .NET

EDIT: this is a very old answer. SHA1 was deprecated in 2011 and has now been broken in practice. https://shattered.io/ Use a newer standard instead (e.g. SHA256, SHA512, etc).

If your answer to the question in my comment is "No", here's what I use:

    public static byte[] HashPassword(string password)
    {
        var provider = new SHA1CryptoServiceProvider();
        var encoding = new UnicodeEncoding();
        return provider.ComputeHash(encoding.GetBytes(password));
    }

How to get the Google Map based on Latitude on Longitude?

Have you gone through google's geocoding api. The following link shall help you get started: http://code.google.com/apis/maps/documentation/geocoding/#GeocodingRequests

How can I split a string into segments of n characters?

If you didn't want to use a regular expression...

var chunks = [];

for (var i = 0, charsLength = str.length; i < charsLength; i += 3) {
    chunks.push(str.substring(i, i + 3));
}

jsFiddle.

...otherwise the regex solution is pretty good :)

How to place and center text in an SVG rectangle

The previous answers gave poor results when using rounded corners or stroke-width that's >1 . For example, you would expect the following code to produce a rounded rectangle, but the corners are clipped by the parent svg component:

_x000D_
_x000D_
<svg width="200" height="100">_x000D_
  <!--this rect should have rounded corners-->_x000D_
  <rect x="0" y="0" rx="5" ry="5" width="200" height="100" stroke="red" stroke-width="10px" fill="white"/>_x000D_
  <text x="50%" y="50%" alignment-baseline="middle" text-anchor="middle">CLIPPED BORDER</text>    _x000D_
</svg>
_x000D_
_x000D_
_x000D_

Instead, I recommend wrapping the text in a svg and then nesting that new svg and the rect together inside a g element, as in the following example:

_x000D_
_x000D_
<!--the outer svg here-->_x000D_
<svg width="400px" height="300px">_x000D_
_x000D_
  <!--the rect/text group-->_x000D_
  <g transform="translate(50,50)">_x000D_
    <rect rx="5" ry="5" width="200" height="100" stroke="green" fill="none" stroke-width="10"/>_x000D_
    <svg width="200px" height="100px">_x000D_
      <text x="50%" y="50%" alignment-baseline="middle" text-anchor="middle">CORRECT BORDER</text>      _x000D_
    </svg>_x000D_
  </g>_x000D_
_x000D_
  <!--rest of the image's code-->_x000D_
</svg>
_x000D_
_x000D_
_x000D_

This fixes the clipping problem that occurs in the answers above. I also translated the rect/text group using the transform="translate(x,y)" attribute to demonstrate that this provides a more intuitive approach to positioning the rect/text on-screen.

Xamarin.Forms ListView: Set the highlight color of a tapped item

To change color of selected ViewCell, there is a simple process without using custom renderer. Make Tapped event of your ViewCell as below

<ListView.ItemTemplate>
    <DataTemplate>
        <ViewCell Tapped="ViewCell_Tapped">            
        <Label Text="{Binding StudentName}" TextColor="Black" />
        </ViewCell>
    </DataTemplate>
</ListView.ItemTemplate>

In your ContentPage or .cs file, implement the event

private void ViewCell_Tapped(object sender, System.EventArgs e)
{
    if(lastCell!=null)
    lastCell.View.BackgroundColor = Color.Transparent;
    var viewCell = (ViewCell)sender;
    if (viewCell.View != null)
    {
        viewCell.View.BackgroundColor = Color.Red;
        lastCell = viewCell;
    }
} 

Declare lastCell at the top of your ContentPage like this ViewCell lastCell;

JQuery find first parent element with specific class prefix

Use .closest() with a selector:

var $div = $('#divid').closest('div[class^="div-a"]');

Are static class variables possible in Python?

@Blair Conrad said static variables declared inside the class definition, but not inside a method are class or "static" variables:

>>> class Test(object):
...     i = 3
...
>>> Test.i
3

There are a few gotcha's here. Carrying on from the example above:

>>> t = Test()
>>> t.i     # "static" variable accessed via instance
3
>>> t.i = 5 # but if we assign to the instance ...
>>> Test.i  # we have not changed the "static" variable
3
>>> t.i     # we have overwritten Test.i on t by creating a new attribute t.i
5
>>> Test.i = 6 # to change the "static" variable we do it by assigning to the class
>>> t.i
5
>>> Test.i
6
>>> u = Test()
>>> u.i
6           # changes to t do not affect new instances of Test

# Namespaces are one honking great idea -- let's do more of those!
>>> Test.__dict__
{'i': 6, ...}
>>> t.__dict__
{'i': 5}
>>> u.__dict__
{}

Notice how the instance variable t.i got out of sync with the "static" class variable when the attribute i was set directly on t. This is because i was re-bound within the t namespace, which is distinct from the Test namespace. If you want to change the value of a "static" variable, you must change it within the scope (or object) where it was originally defined. I put "static" in quotes because Python does not really have static variables in the sense that C++ and Java do.

Although it doesn't say anything specific about static variables or methods, the Python tutorial has some relevant information on classes and class objects.

@Steve Johnson also answered regarding static methods, also documented under "Built-in Functions" in the Python Library Reference.

class Test(object):
    @staticmethod
    def f(arg1, arg2, ...):
        ...

@beid also mentioned classmethod, which is similar to staticmethod. A classmethod's first argument is the class object. Example:

class Test(object):
    i = 3 # class (or static) variable
    @classmethod
    def g(cls, arg):
        # here we can use 'cls' instead of the class name (Test)
        if arg > cls.i:
            cls.i = arg # would be the same as Test.i = arg1

Pictorial Representation Of Above Example

Convert file: Uri to File in Android

Get the input stream using content resolver

InputStream inputStream = getContentResolver().openInputStream(uri);

Then copy the input stream into a file

FileUtils.copyInputStreamToFile(inputStream, file);

Sample utility method:

private File toFile(Uri uri) throws IOException {
        String displayName = "";
        Cursor cursor = getContentResolver().query(uri, null, null, null, null);

        if(cursor != null && cursor.moveToFirst()){
            try {
                displayName = cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
            }finally {
                cursor.close();
            }
        }

        File file =  File.createTempFile(
                FilenameUtils.getBaseName(displayName),
                "."+FilenameUtils.getExtension(displayName)
        );
        InputStream inputStream = getContentResolver().openInputStream(uri);
        FileUtils.copyInputStreamToFile(inputStream, file);
        return file;
    }

fork and exec in bash

How about:

(sleep 5; echo "Hello World") &

What is the difference between "word-break: break-all" versus "word-wrap: break-word" in CSS

word-wrap: break-word recently changed to overflow-wrap: break-word

  • will wrap long words onto the next line.
  • adjusts different words so that they do not break in the middle.

word-break: break-all

  • irrespective of whether it’s a continuous word or many words, breaks them up at the edge of the width limit. (i.e. even within the characters of the same word)

So if you have many fixed-size spans which get content dynamically, you might just prefer using word-wrap: break-word, as that way only the continuous words are broken in between, and in case it’s a sentence comprising many words, the spaces are adjusted to get intact words (no break within a word).

And if it doesn’t matter, go for either.

programmatically add column & rows to WPF Datagrid

If you already have the databinding in place John Myczek answer is complete. If not you have at least 2 options I know of if you want to specify the source of your data. (However I am not sure whether or not this is in line with most guidelines, like MVVM)

Then you just bind to Users collections and columns are autogenerated as you speficy them. Strings passed to property descriptors are names for column headers. At runtime you can add more PropertyDescriptors to 'Users' add another column to the grid.

JQuery - File attributes

To get the filenames, use:

var files = document.getElementById('inputElementID').files;

Using jQuery (since you already are) you can adapt this to the following:

$('input[type="file"][multiple]').change(
    function(e){
        var files = this.files;
        for (i=0;i<files.length;i++){
            console.log(files[i].fileName + ' (' + files[i].fileSize + ').');
        }
        return false;
    });

JS Fiddle demo.

Create a File object in memory from a string in Java

Usually when a method accepts a file, there's another method nearby that accepts a stream. If this isn't the case, the API is badly coded. Otherwise, you can use temporary files, where permission is usually granted in many cases. If it's applet, you can request write permission.

An example:

try {
    // Create temp file.
    File temp = File.createTempFile("pattern", ".suffix");

    // Delete temp file when program exits.
    temp.deleteOnExit();

    // Write to temp file
    BufferedWriter out = new BufferedWriter(new FileWriter(temp));
    out.write("aString");
    out.close();
} catch (IOException e) {
}

Why is my Spring @Autowired field null?

Also note that if, for whatever reason, you make a method in a @Service as final, the autowired beans you will access from it will always be null.

Generate random numbers with a given (numerical) distribution

Here is a more effective way of doing this:

Just call the following function with your 'weights' array (assuming the indices as the corresponding items) and the no. of samples needed. This function can be easily modified to handle ordered pair.

Returns indexes (or items) sampled/picked (with replacement) using their respective probabilities:

def resample(weights, n):
    beta = 0

    # Caveat: Assign max weight to max*2 for best results
    max_w = max(weights)*2

    # Pick an item uniformly at random, to start with
    current_item = random.randint(0,n-1)
    result = []

    for i in range(n):
        beta += random.uniform(0,max_w)

        while weights[current_item] < beta:
            beta -= weights[current_item]
            current_item = (current_item + 1) % n   # cyclic
        else:
            result.append(current_item)
    return result

A short note on the concept used in the while loop. We reduce the current item's weight from cumulative beta, which is a cumulative value constructed uniformly at random, and increment current index in order to find the item, the weight of which matches the value of beta.

node.js remove file

fs-extra provides a remove method:

const fs = require('fs-extra')

fs.remove('/tmp/myfile')
.then(() => {
  console.log('success!')
})
.catch(err => {
  console.error(err)
})

https://github.com/jprichardson/node-fs-extra/blob/master/docs/remove.md

Convert Uri to String and String to Uri

You can use Drawable instead of Uri.

   ImageView iv=(ImageView)findViewById(R.id.imageView1);
   String pathName = "/external/images/media/470939"; 
   Drawable image = Drawable.createFromPath(pathName);
   iv.setImageDrawable(image);

This would work.

How to add font-awesome to Angular 2 + CLI project

Edit: I'm using angular ^4.0.0 and Electron ^1.4.3

If you have issues with ElectronJS or similar and have a sort of 404 error, a possible workaround is to uedit your webpack.config.js, by adding (and by assuming that you have the font-awesome node module installed through npm or in the package.json file):

new CopyWebpackPlugin([
     { from: 'node_modules/font-awesome/fonts', to: 'assets' },
     { from: 'src/assets', to: 'assets' }
]),

Note that the webpack configuration I'm using has src/app/dist as output, and, in dist, an assets folder is created by webpack:

// our angular app
entry: {
    'polyfills': './src/polyfills.ts',
    'vendor': './src/vendor.ts',
    'app': './src/app/app',
},

// Config for our build files
output: {
    path: helpers.root('src/app/dist'),
    filename: '[name].js',
    sourceMapFilename: '[name].map',
    chunkFilename: '[id].chunk.js'
},

So basically, what is currently happening is:

  • Webpack is copying the fonts folder to the dev assets folder.
  • Webpack is copying the dev assets folder to the dist assets folder

Now, when the build process will be finished, the application will need to look for the .scss file and the folder containing the icons, resolving them properly. To resolve them, I've used this in my webpack config:

// support for fonts
{
    test: /\.(ttf|eot|svg|woff(2)?)(\?[a-z0-9=&.]+)?$/,
    loader: 'file-loader?name=dist/[name]-[hash].[ext]'
},

Finally, in the .scss file, I'm importing the font-awesome .scss and defining the path of the fonts, which is, again, dist/assets/font-awesome/fonts. The path is dist because in my webpack.config the output.path is set as helpers.root('src/app/dist');

So, in app.scss:

$fa-font-path: "dist/assets/font-awesome/fonts";
@import "~font-awesome/scss/font-awesome.scss";

Note that, in this way, it will define the font path (used later in the .scss file) and import the .scss file using ~font-awesome to resolve the font-awesome path in node_modules.

This is quite tricky, but it's the only way I've found to get around the 404 error issue with Electron.js

How to get year/month/day from a date object?

Nice formatting add-in: http://blog.stevenlevithan.com/archives/date-time-format.

With that you could write:

var now = new Date();
now.format("yyyy/mm/dd");

Insert and set value with max()+1 problems

None of the about answers works for my case. I got the answer from here, and my SQL is:

INSERT INTO product (id, catalog_id, status_id, name, measure_unit_id, description, create_time)
VALUES (
  (SELECT id FROM (SELECT COALESCE(MAX(id),0)+1 AS id FROM product) AS temp),
  (SELECT id FROM product_catalog WHERE name="AppSys1"),
  (SELECT id FROM product_status WHERE name ="active"),
  "prod_name_x",
  (SELECT id FROM measure_unit WHERE name ="unit"),
  "prod_description_y",
  UNIX_TIMESTAMP(NOW())
)

How to change permissions for a folder and its subfolders/files in one step?

For Mac OS X 10.7 (Lion), it is:

chmod -R 755 /directory

And yes, as all other say, be careful when doing this.

What is an .axd file?

from Google

An .axd file is a HTTP Handler file. There are two types of .axd files.

  1. ScriptResource.axd
  2. WebResource.axd

These are files which are generated at runtime whenever you use ScriptManager in your Web app. This is being generated only once when you deploy it on the server.

Simply put the ScriptResource.AXD contains all of the clientside javascript routines for Ajax. Just because you include a scriptmanager that loads a script file it will never appear as a ScriptResource.AXD - instead it will be merely passed as the .js file you send if you reference a external script file. If you embed it in code then it may merely appear as part of the html as a tag and code but depending if you code according to how the ToolKit handles it - may or may not appear as as a ScriptResource.axd. ScriptResource.axd is only introduced with AJAX and you will never see it elsewhere

And ofcourse it is necessary

How to re-index all subarray elements of a multidimensional array?

$array[9] = 'Apple';
$array[12] = 'Orange';
$array[5] = 'Peach';

$array = array_values($array);

through this function you can reset your array

$array[0] = 'Apple';
$array[1] = 'Orange';
$array[2] = 'Peach';

Huge performance difference when using group by vs distinct

The two queries express the same question. Apparently the query optimizer chooses two different execution plans. My guess would be that the distinct approach is executed like:

  • Copy all business_key values to a temporary table
  • Sort the temporary table
  • Scan the temporary table, returning each item that is different from the one before it

The group by could be executed like:

  • Scan the full table, storing each value of business key in a hashtable
  • Return the keys of the hashtable

The first method optimizes for memory usage: it would still perform reasonably well when part of the temporary table has to be swapped out. The second method optimizes for speed, but potentially requires a large amount of memory if there are a lot of different keys.

Since you either have enough memory or few different keys, the second method outperforms the first. It's not unusual to see performance differences of 10x or even 100x between two execution plans.

Calculate row means on subset of columns

(Another solution using pivot_longer & pivot_wider from latest Tidyr update)

You should try using pivot_longer to get your data from wide to long form Read latest tidyR update on pivot_longer & pivot_wider (https://tidyr.tidyverse.org/articles/pivot.html)

library(tidyverse)
C1<-c(3,2,4,4,5)
C2<-c(3,7,3,4,5)
C3<-c(5,4,3,6,3)
DF<-data.frame(ID=c("A","B","C","D","E"),C1=C1,C2=C2,C3=C3)

Output here

  ID     mean
  <fct> <dbl>
1 A      3.67
2 B      4.33
3 C      3.33
4 D      4.67
5 E      4.33

How to iterate for loop in reverse order in swift?

For me, this is the best way.

var arrayOfNums = [1,4,5,68,9,10]

for i in 0..<arrayOfNums.count {
    print(arrayOfNums[arrayOfNums.count - i - 1])
}

how to check if string contains '+' character

You need this instead:

if(s.contains("+"))

contains() method of String class does not take regular expression as a parameter, it takes normal text.


EDIT:

String s = "ddjdjdj+kfkfkf";

if(s.contains("+"))
{
    String parts[] = s.split("\\+");
    System.out.print(parts[0]);
}

OUTPUT:

ddjdjdj

Importing variables from another file?

In Python you can access the contents of other files like as if they
are some kind of a library, compared to other languages like java or any oop base languages , This is really cool ;

This makes accessing the contents of the file or import it to to process it or to do anything with it ; And that is the Main reason why Python is highly preferred Language for Data Science and Machine Learning etc. ;

And this is the picture of project structure This

Where I am accessing variables from .env file where the API links and Secret keys reside .

General Structure:

from <File-Name> import *

Round double in two decimal places in C#?

Math.Round(inputValue, 2, MidpointRounding.AwayFromZero)

How do I create a simple 'Hello World' module in Magento?

I was trying to make my module from magaplaza hello world tutorial, but something went wrong. I imported code of this module https://github.com/astorm/magento2-hello-world from github and it worked. from that module, i created it a categories subcategories ajax select drop downs Module. After installing it in aap/code directory of your magento2 installation follow this URL.. http://www.example.com/hello_mvvm/hello/world You can download its code from here https://github.com/sanaullahAhmad/Magento2_cat_subcat_ajax_select_dropdowns and place it in your aap/code folder. than run these commands...

php bin/magento setup:update
php bin/magento setup:static-content:deploy -f
php bin/magento c:c

Now you can check module functionality with following URL http://{{www.example.com}}/hello_mvvm/hello/world

copy-item With Alternate Credentials

that evidently powershell's cmdlets such as copy-item, test-path, etc do not support alternate credentials...

It looks like they do here, copy-item certainly includes a -Credential parameter.

PS C:\> gcm -syn copy-item
Copy-Item [-Path] <String[]> [[-Destination] <String>] [-Container] [-Force] [-Filter <String>] [-I
nclude <String[]>] [-Exclude <String[]>] [-Recurse] [-PassThru] [-Credential <PSCredential>] [...]

Extract source code from .jar file

I believe this can be done very easily. You can always extract the source files (Java files) of a jar file into a zip.

Steps to get sources of a jar file as a zip :

  1. Download JAD from http://techieme.in/resources-needed/ and save it at any
    location on your system.
  2. Drag and drop the jar for which you want the sources on the JAD. 3 JAD UI will open with all the package structure in a tree format.
  3. Click on File menu and select save jar sources.
  4. It will save the sources as a zip with the same name as the jar.

Hope this helps.

The link is dead due to some reason so adding the link from where you can download the JDGUI

java collections - keyset() vs entrySet() in map

Traversal over the large map entrySet() is much better than the keySet(). Check this tutorial how they optimise the traversal over the large object with the help of entrySet() and how it helps for performance tuning.

Python regex to match dates

Well, from my understanding, simply for matching this format in a given string, I prefer this regular expression:

pattern='[0-9|/]+'

to match the format in a more strict way, the following works:

pattern='(?:[0-9]{2}/){2}[0-9]{2}'

Personally, I cannot agree with unutbu's answer since sometimes we use regular expression for "finding" and "extract", not only "validating".

How to get image size (height & width) using JavaScript?

The thing all other have forgot is that you cant check image size before it loads. When the author checks all of posted methods it will work probably only on localhost. Since jQuery could be used here, remember that 'ready' event is fired before images are loaded. $('#xxx').width() and .height() should be fired in onload event or later.

How do I check form validity with angularjs?

When you put <form> tag inside you ngApp, AngularJS automatically adds form controller (actually there is a directive, called form that add nessesary behaviour). The value of the name attribute will be bound in your scope; so something like <form name="yourformname">...</form> will satisfy:

A form is an instance of FormController. The form instance can optionally be published into the scope using the name attribute.

So to check form validity, you can check value of $scope.yourformname.$valid property of scope.

More information you can get at Developer's Guide section about forms.

Parsing XML in Python using ElementTree example

If I understand your question correctly:

for elem in doc.findall('timeSeries/values/value'):
    print elem.get('dateTime'), elem.text

or if you prefer (and if there is only one occurrence of timeSeries/values:

values = doc.find('timeSeries/values')
for value in values:
    print value.get('dateTime'), elem.text

The findall() method returns a list of all matching elements, whereas find() returns only the first matching element. The first example loops over all the found elements, the second loops over the child elements of the values element, in this case leading to the same result.

I don't see where the problem with not finding timeSeries comes from however. Maybe you just forgot the getroot() call? (note that you don't really need it because you can work from the elementtree itself too, if you change the path expression to for example /timeSeriesResponse/timeSeries/values or //timeSeries/values)

Windows cannot find 'http:/.127.0.0.1:%HTTPPORT%/apex/f?p=4950'. Make sure you typed the name correctly, and then try again

I was also facing this issue

Error- Windows cannot find 'http://127.0.01:%HTTPPORT%/apex/f?p=4950'. Make sure you typed the name correctly, and then try again

After some research work, I found out that my HTTPPORT ie. 8080 was occupied by Apace HTTP Server and hence connection by OracleServiceXE could not be established.

What I did to solve this issue was :

  1. Go to Windows -> Services, found out Apache2.4 and manually stopped it to free my 8080 port.
  2. Clicked on Start Database, and I received message :

The OracleServiceXE service is starting.............. The OracleServiceXE service was started successfully.

  1. Manually entered http://127.0.0.1:8080/apex/f?p=4950 url to my browser which auto redirected me to http://127.0.0.1:8080/apex/f?p=4950:1:3763261197573303

That's it my issue got resolved.

In order to remember this new url and make sure that next time whenever I hit Get Started I should be redirected to http://127.0.0.1:8080/apex/f?p=4950:1:3763261197573303 instead of http://127.0.0.1:8080/apex/f?p=4950, what I did was :

  1. Browse to Directory:\OracleDatabase\app\oracle\product\11.2.0\server and search for Get_Started.html.
  2. Right Click on Get_Started.html and select Properties
  3. Modify your url and click Apply

Hope this Helps.

Create a txt file using batch file in a specific folder

Changed the set to remove % as that will write to text file as Echo on or off

echo off
title Custom Text File
cls
set /p txt=What do you want it to say? ; 
echo %txt% > "D:\Testing\dblank.txt"
exit

mysql after insert trigger which updates another table's column

With your requirements you don't need BEGIN END and IF with unnecessary SELECT in your trigger. So you can simplify it to this

CREATE TRIGGER occupy_trig AFTER INSERT ON occupiedroom 
FOR EACH ROW
  UPDATE BookingRequest
     SET status = 1
   WHERE idRequest = NEW.idRequest;

How to make a radio button look like a toggle button

_x000D_
_x000D_
$(document).ready(function () {
    $('#divType button').click(function () {
        $(this).addClass('active').siblings().removeClass('active');
        $('#<%= hidType.ClientID%>').val($(this).data('value'));
        //alert($(this).data('value'));             
    });
});
_x000D_
<div class="col-xs-12">
    <div class="form-group">
        <asp:HiddenField ID="hidType" runat="server" />
        <div class="btn-group" role="group" aria-label="Selection type" id="divType">
            <button type="button" class="btn btn-default BtnType" data-value="1">Food</button>                        
            <button type="button" class="btn btn-default BtnType" data-value="2">Drink</button>
        </div>
    </div>
</div>
_x000D_
_x000D_
_x000D_

How to get just the date part of getdate()?

SELECT CAST(FLOOR(CAST(GETDATE() AS float)) as datetime)

or

SELECT CONVERT(datetime,FLOOR(CONVERT(float,GETDATE())))

Remove Object from Array using JavaScript

You could also try doing something like this:

var myArray = [{'name': 'test'}, {'name':'test2'}];
var myObject = {'name': 'test'};
myArray.splice(myArray.indexOf(myObject),1);

How to start rails server?

You have to cd to your master directory and then rails s command will work without problems.

But do not forget bundle-install command when you didn't do it before.

Importing packages in Java

You should use

import Dan.Vik;

This makes the class visible and the its public methods available.

break out of if and foreach

A safer way to approach breaking a foreach or while loop in PHP is to nest an incrementing counter variable and if conditional inside of the original loop. This gives you tighter control than break; which can cause havoc elsewhere on a complicated page.

Example:

// Setup a counter
$ImageCounter = 0;

// Increment through repeater fields
while ( condition ):
  $ImageCounter++;

   // Only print the first while instance
   if ($ImageCounter == 1) {
    echo 'It worked just once';
   }

// Close while statement
endwhile;

How To Include CSS and jQuery in my WordPress plugin?

Put it in the init() function for your plugin.

function your_namespace() {
    wp_register_style('your_namespace', plugins_url('style.css',__FILE__ ));
    wp_enqueue_style('your_namespace');
    wp_register_script( 'your_namespace', plugins_url('your_script.js',__FILE__ ));
    wp_enqueue_script('your_namespace');
}

add_action( 'admin_init','your_namespace');

It took me also some time before I found the (for me) best solution which is foolproof imho.

Cheers

How to replace plain URLs with links?

This solution works like many of the others, and in fact uses the same regex as one of them, however in stead of returning a HTML String this will return a document fragment containing the A element and any applicable text nodes.

 function make_link(string) {
    var words = string.split(' '),
        ret = document.createDocumentFragment();
    for (var i = 0, l = words.length; i < l; i++) {
        if (words[i].match(/[-a-zA-Z0-9@:%_\+.~#?&//=]{2,256}\.[a-z]{2,4}\b(\/[-a-zA-Z0-9@:%_\+.~#?&//=]*)?/gi)) {
            var elm = document.createElement('a');
            elm.href = words[i];
            elm.textContent = words[i];
            if (ret.childNodes.length > 0) {
                ret.lastChild.textContent += ' ';
            }
            ret.appendChild(elm);
        } else {
            if (ret.lastChild && ret.lastChild.nodeType === 3) {
                ret.lastChild.textContent += ' ' + words[i];
            } else {
                ret.appendChild(document.createTextNode(' ' + words[i]));
            }
        }
    }
    return ret;
}

There are some caveats, namely with older IE and textContent support.

here is a demo.

How to extract one column of a csv file

The other answers work well, but since you asked for a solution using just the bash shell, you can do this:

AirBoxOmega:~ d$ cat > file #First we'll create a basic CSV
a,b,c,d,e,f,g,h,i,k
1,2,3,4,5,6,7,8,9,10
a,b,c,d,e,f,g,h,i,k
1,2,3,4,5,6,7,8,9,10
a,b,c,d,e,f,g,h,i,k
1,2,3,4,5,6,7,8,9,10
a,b,c,d,e,f,g,h,i,k
1,2,3,4,5,6,7,8,9,10
a,b,c,d,e,f,g,h,i,k
1,2,3,4,5,6,7,8,9,10
a,b,c,d,e,f,g,h,i,k
1,2,3,4,5,6,7,8,9,10

And then you can pull out columns (the first in this example) like so:

AirBoxOmega:~ d$ while IFS=, read -a csv_line;do echo "${csv_line[0]}";done < file
a
1
a
1
a
1
a
1
a
1
a
1

So there's a couple of things going on here:

  • while IFS=, - this is saying to use a comma as the IFS (Internal Field Separator), which is what the shell uses to know what separates fields (blocks of text). So saying IFS=, is like saying "a,b" is the same as "a b" would be if the IFS=" " (which is what it is by default.)

  • read -a csv_line; - this is saying read in each line, one at a time and create an array where each element is called "csv_line" and send that to the "do" section of our while loop

  • do echo "${csv_line[0]}";done < file - now we're in the "do" phase, and we're saying echo the 0th element of the array "csv_line". This action is repeated on every line of the file. The < file part is just telling the while loop where to read from. NOTE: remember, in bash, arrays are 0 indexed, so the first column is the 0th element.

So there you have it, pulling out a column from a CSV in the shell. The other solutions are probably more practical, but this one is pure bash.

Inheritance and init method in Python

In the first situation, Num2 is extending the class Num and since you are not redefining the special method named __init__() in Num2, it gets inherited from Num.

When a class defines an __init__() method, class instantiation automatically invokes __init__() for the newly-created class instance.

In the second situation, since you are redefining __init__() in Num2 you need to explicitly call the one in the super class (Num) if you want to extend its behavior.

class Num2(Num):
    def __init__(self,num):
        Num.__init__(self,num)
        self.n2 = num*2

Linux Shell Script For Each File in a Directory Grab the filename and execute a program

for i in *.xls ; do 
  [[ -f "$i" ]] || continue
  xls2csv "$i" "${i%.xls}.csv"
done

The first line in the do checks if the "matching" file really exists, because in case nothing matches in your for, the do will be executed with "*.xls" as $i. This could be horrible for your xls2csv.

How to normalize an array in NumPy to a unit vector?

If you're using scikit-learn you can use sklearn.preprocessing.normalize:

import numpy as np
from sklearn.preprocessing import normalize

x = np.random.rand(1000)*10
norm1 = x / np.linalg.norm(x)
norm2 = normalize(x[:,np.newaxis], axis=0).ravel()
print np.all(norm1 == norm2)
# True

How do I block comment in Jupyter notebook?

After searching for a while I have found a solution to comment on an AZERTY mac. The shortcut is Ctrl +/= key

T-SQL substring - separating first and last name

I think below query will be helpful to split FirstName and LastName from FullName even if there is only FirstName. For example: 'Philip John' can be split into Philip and John. But if there is only Philip, because of the charIndex of Space is 0, it will only give you ''.

Try the below one.

declare @FullName varchar(100)='Philp John'

Select  
    LTRIM(RTRIM(SUBSTRING(@FullName, 0, CHARINDEX(' ', @FullName+' ')))) As FirstName
,   LTRIM(RTRIM(SUBSTRING(@FullName, CHARINDEX(' ', @FullName+' ')+1, 8000)))As LastName

Hope this will help you. :)

Checking if a variable is initialized

If you mean how to check whether member variables have been initialized, you can do this by assigning them sentinel values in the constructor. Choose sentinel values as values that will never occur in normal usage of that variable. If a variables entire range is considered valid, you can create a boolean to indicate whether it has been initialized.

#include <limits>

class MyClass
{
    void SomeMethod();

    char mCharacter;
    bool isCharacterInitialized;
    double mDecimal;

    MyClass()
    : isCharacterInitialized(false)
    , mDecimal( std::numeric_limits<double>::quiet_NaN() )
    {}


};


void MyClass::SomeMethod()
{
    if ( isCharacterInitialized == false )
    {
        // do something with mCharacter.
    }

    if ( mDecimal != mDecimal ) // if true, mDecimal == NaN
    {
        // define mDecimal.
    }
}

Shell equality operators (=, ==, -eq)

Several answers show dangerous examples. OP's example [ $a == $b ] specifically used unquoted variable substitution (as of Oct '17 edit). For [...] that is safe for string equality.

But if you're going to enumerate alternatives like [[...]], you must inform also that the right-hand-side must be quoted. If not quoted, it is a pattern match! (From bash man page: "Any part of the pattern may be quoted to force it to be matched as a string.").

Here in bash, the two statements yielding "yes" are pattern matching, other three are string equality:

$ rht="A*"
$ lft="AB"
$ [ $lft = $rht ] && echo yes
$ [ $lft == $rht ] && echo yes
$ [[ $lft = $rht ]] && echo yes
yes
$ [[ $lft == $rht ]] && echo yes
yes
$ [[ $lft == "$rht" ]] && echo yes
$

Send and Receive a file in socket programming in Linux with C/C++ (GCC/G++)

Minimal runnable POSIX read + write example

Usage:

  1. get two computers on a LAN.

    For example, this will work if both computers are connected to your home router in most cases, which is how I tested it.

  2. On the server computer:

    1. Find the server local IP with ifconfig, e.g. 192.168.0.10

    2. Run:

      ./server output.tmp 12345
      
  3. On the client computer:

    printf 'ab\ncd\n' > input.tmp
    ./client input.tmp 192.168.0.10 12345
    
  4. Outcome: a file output.tmp is created on the sever computer containing 'ab\ncd\n'!

server.c

/*
Receive a file over a socket.

Saves it to output.tmp by default.

Interface:

    ./executable [<output_file> [<port>]]

Defaults:

- output_file: output.tmp
- port: 12345
*/

#define _XOPEN_SOURCE 700

#include <stdio.h>
#include <stdlib.h>

#include <arpa/inet.h>
#include <fcntl.h>
#include <netdb.h> /* getprotobyname */
#include <netinet/in.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <unistd.h>

int main(int argc, char **argv) {
    char *file_path = "output.tmp";
    char buffer[BUFSIZ];
    char protoname[] = "tcp";
    int client_sockfd;
    int enable = 1;
    int filefd;
    int i;
    int server_sockfd;
    socklen_t client_len;
    ssize_t read_return;
    struct protoent *protoent;
    struct sockaddr_in client_address, server_address;
    unsigned short server_port = 12345u;

    if (argc > 1) {
        file_path = argv[1];
        if (argc > 2) {
            server_port = strtol(argv[2], NULL, 10);
        }
    }

    /* Create a socket and listen to it.. */
    protoent = getprotobyname(protoname);
    if (protoent == NULL) {
        perror("getprotobyname");
        exit(EXIT_FAILURE);
    }
    server_sockfd = socket(
        AF_INET,
        SOCK_STREAM,
        protoent->p_proto
    );
    if (server_sockfd == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }
    if (setsockopt(server_sockfd, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(enable)) < 0) {
        perror("setsockopt(SO_REUSEADDR) failed");
        exit(EXIT_FAILURE);
    }
    server_address.sin_family = AF_INET;
    server_address.sin_addr.s_addr = htonl(INADDR_ANY);
    server_address.sin_port = htons(server_port);
    if (bind(
            server_sockfd,
            (struct sockaddr*)&server_address,
            sizeof(server_address)
        ) == -1
    ) {
        perror("bind");
        exit(EXIT_FAILURE);
    }
    if (listen(server_sockfd, 5) == -1) {
        perror("listen");
        exit(EXIT_FAILURE);
    }
    fprintf(stderr, "listening on port %d\n", server_port);

    while (1) {
        client_len = sizeof(client_address);
        puts("waiting for client");
        client_sockfd = accept(
            server_sockfd,
            (struct sockaddr*)&client_address,
            &client_len
        );
        filefd = open(file_path,
                O_WRONLY | O_CREAT | O_TRUNC,
                S_IRUSR | S_IWUSR);
        if (filefd == -1) {
            perror("open");
            exit(EXIT_FAILURE);
        }
        do {
            read_return = read(client_sockfd, buffer, BUFSIZ);
            if (read_return == -1) {
                perror("read");
                exit(EXIT_FAILURE);
            }
            if (write(filefd, buffer, read_return) == -1) {
                perror("write");
                exit(EXIT_FAILURE);
            }
        } while (read_return > 0);
        close(filefd);
        close(client_sockfd);
    }
    return EXIT_SUCCESS;
}

client.c

/*
Send a file over a socket.

Interface:

    ./executable [<input_path> [<sever_hostname> [<port>]]]

Defaults:

- input_path: input.tmp
- server_hostname: 127.0.0.1
- port: 12345
*/

#define _XOPEN_SOURCE 700

#include <stdio.h>
#include <stdlib.h>

#include <arpa/inet.h>
#include <fcntl.h>
#include <netdb.h> /* getprotobyname */
#include <netinet/in.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <unistd.h>

int main(int argc, char **argv) {
    char protoname[] = "tcp";
    struct protoent *protoent;
    char *file_path = "input.tmp";
    char *server_hostname = "127.0.0.1";
    char *server_reply = NULL;
    char *user_input = NULL;
    char buffer[BUFSIZ];
    in_addr_t in_addr;
    in_addr_t server_addr;
    int filefd;
    int sockfd;
    ssize_t i;
    ssize_t read_return;
    struct hostent *hostent;
    struct sockaddr_in sockaddr_in;
    unsigned short server_port = 12345;

    if (argc > 1) {
        file_path = argv[1];
        if (argc > 2) {
            server_hostname = argv[2];
            if (argc > 3) {
                server_port = strtol(argv[3], NULL, 10);
            }
        }
    }

    filefd = open(file_path, O_RDONLY);
    if (filefd == -1) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    /* Get socket. */
    protoent = getprotobyname(protoname);
    if (protoent == NULL) {
        perror("getprotobyname");
        exit(EXIT_FAILURE);
    }
    sockfd = socket(AF_INET, SOCK_STREAM, protoent->p_proto);
    if (sockfd == -1) {
        perror("socket");
        exit(EXIT_FAILURE);
    }
    /* Prepare sockaddr_in. */
    hostent = gethostbyname(server_hostname);
    if (hostent == NULL) {
        fprintf(stderr, "error: gethostbyname(\"%s\")\n", server_hostname);
        exit(EXIT_FAILURE);
    }
    in_addr = inet_addr(inet_ntoa(*(struct in_addr*)*(hostent->h_addr_list)));
    if (in_addr == (in_addr_t)-1) {
        fprintf(stderr, "error: inet_addr(\"%s\")\n", *(hostent->h_addr_list));
        exit(EXIT_FAILURE);
    }
    sockaddr_in.sin_addr.s_addr = in_addr;
    sockaddr_in.sin_family = AF_INET;
    sockaddr_in.sin_port = htons(server_port);
    /* Do the actual connection. */
    if (connect(sockfd, (struct sockaddr*)&sockaddr_in, sizeof(sockaddr_in)) == -1) {
        perror("connect");
        return EXIT_FAILURE;
    }

    while (1) {
        read_return = read(filefd, buffer, BUFSIZ);
        if (read_return == 0)
            break;
        if (read_return == -1) {
            perror("read");
            exit(EXIT_FAILURE);
        }
        /* TODO use write loop: https://stackoverflow.com/questions/24259640/writing-a-full-buffer-using-write-system-call */
        if (write(sockfd, buffer, read_return) == -1) {
            perror("write");
            exit(EXIT_FAILURE);
        }
    }
    free(user_input);
    free(server_reply);
    close(filefd);
    exit(EXIT_SUCCESS);
}

GitHub upstream.

Further comments

Possible improvements:

  • Currently output.tmp gets overwritten each time a send is done.

    This begs for the creation of a simple protocol that allows to pass a filename so that multiple files can be uploaded, e.g.: filename up to the first newline character, max filename 256 chars, and the rest until socket closure are the contents. Of course, that would require sanitation to avoid a path transversal vulnerability.

    Alternatively, we could make a server that hashes the files to find filenames, and keeps a map from original paths to hashes on disk (on a database).

  • Only one client can connect at a time.

    This is specially harmful if there are slow clients whose connections last for a long time: the slow connection halts everyone down.

    One way to work around that is to fork a process / thread for each accept, start listening again immediately, and use file lock synchronization on the files.

  • Add timeouts, and close clients if they take too long. Or else it would be easy to do a DoS.

    poll or select are some options: How to implement a timeout in read function call?

A simple HTTP wget implementation is shown at: How to make an HTTP get request in C without libcurl?

Tested on Ubuntu 15.10.

jquery getting post action url

Try this ocde;;

var formAction = $("#signup").attr('action');

How do we change the URL of a working GitLab install?

GitLab Omnibus

For an Omnibus install, it is a little different.

The correct place in an Omnibus install is:

/etc/gitlab/gitlab.rb
    external_url 'http://gitlab.example.com'

Finally, you'll need to execute sudo gitlab-ctl reconfigure and sudo gitlab-ctl restart so the changes apply.


I was making changes in the wrong places and they were getting blown away.

The incorrect paths are:

/opt/gitlab/embedded/service/gitlab-rails/config/gitlab.yml
/var/opt/gitlab/.gitconfig
/var/opt/gitlab/nginx/conf/gitlab-http.conf

Pay attention to those warnings that read:

# This file is managed by gitlab-ctl. Manual changes will be
# erased! To change the contents below, edit /etc/gitlab/gitlab.rb
# and run `sudo gitlab-ctl reconfigure`.

How to create a delay in Swift?

Comparison between different approaches in swift 3.0

1. Sleep

This method does not have a call back. Put codes directly after this line to be executed in 4 seconds. It will stop user from iterating with UI elements like the test button until the time is gone. Although the button is kind of frozen when sleep kicks in, other elements like activity indicator is still spinning without freezing. You cannot trigger this action again during the sleep.

sleep(4)
print("done")//Do stuff here

enter image description here

2. Dispatch, Perform and Timer

These three methods work similarly, they are all running on the background thread with call backs, just with different syntax and slightly different features.

Dispatch is commonly used to run something on the background thread. It has the callback as part of the function call

DispatchQueue.main.asyncAfter(deadline: .now() + .seconds(4), execute: {
    print("done")
})

Perform is actually a simplified timer. It sets up a timer with the delay, and then trigger the function by selector.

perform(#selector(callback), with: nil, afterDelay: 4.0)

func callback() {
    print("done")
}}

And finally, timer also provides ability to repeat the callback, which is not useful in this case

Timer.scheduledTimer(timeInterval: 4, target: self, selector: #selector(callback), userInfo: nil, repeats: false)


func callback() {
    print("done")
}}

For all these three method, when you click on the button to trigger them, UI will not freeze and you are allowed to click on it again. If you click on the button again, another timer is set up and the callback will be triggered twice.

enter image description here

In conclusion

None of the four method works good enough just by themselves. sleep will disable user interaction, so the screen "freezes"(not actually) and results bad user experience. The other three methods will not freeze the screen, but you can trigger them multiple times, and most of the times, you want to wait until you get the call back before allowing user to make the call again.

So a better design will be using one of the three async methods with screen blocking. When user click on the button, cover the entire screen with some translucent view with a spinning activity indicator on top, telling user that the button click is being handled. Then remove the view and indicator in the call back function, telling user that the the action is properly handled, etc.

C# Dictionary get item by index

If you need to extract an element key based on index, this function can be used:

public string getCard(int random)
{
    return Karta._dict.ElementAt(random).Key;
}

If you need to extract the Key where the element value is equal to the integer generated randomly, you can used the following function:

public string getCard(int random)
{
    return Karta._dict.FirstOrDefault(x => x.Value == random).Key;
}

Side Note: The first element of the dictionary is The Key and the second is the Value

How do I serialize an object and save it to a file in Android?

I use SharePrefrences:

package myapps.serializedemo;

import android.content.Context;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;

import java.io.IOException;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

//Create the SharedPreferences
    SharedPreferences sharedPreferences = this.getSharedPreferences("myapps.serilizerdemo", Context.MODE_PRIVATE);
    ArrayList<String> friends = new ArrayList<>();
    friends.add("Jack");
    friends.add("Joe");
    try {

 //Write / Serialize
 sharedPreferences.edit().putString("friends",
    ObjectSerializer.serialize(friends)).apply();
    } catch (IOException e) {
        e.printStackTrace();
    }
//READ BACK
    ArrayList<String> newFriends = new ArrayList<>();
    try {
        newFriends = (ArrayList<String>) ObjectSerializer.deserialize(
                sharedPreferences.getString("friends", ObjectSerializer.serialize(new ArrayList<String>())));
    } catch (IOException e) {
        e.printStackTrace();
    }
    Log.i("***NewFriends", newFriends.toString());
}
}

Standard concise way to copy a file in Java?

NIO copy with a buffer is the fastest according to my test. See the working code below from a test project of mine at https://github.com/mhisoft/fastcopy

import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.text.DecimalFormat;


public class test {

private static final int BUFFER = 4096*16;
static final DecimalFormat df = new DecimalFormat("#,###.##");
public static void nioBufferCopy(final File source, final File target )  {
    FileChannel in = null;
    FileChannel out = null;
    double  size=0;
    long overallT1 =  System.currentTimeMillis();

    try {
        in = new FileInputStream(source).getChannel();
        out = new FileOutputStream(target).getChannel();
        size = in.size();
        double size2InKB = size / 1024 ;
        ByteBuffer buffer = ByteBuffer.allocateDirect(BUFFER);

        while (in.read(buffer) != -1) {
            buffer.flip();

            while(buffer.hasRemaining()){
                out.write(buffer);
            }

            buffer.clear();
        }
        long overallT2 =  System.currentTimeMillis();
        System.out.println(String.format("Copied %s KB in %s millisecs", df.format(size2InKB),  (overallT2 - overallT1)));
    }
    catch (IOException e) {
        e.printStackTrace();
    }

    finally {
        close(in);
        close(out);
    }
}

private static void close(Closeable closable)  {
    if (closable != null) {
        try {
            closable.close();
        } catch (IOException e) {
            if (FastCopy.debug)
                e.printStackTrace();
        }    
    }
}

}

Working with SQL views in Entity Framework Core

It is possible to scaffold a view. Just use -Tables the way you would to scaffold a table, only use the name of your view. E.g., If the name of your view is ‘vw_inventory’, then run this command in the Package Manager Console (substituting your own information for "My..."):

PM> Scaffold-DbContext "Server=MyServer;Database=MyDatabase;user id=MyUserId;password=MyPassword" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Temp -Tables vw_inventory

This command will create a model file and context file in the Temp directory of your project. You can move the model file into your models directory (remember to change the namespace name). You can copy what you need from the context file and paste it into the appropriate existing context file in your project.

Note: If you want to use your view in an integration test using a local db, you'll need to create the view as part of your db setup. If you’re going to use the view in more than one test, make sure to add a check for existence of the view. In this case, since the SQL ‘Create View’ statement is required to be the only statement in the batch, you’ll need to run the create view as dynamic Sql within the existence check statement. Alternatively you could run separate ‘if exists drop view…’, then ‘create view’ statements, but if multiple tests are running concurrently, you don’t want the view to be dropped if another test is using it. Example:

  void setupDb() {
    ...
    SomeDb.Command(db => db.Database.ExecuteSqlRaw(CreateInventoryView()));
    ...
  }
  public string CreateInventoryView() => @"
  IF OBJECT_ID('[dbo].[vw_inventory]') IS NULL
    BEGIN EXEC('CREATE VIEW [dbo].[vw_inventory] AS
       SELECT ...')
    END";

Draw Circle using css alone

Yep, draw a box and give it a border radius that is half the width of the box:

#circle {
    background: #f00;
    width: 200px;
    height: 200px;
    border-radius: 50%;
}

Working demo:

http://jsfiddle.net/DsW9h/1/

_x000D_
_x000D_
#circle {_x000D_
    background: #f00;_x000D_
    width: 200px;_x000D_
    height: 200px;_x000D_
    border-radius: 50%;_x000D_
}
_x000D_
<div id="circle"></div>
_x000D_
_x000D_
_x000D_

Jenkins Host key verification failed

Change to the jenkins user and run the command manually:

git ls-remote -h [email protected]:person/projectmarket.git HEAD

You will get the standard SSH warning when first connecting to a new host via SSH:

The authenticity of host 'bitbucket.org (207.223.240.181)' can't be established.
RSA key fingerprint is 97:8c:1b:f2:6f:14:6b:5c:3b:ec:aa:46:46:74:7c:40.
Are you sure you want to continue connecting (yes/no)?

Type yes and press Enter. The host key for bitbucket.org will now be added to the ~/.ssh/known_hosts file and you won't get this error in Jenkins anymore.

How can I convert a Unix timestamp to DateTime and vice versa?

Here's what you need:

public static DateTime UnixTimeStampToDateTime( double unixTimeStamp )
{
    // Unix timestamp is seconds past epoch
    System.DateTime dtDateTime = new DateTime(1970,1,1,0,0,0,0,System.DateTimeKind.Utc);
    dtDateTime = dtDateTime.AddSeconds( unixTimeStamp ).ToLocalTime();
    return dtDateTime;
}

Or, for Java (which is different because the timestamp is in milliseconds, not seconds):

public static DateTime JavaTimeStampToDateTime( double javaTimeStamp )
{
    // Java timestamp is milliseconds past epoch
    System.DateTime dtDateTime = new DateTime(1970,1,1,0,0,0,0,System.DateTimeKind.Utc);
    dtDateTime = dtDateTime.AddMilliseconds( javaTimeStamp ).ToLocalTime();
    return dtDateTime;
}

Build and Install unsigned apk on device without the development server?

After you follow the first response, you can run your app using

react-native run-android --variant=debug

And your app will run without need for the packager

stdcall and cdecl

It's specified in the function type. When you have a function pointer, it's assumed to be cdecl if not explicitly stdcall. This means that if you get a stdcall pointer and a cdecl pointer, you can't exchange them. The two function types can call each other without issues, it's just getting one type when you expect the other. As for speed, they both perform the same roles, just in a very slightly different place, it's really irrelevant.

Proper way to set response status and JSON content in a REST API made with nodejs and express

try {
  var data = {foo: "bar"};
  res.json(JSON.stringify(data));
}
catch (e) {
  res.status(500).json(JSON.stringify(e));
}

How do I pass command-line arguments to a WinForms application?

You can grab the command line of any .Net application by accessing the Environment.CommandLine property. It will have the command line as a single string but parsing out the data you are looking for shouldn't be terribly difficult.

Having an empty Main method will not affect this property or the ability of another program to add a command line parameter.

Is < faster than <=?

You should not be able to notice the difference even if there is any. Besides, in practice, you'll have to do an additional a + 1 or a - 1 to make the condition stand unless you're going to use some magic constants, which is a very bad practice by all means.

Electron: jQuery is not defined

electron FAQ answer :

http://electron.atom.io/docs/faq/

I can not use jQuery/RequireJS/Meteor/AngularJS in Electron.

Due to the Node.js integration of Electron, there are some extra symbols inserted into the DOM like module, exports, require. This causes problems for some libraries since they want to insert the symbols with the same names.

To solve this, you can turn off node integration in Electron:

// In the main process.

let win = new BrowserWindow({  
 webPreferences: {
 nodeIntegration: false   } });

But if you want to keep the abilities of using Node.js and Electron APIs, you have to rename the symbols in the page before including other libraries:

<head> 
<script> 
window.nodeRequire = require; 
delete window.require;
delete window.exports; delete window.module; 
</script> 
<script type="text/javascript" src="jquery.js"></script> 
</head>

Why doesn't CSS ellipsis work in table cell?

If you don't want to set max-width to td (like in this answer), you can set max-width to div:

function so_hack(){}

function so_hack(){} http://jsfiddle.net/fd3Zx/754/ function so_hack(){}

function so_hack(){}

Note: 100% doesn't work, but 99% does the trick in FF. Other modern browsers doesn't need silly div hacks.

td {
  border: 1px solid black;
    padding-left:5px;
    padding-right:5px;
}
td>div{
    max-width: 99%;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;

}

What do "branch", "tag" and "trunk" mean in Subversion repositories?

I think that some of the confusion comes from the difference between the concept of a tag and the implementation in SVN. To SVN a tag is a branch which is a copy. Modifying tags is considered wrong and in fact tools like TortoiseSVN will warn you if you attempt to modify anything with ../tags/.. in the path.

Android set height and width of Custom view programmatically

You can set height and width like this:

myGraphView.setLayoutParams(new LayoutParams(width, height));

Execute SQL script to create tables and rows

In the MySQL interactive client you can type:

source yourfile.sql

Alternatively you can pipe the data into mysql from the command line:

mysql < yourfile.sql

If the file doesn't specify a database then you will also need to add that:

mysql db_name < yourfile.sql

See the documentation for more details:

Get host domain from URL?

The best way, and the right way to do it is using Uri.Authority field

Load and use Uri like so :

Uri NewUri;

if (Uri.TryCreate([string with your Url], UriKind.Absolute, out NewUri))
{
     Console.Writeline(NewUri.Authority);
}

Input : http://support.domain.com/default.aspx?id=12345
Output : support.domain.com

Input : http://www.domain.com/default.aspx?id=12345
output : www.domain.com

Input : http://localhost/default.aspx?id=12345
Output : localhost

If you want to manipulate Url, using Uri object is the good way to do it. https://msdn.microsoft.com/en-us/library/system.uri(v=vs.110).aspx

From milliseconds to hour, minutes, seconds and milliseconds

milliseconds = x
total = 0
while (milliseconds >= 1000) {
  milliseconds = (milliseconds - 1000)
  total = total + 1
}
hr = 0
min = 0
while (total >= 60) {
  total = total - 60
  min = min + 1
  if (min >= 60) hr = hr + 1
  if (min == 60) min = 0
}
sec = total

This is on groovy, but I thing that this is not problem for you. Method work perfect.

Check if passed argument is file or directory in Bash

A more elegant solution

echo "Enter the file name"
read x
if [ -f $x ]
then
    echo "This is a regular file"
else
    echo "This is a directory"
fi

Speed up rsync with Simultaneous/Concurrent File Transfers?

Have you tried using rclone.org?

With rclone you could do something like

rclone copy "${source}/${subfolder}/" "${target}/${subfolder}/" --progress --multi-thread-streams=N

where --multi-thread-streams=N represents the number of threads you wish to spawn.

How to fit a smooth curve to my data in R?

In order to get it REALLY smoooth...

x <- 1:10
y <- c(2,4,6,8,7,8,14,16,18,20)
lo <- loess(y~x)
plot(x,y)
xl <- seq(min(x),max(x), (max(x) - min(x))/1000)
lines(xl, predict(lo,xl), col='red', lwd=2)

This style interpolates lots of extra points and gets you a curve that is very smooth. It also appears to be the the approach that ggplot takes. If the standard level of smoothness is fine you can just use.

scatter.smooth(x, y)

How to autosize a textarea using Prototype?

Check the below link: http://james.padolsey.com/javascript/jquery-plugin-autoresize/

$(document).ready(function () {
    $('.ExpandableTextCSS').autoResize({
        // On resize:
        onResize: function () {
            $(this).css({ opacity: 0.8 });
        },
        // After resize:
        animateCallback: function () {
            $(this).css({ opacity: 1 });
        },
        // Quite slow animation:
        animateDuration: 300,
        // More extra space:
        extraSpace:20,
        //Textarea height limit
        limit:10
    });
});

Parse XML using JavaScript

I'm guessing from your last question, asked 20 minutes before this one, that you are trying to parse (read and convert) the XML found through using GeoNames' FindNearestAddress.

If your XML is in a string variable called txt and looks like this:

<address>
  <street>Roble Ave</street>
  <mtfcc>S1400</mtfcc>
  <streetNumber>649</streetNumber>
  <lat>37.45127</lat>
  <lng>-122.18032</lng>
  <distance>0.04</distance>
  <postalcode>94025</postalcode>
  <placename>Menlo Park</placename>
  <adminCode2>081</adminCode2>
  <adminName2>San Mateo</adminName2>
  <adminCode1>CA</adminCode1>
  <adminName1>California</adminName1>
  <countryCode>US</countryCode>
</address>

Then you can parse the XML with Javascript DOM like this:

if (window.DOMParser)
{
    parser = new DOMParser();
    xmlDoc = parser.parseFromString(txt, "text/xml");
}
else // Internet Explorer
{
    xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
    xmlDoc.async = false;
    xmlDoc.loadXML(txt);
}

And get specific values from the nodes like this:

//Gets house address number
xmlDoc.getElementsByTagName("streetNumber")[0].childNodes[0].nodeValue;

//Gets Street name
xmlDoc.getElementsByTagName("street")[0].childNodes[0].nodeValue;

//Gets Postal Code
xmlDoc.getElementsByTagName("postalcode")[0].childNodes[0].nodeValue;

JSFiddle


Feb. 2019 edit:

In response to @gaugeinvariante's concerns about xml with Namespace prefixes. Should you have a need to parse xml with Namespace prefixes, everything should work almost identically:

NOTE: this will only work in browsers that support xml namespace prefixes such as Microsoft Edge

_x000D_
_x000D_
// XML with namespace prefixes 's', 'sn', and 'p' in a variable called txt_x000D_
txt = `_x000D_
<address xmlns:p='example.com/postal' xmlns:s='example.com/street' xmlns:sn='example.com/streetNum'>_x000D_
  <s:street>Roble Ave</s:street>_x000D_
  <sn:streetNumber>649</sn:streetNumber>_x000D_
  <p:postalcode>94025</p:postalcode>_x000D_
</address>`;_x000D_
_x000D_
//Everything else the same_x000D_
if (window.DOMParser)_x000D_
{_x000D_
    parser = new DOMParser();_x000D_
    xmlDoc = parser.parseFromString(txt, "text/xml");_x000D_
}_x000D_
else // Internet Explorer_x000D_
{_x000D_
    xmlDoc = new ActiveXObject("Microsoft.XMLDOM");_x000D_
    xmlDoc.async = false;_x000D_
    xmlDoc.loadXML(txt);_x000D_
}_x000D_
_x000D_
//The prefix should not be included when you request the xml namespace_x000D_
//Gets "streetNumber" (note there is no prefix of "sn"_x000D_
console.log(xmlDoc.getElementsByTagName("streetNumber")[0].childNodes[0].nodeValue);_x000D_
_x000D_
//Gets Street name_x000D_
console.log(xmlDoc.getElementsByTagName("street")[0].childNodes[0].nodeValue);_x000D_
_x000D_
//Gets Postal Code_x000D_
console.log(xmlDoc.getElementsByTagName("postalcode")[0].childNodes[0].nodeValue);
_x000D_
_x000D_
_x000D_

How to generate a core dump in Linux on a segmentation fault?

In order to activate the core dump do the following:

  1. In /etc/profile comment the line:

    # ulimit -S -c 0 > /dev/null 2>&1
    
  2. In /etc/security/limits.conf comment out the line:

    *               soft    core            0
    
  3. execute the cmd limit coredumpsize unlimited and check it with cmd limit:

    # limit coredumpsize unlimited
    # limit
    cputime      unlimited
    filesize     unlimited
    datasize     unlimited
    stacksize    10240 kbytes
    coredumpsize unlimited
    memoryuse    unlimited
    vmemoryuse   unlimited
    descriptors  1024
    memorylocked 32 kbytes
    maxproc      528383
    #
    
  4. to check if the corefile gets written you can kill the relating process with cmd kill -s SEGV <PID> (should not be needed, just in case no core file gets written this can be used as a check):

    # kill -s SEGV <PID>
    

Once the corefile has been written make sure to deactivate the coredump settings again in the relating files (1./2./3.) !

How to overwrite existing files in batch?

Add /y to the command line of xcopy:

Example:

xcopy /y c:\mmyinbox\test.doc C:\myoutbox

In CSS what is the difference between "." and "#" when declaring a set of styles?

It is also worth noting that in the cascade, an id (#) selector is more specific than a b (.) selector. Therefore, rules in the id statement will override rules in the class statement.

For example, if both of the following statements:

.headline {
  color:red;
  font-size: 3em;
}

#specials {
  color:blue;
  font-style: italic;
}

are applied to the same HTML element:

<h1 id="specials" class="headline">Today's Specials</h1>

the color:blue rule would override the color:red rule.

How can I throw a general exception in Java?

You could create your own Exception class:

public class InvalidSpeedException extends Exception {

  public InvalidSpeedException(String message){
     super(message);
  }

}

In your code:

throw new InvalidSpeedException("TOO HIGH");

What is AndroidX?

AndroidX - Android Extension Library

From AndroidX documentation

We are rolling out a new package structure to make it clearer which packages are bundled with the Android operating system, and which are packaged with your app's APK. Going forward, the android.* package hierarchy will be reserved for Android packages that ship with the operating system. Other packages will be issued in the new androidx.* package hierarchy as part of the AndroidX library.

Need of AndroidX

AndroidX is a redesigned library to make package names more clear. So from now on android hierarchy will be for only android default classes, which comes with android operating system and other library/dependencies will be part of androidx (makes more sense). So from now on all the new development will be updated in androidx.

com.android.support.** : androidx.
com.android.support:appcompat-v7 : androidx.appcompat:appcompat com.android.support:recyclerview-v7 : androidx.recyclerview:recyclerview com.android.support:design : com.google.android.material:material

Complete Artifact mappings for AndroidX packages

AndroidX uses Semantic-version

Previously, support library used the SDK version but AndroidX uses the Semantic-version. It’s going to re-version from 28.0.0 ? 1.0.0.

How to migrate current project

In Android Studio 3.2 (September 2018), there is a direct option to migrate existing project to AndroidX. This refactor all packages automatically.

Before you migrate, it is strongly recommended to backup your project.

Existing project

  • Android Studio > Refactor Menu > Migrate to AndroidX...
  • It will analyze and will open Refractor window in bottom. Accept changes to be done.

image

New project

Put these flags in your gradle.properties

android.enableJetifier=true
android.useAndroidX=true

Check @Library mappings for equal AndroidX package.

Check @Official page of Migrate to AndroidX

What is Jetifier?

Bugs of migrating

  • If you build app, and find some errors after migrating, then you need to fix those minor errors. You will not get stuck there, because that can be easily fixed.
  • 3rd party libraries are not converted to AndroidX in directory, but they get converted at run time by Jetifier, so don't worry about compile time errors, your app will run perfectly.

Support 28.0.0 is last release?

From Android Support Revision 28.0.0

This will be the last feature release under the android.support packaging, and developers are encouraged to migrate to AndroidX 1.0.0

So go with AndroidX, because Android will update only androidx package from now.

Further Reading

https://developer.android.com/topic/libraries/support-library/androidx-overview

https://android-developers.googleblog.com/2018/05/hello-world-androidx.html

Order data frame rows according to vector with specific order

If you don't want to use any libraries and you have reoccurrences in your data, you can use which with sapply as well.

new_order <- sapply(target, function(x,df){which(df$name == x)}, df=df)
df        <- df[new_order,]

Convert from java.util.date to JodaTime

http://joda-time.sourceforge.net/quickstart.html

Each datetime class provides a variety of constructors. These include the Object constructor. This allows you to construct, for example, DateTime from the following objects:

* Date - a JDK instant
* Calendar - a JDK calendar
* String - in ISO8601 format
* Long - in milliseconds
* any Joda-Time datetime class

How can I avoid getting this MySQL error Incorrect column specifier for column COLUMN NAME?

You cannot auto increment the char values. It should be int or long(integers or floating points). Try with this,

CREATE TABLE discussion_topics (
    topic_id int(5) NOT NULL AUTO_INCREMENT,
    project_id char(36) NOT NULL,
    topic_subject VARCHAR(255) NOT NULL,
    topic_content TEXT default NULL,
    date_created DATETIME NOT NULL,
    date_last_post DATETIME NOT NULL,
    created_by_user_id char(36) NOT NULL,
    last_post_user_id char(36) NOT NULL,
    posts_count char(36) default NULL,
    PRIMARY KEY (`topic_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1;

Hope this helps

Google Chrome Full Black Screen

For Ubuntu users - Instead of changing the settings within the Chrome browser, which risks propagating them to other machines that do not have that issue, it is best to just edit the .desktop launcher:

Open the appropriate file for your situation.

/usr/share/applications/google-chrome.desktop
/usr/share/applications/chromium-browser.desktop

Just append the flag (-disable-gpu) to the end of the three Exec= lines in your file.

...
Exec=/usr/bin/google-chrome-stable %U -disable-gpu
...
Exec=/usr/bin/google-chrome-stable -disable-gpu
...
Exec=/usr/bin/google-chrome-stable --incognito -disable-gpu
...

How to set Java classpath in Linux?

You have to use ':' colon instead of ';' semicolon.

As it stands now you try to execute the jar file which has not the execute bit set, hence the Permission denied.

And the variable must be CLASSPATH not classpath.

Git with SSH on Windows

If Git for windows is installed, run Git Bash shell:

  bash

You can run ssh from within Bash shell (Bash is aware of the path of ssh)

To know the exact path of ssh, run "where" command in Bash shell:

  $ where ssh

you get:

  c:\Program Files\Git\usr\bin\ssh.exe

Selecting and manipulating CSS pseudo-elements such as ::before and ::after using javascript (or jQuery)

_x000D_
_x000D_
 $('.span').attr('data-txt', 'foo');_x000D_
        $('.span').click(function () {_x000D_
         $(this).attr('data-txt',"any other text");_x000D_
        })
_x000D_
.span{_x000D_
}_x000D_
.span:after{ _x000D_
  content: attr(data-txt);_x000D_
 }
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>_x000D_
<div class='span'></div>
_x000D_
_x000D_
_x000D_

JavaScript getElementByID() not working

Because when the script executes the browser has not yet parsed the <body>, so it does not know that there is an element with the specified id.

Try this instead:

<html>
<head>
    <title></title>
    <script type="text/javascript">
        window.onload = (function () {
            var refButton = document.getElementById("btnButton");

            refButton.onclick = function() {
                alert('Dhoor shala!');
            };
        });
    </script>
    </head>
<body>
    <form id="form1">
    <div>
        <input id="btnButton" type="button" value="Click me"/>
    </div>
</form>
</body>
</html>

Note that you may as well use addEventListener instead of window.onload = ... to make that function only execute after the whole document has been parsed.

Get random sample from list while maintaining ordering of items?

Simple-to-code O(N + K*log(K)) way

Take a random sample without replacement of the indices, sort the indices, and take them from the original.

indices = random.sample(range(len(myList)), K)
[myList[i] for i in sorted(indices)]

Or more concisely:

[x[1] for x in sorted(random.sample(enumerate(myList),K))]

Optimized O(N)-time, O(1)-auxiliary-space way

You can alternatively use a math trick and iteratively go through myList from left to right, picking numbers with dynamically-changing probability (N-numbersPicked)/(total-numbersVisited). The advantage of this approach is that it's an O(N) algorithm since it doesn't involve sorting!

from __future__ import division

def orderedSampleWithoutReplacement(seq, k):
    if not 0<=k<=len(seq):
        raise ValueError('Required that 0 <= sample_size <= population_size')

    numbersPicked = 0
    for i,number in enumerate(seq):
        prob = (k-numbersPicked)/(len(seq)-i)
        if random.random() < prob:
            yield number
            numbersPicked += 1

Proof of concept and test that probabilities are correct:

Simulated with 1 trillion pseudorandom samples over the course of 5 hours:

>>> Counter(
        tuple(orderedSampleWithoutReplacement([0,1,2,3], 2))
        for _ in range(10**9)
    )
Counter({
    (0, 3): 166680161, 
    (1, 2): 166672608, 
    (0, 2): 166669915, 
    (2, 3): 166667390, 
    (1, 3): 166660630, 
    (0, 1): 166649296
})

Probabilities diverge from true probabilities by less a factor of 1.0001. Running this test again resulted in a different order meaning it isn't biased towards one ordering. Running the test with fewer samples for [0,1,2,3,4], k=3 and [0,1,2,3,4,5], k=4 had similar results.

edit: Not sure why people are voting up wrong comments or afraid to upvote... NO, there is nothing wrong with this method. =)

(Also a useful note from user tegan in the comments: If this is python2, you will want to use xrange, as usual, if you really care about extra space.)

edit: Proof: Considering the uniform distribution (without replacement) of picking a subset of k out of a population seq of size len(seq), we can consider a partition at an arbitrary point i into 'left' (0,1,...,i-1) and 'right' (i,i+1,...,len(seq)). Given that we picked numbersPicked from the left known subset, the remaining must come from the same uniform distribution on the right unknown subset, though the parameters are now different. In particular, the probability that seq[i] contains a chosen element is #remainingToChoose/#remainingToChooseFrom, or (k-numbersPicked)/(len(seq)-i), so we simulate that and recurse on the result. (This must terminate since if #remainingToChoose == #remainingToChooseFrom, then all remaining probabilities are 1.) This is similar to a probability tree that happens to be dynamically generated. Basically you can simulate a uniform probability distribution by conditioning on prior choices (as you grow the probability tree, you pick the probability of the current branch such that it is aposteriori the same as prior leaves, i.e. conditioned on prior choices; this will work because this probability is uniformly exactly N/k).

edit: Timothy Shields mentions Reservoir Sampling, which is the generalization of this method when len(seq) is unknown (such as with a generator expression). Specifically the one noted as "algorithm R" is O(N) and O(1) space if done in-place; it involves taking the first N element and slowly replacing them (a hint at an inductive proof is also given). There are also useful distributed variants and miscellaneous variants of reservoir sampling to be found on the wikipedia page.

edit: Here's another way to code it below in a more semantically obvious manner.

from __future__ import division
import random

def orderedSampleWithoutReplacement(seq, sampleSize):
    totalElems = len(seq)
    if not 0<=sampleSize<=totalElems:
        raise ValueError('Required that 0 <= sample_size <= population_size')

    picksRemaining = sampleSize
    for elemsSeen,element in enumerate(seq):
        elemsRemaining = totalElems - elemsSeen
        prob = picksRemaining/elemsRemaining
        if random.random() < prob:
            yield element
            picksRemaining -= 1

from collections import Counter         
Counter(
    tuple(orderedSampleWithoutReplacement([0,1,2,3], 2))
    for _ in range(10**5)

)

IF EXISTS in T-SQL

There's no need for "else" in this case:

IF EXISTS(SELECT *  FROM  table1  WHERE Name='John' ) return 1
return 0

Install Qt on Ubuntu

The ubuntu package name is qt5-default, not qt.

JavaFX - create custom button with image

You just need to create your own class inherited from parent. Place an ImageView on that, and on the mousedown and mouse up events just change the images of the ImageView.

public class ImageButton extends Parent {

    private static final Image NORMAL_IMAGE = ...;
    private static final Image PRESSED_IMAGE = ...;

    private final ImageView iv;

    public ImageButton() {
        this.iv = new ImageView(NORMAL_IMAGE);
        this.getChildren().add(this.iv);

        this.iv.setOnMousePressed(new EventHandler<MouseEvent>() {

            public void handle(MouseEvent evt) {
                iv.setImage(PRESSED_IMAGE);
            }

        });

        // TODO other event handlers like mouse up

    } 

}

Primefaces valueChangeListener or <p:ajax listener not firing for p:selectOneMenu

If you want to use valueChangeListener, you need to submit the form every time a new option is chosen. Something like this:

<p:selectOneMenu value="#{mymb.employee}" onchange="submit()"
                 valueChangeListener="#{mymb.handleChange}" >
    <f:selectItems value="#{mymb.employeesList}" var="emp"
                   itemLabel="#{emp.employeeName}" itemValue="#{emp.employeeID}" />
</p:selectOneMenu>

public void handleChange(ValueChangeEvent event){  
    System.out.println("New value: " + event.getNewValue());
}

Or else, if you want to use <p:ajax>, it should look like this:

<p:selectOneMenu value="#{mymb.employee}" >
    <p:ajax listener="#{mymb.handleChange}" />
    <f:selectItems value="#{mymb.employeesList}" var="emp"
                   itemLabel="#{emp.employeeName}" itemValue="#{emp.employeeID}" />
</p:selectOneMenu>

private String employeeID;

public void handleChange(){  
    System.out.println("New value: " + employee);
}

One thing to note is that in your example code, I saw that the value attribute of your <p:selectOneMenu> is #{mymb.employeesList} which is the same as the value of <f:selectItems>. The value of your <p:selectOneMenu> should be similar to my examples above which point to a single employee, not a list of employees.

Get current date in Swift 3?

You say in a comment you want to get "15.09.2016".

For this, use Date and DateFormatter:

let date = Date()
let formatter = DateFormatter()

Give the format you want to the formatter:

formatter.dateFormat = "dd.MM.yyyy"

Get the result string:

let result = formatter.string(from: date)

Set your label:

label.text = result

Result:

15.09.2016

How to replace substrings in windows batch file

I have made a function for that, you only call it in a batch program within needing to code more.

The working is basically the same as the others, as it's the best way to do it.
Here's the link where I have that function

Call PHP function from jQuery?

This is exactly what ajax is for. See here:

http://api.jquery.com/load/

Basically, you ajax/test.php and put the returned HTML code to the element which has the result id.

$('#result').load('ajax/test.php');

Of course, you will need to put the functionality which takes time to a new php file (or call the old one with a GET parameter which will activate that functionality only).

How to get the squared symbol (²) to display in a string

No need to get too complicated. If all you need is ² then use the unicode representation.

http://en.wikipedia.org/wiki/Unicode_subscripts_and_superscripts

(which is how I assume you got the ² to appear in your question. )

Get my phone number in android

As Answered here

Use below code :

TelephonyManager tMgr = (TelephonyManager)mAppContext.getSystemService(Context.TELEPHONY_SERVICE);
String mPhoneNumber = tMgr.getLine1Number();

In AndroidManifest.xml, give the following permission:

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

But remember, this code does not always work, since Cell phone number is dependent on the SIM Card and the Network operator / Cell phone carrier.

Also, try checking in Phone--> Settings --> About --> Phone Identity, If you are able to view the Number there, the probability of getting the phone number from above code is higher. If you are not able to view the phone number in the settings, then you won't be able to get via this code!

Suggested Workaround:

  1. Get the user's phone number as manual input from the user.
  2. Send a code to the user's mobile number via SMS.
  3. Ask user to enter the code to confirm the phone number.
  4. Save the number in sharedpreference.

Do the above 4 steps as one time activity during the app's first launch. Later on, whenever phone number is required, use the value available in shared preference.

PHP Regex to check date is in YYYY-MM-DD format

Probably useful to someone:

$patterns = array(
            'Y'           =>'/^[0-9]{4}$/',
            'Y-m'         =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])$/',
            'Y-m-d'       =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])$/',
            'Y-m-d H'     =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])\s(0|[0-1][0-9]|2[0-4])$/',
            'Y-m-d H:i'   =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])\s(0|[0-1][0-9]|2[0-4]):?(0|[0-5][0-9]|60)$/',
            'Y-m-d H:i:s' =>'/^[0-9]{4}(-|\/)([1-9]|0[1-9]|1[0-2])(-|\/)([1-9]|0[1-9]|[1-2][0-9]|3[0-1])\s(0|[0-1][0-9]|2[0-4]):?((0|[0-5][0-9]):?(0|[0-5][0-9])|6000|60:00)$/',
        );
echo preg_match($patterns['Y'], '1996'); // true
echo preg_match($patterns['Y'], '19966'); // false
echo preg_match($patterns['Y'], '199z'); // false
echo preg_match($patterns['Y-m'], '1996-0'); // false
echo preg_match($patterns['Y-m'], '1996-09'); // true
echo preg_match($patterns['Y-m'], '1996-1'); // true
echo preg_match($patterns['Y-m'], '1996/1'); // true
echo preg_match($patterns['Y-m'], '1996/12'); // true
echo preg_match($patterns['Y-m'], '1996/13'); // false
echo preg_match($patterns['Y-m-d'], '1996-11-1'); // true
echo preg_match($patterns['Y-m-d'], '1996-11-0'); // false
echo preg_match($patterns['Y-m-d'], '1996-11-32'); // false
echo preg_match($patterns['Y-m-d H'], '1996-11-31 0'); // true
echo preg_match($patterns['Y-m-d H'], '1996-11-31 00'); // true
echo preg_match($patterns['Y-m-d H'], '1996-11-31 24'); // true
echo preg_match($patterns['Y-m-d H'], '1996-11-31 25'); // false
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 2400'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:00'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:59'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:60'); // true
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:61'); // false
echo preg_match($patterns['Y-m-d H:i'], '1996-11-31 24:61'); // false
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:6000'); // true
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:60:00'); // true
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:59:59'); // true
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:59:60'); // false
echo preg_match($patterns['Y-m-d H:i:s'], '1996-11-31 24:60:01'); // false

JavaScript - XMLHttpRequest, Access-Control-Allow-Origin errors

I think you've missed the point of access control.

A quick recap on why CORS exists: Since JS code from a website can execute XHR, that site could potentially send requests to other sites, masquerading as you and exploiting the trust those sites have in you(e.g. if you have logged in, a malicious site could attempt to extract information or execute actions you never wanted) - this is called a CSRF attack. To prevent that, web browsers have very stringent limitations on what XHR you can send - you are generally limited to just your domain, and so on.

Now, sometimes it's useful for a site to allow other sites to contact it - sites that provide APIs or services, like the one you're trying to access, would be prime candidates. CORS was developed to allow site A(e.g. paste.ee) to say "I trust site B, so you can send XHR from it to me". This is specified by site A sending "Access-Control-Allow-Origin" headers in its responses.

In your specific case, it seems that paste.ee doesn't bother to use CORS. Your best bet is to contact the site owner and find out why, if you want to use paste.ee with a browser script. Alternatively, you could try using an extension(those should have higher XHR privileges).

Insert json file into mongodb

In MS Windows, the mongoimport command has to be run in a normal Windows command prompt, not from the mongodb command prompt.

How to reference a file for variables using Bash?

If the variables are being generated and not saved to a file you cannot pipe them in into source. The deceptively simple way to do it is this:

some command | xargs

Authentication plugin 'caching_sha2_password' is not supported

This question is already answered here and this solution works.

caching sha2 password is not supported mysql

Just try this command :

pip install mysql-connector-python

JsonParseException: Unrecognized token 'http': was expecting ('true', 'false' or 'null')

It might be obvious, but make sure that you are sending to the parser URL object not a String containing www adress. This will not work:

    ObjectMapper mapper = new ObjectMapper();
    String www = "www.sample.pl";
    Weather weather = mapper.readValue(www, Weather.class);

But this will:

    ObjectMapper mapper = new ObjectMapper();
    URL www = new URL("http://www.oracle.com/");
    Weather weather = mapper.readValue(www, Weather.class);

How to deal with page breaks when printing a large HTML table

Well Guys... Most of the Solutions up here didn't worked for. So this is how things worked for me..

HTML

<table>
  <thead>
   <tr>
     <th style="border:none;height:26px;"></th>
     <th style="border:none;height:26px;"></th>
     .
     .
   </tr>
   <tr>
     <th style="border:1px solid black">ABC</th>
     <th style="border:1px solid black">ABC</th>
     .
     .
   <tr>
  </thead>
<tbody>

    //YOUR CODE

</tbody>
</table>

The first set of head is used as a dummy one so that there won't be a missing top border in 2nd head(i.e. original head) while page break.

How to check if a float value is a whole number

All the answers are good but a sure fire method would be

def whole (n):
     return (n*10)%10==0

The function returns True if it's a whole number else False....I know I'm a bit late but here's one of the interesting methods which I made...

Edit: as stated by the comment below, a cheaper equivalent test would be:

def whole(n):
    return n%1==0

Find out whether radio button is checked with JQuery?

$("#radio_1").prop("checked", true);

For versions of jQuery prior to 1.6, use:

$("#radio_1").attr('checked', 'checked');

How to concat string + i?

Try the following:

for i = 1:4
    result = strcat('f',int2str(i));
end

If you use this for naming several files that your code generates, you are able to concatenate more parts to the name. For example, with the extension at the end and address at the beginning:

filename = strcat('c:\...\name',int2str(i),'.png'); 

Setting an image button in CSS - image:active

Check this link . You were missing . before myButton. It was a small error. :)

.myButton{
    background:url(./images/but.png) no-repeat;
    cursor:pointer;
    border:none;
    width:100px;
    height:100px;
}

.myButton:active  /* use Dot here */
{   
    background:url(./images/but2.png) no-repeat;
}

MySQL - force not to use cache for testing speed of query

I'd Use the following:

SHOW VARIABLES LIKE 'query_cache_type';
SET SESSION query_cache_type = OFF;
SHOW VARIABLES LIKE 'query_cache_type';

How to construct a REST API that takes an array of id's for the resources

You can build a Rest API or a restful project using ASP.NET MVC and return data as a JSON. An example controller function would be:

        public JsonpResult GetUsers(string userIds)
        {
           var values = JsonConvert.DeserializeObject<List<int>>(userIds);

            var users = _userRepository.GetAllUsersByIds(userIds);

            var collection = users.Select(user => new { id = user.Id, fullname = user.FirstName +" "+ user.LastName });
            var result = new { users = collection };

            return this.Jsonp(result);
        }
        public IQueryable<User> GetAllUsersByIds(List<int> ids)
        {
            return _db.Users.Where(c=> ids.Contains(c.Id));
        }

Then you just call the GetUsers function via a regular AJAX function supplying the array of Ids(in this case I am using jQuery stringify to send the array as string and dematerialize it back in the controller but you can just send the array of ints and receive it as an array of int's in the controller). I've build an entire Restful API using ASP.NET MVC that returns the data as cross domain json and that can be used from any app. That of course if you can use ASP.NET MVC.

function GetUsers()
    {
           var link = '<%= ResolveUrl("~")%>users?callback=?';
           var userIds = [];
            $('#multiselect :selected').each(function (i, selected) {
                userIds[i] = $(selected).val();
            });

            $.ajax({
                url: link,
                traditional: true,
                data: { 'userIds': JSON.stringify(userIds) },
                dataType: "jsonp",
                jsonpCallback: "refreshUsers"
            });
    }

How can I check if a var is a string in JavaScript?

You were close:

if (typeof a_string === 'string') {
    // this is a string
}

On a related note: the above check won't work if a string is created with new String('hello') as the type will be Object instead. There are complicated solutions to work around this, but it's better to just avoid creating strings that way, ever.

XML Error: There are multiple root elements

You can do it without modifying the XML stream: Tell the XmlReader to not be so picky. Setting the XmlReaderSettings.ConformanceLevel to ConformanceLevel.Fragment will let the parser ignore the fact that there is no root node.

        XmlReaderSettings settings = new XmlReaderSettings();
        settings.ConformanceLevel = ConformanceLevel.Fragment;
        using (XmlReader reader = XmlReader.Create(tr,settings))
        {
             ...
        }

Now you can parse something like this (which is an real time XML stream, where it is impossible to wrap with a node).

<event>
  <timeStamp>1354902435238</timeStamp>
  <eventId>7073822</eventId>
</event>
<data>
  <time>1354902435341</time>
  <payload type='80'>7d1300786a0000000bf9458b0518000000000000000000000000000000000c0c030306001b</payload>
</data>
<data>
  <time>1354902435345</time>
  <payload type='80'>fd1260780912ff3028fea5ffc0387d640fa550f40fbdf7afffe001fff8200fff00f0bf0e000042201421100224ff40312300111400004f000000e0c0fbd1e0000f10e0fccc2ff0000f0fe00f00f0eed00f11e10d010021420401</payload>
</data>
<data>
  <time>1354902435347</time>
  <payload type='80'>fd126078ad11fc4015fefdf5b042ff1010223500000000000000003007ff00f20e0f01000e0000dc0f01000f000000000000004f000000f104ff001000210f000013010000c6da000000680ffa807800200000000d00c0f0</payload>
</data>

Adding Only Untracked Files

You can add this to your ~/.gitconfig file:

[alias]
    add-untracked = !"git status --porcelain | awk '/\\?\\?/{ print $2 }' | xargs git add"

Then, from the commandline, just run:

git add-untracked

Is there a real solution to debug cordova apps

On Android 4.4+ w/SDK installed:

adb logcat chromium:D SystemWebViewClient:D \*:S

Get current user id in ASP.NET Identity 2.0

I had the same issue. I am currently using Asp.net Core 2.2. I solved this problem with the following piece of code.

using Microsoft.AspNetCore.Identity;
var user = await _userManager.FindByEmailAsync(User.Identity.Name);

I hope this will be useful to someone.

addEventListener for keydown on Canvas

Set the tabindex of the canvas element to 1 or something like this

<canvas tabindex='1'></canvas>

It's an old trick to make any element focusable

How can I login to a website with Python?

Maybe you want to use twill. It's quite easy to use and should be able to do what you want.

It will look like the following:

from twill.commands import *
go('http://example.org')

fv("1", "email-email", "blabla.com")
fv("1", "password-clear", "testpass")

submit('0')

You can use showforms() to list all forms once you used go… to browse to the site you want to login. Just try it from the python interpreter.

How does GPS in a mobile phone work exactly?

GPS, the Global Positioning System run by the United States Military, is free for civilian use, though the reality is that we're paying for it with tax dollars.

However, GPS on cell phones is a bit more murky. In general, it won't cost you anything to turn on the GPS in your cell phone, but when you get a location it usually involves the cell phone company in order to get it quickly with little signal, as well as get a location when the satellites aren't visible (since the gov't requires a fix even if the satellites aren't visible for emergency 911 purposes). It uses up some cellular bandwidth. This also means that for phones without a regular GPS receiver, you cannot use the GPS at all if you don't have cell phone service.

For this reason most cell phone companies have the GPS in the phone turned off except for emergency calls and for services they sell you (such as directions).

This particular kind of GPS is called assisted GPS (AGPS), and there are several levels of assistance used.

GPS

A normal GPS receiver listens to a particular frequency for radio signals. Satellites send time coded messages at this frequency. Each satellite has an atomic clock, and sends the current exact time as well.

The GPS receiver figures out which satellites it can hear, and then starts gathering those messages. The messages include time, current satellite positions, and a few other bits of information. The message stream is slow - this is to save power, and also because all the satellites transmit on the same frequency and they're easier to pick out if they go slow. Because of this, and the amount of information needed to operate well, it can take 30-60 seconds to get a location on a regular GPS.

When it knows the position and time code of at least 3 satellites, a GPS receiver can assume it's on the earth's surface and get a good reading. 4 satellites are needed if you aren't on the ground and you want altitude as well.

AGPS

As you saw above, it can take a long time to get a position fix with a normal GPS. There are ways to speed this up, but unless you're carrying an atomic clock with you all the time, or leave the GPS on all the time, then there's always going to be a delay of between 5-60 seconds before you get a location.

In order to save cost, most cell phones share the GPS receiver components with the cellular components, and you can't get a fix and talk at the same time. People don't like that (especially when there's an emergency) so the lowest form of GPS does the following:

  1. Get some information from the cell phone company to feed to the GPS receiver - some of this is gross positioning information based on what cellular towers can 'hear' your phone, so by this time they already phone your location to within a city block or so.
  2. Switch from cellular to GPS receiver for 0.1 second (or some small, practically unoticable period of time) and collect the raw GPS data (no processing on the phone).
  3. Switch back to the phone mode, and send the raw data to the phone company
  4. The phone company processes that data (acts as an offline GPS receiver) and send the location back to your phone.

This saves a lot of money on the phone design, but it has a heavy load on cellular bandwidth, and with a lot of requests coming it requires a lot of fast servers. Still, overall it can be cheaper and faster to implement. They are reluctant, however, to release GPS based features on these phones due to this load - so you won't see turn by turn navigation here.

More recent designs include a full GPS chip. They still get data from the phone company - such as current location based on tower positioning, and current satellite locations - this provides sub 1 second fix times. This information is only needed once, and the GPS can keep track of everything after that with very little power. If the cellular network is unavailable, then they can still get a fix after awhile. If the GPS satellites aren't visible to the receiver, then they can still get a rough fix from the cellular towers.

But to completely answer your question - it's as free as the phone company lets it be, and so far they do not charge for it at all. I doubt that's going to change in the future. In the higher end phones with a full GPS receiver you may even be able to load your own software and access it, such as with mologogo on a motorola iDen phone - the J2ME development kit is free, and the phone is only $40 (prepaid phone with $5 credit). Unlimited internet is about $10 a month, so for $40 to start and $10 a month you can get an internet tracking system. (Prices circa August 2008)

It's only going to get cheaper and more full featured from here on out...

Re: Google maps and such

Yes, Google maps and all other cell phone mapping systems require a data connection of some sort at varying times during usage. When you move far enough in one direction, for instance, it'll request new tiles from its server. Your average phone doesn't have enough storage to hold a map of the US, nor the processor power to render it nicely. iPhone would be able to if you wanted to use the storage space up with maps, but given that most iPhones have a full time unlimited data plan most users would rather use that space for other things.

hadoop copy a local file system folder to HDFS

To copy a folder file from local to hdfs, you can the below command

hadoop fs -put /path/localpath  /path/hdfspath

or

hadoop fs -copyFromLocal /path/localpath  /path/hdfspath

memory error in python

This one here:

s = raw_input()
a=len(s)
for i in xrange(0, a):
    for j in xrange(0, a):
        if j >= i:
            if len(s[i:j+1]) > 0:
                sub_strings.append(s[i:j+1])

seems to be very inefficient and expensive for large strings.

Better do

for i in xrange(0, a):
    for j in xrange(i, a): # ensures that j >= i, no test required
        part = buffer(s, i, j+1-i) # don't duplicate data
        if len(part) > 0:
            sub_Strings.append(part)

A buffer object keeps a reference to the original string and start and length attributes. This way, no unnecessary duplication of data occurs.

A string of length l has l*l/2 sub strings of average length l/2, so the memory consumption would roughly be l*l*l/4. With a buffer, it is much smaller.

Note that buffer() only exists in 2.x. 3.x has memoryview(), which is utilized slightly different.

Even better would be to compute the indexes and cut out the substring on demand.

Load CSV data into MySQL in Python

If you do not have the pandas and sqlalchemy libraries, import using pip

pip install pandas
pip install sqlalchemy

We can use pandas and sqlalchemy to directly insert into the database

import csv
import pandas as pd
from sqlalchemy import create_engine, types

engine = create_engine('mysql://root:*Enter password here*@localhost/*Enter Databse name here*') # enter your password and database names here

df = pd.read_csv("Excel_file_name.csv",sep=',',quotechar='\'',encoding='utf8') # Replace Excel_file_name with your excel sheet name
df.to_sql('Table_name',con=engine,index=False,if_exists='append') # Replace Table_name with your sql table name

Generic XSLT Search and Replace template

Here's one way in XSLT 2

<?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">   <xsl:template match="@*|node()">     <xsl:copy>       <xsl:apply-templates select="@*|node()"/>     </xsl:copy>   </xsl:template>   <xsl:template match="text()">     <xsl:value-of select="translate(.,'&quot;','''')"/>   </xsl:template> </xsl:stylesheet> 

Doing it in XSLT1 is a little more problematic as it's hard to get a literal containing a single apostrophe, so you have to resort to a variable:

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">   <xsl:template match="@*|node()">     <xsl:copy>       <xsl:apply-templates select="@*|node()"/>     </xsl:copy>   </xsl:template>   <xsl:variable name="apos">'</xsl:variable>   <xsl:template match="text()">     <xsl:value-of select="translate(.,'&quot;',$apos)"/>   </xsl:template> </xsl:stylesheet> 

Float to String format specifier

In C#, float is an alias for System.Single (a bit like intis an alias for System.Int32).

Java :Add scroll into text area

My naive assumption was that the size of scroll pane will be determined automatically...

The only solution that actually worked for me was explicitly seeting bounds of JScrollPane:

import javax.swing.*;

public class MyFrame extends JFrame {

    public MyFrame()
    {
        setBounds(100, 100, 491, 310);
        getContentPane().setLayout(null);

        JTextArea textField = new JTextArea();
        textField.setEditable(false);

        String str = "";
        for (int i = 0; i < 50; ++i)
            str += "Some text\n";
        textField.setText(str);

        JScrollPane scroll = new JScrollPane(textField);
        scroll.setBounds(10, 11, 455, 249);                     // <-- THIS

        getContentPane().add(scroll);
        setLocationRelativeTo ( null );
    }
}

Maybe it will help some future visitors :)

Excel select a value from a cell having row number calculated

You could use the INDIRECT function. This takes a string and converts it into a range

More info here

=INDIRECT("K"&A2)

But it's preferable to use INDEX as it is less volatile.

=INDEX(K:K,A2)

This returns a value or the reference to a value from within a table or range

More info here

Put either function into cell B2 and fill down.

Testing if a checkbox is checked with jQuery

Try this

$('input:checkbox:checked').click(function(){
    var val=(this).val(); // it will get value from checked checkbox;
})

Here flag is true if checked otherwise false

var flag=$('#ans').attr('checked');

Again this will make cheked

$('#ans').attr('checked',true);

Linear regression with matplotlib / numpy

This code:

from scipy.stats import linregress

linregress(x,y) #x and y are arrays or lists.

gives out a list with the following:

slope : float
slope of the regression line
intercept : float
intercept of the regression line
r-value : float
correlation coefficient
p-value : float
two-sided p-value for a hypothesis test whose null hypothesis is that the slope is zero
stderr : float
Standard error of the estimate

Source

Javascript communication between browser tabs/windows

There is also an experimental technology called Broadcast Channel API that is designed specifically for communication between different browser contexts with same origin. You can post messages to and recieve messages from another browser context without having a reference to it:

var channel = new BroadcastChannel("foo");
channel.onmessage = function( e ) {
  // Process messages from other contexts.
};
// Send message to other listening contexts.
channel.postMessage({ value: 42, type: "bar"});

Obviously this is experiental technology and is not supported accross all browsers yet.

how to include glyphicons in bootstrap 3

I think your particular problem isn't how to use Glyphicons but understanding how Bootstrap files work together.

Bootstrap requires a specific file structure to work. I see from your code you have this:

<link href="bootstrap.css" rel="stylesheet" media="screen">

Your Bootstrap.css is being loaded from the same location as your page, this would create a problem if you didn't adjust your file structure.

But first, let me recommend you setup your folder structure like so:

/css      <-- Bootstrap.css here
/fonts    <-- Bootstrap fonts here
/img
/js       <-- Bootstrap JavaScript here
index.html

If you notice, this is also how Bootstrap structures its files in its download ZIP.

You then include your Bootstrap file like so:

<link href="css/bootstrap.css" rel="stylesheet" media="screen">
or
<link href="./css/bootstrap.css" rel="stylesheet" media="screen">
or
<link href="/css/bootstrap.css" rel="stylesheet" media="screen">

Depending on your server structure or what you're going for.

The first and second are relative to your file's current directory. The second one is just more explicit by saying "here" (./) first then css folder (/css).

The third is good if you're running a web server, and you can just use relative to root notation as the leading "/" will be always start at the root folder.

So, why do this?

Bootstrap.css has this specific line for Glyphfonts:

@font-face {
    font-family: 'Glyphicons Halflings';
    src: url('../fonts/glyphicons-halflings-regular.eot');
    src: url('../fonts/glyphicons-halflings-regular.eot?#iefix') format('embedded-opentype'), url('../fonts/glyphicons-halflings-regular.woff') format('woff'), url('../fonts/glyphicons-halflings-regular.ttf') format('truetype'), url('../fonts/glyphicons-halflings-regular.svg#glyphicons-halflingsregular') format('svg');
}

What you can see is that that Glyphfonts are loaded by going up one directory ../ and then looking for a folder called /fonts and THEN loading the font file.

The URL address is relative to the location of the CSS file. So, if your CSS file is at the same location like this:

/fonts
Bootstrap.css
index.html

The CSS file is going one level deeper than looking for a /fonts folder.

So, let's say the actual location of these files are:

C:\www\fonts
C:\www\Boostrap.css
C:\www\index.html

The CSS file would technically be looking for a folder at:

C:\fonts

but your folder is actually in:

C:\www\fonts

So see if that helps. You don't have to do anything 'special' to load Bootstrap Glyphicons, except make sure your folder structure is set up appropriately.

When you get that fixed, your HTML should simply be:

<span class="glyphicon glyphicon-comment"></span>

Note, you need both classes. The first class glyphicon sets up the basic styles while glyphicon-comment sets the specific image.

filename and line number of Python script

Just to contribute,

there is a linecache module in python, here is two links that can help.

linecache module documentation
linecache source code

In a sense, you can "dump" a whole file into its cache , and read it with linecache.cache data from class.

import linecache as allLines
## have in mind that fileName in linecache behaves as any other open statement, you will need a path to a file if file is not in the same directory as script
linesList = allLines.updatechache( fileName ,None)
for i,x in enumerate(lineslist): print(i,x) #prints the line number and content
#or for more info
print(line.cache)
#or you need a specific line
specLine = allLines.getline(fileName,numbOfLine)
#returns a textual line from that number of line

For additional info, for error handling, you can simply use

from sys import exc_info
try:
     raise YourError # or some other error
except Exception:
     print(exc_info() )

VBA Macro On Timer style to run code every set number of seconds, i.e. 120 seconds

(This is paraphrased from the MS Access help files. I'm sure XL has something similar.) Basically, TimerInterval is a form-level property. Once set, use the sub Form_Timer to carry out your intended action.

Sub Form_Load()
    Me.TimerInterval = 1000 '1000 = 1 second
End Sub

Sub Form_Timer()
    'Do Stuff
End Sub

Creating a random string with A-Z and 0-9 in Java

Here you can use my method for generating Random String

protected String getSaltString() {
        String SALTCHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
        StringBuilder salt = new StringBuilder();
        Random rnd = new Random();
        while (salt.length() < 18) { // length of the random string.
            int index = (int) (rnd.nextFloat() * SALTCHARS.length());
            salt.append(SALTCHARS.charAt(index));
        }
        String saltStr = salt.toString();
        return saltStr;

    }

The above method from my bag using to generate a salt string for login purpose.

Replace all occurrences of a string in a data frame

Here is a dplyr solution

library(dplyr)
library(stringr)

Censor_consistently <-  function(x){
  str_replace(x, '^\\s*([<>])\\s*(\\d+)', '\\1\\2')
}


test_df <- tibble(x = c('0.001', '<0.002', ' < 0.003', ' >  100'),  y = 4:1)

mutate_all(test_df, funs(Censor_consistently))

# A tibble: 4 × 2
x     y
<chr> <chr>
1  0.001     4
2 <0.002     3
3 <0.003     2
4   >100     1

Creating all possible k combinations of n items in C++

From Rosetta code

#include <algorithm>
#include <iostream>
#include <string>
 
void comb(int N, int K)
{
    std::string bitmask(K, 1); // K leading 1's
    bitmask.resize(N, 0); // N-K trailing 0's
 
    // print integers and permute bitmask
    do {
        for (int i = 0; i < N; ++i) // [0..N-1] integers
        {
            if (bitmask[i]) std::cout << " " << i;
        }
        std::cout << std::endl;
    } while (std::prev_permutation(bitmask.begin(), bitmask.end()));
}
 
int main()
{
    comb(5, 3);
}

output

 0 1 2
 0 1 3
 0 1 4
 0 2 3
 0 2 4
 0 3 4
 1 2 3
 1 2 4
 1 3 4
 2 3 4

Analysis and idea

The whole point is to play with the binary representation of numbers for example the number 7 in binary is 0111

So this binary representation can also be seen as an assignment list as such:

For each bit i if the bit is set (i.e is 1) means the ith item is assigned else not.

Then by simply computing a list of consecutive binary numbers and exploiting the binary representation (which can be very fast) gives an algorithm to compute all combinations of N over k.

The sorting at the end (of some implementations) is not needed. It is just a way to deterministicaly normalize the result, i.e for same numbers (N, K) and same algorithm same order of combinations is returned

For further reading about number representations and their relation to combinations, permutations, power sets (and other interesting stuff), have a look at Combinatorial number system , Factorial number system

PS: You may want to check out my combinatorics framework Abacus which computes many types of combinatorial objects efficiently and its routines (originaly in JavaScript) can be adapted easily to many other languages.

How to convert timestamp to datetime in MySQL?

Use the FROM_UNIXTIME() function in MySQL

Remember that if you are using a framework that stores it in milliseconds (for example Java's timestamp) you have to divide by 1000 to obtain the right Unix time in seconds.

Difference between Interceptor and Filter in Spring MVC

From HandlerIntercepter's javadoc:

HandlerInterceptor is basically similar to a Servlet Filter, but in contrast to the latter it just allows custom pre-processing with the option of prohibiting the execution of the handler itself, and custom post-processing. Filters are more powerful, for example they allow for exchanging the request and response objects that are handed down the chain. Note that a filter gets configured in web.xml, a HandlerInterceptor in the application context.

As a basic guideline, fine-grained handler-related pre-processing tasks are candidates for HandlerInterceptor implementations, especially factored-out common handler code and authorization checks. On the other hand, a Filter is well-suited for request content and view content handling, like multipart forms and GZIP compression. This typically shows when one needs to map the filter to certain content types (e.g. images), or to all requests.

With that being said:

So where is the difference between Interceptor#postHandle() and Filter#doFilter()?

postHandle will be called after handler method invocation but before the view being rendered. So, you can add more model objects to the view but you can not change the HttpServletResponse since it's already committed.

doFilter is much more versatile than the postHandle. You can change the request or response and pass it to the chain or even block the request processing.

Also, in preHandle and postHandle methods, you have access to the HandlerMethod that processed the request. So, you can add pre/post-processing logic based on the handler itself. For example, you can add a logic for handler methods that have some annotations.

What is the best practise in which use cases it should be used?

As the doc said, fine-grained handler-related pre-processing tasks are candidates for HandlerInterceptor implementations, especially factored-out common handler code and authorization checks. On the other hand, a Filter is well-suited for request content and view content handling, like multipart forms and GZIP compression. This typically shows when one needs to map the filter to certain content types (e.g. images), or to all requests.

How to check if a Java 8 Stream is empty?

If you can live with limited parallel capablilities, the following solution will work:

private static <T> Stream<T> nonEmptyStream(
    Stream<T> stream, Supplier<RuntimeException> e) {

    Spliterator<T> it=stream.spliterator();
    return StreamSupport.stream(new Spliterator<T>() {
        boolean seen;
        public boolean tryAdvance(Consumer<? super T> action) {
            boolean r=it.tryAdvance(action);
            if(!seen && !r) throw e.get();
            seen=true;
            return r;
        }
        public Spliterator<T> trySplit() { return null; }
        public long estimateSize() { return it.estimateSize(); }
        public int characteristics() { return it.characteristics(); }
    }, false);
}

Here is some example code using it:

List<String> l=Arrays.asList("hello", "world");
nonEmptyStream(l.stream(), ()->new RuntimeException("No strings available"))
  .forEach(System.out::println);
nonEmptyStream(l.stream().filter(s->s.startsWith("x")),
               ()->new RuntimeException("No strings available"))
  .forEach(System.out::println);

The problem with (efficient) parallel execution is that supporting splitting of the Spliterator requires a thread-safe way to notice whether either of the fragments has seen any value in a thread-safe manner. Then the last of the fragments executing tryAdvance has to realize that it is the last one (and it also couldn’t advance) to throw the appropriate exception. So I didn’t add support for splitting here.

When should we use mutex and when should we use semaphore

See "The Toilet Example" - http://pheatt.emporia.edu/courses/2010/cs557f10/hand07/Mutex%20vs_%20Semaphore.htm:

Mutex:

Is a key to a toilet. One person can have the key - occupy the toilet - at the time. When finished, the person gives (frees) the key to the next person in the queue.

Officially: "Mutexes are typically used to serialise access to a section of re-entrant code that cannot be executed concurrently by more than one thread. A mutex object only allows one thread into a controlled section, forcing other threads which attempt to gain access to that section to wait until the first thread has exited from that section." Ref: Symbian Developer Library

(A mutex is really a semaphore with value 1.)

Semaphore:

Is the number of free identical toilet keys. Example, say we have four toilets with identical locks and keys. The semaphore count - the count of keys - is set to 4 at beginning (all four toilets are free), then the count value is decremented as people are coming in. If all toilets are full, ie. there are no free keys left, the semaphore count is 0. Now, when eq. one person leaves the toilet, semaphore is increased to 1 (one free key), and given to the next person in the queue.

Officially: "A semaphore restricts the number of simultaneous users of a shared resource up to a maximum number. Threads can request access to the resource (decrementing the semaphore), and can signal that they have finished using the resource (incrementing the semaphore)." Ref: Symbian Developer Library

Change the size of a JTextField inside a JBorderLayout

Any component added to the GridLayout will be resized to the same size as the largest component added. If you want a component to remain at its preferred size, then wrap that component in a JPanel and then the panel will be resized:

JPanel displayPanel = new JPanel(new GridLayout(4, 2)); 
JTextField titleText = new JTextField("title"); 
JPanel wrapper = new JPanel( new FlowLayout(0, 0, FlowLayout.LEADING) );
wrapper.add( titleText );
displayPanel.add(wrapper); 
//displayPanel.add(titleText); 

How can I check if a Perl array contains a particular value?

Method 1: grep (may careful while value is expected to be a regex).

Try to avoid using grep, if looking at resources.

if ( grep( /^$value$/, @badparams ) ) {
  print "found";
}

Method 2: Linear Search

for (@badparams) {
    if ($_ eq $value) {
       print "found";
       last;
    }
}

Method 3: Use a hash

my %hash = map {$_ => 1} @badparams;
print "found" if (exists $hash{$value});

Method 4: smartmatch

(added in Perl 5.10, marked is experimental in Perl 5.18).

use experimental 'smartmatch';  # for perl 5.18
print "found" if ($value ~~ @badparams);

Method 5: Use the module List::MoreUtils

use List::MoreUtils qw(any);
@badparams = (1,2,3);
$value = 1;
print "found" if any {$_ == $value} @badparams;

LDAP: error code 49 - 80090308: LdapErr: DSID-0C0903A9, comment: AcceptSecurityContext error, data 52e, v1db1

52e 1326 ERROR_LOGON_FAILURE Returns when username is valid but password/credential is invalid. Will prevent most other errors from being displayed as noted.

http://ldapwiki.com/wiki/Common%20Active%20Directory%20Bind%20Errors

Pointers, smart pointers or shared pointers?

the term "smart pointer" includes shared pointers, auto pointers, locking pointers and others. you meant to say auto pointer (more ambiguously known as "owning pointer"), not smart pointer.

Dumb pointers (T*) are never the best solution. They make you do explicit memory management, which is verbose, error prone, and sometimes nigh impossible. But more importantly, they don't signal your intent.

Auto pointers delete the pointee at destruction. For arrays, prefer encapsulations like vector and deque. For other objects, there's very rarely a need to store them on the heap - just use locals and object composition. Still the need for auto pointers arises with functions that return heap pointers -- such as factories and polymorphic returns.

Shared pointers delete the pointee when the last shared pointer to it is destroyed. This is useful when you want a no-brainer, open-ended storage scheme where expected lifetime and ownership can vary widely depending on the situation. Due to the need to keep an (atomic) counter, they're a bit slower than auto pointers. Some say half in jest that shared pointers are for people who can't design systems -- judge for yourself.

For an essential counterpart to shared pointers, look up weak pointers too.

Load a WPF BitmapImage from a System.Drawing.Bitmap

Thanks to Hallgrim, here is the code I ended up with:

ScreenCapture = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
   bmp.GetHbitmap(), 
   IntPtr.Zero, 
   System.Windows.Int32Rect.Empty, 
   BitmapSizeOptions.FromWidthAndHeight(width, height));

I also ended up binding to a BitmapSource instead of a BitmapImage as in my original question

Open Google Chrome from VBA/Excel

shell("C:\Users\USERNAME\AppData\Local\Google\Chrome\Application\Chrome.exe -url http:google.ca")

Hexadecimal To Decimal in Shell Script

I have this handy script on my $PATH to filter 0x1337-like; 1337; or "0x1337" lines of input into decimal strings (expanded for clarity):

#!/usr/bin/env bash

while read data; do
  withoutQuotes=`echo ${data} | sed s/\"//g`
  without0x=`echo ${withoutQuotes} | sed s/0x//g`
  clean=${without0x}
  echo $((16#${clean}))
done

How to send json data in POST request using C#

This works for me.

var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://url");
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "POST";
using (var streamWriter = new 

StreamWriter(httpWebRequest.GetRequestStream()))
{
    string json = new JavaScriptSerializer().Serialize(new
                {
                    Username = "myusername",
                    Password = "password"
                });

    streamWriter.Write(json);
}
var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
    var result = streamReader.ReadToEnd();
}

How to sort List<Integer>?

You can use the utility method in Collections class public static <T extends Comparable<? super T>> void sort(List<T> list) or

public static <T> void sort(List<T> list,Comparator<? super T> c)

Refer to Comparable and Comparator interfaces for more flexibility on sorting the object.

"Debug certificate expired" error in Eclipse Android plugins

If a certificate expires in the middle of project debugging, you must do a manual uninstall:

Please execute adb uninstall <package_name> in a shell.

Python Linked List

For some needs, a deque may also be useful. You can add and remove items on both ends of a deque at O(1) cost.

from collections import deque
d = deque([1,2,3,4])

print d
for x in d:
    print x
print d.pop(), d

Detect if page has finished loading

Is this what you had in mind?

$("document").ready( function() {
    // do your stuff
}

How to check if command line tools is installed

% xcode-select -h Usage: xcode-select [options]

Print or change the path to the active developer directory. This directory controls which tools are used for the Xcode command line tools (for example, xcodebuild) as well as the BSD development commands (such as cc and make).

Options: -h, --help print this help message and exit -p, --print-path print the path of the active developer directory -s , --switch set the path for the active developer directory --install open a dialog for installation of the command line developer tools -v, --version print the xcode-select version -r, --reset reset to the default command line tools path

How can I check if an ip is in a network in Python?

Using ipaddress (in the stdlib since 3.3, at PyPi for 2.6/2.7):

>>> import ipaddress
>>> ipaddress.ip_address('192.168.0.1') in ipaddress.ip_network('192.168.0.0/24')
True

If you want to evaluate a lot of IP addresses this way, you'll probably want to calculate the netmask upfront, like

n = ipaddress.ip_network('192.0.0.0/16')
netw = int(n.network_address)
mask = int(n.netmask)

Then, for each address, calculate the binary representation with one of

a = int(ipaddress.ip_address('192.0.43.10'))
a = struct.unpack('!I', socket.inet_pton(socket.AF_INET, '192.0.43.10'))[0]
a = struct.unpack('!I', socket.inet_aton('192.0.43.10'))[0]  # IPv4 only

Finally, you can simply check:

in_network = (a & mask) == netw