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Sprintf equivalent in Java

// Store the formatted string in 'result'
String result = String.format("%4d", i * j);

// Write the result to standard output
System.out.println( result );

See format and its syntax

How do I efficiently iterate over each entry in a Java Map?

    Iterator iterator = map.entrySet().iterator();
    while (iterator.hasNext()) {
        Map.Entry element = (Map.Entry);
        LOGGER.debug("Key: " + element.getKey());
        LOGGER.debug("value: " + element.getValue());    

How do you create a foreign key relationship in a SQL Server CE (Compact Edition) Database?

Alan is correct when he says there's designer support. Rhywun is incorrect when he implies you cannot choose the foreign key table. What he means is that in the UI the foreign key table drop down is greyed out - all that means is he has not right clicked on the correct table to add the foreign key to.

In summary, right click on the foriegn key table and then via the 'Table Properties' > 'Add Relations' option you select the related primary key table.

I've done it numerous times and it works.

How can I send an email by Java application using GMail, Yahoo, or Hotmail?

This is what I do when i want to send email with attachment, work fine. :)

 public class NewClass {

    public static void main(String[] args) {
        try {
            Properties props = System.getProperties();
            props.put("mail.smtp.starttls.enable", "true");
            props.put("", "");
            props.put("mail.smtp.auth", "true");
            props.put("mail.smtp.port", "465"); // smtp port
            Authenticator auth = new Authenticator() {

                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("username-gmail", "password-gmail");
            Session session = Session.getDefaultInstance(props, auth);
            MimeMessage msg = new MimeMessage(session);
            msg.setFrom(new InternetAddress("[email protected]"));
            msg.setSubject("Try attachment gmail");
            msg.setRecipient(RecipientType.TO, new InternetAddress("[email protected]"));
            //add atleast simple body
            MimeBodyPart body = new MimeBodyPart();
            body.setText("Try attachment");
            //do attachment
            MimeBodyPart attachMent = new MimeBodyPart();
            FileDataSource dataSource = new FileDataSource(new File("file-sent.txt"));
            attachMent.setDataHandler(new DataHandler(dataSource));
            Multipart multipart = new MimeMultipart();
        } catch (AddressException ex) {
            Logger.getLogger(NewClass.class.getName()).log(Level.SEVERE, null, ex);
        } catch (MessagingException ex) {
            Logger.getLogger(NewClass.class.getName()).log(Level.SEVERE, null, ex);


When do you use POST and when do you use GET?

I use POST when I don't want people to see the QueryString or when the QueryString gets large. Also, POST is needed for file uploads.

I don't see a problem using GET though, I use it for simple things where it makes sense to keep things on the QueryString.

Using GET will allow linking to a particular page possible too where POST would not work.

Response.Redirect with POST instead of Get?

The GET (and HEAD) method should never be used to do anything that has side-effects. A side-effect might be updating the state of a web application, or it might be charging your credit card. If an action has side-effects another method (POST) should be used instead.

So, a user (or their browser) shouldn't be held accountable for something done by a GET. If some harmful or expensive side-effect occurred as the result of a GET, that would be the fault of the web application, not the user. According to the spec, a user agent must not automatically follow a redirect unless it is a response to a GET or HEAD request.

Of course, a lot of GET requests do have some side-effects, even if it's just appending to a log file. The important thing is that the application, not the user, should be held responsible for those effects.

The relevant sections of the HTTP spec are 9.1.1 and 9.1.2, and 10.3.

htmlentities() vs. htmlspecialchars()

The differences between htmlspecialchars() and htmlentities() is very small. Lets see some examples:


htmlspecialchars(string $string) takes multiple arguments where as the first argument is a string and all other arguments (certain flags, certain encodings etc. ) are optional. htmlspecialchars converts special characters in the string to HTML entities. For example if you have < br > in your string, htmlspecialchars will convert it into &lt; b &gt;. Whereas characters like µ † etc. have no special significance in HTML. So they will be not converted to HTML entities by htmlspecialchars function as shown in the below example.

echo htmlspecialchars('An example <br>'); // This will print - An example &lt; br &gt;
echo htmlspecialchars('µ †');             // This will print -  µ †


htmlentities ( string $string) is very similar to htmlspecialchars and takes multiple arguments where as the first argument is a string and all other arguments are optional (certain flags, certain encodings etc.). Unlike htmlspecialchars, htmlentities converts not only special characters in the string to HTML entities but all applicable characters to HTML entities.

echo htmlentities('An example <br>'); // This will print - An example &lt; br &gt;
echo htmlentities('µ †');             // This will print -  &micro; &dagger; 

Possible to perform cross-database queries with PostgreSQL?

I have checked and tried to create a foreign key relationships between 2 tables in 2 different databases using both dblink and postgres_fdw but with no result.

Having read the other peoples feedback on this, for example here and here and in some other sources it looks like there is no way to do that currently:

The dblink and postgres_fdw indeed enable one to connect to and query tables in other databases, which is not possible with the standard Postgres, but they do not allow to establish foreign key relationships between tables in different databases.

How to validate an email address in JavaScript

I'd like to add a short note about non-ASCII characters. Rnevius's (and co.) solution is brilliant, but it allows to add Cyrillic, Japanese, Emoticons and other unicode symbols which may be restricted by some servers.

The code below will print true though it contains UTF-8 character ?.

console.log (/^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/.test ('[email protected]'))

In my case all non-ASCII symbols are prohibited so I have modified the original expression to exclude all characters above U+007F:


Maybe this will help someone to prevent undesired behaviour.

How do you move a file?

Check out section 5.14.2. Moving files and folders (or check out "move" in the Index of the help) of the TortoiseSVN help. You do a move via right-dragging. It also mentions that you need to commit from the parent folder to make it "one" revision. This works for doing the change in a working copy.

(Note that the SVN items in the following image will only show up if the destination folder has already been added to the repository.)

tortoise move menu

You can also do the move via the Repo Browser (section 5.23. The Repository Browser of the help).

php execute a background process

Write the process as a server-side script in whatever language (php/bash/perl/etc) is handy and then call it from the process control functions in your php script.

The function probably detects if standard io is used as the output stream and if it is then that will set the return value..if not then it ends

proc_close( proc_open( "./command --foo=1 &", array(), $foo ) );

I tested this quickly from the command line using "sleep 25s" as the command and it worked like a charm.

(Answer found here)

How do you add an image?

Never mind -- I'm an idiot. I just needed <xsl:value-of select="/root/Image/node()"/>

How do you automatically set the focus to a textbox when a web page loads?

Using plain vanilla html and javascript

<input type='text' id='txtMyInputBox' />

<script language='javascript' type='text/javascript'>
function SetFocus()
    // safety check, make sure its a post 1999 browser
    if (!document.getElementById)

    var txtMyInputBoxElement = document.getElementById("txtMyInputBox");

    if (txtMyInputBoxElement != null)

For those out there using the .net framework and 2.0 or above, its trivial. If you are using older versions of the framework, you'd need to write some javascript similar to above.

In your OnLoad handler (generally page_load if you are using the stock page template supplied with visual studio) you can use:


protected void PageLoad(object sender, EventArgs e)


Protected Sub PageLoad(sender as Object, e as EventArgs)


End Sub

(* Note I removed the underscore character from the function name that is generally Page_Load since in a code block it refused to render properly! I could not see in the markup documentation how to get underscores to render unescaped.)

Hope this helps.

SQL: How to get the id of values I just INSERTed?

SELECT @@Scope_Identity as Id

There is also @@identity, but if you have a trigger, it will return the results of something that happened during the trigger, where scope_identity respects your scope.

How do you detect/avoid Memory leaks in your (Unmanaged) code?

At least for MS VC++, the C Runtime library has several functions that I've found helpful in the past. Check the MSDN help for the _Crt* functions.

Get month and year from a datetime in SQL Server 2005

The question is about SQL Server 2005, many of the answers here are for later version SQL Server.

select convert (varchar(7), getdate(),20)
--Typical output 2015-04

SQL Server 2005 does not have date function which was introduced in SQL Server 2008

MySQL Error 1093 - Can't specify target table for update in FROM clause

If you can't do

UPDATE table SET a=value WHERE x IN
    (SELECT x FROM table WHERE condition);

because it is the same table, you can trick and do :

UPDATE table SET a=value WHERE x IN
    (SELECT * FROM (SELECT x FROM table WHERE condition) as t)

[update or delete or whatever]

How do you force Visual Studio to regenerate the .designer files for aspx/ascx files?

There is another possibility: You may have an error in your .aspx file that does not allow Visual Studio to regenerate the designer.

If you switch to Design View, it will show the control as unable to be rendered. Fixing the control (in my case it was an extra quote in the properties) and recompiling should regenerate the designer.

Why does the order in which libraries are linked sometimes cause errors in GCC?

The GNU ld linker is a so-called smart linker. It will keep track of the functions used by preceding static libraries, permanently tossing out those functions that are not used from its lookup tables. The result is that if you link a static library too early, then the functions in that library are no longer available to static libraries later on the link line.

The typical UNIX linker works from left to right, so put all your dependent libraries on the left, and the ones that satisfy those dependencies on the right of the link line. You may find that some libraries depend on others while at the same time other libraries depend on them. This is where it gets complicated. When it comes to circular references, fix your code!

How to parse a string into a nullable int

I felt I should share mine which is a bit more generic.


var result = "123".ParseBy(int.Parse);

var result2 = "123".ParseBy<int>(int.TryParse);


public static class NullableParse
    public static Nullable<T> ParseBy<T>(this string input, Func<string, T> parser)
        where T : struct
            return parser(input);
        catch (Exception exc)
            return null;

    public delegate bool TryParseDelegate<T>(string input, out T result);

    public static Nullable<T> ParseBy<T>(this string input, TryParseDelegate<T> parser)
        where T : struct
        T t;
        if (parser(input, out t)) return t;
        return null;

First version is a slower since it requires a try-catch but it looks cleaner. If it won't be called many times with invalid strings, it is not that important. If performance is an issue, please note that when using TryParse methods, you need to specify the type parameter of ParseBy as it can not be inferred by the compiler. I also had to define a delegate as out keyword can not be used within Func<>, but at least this time compiler does not require an explicit instance.

Finally, you can use it with other structs as well, i.e. decimal, DateTime, Guid, etc.

Safely turning a JSON string into an object

The easiest way using parse() method:

var response = '{"result":true,"count":1}';
var JsonObject= JSON.parse(response);

Then you can get the values of the JSON elements, for example:

var myResponseResult = JsonObject.result;
var myResponseCount = JsonObject.count;

Using jQuery as described in the jQuery.parseJSON() documentation:


Complex CSS selector for parent of active child

I actually ran into the same issue as the original poster. There is a simple solution of just using .parent() jQuery selector. My problem was, I was using .parent instead of .parent(). Stupid mistake I know.

Bind the events (in this case since my tabs are in Modal I needed to bind them with .live instead of a basic .click.

$('#testTab1 .tabLink').live('click', function() {
    $('#modal ul.tabs li').removeClass("current"); //Remove any "current" class
    $(this).parent().addClass("current"); //Add "current" class to selected tab
    $('#modal div#testTab1 .tabContent').hide();
    return false;
$('#testTab2 .tabLink').live('click', function() {
    $('#modal ul.tabs li').removeClass("current"); //Remove any "current" class
    $(this).parent().addClass("current"); //Add "current" class to selected tab
    $('#modal div#testTab2 .tabContent').hide();
    return false;

Here is the HTML..

<div id="tabView1" style="display:none;">
  <!-- start: the code for tabView 1 -->
  <div id="testTab1" style="width:1080px; height:640px; position:relative;">
    <h1 class="Bold_Gray_45px">Modal Header</h1>
    <div class="tabBleed"></div>
    <ul class="tabs">
      <li class="current"> <a href="#" class="tabLink" id="link1">Tab Title Link</a>
        <div class="tabContent" id="tabContent1-1">
          <div class="modalCol">
            <p>Your Tab Content</p>
            <p><a href="#" class="tabShopLink">tabBased Anchor Link</a> </p>
          <div class="tabsImg"> </div>
      <li> <a href="#" class="tabLink" id="link2">Tab Title Link</a>
        <div class="tabContent" id="tabContent1-2">
          <div class="modalCol">
            <p>Your Tab Content</p>
            <p><a href="#" class="tabShopLink">tabBased Anchor Link</a> </p>
          <div class="tabsImg"> </div>

Of course you can repeat that pattern..with more LI's

What is a monad?

In addition to the excellent answers above, let me offer you a link to the following article (by Patrick Thomson) which explains monads by relating the concept to the JavaScript library jQuery (and its way of using "method chaining" to manipulate the DOM): jQuery is a Monad

The jQuery documentation itself doesn't refer to the term "monad" but talks about the "builder pattern" which is probably more familiar. This doesn't change the fact that you have a proper monad there maybe without even realizing it.

Explicit vs implicit SQL joins

@lomaxx: Just to clarify, I'm pretty certain that both above syntax are supported by SQL Serv 2005. The syntax below is NOT supported however

select a.*, b.*  
from table a, table b  
where *=;

Specifically, the outer join (*=) is not supported.

Java Delegates?

While it is nowhere nearly as clean, but you could implement something like C# delegates using a Java Proxy.

C# switch statement limitations - why?

According to the switch statement documentation if there is an unambiguous way to implicitly convert the the object to an integral type, then it will be allowed. I think you are expecting a behavior where for each case statement it would be replaced with if (t == typeof(int)), but that would open a whole can of worms when you get to overload that operator. The behavior would change when implementation details for the switch statement changed if you wrote your == override incorrectly. By reducing the comparisons to integral types and string and those things that can be reduced to integral types (and are intended to) they avoid potential issues.

Can someone explain __all__ in Python?

It also changes what pydoc will show:

a = "A"
b = "B"
c = "C"

__all__ = ['a', 'b']

a = "A"
b = "B"
c = "C"

$ pydoc module1

Help on module module1:



    a = 'A'
    b = 'B'
    c = 'C'

$ pydoc module2

Help on module module2:



    __all__ = ['a', 'b']
    a = 'A'
    b = 'B'

I declare __all__ in all my modules, as well as underscore internal details, these really help when using things you've never used before in live interpreter sessions.

How would you make a comma-separated string from a list of strings?

Here is an example with list

>>> myList = [['Apple'],['Orange']]
>>> myList = ','.join(map(str, [i[0] for i in myList])) 
>>> print "Output:", myList
Output: Apple,Orange

More Accurate:-

>>> myList = [['Apple'],['Orange']]
>>> myList = ','.join(map(str, [type(i) == list and i[0] for i in myList])) 
>>> print "Output:", myList
Output: Apple,Orange

Example 2:-

myList = ['Apple','Orange']
myList = ','.join(map(str, myList)) 
print "Output:", myList
Output: Apple,Orange

VB.NET Empty String Array

Dim array As String() = Array.Empty(Of String)

Reading Email using Pop3 in C#

HigLabo.Mail is easy to use. Here is a sample usage:

using (Pop3Client cl = new Pop3Client()) 
    cl.UserName = "MyUserName"; 
    cl.Password = "MyPassword"; 
    cl.ServerName = "MyServer"; 
    cl.AuthenticateMode = Pop3AuthenticateMode.Pop; 
    cl.Ssl = false; 
    ///Get first mail of my mailbox 
    Pop3Message mg = cl.GetMessage(1); 
    String MyText = mg.BodyText; 
    ///If the message have one attachment 
    Pop3Content ct = mg.Contents[0];         
    ///you can save it to local disk 
    ct.DecodeData("your file path"); 

you can get it from or Nuget [HigLabo]

How do I get the current location of an iframe?

You can use Ra-Ajax and have an iframe wrapped inside e.g. a Window control. Though in general terms I don't encourage people to use iframes (for anything)

Another alternative is to load the HTML on the server and send it directly into the Window as the content of a Label or something. Check out how this Ajax RSS parser is loading the RSS items in the source which can be downloaded here (Open Source - LGPL)

(Disclaimer; I work with Ra-Ajax...)

Differences in string compare methods in C#

In the forms you listed here, there's not much difference between the two. CompareTo ends up calling a CompareInfo method that does a comparison using the current culture; Equals is called by the == operator.

If you consider overloads, then things get different. Compare and == can only use the current culture to compare a string. Equals and String.Compare can take a StringComparison enumeration argument that let you specify culture-insensitive or case-insensitive comparisons. Only String.Compare allows you to specify a CultureInfo and perform comparisons using a culture other than the default culture.

Because of its versatility, I find I use String.Compare more than any other comparison method; it lets me specify exactly what I want.

Extending the User model with custom fields in Django

Note: this answer is deprecated. see other answers if you are using Django 1.7 or later.

This is how I do it.

from django.contrib.auth.models import User
from django.db.models.signals import post_save

class UserProfile(models.Model):  
    user = models.OneToOneField(User)  
    #other fields here

    def __str__(self):  
          return "%s's profile" % self.user  

def create_user_profile(sender, instance, created, **kwargs):  
    if created:  
       profile, created = UserProfile.objects.get_or_create(user=instance)  

post_save.connect(create_user_profile, sender=User) 


This will create a userprofile each time a user is saved if it is created. You can then use


Here is some more info from the docs

Update: Please note that AUTH_PROFILE_MODULE is deprecated since v1.5:

Truncate (not round) decimal places in SQL Server

Here's the way I was able to truncate and not round:

select 100.0019-(100.0019%.001)

returns 100.0010

And your example:

select 123.456-(123.456%.001)

returns 123.450

Now if you want to get rid of the ending zero, simply cast it:

select cast((123.456-(123.456%.001)) as decimal (18,2))

returns 123.45

Changing the default title of confirm() in JavaScript?

You can't unfortunately. The only way is to simulate this with a call.

How to concatenate strings of a string field in a PostgreSQL 'group by' query?

I found this PostgreSQL documentation helpful:

In my case, I sought plain SQL to concatenate a field with brackets around it, if the field is not empty.

select itemid, 
    itemdescription WHEN '' THEN itemname 
    ELSE itemname || ' (' || itemdescription || ')' 
from items;

How SID is different from Service name in Oracle tnsnames.ora

what is a SID and Service name

please look into oracle's documentation at

In case if the above link is not accessable in future, At the time time of writing this answer, the above link will direct you to, "Database Service and Database Instance Identification" topic in Connectivity Concepts chapter of "Database Net Services Administrator's Guide". This guide is published by oracle as part of "Oracle Database Online Documentation, 10g Release 2 (10.2)"

When I have to use one or another? Why do I need two of them?

Consider below mapping in a RAC Environment,

bob1    bob
bob2    bob
bob3    bob
bob4    bob

if load balancing is configured, the listener will 'balance' the workload across all four SIDs. Even if load balancing is configured, you can connect to bob1 all the time if you want to by using the SID instead of SERVICE_NAME.

Please refer,

How to convert a date String to a Date or Calendar object?


LocalDate.parse( "2015-01-02" )


Java 8 and later has a new java.time framework that makes these other answers outmoded. This framework is inspired by Joda-Time, defined by JSR 310, and extended by the ThreeTen-Extra project. See the Tutorial.

The old bundled classes, java.util.Date/.Calendar, are notoriously troublesome and confusing. Avoid them.


Like Joda-Time, java.time has a class LocalDate to represent a date-only value without time-of-day and without time zone.

ISO 8601

If your input string is in the standard ISO 8601 format of yyyy-MM-dd, you can ask that class to directly parse the string with no need to specify a formatter.

The ISO 8601 formats are used by default in java.time, for both parsing and generating string representations of date-time values.

LocalDate localDate = LocalDate.parse( "2015-01-02" );


If you have a different format, specify a formatter from the java.time.format package. You can either specify your own formatting pattern or let java.time automatically localize as appropriate to a Locale specifying a human language for translation and cultural norms for deciding issues such as period versus comma.

Formatting pattern

Read the DateTimeFormatter class doc for details on the codes used in the format pattern. They vary a bit from the old outmoded java.text.SimpleDateFormat class patterns.

Note how the second argument to the parse method is a method reference, syntax added to Java 8 and later.

String input = "January 2, 2015";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern ( "MMMM d, yyyy" , Locale.US );
LocalDate localDate = LocalDate.parse ( input , formatter );

Dump to console.

System.out.println ( "localDate: " + localDate );

localDate: 2015-01-02

Localize automatically

Or rather than specify a formatting pattern, let java.time localize for you. Call DateTimeFormatter.ofLocalizedDate, and be sure to specify the desired/expected Locale rather than rely on the JVM’s current default which can change at any moment during runtime(!).

String input = "January 2, 2015";
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDate ( FormatStyle.LONG );
formatter = formatter.withLocale ( Locale.US );
LocalDate localDate = LocalDate.parse ( input , formatter );

Dump to console.

System.out.println ( "input: " + input + " | localDate: " + localDate );

input: January 2, 2015 | localDate: 2015-01-02

How do I style (css) radio buttons and labels?

For any CSS3-enabled browser you can use an adjacent sibling selector for styling your labels

input:checked + label {
    color: white;

MDN's browser compatibility table says essentially all of the current, popular browsers (Chrome, IE, Firefox, Safari), on both desktop and mobile, are compatible.

How to find the mime type of a file in python?

For byte Array type data you can use magic.from_buffer(_byte_array,mime=True)

Can I write native iPhone apps using Python?

BeeWare is an open source framework for authoring native iOS & Android apps.

Comparing two byte arrays in .NET

Span<T> offers an extremely competitive alternative without having to throw confusing and/or non-portable fluff into your own application's code base:

// byte[] is implicitly convertible to ReadOnlySpan<byte>
static bool ByteArrayCompare(ReadOnlySpan<byte> a1, ReadOnlySpan<byte> a2)
    return a1.SequenceEqual(a2);

The (guts of the) implementation as of .NET 5.0.0 can be found here.

I've revised @EliArbel's gist to add this method as SpansEqual, drop most of the less interesting performers in others' benchmarks, run it with different array sizes, output graphs, and mark SpansEqual as the baseline so that it reports how the different methods compare to SpansEqual.

The below numbers are from the results, lightly edited to remove "Error" column.

|        Method |  ByteCount |               Mean |            StdDev | Ratio | RatioSD |
|-------------- |----------- |-------------------:|------------------:|------:|--------:|
|    SpansEqual |         15 |           4.629 ns |         0.0289 ns |  1.00 |    0.00 |
|  LongPointers |         15 |           4.598 ns |         0.0416 ns |  0.99 |    0.01 |
|      Unrolled |         15 |          18.199 ns |         0.0291 ns |  3.93 |    0.02 |
| PInvokeMemcmp |         15 |           9.872 ns |         0.0441 ns |  2.13 |    0.02 |
|               |            |                    |                   |       |         |
|    SpansEqual |       1026 |          19.965 ns |         0.0880 ns |  1.00 |    0.00 |
|  LongPointers |       1026 |          63.005 ns |         0.5217 ns |  3.16 |    0.04 |
|      Unrolled |       1026 |          38.731 ns |         0.0166 ns |  1.94 |    0.01 |
| PInvokeMemcmp |       1026 |          40.355 ns |         0.0202 ns |  2.02 |    0.01 |
|               |            |                    |                   |       |         |
|    SpansEqual |    1048585 |      43,761.339 ns |        30.8744 ns |  1.00 |    0.00 |
|  LongPointers |    1048585 |      59,585.479 ns |        17.3907 ns |  1.36 |    0.00 |
|      Unrolled |    1048585 |      54,646.243 ns |        35.7638 ns |  1.25 |    0.00 |
| PInvokeMemcmp |    1048585 |      55,198.289 ns |        23.9732 ns |  1.26 |    0.00 |
|               |            |                    |                   |       |         |
|    SpansEqual | 2147483591 | 240,607,692.857 ns | 2,733,489.4894 ns |  1.00 |    0.00 |
|  LongPointers | 2147483591 | 238,223,478.571 ns | 2,033,769.5979 ns |  0.99 |    0.02 |
|      Unrolled | 2147483591 | 236,227,340.000 ns | 2,189,627.0164 ns |  0.98 |    0.00 |
| PInvokeMemcmp | 2147483591 | 238,724,660.000 ns | 3,726,140.4720 ns |  0.99 |    0.02 |

I was surprised to see SpansEqual not come out on top for the max-array-size methods, but the difference is so minor that I don't think it'll ever matter.

My system info:

BenchmarkDotNet=v0.12.1, OS=Windows 10.0.19042
Intel Core i7-6850K CPU 3.60GHz (Skylake), 1 CPU, 12 logical and 6 physical cores
.NET Core SDK=5.0.100
  [Host]     : .NET Core 5.0.0 (CoreCLR, CoreFX, X64 RyuJIT
  DefaultJob : .NET Core 5.0.0 (CoreCLR, CoreFX, X64 RyuJIT

T-SQL stored procedure that accepts multiple Id values

Try This One:

@list_of_params varchar(20) -- value 1, 2, 5, 7, 20 

SELECT d.[Name]
FROM Department d
where @list_of_params like ('%'+ CONVERT(VARCHAR(10),d.Id)  +'%')

very simple.

How do I calculate a trendline for a graph?

This is the way i calculated the slope: Source:

class Program
        public double CalculateTrendlineSlope(List<Point> graph)
            int n = graph.Count;
            double a = 0;
            double b = 0;
            double bx = 0;
            double by = 0;
            double c = 0;
            double d = 0;
            double slope = 0;

            foreach (Point point in graph)
                a += point.x * point.y;
                bx = point.x;
                by = point.y;
                c += Math.Pow(point.x, 2);
                d += point.x;
            a *= n;
            b = bx * by;
            c *= n;
            d = Math.Pow(d, 2);

            slope = (a - b) / (c - d);
            return slope;

    class Point
        public double x;
        public double y;

What are some resources for getting started in operating system development?

There are good resources for operating system fundamentals in books. Since there isn't much call to create new OS's from scratch you won't find a ton of hobbyist type information on the internet.

I recommend the standard text book, "Modern Operating Systems" by Tanenbaum. You may also be able to find "Operating System Elements" by Calingaert useful - it's a thin overview of a book which give a rough sketch of what an OS is from a designer's standpoint.

If you have any interest in real time systems (and you should at least understand the differences and reasons for real time OS's) then I'd also recommend "MicroC/OS-II" by Labrosse.


Can you specify what you mean by "more technical"? These books give pseudo code implementation details, but are you looking for an example OS, or code snippets for a particular machine/language?


Easy way to write contents of a Java InputStream to an OutputStream

Java 9

Since Java 9, InputStream provides a method called transferTo with the following signature:

public long transferTo(OutputStream out) throws IOException

As the documentation states, transferTo will:

Reads all bytes from this input stream and writes the bytes to the given output stream in the order that they are read. On return, this input stream will be at end of stream. This method does not close either stream.

This method may block indefinitely reading from the input stream, or writing to the output stream. The behavior for the case where the input and/or output stream is asynchronously closed, or the thread interrupted during the transfer, is highly input and output stream specific, and therefore not specified

So in order to write contents of a Java InputStream to an OutputStream, you can write:


Algorithm to randomly generate an aesthetically-pleasing color palette

In php:

function pastelColors() {
    $r = dechex(round(((float) rand() / (float) getrandmax()) * 127) + 127);
    $g = dechex(round(((float) rand() / (float) getrandmax()) * 127) + 127);
    $b = dechex(round(((float) rand() / (float) getrandmax()) * 127) + 127);

    return "#" . $r . $g . $b;


How do you get the index of the current iteration of a foreach loop?

This way you can use the index and value using LINQ:

ListValues.Select((x, i) => new { Value = x, Index = i }).ToList().ForEach(element =>
        // element.Index
        // element.Value


How to get the last day of the month?

This is the simplest solution for me using just the standard datetime library:

import datetime

def get_month_end(dt):
    first_of_month = datetime.datetime(dt.year, dt.month, 1)
    next_month_date = first_of_month + datetime.timedelta(days=32)
    new_dt = datetime.datetime(next_month_date.year, next_month_date.month, 1)
    return new_dt - datetime.timedelta(days=1)

Best way to get identity of inserted row?

  • @@IDENTITY returns the last identity value generated for any table in the current session, across all scopes. You need to be careful here, since it's across scopes. You could get a value from a trigger, instead of your current statement.

  • SCOPE_IDENTITY() returns the last identity value generated for any table in the current session and the current scope. Generally what you want to use.

  • IDENT_CURRENT('tableName') returns the last identity value generated for a specific table in any session and any scope. This lets you specify which table you want the value from, in case the two above aren't quite what you need (very rare). Also, as @Guy Starbuck mentioned, "You could use this if you want to get the current IDENTITY value for a table that you have not inserted a record into."

  • The OUTPUT clause of the INSERT statement will let you access every row that was inserted via that statement. Since it's scoped to the specific statement, it's more straightforward than the other functions above. However, it's a little more verbose (you'll need to insert into a table variable/temp table and then query that) and it gives results even in an error scenario where the statement is rolled back. That said, if your query uses a parallel execution plan, this is the only guaranteed method for getting the identity (short of turning off parallelism). However, it is executed before triggers and cannot be used to return trigger-generated values.

How do you rotate a two dimensional array?

private static int[][] rotate(int[][] matrix, int n) {
    int[][] rotated = new int[n][n];
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            rotated[i][j] = matrix[n-j-1][i];
    return rotated;

How do you get the footer to stay at the bottom of a Web page?

Since the Grid solution hasn't been presented yet, here it is, with just two declarations for the parent element, if we take the height: 100% and margin: 0 for granted:

html, body {height: 100%}_x000D_
body {_x000D_
  display: grid; /* generates a block-level grid */_x000D_
  align-content: space-between; /* places an even amount of space between each grid item, with no space at the far ends */_x000D_
  margin: 0;_x000D_
.content {_x000D_
  background: lightgreen;_x000D_
  /* demo / for default snippet window */_x000D_
  height: 1em;_x000D_
  animation: height 2.5s linear alternate infinite;_x000D_
footer {background: lightblue}_x000D_
@keyframes height {to {height: 250px}}
<div class="content">Content</div>_x000D_

The items are evenly distributed within the alignment container along the cross axis. The spacing between each pair of adjacent items is the same. The first item is flush with the main-start edge, and the last item is flush with the main-end edge.

function declaration isn't a prototype

In C int foo() and int foo(void) are different functions. int foo() accepts an arbitrary number of arguments, while int foo(void) accepts 0 arguments. In C++ they mean the same thing. I suggest that you use void consistently when you mean no arguments.

If you have a variable a, extern int a; is a way to tell the compiler that a is a symbol that might be present in a different translation unit (C compiler speak for source file), don't resolve it until link time. On the other hand, symbols which are function names are anyway resolved at link time. The meaning of a storage class specifier on a function (extern, static) only affects its visibility and extern is the default, so extern is actually unnecessary.

I suggest removing the extern, it is extraneous and is usually omitted.

How do I handle newlines in JSON?

You could just escape your string on the server when writing the value of the JSON field and unescape it when retrieving the value in the client browser, for instance.

The JavaScript implementation of all major browsers have the unescape command.


On the server:

response.write "{""field1"":""" & escape(RS_Temp("textField")) & """}"

In the browser:

document.getElementById("text1").value = unescape(jsonObject.field1)

How do I get the difference between two Dates in JavaScript?


var startTime=("08:00:00").split(":");
var endTime=("16:00:00").split(":");
var HoursInMinutes=((parseInt(endTime[0])*60)+parseInt(endTime[1]))-((parseInt(startTime[0])*60)+parseInt(startTime[1]));

How do I download code using SVN/Tortoise from Google Code?

Select Tortoise SVN - > Settings - > NetWork

Fill the required proxy if any and then check.

How do you properly use namespaces in C++?

Bigger C++ projects I've seen hardly used more than one namespace (e.g. boost library).

Actually boost uses tons of namespaces, typically every part of boost has its own namespace for the inner workings and then may put only the public interface in the top-level namespace boost.

Personally I think that the larger a code-base becomes, the more important namespaces become, even within a single application (or library). At work we put each module of our application in its own namespace.

Another use (no pun intended) of namespaces that I use a lot is the anonymous namespace:

namespace {
  const int CONSTANT = 42;

This is basically the same as:

static const int CONSTANT = 42;

Using an anonymous namespace (instead of static) is however the recommended way for code and data to be visible only within the current compilation unit in C++.

Use of var keyword in C#

Stolen from the post on this issue at CodingHorror:

Unfortunately, you and everyone else pretty much got it wrong. While I agree with you that redundancy is not a good thing, the better way to solve this issue would have been to do something like the following:

MyObject m = new();

Or if you are passing parameters:

Person p = new("FirstName", "LastName);

Where in the creation of a new object, the compiler infers the type from the left-hand side, and not the right. This has other advantages over "var", in that it could be used in field declarations as well (there are also some other areas that it could be useful as well, but I won't get into it here).

In the end, it just wasn't intended to reduce redundancy. Don't get me wrong, "var" is VERY important in C# for anonymous types/projections, but the use here is just WAY off (and I've been saying this for a long, long time) as you obfuscate the type that is being used. Having to type it twice is too often, but declaring it zero times is too few.

Nicholas Paldino .NET/C# MVP on June 20, 2008 08:00 AM

I guess if your main concern is to have to type less -- then there isn't any argument that's going to sway you from using it.

If you are only going to ever be the person who looks at your code, then who cares? Otherwise, in a case like this:

var people = Managers.People

it's fine, but in a case like this:

var fc = Factory.Run();

it short circuits any immediate type deductions my brain could begin forming from the 'English' of the code.

Otherwise, just use your best judgment and programming 'courtesy' towards others who might have to work on your project.

How can I add reflection to a C++ application?

There are two kinds of reflection swimming around.

  1. Inspection by iterating over members of a type, enumerating its methods and so on.

    This is not possible with C++.
  2. Inspection by checking whether a class-type (class, struct, union) has a method or nested type, is derived from another particular type.

    This kind of thing is possible with C++ using template-tricks. Use boost::type_traits for many things (like checking whether a type is integral). For checking for the existance of a member function, use Is it possible to write a template to check for a function's existence? . For checking whether a certain nested type exists, use plain SFINAE .

If you are rather looking for ways to accomplish 1), like looking how many methods a class has, or like getting the string representation of a class id, then i'm afraid there is no Standard C++ way of doing this. You have to use either

  • A Meta Compiler like the Qt Meta Object Compiler which translates your code adding additional meta informations.
  • A Framework constisting of macros that allow you to add the required meta-informations. You would need to tell the framework all methods, the class-names, base-classes and everything it needs.

C++ is made with speed in mind. If you want high-level inspection, like C# or Java has, then I'm afraid i have to tell you there is no way without some effort.

I get a "An attempt was made to load a program with an incorrect format" error on a SQL Server replication project

We recently had the issue when trying to run the code from Visual Studio. In that case you need to do
TOOLS > OPTIONS > Projects and Solutions > WEB PROJECTS and check the "Use the 64 bit version of IIS Express for web sites and projects".

Checking if a list is empty with LINQ

I would make one small addition to the code you seem to have settled on: check also for ICollection, as this is implemented even by some non-obsolete generic classes as well (i.e., Queue<T> and Stack<T>). I would also use as instead of is as it's more idiomatic and has been shown to be faster.

public static bool IsEmpty<T>(this IEnumerable<T> list)
    if (list == null)
        throw new ArgumentNullException("list");

    var genericCollection = list as ICollection<T>;
    if (genericCollection != null)
        return genericCollection.Count == 0;

    var nonGenericCollection = list as ICollection;
    if (nonGenericCollection != null)
        return nonGenericCollection.Count == 0;

    return !list.Any();

Dynamic LINQ OrderBy on IEnumerable<T> / IQueryable<T>

Just stumbled across this question.

Using Marc's ApplyOrder implementation from above, I slapped together an Extension method that handles SQL-like strings like:

list.OrderBy("MyProperty DESC, MyOtherProperty ASC");

Details can be found here:

Java and SQLite

I understand you asked specifically about SQLite, but maybe HSQL database would be a better fit with Java. It is written in Java itself, runs in the JVM, supports in-memory tables etc. and all that features make it quite usable for prototyping and unit-testing.

WCF Service Returning "Method Not Allowed"

I've been having this same problem for over a day now - finally figured it out. Thanks to @Sameh for the hint.

Your service is probably working just fine. Testing POST messages using the address bar of a browser won't work. You need to use Fiddler to test a POST message.

Fiddler instructions...

How to generate a random alpha-numeric string

There are lots of use of StringBuilder in previous answers. I guess it's easy, but it requires a function call per character, growing an array, etc...

If using the stringbuilder, a suggestion is to specify the required capacity of the string, i.e.,

new StringBuilder(int capacity);

Here's a version that doesn't use a StringBuilder or String appending, and no dictionary.

public static String randomString(int length)
    SecureRandom random = new SecureRandom();
    char[] chars = new char[length];
    for(int i=0; i<chars.length; i++)
        int v = random.nextInt(10 + 26 + 26);
        char c;
        if (v < 10)
            c = (char)('0' + v);
        else if (v < 36)
            c = (char)('a' - 10 + v);
            c = (char)('A' - 36 + v);
        chars[i] = c;
    return new String(chars);

Find in Files: Search all code in Team Foundation Server

There is currently no way to do this out of the box, but there is a User Voice suggestion for adding it:

While I doubt it is as simple as flipping a switch, if everyone that has viewed this question voted for it, MS would probably implement something.

Update: Just read Brian Harry's blog, which shows this request as being on their radar, and the Online version of Visual Studio has limited support for searching where git is used as the vcs: From this I think it's fair to say it is just a matter of time...

Update 2: There is now a Microsoft provided extension,Code Search which enables searching in code as well as in work items.

How to Automatically Start a Download in PHP?

Here is an example of sending back a pdf.

header('Content-type: application/pdf');
header('Content-Disposition: attachment; filename="' . basename($filename) . '"');
header('Content-Transfer-Encoding: binary');

@Swish I didn't find application/force-download content type to do anything different (tested in IE and Firefox). Is there a reason for not sending back the actual MIME type?

Also in the PHP manual Hayley Watson posted:

If you wish to force a file to be downloaded and saved, instead of being rendered, remember that there is no such MIME type as "application/force-download". The correct type to use in this situation is "application/octet-stream", and using anything else is merely relying on the fact that clients are supposed to ignore unrecognised MIME types and use "application/octet-stream" instead (reference: Sections 4.1.4 and 4.5.1 of RFC 2046).

Also according IANA there is no registered application/force-download type.

Execute a large SQL script (with GO commands)

I had the same problem in java and I solved it with a bit of logic and regex. I believe the same logic can be applied.First I read from the slq file into memory. Then I apply the following logic. It's pretty much what has been said before however I believe that using regex word bound is safer than expecting a new line char.

String pattern = "\\bGO\\b|\\bgo\\b";

String[] splitedSql = sql.split(pattern);
for (String chunk : splitedSql) {

This basically splits the sql string into an array of sql strings. The regex is basically to detect full 'go' words either lower case or upper case. Then you execute the different querys sequentially.

How should I cast in VB.NET?

Those are all slightly different, and generally have an acceptable usage.

  • var.ToString() is going to give you the string representation of an object, regardless of what type it is. Use this if var is not a string already.
  • CStr(var) is the VB string cast operator. I'm not a VB guy, so I would suggest avoiding it, but it's not really going to hurt anything. I think it is basically the same as CType.
  • CType(var, String) will convert the given type into a string, using any provided conversion operators.
  • DirectCast(var, String) is used to up-cast an object into a string. If you know that an object variable is, in fact, a string, use this. This is the same as (string)var in C#.
  • TryCast (as mentioned by @NotMyself) is like DirectCast, but it will return Nothing if the variable can't be converted into a string, rather than throwing an exception. This is the same as var as string in C#. The TryCast page on MSDN has a good comparison, too.

What is the best way to give a C# auto-property an initial value?

Have you tried using the DefaultValueAttribute or ShouldSerialize and Reset methods in conjunction with the constructor? I feel like one of these two methods is necessary if you're making a class that might show up on the designer surface or in a property grid.

How do I size a UITextView to its content?

The Best way which I found out to re-size the height of the UITextView according to the size of the text.

CGSize textViewSize = [YOURTEXTVIEW.text sizeWithFont:[UIFont fontWithName:@"SAMPLE_FONT" size:14.0]
                       constrainedToSize:CGSizeMake(YOURTEXTVIEW.frame.size.width, FLT_MAX)];

or You can USE

CGSize textViewSize = [YOURTEXTVIEW.text sizeWithFont:[UIFont fontWithName:@"SAMPLE_FONT" size:14.0]
                       constrainedToSize:CGSizeMake(YOURTEXTVIEW.frame.size.width, FLT_MAX) lineBreakMode:NSLineBreakByTruncatingTail];

How to show all shared libraries used by executables in Linux?

On UNIX system, suppose binary (executable) name is test. Then we use the following command to list the libraries used in the test is

ldd test

Comparing two collections for equality irrespective of the order of items in them

There are many solutions to this problem. If you don't care about duplicates, you don't have to sort both. First make sure that they have the same number of items. After that sort one of the collections. Then binsearch each item from the second collection in the sorted collection. If you don't find a given item stop and return false. The complexity of this: - sorting the first collection: NLog(N) - searching each item from second into the first: NLOG(N) so you end up with 2*N*LOG(N) assuming that they match and you look up everything. This is similar to the complexity of sorting both. Also this gives you the benefit to stop earlier if there's a difference. However, keep in mind that if both are sorted before you step into this comparison and you try sorting by use something like a qsort, the sorting will be more expensive. There are optimizations for this. Another alternative, which is great for small collections where you know the range of the elements is to use a bitmask index. This will give you a O(n) performance. Another alternative is to use a hash and look it up. For small collections it is usually a lot better to do the sorting or the bitmask index. Hashtable have the disadvantage of worse locality so keep that in mind. Again, that's only if you don't care about duplicates. If you want to account for duplicates go with sorting both.

How to pass password to scp?

  1. Make sure password authentication is enabled on the target server. If it runs Ubuntu, then open /etc/ssh/sshd_config on the server, find lines PasswordAuthentication=no and comment all them out (put # at the start of the line), save the file and run sudo systemctl restart ssh to apply the configuration. If there is no such line then you're done.
  2. Add -o PreferredAuthentications="password" to your scp command, e.g.:
    scp -o PreferredAuthentications="password" /path/to/file user@server:/destination/directory

Count a list of cells with the same background color

Yes VBA is the way to go.

But, if you don't need to have a cell with formula that auto-counts/updates the number of cells with a particular colour, an alternative is simply to use the 'Find and Replace' function and format the cell to have the appropriate colour fill.

Hitting 'Find All' will give you the total number of cells found at the bottom left of the dialogue box.

enter image description here

This becomes especially useful if your search range is massive. The VBA script will be very slow but the 'Find and Replace' function will still be very quick.

What is the difference between UNION and UNION ALL?

I add an example,

UNION, it is merging with distinct --> slower, because it need comparing (In Oracle SQL developer, choose query, press F10 to see cost analysis).

UNION ALL, it is merging without distinct --> faster.

SELECT to_date(sysdate, 'yyyy-mm-dd') FROM dual
SELECT to_date(sysdate, 'yyyy-mm-dd') FROM dual;


SELECT to_date(sysdate, 'yyyy-mm-dd') FROM dual
SELECT to_date(sysdate, 'yyyy-mm-dd') FROM dual;

How do we control web page caching, across all browsers?

you can use location block for set individual file instead of whole app get caching in IIS

 <location path="index.html">
          <add name="Cache-Control" value="no-cache" />

Git ignore file for Xcode projects

Here's the .gitignore that GitHub uses by default for new Xcode repositories:

It's likely to be reasonably correct at any given time.

How do I export (and then import) a Subversion repository?

If you do not have file access to the repository, I prefer rsvndump (remote Subversion repository dump) to make the dump file.

How do I create a MessageBox in C#?

Also you can use a MessageBox with OKCancel options, but it requires many codes. The if block is for OK, the else block is for Cancel. Here is the code:

if (MessageBox.Show("Are you sure you want to do this?", "Question", MessageBoxButtons.OKCancel, MessageBoxIcon.Question) == DialogResult.OK)
    MessageBox.Show("You pressed OK!");
    MessageBox.Show("You pressed Cancel!");

You can also use a MessageBox with YesNo options:

if (MessageBox.Show("Are you sure want to doing this?", "Question", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
    MessageBox.Show("You are pressed Yes!");
    MessageBox.Show("You are pressed No!");

How can I make an EXE file from a Python program?


py2exe is a Python Distutils extension which converts Python scripts into executable Windows programs, able to run without requiring a Python installation.

How do I write a for loop in bash

if you're intereased only in bash the "for(( ... ))" solution presented above is the best, but if you want something POSIX SH compliant that will work on all unices you'll have to use "expr" and "while", and that's because "(())" or "seq" or "i=i+1" are not that portable among various shells

Prefer composition over inheritance?

Prefer composition over inheritance as it is more malleable / easy to modify later, but do not use a compose-always approach. With composition, it's easy to change behavior on the fly with Dependency Injection / Setters. Inheritance is more rigid as most languages do not allow you to derive from more than one type. So the goose is more or less cooked once you derive from TypeA.

My acid test for the above is:

  • Does TypeB want to expose the complete interface (all public methods no less) of TypeA such that TypeB can be used where TypeA is expected? Indicates Inheritance.

    • e.g. A Cessna biplane will expose the complete interface of an airplane, if not more. So that makes it fit to derive from Airplane.
  • Does TypeB want only some/part of the behavior exposed by TypeA? Indicates need for Composition.

    • e.g. A Bird may need only the fly behavior of an Airplane. In this case, it makes sense to extract it out as an interface / class / both and make it a member of both classes.

Update: Just came back to my answer and it seems now that it is incomplete without a specific mention of Barbara Liskov's Liskov Substitution Principle as a test for 'Should I be inheriting from this type?'

How do I implement a callback in PHP?

Implementation of a callback is done like so

// This function uses a callback function. 
function doIt($callback) 
    $data = "this is my data";

// This is a sample callback function for doIt(). 
function myCallback($data) 
    print 'Data is: ' .  $data .  "\n"; 

// Call doIt() and pass our sample callback function's name. 

Displays: Data is: this is my data

How do I list loaded plugins in Vim?

:set runtimepath?

This lists the path of all plugins loaded when a file is opened with Vim.

How do I create a foreign key in SQL Server?

I always use this syntax to create the foreign key constraint between 2 tables

Alter Table ForeignKeyTable
Add constraint `ForeignKeyTable_ForeignKeyColumn_FK`
`Foreign key (ForeignKeyColumn)` references `PrimaryKeyTable (PrimaryKeyColumn)`


Alter Table tblEmployee
Add constraint tblEmployee_DepartmentID_FK
foreign key (DepartmentID) references tblDepartment (ID)

How do I position one image on top of another in HTML?

This is a barebones look at what I've done to float one image over another.

img {_x000D_
  position: absolute;_x000D_
  top: 25px;_x000D_
  left: 25px;_x000D_
.imgA1 {_x000D_
  z-index: 1;_x000D_
.imgB1 {_x000D_
  z-index: 3;_x000D_
<img class="imgA1" src="">_x000D_
<img class="imgB1" src="">


Getting the ID of the element that fired an event

You can use (this) to reference the object that fired the function.

'this' is a DOM element when you are inside of a callback function (in the context of jQuery), for example, being called by the click, each, bind, etc. methods.

Here is where you can learn more:

How can you find out which process is listening on a TCP or UDP port on Windows?

netstat -ao and netstat -ab tell you the application, but if you're not a system administrator you'll get "The requested operation requires elevation".

It's not ideal, but if you use Sysinternals' Process Explorer you can go to specific processes' properties and look at the TCP tab to see if they're using the port you're interested in. It is a bit of a needle and haystack thing, but maybe it'll help someone...

Generating (pseudo)random alpha-numeric strings

First list the desired characters

$chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';

Use the str_shuffle($string) function. This function will provide you a randomly shuffled string.

$alpha=substr(str_shuffle($chars), 0, 50);

50 is the Length of string.

Select N random elements from a List<T> in C#

From Dragons in the Algorithm, an interpretation in C#:

int k = 10; // items to select
var items = new List<int>(new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 });
var selected = new List<int>();
double needed = k;
double available = items.Count;
var rand = new Random();
while (selected.Count < k) {
   if( rand.NextDouble() < needed / available ) {

This algorithm will select unique indicies of the items list.

How do you set, clear, and toggle a single bit?

This program is to change any data bit from 0 to 1 or 1 to 0:

    unsigned int data = 0x000000F0;
    int bitpos = 4;
    int bitvalue = 1;
    unsigned int bit = data;
    bit = (bit>>bitpos)&0x00000001;
    int invbitvalue = 0x00000001&(~bitvalue);

    if (bitvalue == 0)
        if (bit == 0)
            printf("%x\n", data);
             data = (data^(invbitvalue<<bitpos));
             printf("%x\n", data);
        if (bit == 1)
            printf("elseif %x\n", data);
            data = (data|(bitvalue<<bitpos));
            printf("else %x\n", data);

round() doesn't seem to be rounding properly

Another potential option is:

def hard_round(number, decimal_places=0):
    - Rounds a float value to a specified number of decimal places
    - Fixes issues with floating point binary approximation rounding in python
    - `number`:
        - Type: int|float
        - What: The number to round
    - `decimal_places`:
        - Type: int 
        - What: The number of decimal places to round to
        - Default: 0
    return int(number*(10**decimal_places)+0.5)/(10**decimal_places)

Objective-C for Windows

You can get an objective c compiler that will work with Windows and play nice with Visual Studio 2008\2010 here.

open-c flite

Just download the latest source. You don't need to build all of CF-Lite there is a solution called objc.sln. You will need to fix a few of the include paths but then it will build just fine. There is even a test project included so you can see some objective-c .m files being compiled and working in visual studio. One sad thing is it only works with Win32 not x64. There is some assembly code that would need to be written for x64 for it to support that.

How do you clear the SQL Server transaction log?

Here is a simple and very inelegant & potentially dangerous way.

  1. Backup DB
  2. Detach DB
  3. Rename Log file
  4. Attach DB
  5. New log file will be recreated
  6. Delete Renamed Log file.

I'm guessing that you are not doing log backups. (Which truncate the log). My advice is to change recovery model from full to simple. This will prevent log bloat.

How to convert a string to a date in sybase

102 is the rule of thumb, convert (varchar, creat_tms, 102) > '2011'

Can I run a 64-bit VMware image on a 32-bit machine?

I honestly doubt it, for a number of reasons, but the most important one is that there are some instructions that are allowed in 32-bit mode, but not in 64-bit mode. Specifically, the REX prefix that is used to encode some instructions and registers in 64-bit mode is a byte of the form 0x4f:0x40, but in 32 bit mode the same byte is either INC or DEC with a fixed operand.
Because of this, any 64-bit instruction that is prefixed by REX will be interpreted as either INC or DEC, and won't give the VMM the chance to emulate the 64-bit instruction (for instance by signaling an undefined opcode exception).

The only way it might be done is to use a trap exception to return to the VMM after each and every instruction so that it can see if it needs special 64-bit handling. I simply can't see that happening.