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Remove columns from DataTable in C#

To remove all columns after the one you want, below code should work. It will remove at index 10 (remember Columns are 0 based), until the Column count is 10 or less.

DataTable dt;
int desiredSize = 10;

while (dt.Columns.Count > desiredSize)

What datatype should be used for storing phone numbers in SQL Server 2005?

We use varchar(15) and certainly index on that field.

The reason being is that International standards can support up to 15 digits

Wikipedia - Telephone Number Formats

If you do support International numbers, I recommend the separate storage of a World Zone Code or Country Code to better filter queries by so that you do not find yourself parsing and checking the length of your phone number fields to limit the returned calls to USA for example

Is there a PowerShell "string does not contain" cmdlet or syntax?

If $arrayofStringsNotInterestedIn is an [array] you should use -notcontains:

Get-Content $FileName | foreach-object { `
   if ($arrayofStringsNotInterestedIn -notcontains $_) { $) }

or better (IMO)

Get-Content $FileName | where { $arrayofStringsNotInterestedIn -notcontains $_}

Any tools to generate an XSD schema from an XML instance document?

There also is XML schema learner which is available on Github.

It can take multiple xml files and extract a common XSD from all of those files.

Bash or KornShell (ksh)?

Bash is the benchmark, but that's mostly because you can be reasonably sure it's installed on every *nix out there. If you're planning to distribute the scripts, use Bash.

I can not really address the actual programming differences between the shells, unfortunately.

How to run a script as root on Mac OS X?

As in any unix-based environment, you can use the sudo command:

$ sudo script-name

It will ask for your password (your own, not a separate root password).

How do I check CPU and Memory Usage in Java?

If you use the runtime/totalMemory solution that has been posted in many answers here (I've done that a lot), be sure to force two garbage collections first if you want fairly accurate/consistent results.

For effiency Java usually allows garbage to fill up all of memory before forcing a GC, and even then it's not usually a complete GC, so your results for runtime.freeMemory() always be somewhere between the "real" amount of free memory and 0.

The first GC doesn't get everything, it gets most of it.

The upswing is that if you just do the freeMemory() call you will get a number that is absolutely useless and varies widely, but if do 2 gc's first it is a very reliable gauge. It also makes the routine MUCH slower (seconds, possibly).

How do you force a CIFS connection to unmount

On RHEL 6 this worked for me also:

umount -f -a -t cifs -l FOLDER_NAME

How to convert DateTime to VarChar

This is how I do it: CONVERT(NVARCHAR(10), DATE1, 103) )

How to do INSERT into a table records extracted from another table

Remove "values" when you're appending a group of rows, and remove the extra parentheses. You can avoid the circular reference by using an alias for avg(CurrencyColumn) (as you did in your example) or by not using an alias at all.

If the column names are the same in both tables, your query would be like this:

INSERT INTO Table2 (LongIntColumn, Junk)
SELECT LongIntColumn, avg(CurrencyColumn) as CurrencyColumn1
FROM Table1
GROUP BY LongIntColumn;

And it would work without an alias:

INSERT INTO Table2 (LongIntColumn, Junk)
SELECT LongIntColumn, avg(CurrencyColumn)
FROM Table1
GROUP BY LongIntColumn;

How to convert numbers between hexadecimal and decimal

Hex -> decimal:

Convert.ToInt64(hexValue, 16);

Decimal -> Hex

string.format("{0:x}", decValue);

What is the difference between explicit and implicit cursors in Oracle?

1.CURSOR: When PLSQL issues sql statements it creates private work area to parse & execute the sql statement is called cursor.

2.IMPLICIT: When any PL/SQLexecutable block issues sql statement. PL/SQL creates implicit cursor and manages automatically means implcit open & close takes place. It used when sql statement return only one row.It has 4 attributes SQL%ROWCOUNT, SQL%FOUND, SQL%NOTFOUND, SQL%ISOPEN.

3.EXPLICIT: It is created & managed by the programmer. It needs every time explicit open,fetch & close. It is used when sql statement returns more than one row. It has also 4 attributes CUR_NAME%ROWCOUNT, CUR_NAME%FOUND, CUR_NAME%NOTFOUND, CUR_NAME%ISOPEN. It process several rows by using loop. The programmer can pass the parameter too to explicit cursor.

  • Example: Explicit Cursor


   cursor emp_cursor 
   select id,name,salary,dept_id 
   from employees; 
   v_salary employees.salary%type; 
   v_dept_id employees.dept_id%type; 
   open emp_cursor; 
   fetch emp_cursor into v_id,v_name,v_salary,v_dept_id; 
   exit when emp_cursor%notfound;
   dbms_output.put_line(v_id||', '||v_name||', '||v_salary||','||v_dept_id); 
   end loop;                    
   close emp_cursor; 

Dropdownlist width in IE

We have the same thing on an asp:dropdownlist:

In Firefox(3.0.5) the dropdown is the width of the longest item in the dropdown, which is like 600 pixels wide or something like that.

String vs. StringBuilder

My approach has always been to use StringBuilder when concatenating 4 or more strings OR When I don't know how may concatenations are to take place.

Good performance related article on it here

Iterating through all the cells in Excel VBA or VSTO 2005

There are several methods to accomplish this, each of which has advantages and disadvantages; First and foremost, you're going to need to have an instance of a Worksheet object, Application.ActiveSheet works if you just want the one the user is looking at.

The Worksheet object has three properties that can be used to access cell data (Cells, Rows, Columns) and a method that can be used to obtain a block of cell data, (get_Range).

Ranges can be resized and such, but you may need to use the properties mentioned above to find out where the boundaries of your data are. The advantage to a Range becomes apparent when you are working with large amounts of data because VSTO add-ins are hosted outside the boundaries of the Excel application itself, so all calls to Excel have to be passed through a layer with overhead; obtaining a Range allows you to get/set all of the data you want in one call which can have huge performance benefits, but it requires you to use explicit details rather than iterating through each entry.

This MSDN forum post shows a VB.Net developer asking a question about getting the results of a Range as an array

What is the dual table in Oracle?

It is a dummy table with one element in it. It is useful because Oracle doesn't allow statements like


You can work around this restriction by writing



How can I start an interactive console for Perl?

Perl doesn't have a console but the debugger can be used as one. At a command prompt, type perl -de 1. (The value "1" doesn't matter, it's just a valid statement that does nothing.)

There are also a couple of options for a Perl shell.

For more information read perlfaq3.

How to terminate a Python script

Another way is:

raise SystemExit

How to duplicate a whole line in Vim?

Default is yyp, but I've been using this rebinding for a year or so and love it:

" set Y to duplicate lines, works in visual mode as well. nnoremap Y yyp vnoremap Y y`>pgv

How do I sort a list of dictionaries by a value of the dictionary?

import operator

'key' is used to sort by an arbitrary value and 'itemgetter' sets that value to each item's 'name' attribute.

How to do relative imports in Python?

From Python doc,

In Python 2.5, you can switch import‘s behaviour to absolute imports using a from __future__ import absolute_import directive. This absolute- import behaviour will become the default in a future version (probably Python 2.7). Once absolute imports are the default, import string will always find the standard library’s version. It’s suggested that users should begin using absolute imports as much as possible, so it’s preferable to begin writing from pkg import string in your code

How do I capitalize first letter of first name and last name in C#?

Like edg indicated, you'll need a more complex algorithm to handle special names (this is probably why many places force everything to upper case).

Something like this untested c# should handle the simple case you requested:

public string SentenceCase(string input)
    return input(0, 1).ToUpper + input.Substring(1).ToLower;

How do you detect Credit card type based on number?

My solution with jQuery:

function detectCreditCardType() {
    var type = new Array;
    type[1] = '^4[0-9]{12}(?:[0-9]{3})?$';      // visa
    type[2] = '^5[1-5][0-9]{14}$';              // mastercard
    type[3] = '^6(?:011|5[0-9]{2})[0-9]{12}$';  // discover
    type[4] = '^3[47][0-9]{13}$';               // amex

    var ccnum = $('.creditcard').val().replace(/[^\d.]/g, '');
    var returntype = 0;

    $.each(type, function(idx, re) {
        var regex = new RegExp(re);
        if(regex.test(ccnum) && idx>0) {
            returntype = idx;

    return returntype;

In case 0 is returned, credit card type is undetected.

"creditcard" class should be added to the credit card input field.

Accessing Websites through a Different Port?

You can use ssh to forward ports onto somewhere else.

If you have two computers, one you browse from, and one which is free to access websites, and is not logged (ie. you own it and it's sitting at home), then you can set up a tunnel between them to forward http traffic over.

For example, I connect to my home computer from work using ssh, with port forwarding, like this:

ssh -L 22222:<target_website>:80 <home_computer>

Then I can point my browser to


And this request will be forwarded over ssh. Since the work computer is first contacting the home computer, and then contacting the target website, it will be hard to log.

However, this is all getting into 'how to bypass web proxies' and the like, and I suggest you create a new question asking what exactly you want to do.

Ie. "How do I bypass web proxies to avoid my traffic being logged?"

How often should Oracle database statistics be run?

At my last job we ran statistics once a week. If I remember correctly, we scheduled them on a Thursday night, and on Friday the DBAs were very careful to monitor the longest running queries for anything unexpected. (Friday was picked because it was often just after a code release, and tended to be a fairly low traffic day.) When they saw a bad query they would find a better query plan and save that one so it wouldn't change again unexpectedly. (Oracle has tools to do this for you automatically, you tell it the query to optimize and it does.)

Many organizations avoid running statistics out of fear of bad query plans popping up unexpectedly. But this usually means that their query plans get worse and worse over time. And when they do run statistics then they encounter a number of problems. The resulting scramble to fix those issues confirms their fears about the dangers of running statistics. But if they ran statistics regularly, used the monitoring tools as they are supposed to, and fixed issues as they came up then they would have fewer headaches, and they wouldn't encounter them all at once.

How do I migrate an SVN repository with history to a new Git repository?

I just wanted to add my contribution to the Git community. I wrote a simple bash script which automates the full import. Unlike other migration tools, this tool relies on native git instead of jGit. This tool also supports repositories with a large revision history and or large blobs. It's available via github:

This script will convert projects stored in SVN with the following format:


This scheme is also popular and supported as well:


Each project will get synchronized over by project name:

Ex: ./migration project1

If you wish to convert the full repo over, use the following syntax:

Ex: ./migration .

Create Generic method constraining T to an Enum

Just for completeness, the following is a Java solution. I am certain the same could be done in C# as well. It avoids having to specify the type anywhere in code - instead, you specify it in the strings you are trying to parse.

The problem is that there isn't any way to know which enumeration the String might match - so the answer is to solve that problem.

Instead of accepting just the string value, accept a String that has both the enumeration and the value in the form "enumeration.value". Working code is below - requires Java 1.8 or later. This would also make the XML more precise as in you would see something like color="" instead of just color="red".

You would call the acceptEnumeratedValue() method with a string containing the enum name dot value name.

The method returns the formal enumerated value.

import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

public class EnumFromString {

    enum NumberEnum {One, Two, Three};
    enum LetterEnum {A, B, C};

    Map<String, Function<String, ? extends Enum>> enumsByName = new HashMap<>();

    public static void main(String[] args) {
        EnumFromString efs = new EnumFromString();

        System.out.print("\nFirst string is NumberEnum.Two - enum is " + efs.acceptEnumeratedValue("NumberEnum.Two").name());
        System.out.print("\nSecond string is LetterEnum.B - enum is " + efs.acceptEnumeratedValue("LetterEnum.B").name());


    public EnumFromString() {
        enumsByName.put("NumberEnum", s -> {return NumberEnum.valueOf(s);});
        enumsByName.put("LetterEnum", s -> {return LetterEnum.valueOf(s);});

    public Enum acceptEnumeratedValue(String enumDotValue) {

        int pos = enumDotValue.indexOf(".");

        String enumName = enumDotValue.substring(0, pos);
        String value = enumDotValue.substring(pos + 1);

        Enum enumeratedValue = enumsByName.get(enumName).apply(value);

        return enumeratedValue;


Is there a C++ gdb GUI for Linux?

Have you tried gdb -w with cygwin gdb. It is supossed to have a windows interface which works fairly well.

The only problem I found is that on my present machine it didn't run that way until after I installed ddd. I suspect that it requires tcltk which was installed when I installed ddd.

How do I programmatically set the value of a select box element using JavaScript?

The easiest way if you need to:
1) Click a button which defines select option
2) Go to another page, where select option is
3) Have that option value selected on another page

1) your button links (say, on home page)

<a onclick="location.href='contact.php?option=1';" style="cursor:pointer;">Sales</a>
<a onclick="location.href='contact.php?option=2';" style="cursor:pointer;">IT</a>

(where contact.php is your page with select options. Note the page url has ?option=1 or 2)

2) put this code on your second page (my case contact.php)

if (isset($_GET['option']) && $_GET['option'] != "") {
$pg = $_GET['option'];              
} ?>

3) make the option value selected, depending on the button clicked

<option value="Sales" <? if ($pg == '1') { echo "selected"; } ?> >Sales</option>
<option value="IT" <? if ($pg == '2') { echo "selected"; } ?> >IT</option>

.. and so on.
So this is an easy way of passing the value to another page (with select option list) through GET in url. No forms, no IDs.. just 3 steps and it works perfect.

Is there an effective tool to convert C# code to Java code?

Try to look at Net2Java It seems to me the best option for automatic (or semi-automatic at least) conversion from C# to Java

Deep cloning objects

I wanted a cloner for very simple objects of mostly primitives and lists. If your object is out of the box JSON serializable then this method will do the trick. This requires no modification or implementation of interfaces on the cloned class, just a JSON serializer like JSON.NET.

public static T Clone<T>(T source)
    var serialized = JsonConvert.SerializeObject(source);
    return JsonConvert.DeserializeObject<T>(serialized);

Also, you can use this extension method

public static class SystemExtension
    public static T Clone<T>(this T source)
        var serialized = JsonConvert.SerializeObject(source);
        return JsonConvert.DeserializeObject<T>(serialized);

How do you get a string from a MemoryStream?

Using a StreamReader to convert the MemoryStream to a String.

<Extension()> _
Public Function ReadAll(ByVal memStream As MemoryStream) As String
    ' Reset the stream otherwise you will just get an empty string.
    ' Remember the position so we can restore it later.
    Dim pos = memStream.Position
    memStream.Position = 0

    Dim reader As New StreamReader(memStream)
    Dim str = reader.ReadToEnd()

    ' Reset the position so that subsequent writes are correct.
    memStream.Position = pos

    Return str
End Function

Why doesn't Java offer operator overloading?

Assuming you wanted to overwrite the previous value of the object referred to by a, then a member function would have to be invoked.

Complex a, b, c;
// ...
a = b.add(c);

In C++, this expression tells the compiler to create three (3) objects on the stack, perform addition, and copy the resultant value from the temporary object into the existing object a.

However, in Java, operator= doesn't perform value copy for reference types, and users can only create new reference types, not value types. So for a user-defined type named Complex, assignment means to copy a reference to an existing value.

Consider instead:

b.set(1, 0); // initialize to real number '1'
a = b; 
b.set(2, 0);
assert( !a.equals(b) ); // this assertion will fail

In C++, this copies the value, so the comparison will result not-equal. In Java, operator= performs reference copy, so a and b are now referring to the same value. As a result, the comparison will produce 'equal', since the object will compare equal to itself.

The difference between copies and references only adds to the confusion of operator overloading. As @Sebastian mentioned, Java and C# both have to deal with value and reference equality separately -- operator+ would likely deal with values and objects, but operator= is already implemented to deal with references.

In C++, you should only be dealing with one kind of comparison at a time, so it can be less confusing. For example, on Complex, operator= and operator== are both working on values -- copying values and comparing values respectively.

How do you run CMD.exe under the Local System Account?

an alternative to this is Process hacker if you go into run as... (Interactive doesnt work for people with the security enhancments but that wont matter) and when box opens put Service into the box type and put SYSTEM into user box and put C:\Users\Windows\system32\cmd.exe leave the rest click ok and boch you have got a window with cmd on it and run as system now do the other steps for yourself because im suggesting you know them

How to access the last value in a vector?

To answer this not from an aesthetical but performance-oriented point of view, I've put all of the above suggestions through a benchmark. To be precise, I've considered the suggestions

  • x[length(x)]
  • mylast(x), where mylast is a C++ function implemented through Rcpp,
  • tail(x, n=1)
  • dplyr::last(x)
  • x[end(x)[1]]]
  • rev(x)[1]

and applied them to random vectors of various sizes (10^3, 10^4, 10^5, 10^6, and 10^7). Before we look at the numbers, I think it should be clear that anything that becomes noticeably slower with greater input size (i.e., anything that is not O(1)) is not an option. Here's the code that I used:

Rcpp::cppFunction('double mylast(NumericVector x) { int n = x.size(); return x[n-1]; }')
for (n in c(1e3,1e4,1e5,1e6,1e7)) {
  x <- runif(n);
                                       tail(x, n=1),

It gives me

Unit: nanoseconds
           expr   min      lq     mean  median      uq   max neval
   x[length(x)]   171   291.5   388.91   337.5   390.0  3233   100
      mylast(x)  1291  1832.0  2329.11  2063.0  2276.0 19053   100
 tail(x, n = 1)  7718  9589.5 11236.27 10683.0 12149.0 32711   100
 dplyr::last(x) 16341 19049.5 22080.23 21673.0 23485.5 70047   100
   x[end(x)[1]]  7688 10434.0 13288.05 11889.5 13166.5 78536   100
      rev(x)[1]  7829  8951.5 10995.59  9883.0 10890.0 45763   100
Unit: nanoseconds
           expr   min      lq     mean  median      uq    max neval
   x[length(x)]   204   323.0   475.76   386.5   459.5   6029   100
      mylast(x)  1469  2102.5  2708.50  2462.0  2995.0   9723   100
 tail(x, n = 1)  7671  9504.5 12470.82 10986.5 12748.0  62320   100
 dplyr::last(x) 15703 19933.5 26352.66 22469.5 25356.5 126314   100
   x[end(x)[1]] 13766 18800.5 27137.17 21677.5 26207.5  95982   100
      rev(x)[1] 52785 58624.0 78640.93 60213.0 72778.0 851113   100
Unit: nanoseconds
           expr     min        lq       mean    median        uq     max neval
   x[length(x)]     214     346.0     583.40     529.5     720.0    1512   100
      mylast(x)    1393    2126.0    4872.60    4905.5    7338.0    9806   100
 tail(x, n = 1)    8343   10384.0   19558.05   18121.0   25417.0   69608   100
 dplyr::last(x)   16065   22960.0   36671.13   37212.0   48071.5   75946   100
   x[end(x)[1]]  360176  404965.5  432528.84  424798.0  450996.0  710501   100
      rev(x)[1] 1060547 1140149.0 1189297.38 1180997.5 1225849.0 1383479   100
Unit: nanoseconds
           expr     min        lq        mean    median         uq      max neval
   x[length(x)]     327     584.0     1150.75     996.5     1652.5     3974   100
      mylast(x)    2060    3128.5     7541.51    8899.0     9958.0    16175   100
 tail(x, n = 1)   10484   16936.0    30250.11   34030.0    39355.0    52689   100
 dplyr::last(x)   19133   47444.5    55280.09   61205.5    66312.5   105851   100
   x[end(x)[1]] 1110956 2298408.0  3670360.45 2334753.0  4475915.0 19235341   100
      rev(x)[1] 6536063 7969103.0 11004418.46 9973664.5 12340089.5 28447454   100
Unit: nanoseconds
           expr      min         lq         mean      median          uq       max neval
   x[length(x)]      327      722.0      1644.16      1133.5      2055.5     13724   100
      mylast(x)     1962     3727.5      9578.21      9951.5     12887.5     41773   100
 tail(x, n = 1)     9829    21038.0     36623.67     43710.0     48883.0     66289   100
 dplyr::last(x)    21832    35269.0     60523.40     63726.0     75539.5    200064   100
   x[end(x)[1]] 21008128 23004594.5  37356132.43  30006737.0  47839917.0 105430564   100
      rev(x)[1] 74317382 92985054.0 108618154.55 102328667.5 112443834.0 187925942   100

This immediately rules out anything involving rev or end since they're clearly not O(1) (and the resulting expressions are evaluated in a non-lazy fashion). tail and dplyr::last are not far from being O(1) but they're also considerably slower than mylast(x) and x[length(x)]. Since mylast(x) is slower than x[length(x)] and provides no benefits (rather, it's custom and does not handle an empty vector gracefully), I think the answer is clear: Please use x[length(x)].

When to throw an exception?

Others propose that exceptions should not be used because the bad login is to be expected in a normal flow if the user mistypes. I disagree and I don't get the reasoning. Compare it with opening a file.. if the file doesn't exist or is not available for some reason then an exception will be thrown by the framework. Using the logic above this was a mistake by Microsoft. They should have returned an error code. Same for parsing, webrequests, etc., etc..

I don't consider a bad login part of a normal flow, it's exceptional. Normally the user types the correct password, and the file does exist. The exceptional cases are exceptional and it's perfectly fine to use exceptions for those. Complicating your code by propagating return values through n levels up the stack is a waste of energy and will result in messy code. Do the simplest thing that could possibly work. Don't prematurely optimize by using error codes, exceptional stuff by definition rarely happens, and exceptions don't cost anything unless you throw them.

How to automatically generate a stacktrace when my program crashes

It's important to note that once you generate a core file you'll need to use the gdb tool to look at it. For gdb to make sense of your core file, you must tell gcc to instrument the binary with debugging symbols: to do this, you compile with the -g flag:

$ g++ -g prog.cpp -o prog

Then, you can either set "ulimit -c unlimited" to let it dump a core, or just run your program inside gdb. I like the second approach more:

$ gdb ./prog
... gdb startup output ...
(gdb) run
... program runs and crashes ...
(gdb) where
... gdb outputs your stack trace ...

I hope this helps.

How to get progress from XMLHttpRequest

For the total uploaded there doesn't seem to be a way to handle that, but there's something similar to what you want for download. Once readyState is 3, you can periodically query responseText to get all the content downloaded so far as a String (this doesn't work in IE), up until all of it is available at which point it will transition to readyState 4. The total bytes downloaded at any given time will be equal to the total bytes in the string stored in responseText.

For a all or nothing approach to the upload question, since you have to pass a string for upload (and it's possible to determine the total bytes of that) the total bytes sent for readyState 0 and 1 will be 0, and the total for readyState 2 will be the total bytes in the string you passed in. The total bytes both sent and received in readyState 3 and 4 will be the sum of the bytes in the original string plus the total bytes in responseText.

General guidelines to avoid memory leaks in C++

You can intercept the memory allocation functions and see if there are some memory zones not freed upon program exit (though it is not suitable for all the applications).

It can also be done at compile time by replacing operators new and delete and other memory allocation functions.

For example check in this site [Debugging memory allocation in C++] Note: There is a trick for delete operator also something like this:

#define DEBUG_DELETE PrepareDelete(__LINE__,__FILE__); delete
#define delete DEBUG_DELETE

You can store in some variables the name of the file and when the overloaded delete operator will know which was the place it was called from. This way you can have the trace of every delete and malloc from your program. At the end of the memory checking sequence you should be able to report what allocated block of memory was not 'deleted' identifying it by filename and line number which is I guess what you want.

You could also try something like BoundsChecker under Visual Studio which is pretty interesting and easy to use.

SOAP or REST for Web Services?

Quick lowdown for 2012 question:

Areas that REST works really well for are:

  • Limited bandwidth and resources. Remember the return structure is really in any format (developer defined). Plus, any browser can be used because the REST approach uses the standard GET, PUT, POST, and DELETE verbs. Again, remember that REST can also use the XMLHttpRequest object that most modern browsers support today, which adds an extra bonus of AJAX.

  • Totally stateless operations. If an operation needs to be continued, then REST is not the best approach and SOAP may fit it better. However, if you need stateless CRUD (Create, Read, Update, and Delete) operations, then REST is it.

  • Caching situations. If the information can be cached because of the totally stateless operation of the REST approach, this is perfect.That covers a lot of solutions in the above three.

So why would I even consider SOAP? Again, SOAP is fairly mature and well-defined and does come with a complete specification. The REST approach is just that, an approach and is wide open for development, so if you have the following then SOAP is a great solution:

  • Asynchronous processing and invocation. If your application needs a guaranteed level of reliability and security then SOAP 1.2 offers additional standards to ensure this type of operation. Things like WSRM – WS-Reliable Messaging.

  • Formal contracts. If both sides (provider and consumer) have to agree on the exchange format then SOAP 1.2 gives the rigid specifications for this type of interaction.

  • Stateful operations. If the application needs contextual information and conversational state management then SOAP 1.2 has the additional specification in the WS* structure to support those things (Security, Transactions, Coordination, etc). Comparatively, the REST approach would make the developers build this custom plumbing.

Change the color of a bullet in a html list?

<li style="color:#ddd;"><span style="color:#000;">List Item</span></li>

Using MySQL with Entity Framework

You might also look at

DevArt's connector supports EF and MySQL.

How can I open Java .class files in a human-readable way?

JAD and/or JADclipse Eclipse plugin, for sure.

How can I delete a service in Windows?

Before removing the service you should review the dependencies.

You can check it:

Open services.msc and find the service name, switch to the "Dependencies" tab.


When are you supposed to use escape instead of encodeURI / encodeURIComponent?


Don't use it! escape() is defined in section B.2.1.2 escape and the introduction text of Annex B says:

... All of the language features and behaviours specified in this annex have one or more undesirable characteristics and in the absence of legacy usage would be removed from this specification. ...
... Programmers should not use or assume the existence of these features and behaviours when writing new ECMAScript code....


Special characters are encoded with the exception of: @*_+-./

The hexadecimal form for characters, whose code unit value is 0xFF or less, is a two-digit escape sequence: %xx.

For characters with a greater code unit, the four-digit format %uxxxx is used. This is not allowed within a query string (as defined in RFC3986):

query       = *( pchar / "/" / "?" )
pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
unreserved    = ALPHA / DIGIT / "-" / "." / "_" / "~"
pct-encoded   = "%" HEXDIG HEXDIG
sub-delims    = "!" / "$" / "&" / "'" / "(" / ")"
              / "*" / "+" / "," / ";" / "="

A percent sign is only allowed if it is directly followed by two hexdigits, percent followed by u is not allowed.


Use encodeURI when you want a working URL. Make this call:

encodeURI(" file with spaces.html")

to get:

Don't call encodeURIComponent since it would destroy the URL and return

Note that encodeURI, like encodeURIComponent, does not escape the ' character.


Use encodeURIComponent when you want to encode the value of a URL parameter.

var p1 = encodeURIComponent("")

Then you may create the URL you need:

var url = "" + p1 + "&param2=99";

And you will get this complete URL:

Note that encodeURIComponent does not escape the ' character. A common bug is to use it to create html attributes such as href='MyUrl', which could suffer an injection bug. If you are constructing html from strings, either use " instead of ' for attribute quotes, or add an extra layer of encoding (' can be encoded as %27).

For more information on this type of encoding you can check:

How to implement Enums in Ruby?

Two ways. Symbols (:foo notation) or constants (FOO notation).

Symbols are appropriate when you want to enhance readability without littering code with literal strings.

postal_code[:minnesota] = "MN"
postal_code[:new_york] = "NY"

Constants are appropriate when you have an underlying value that is important. Just declare a module to hold your constants and then declare the constants within that.

module Foo
  BAR = 1
  BAZ = 2
  BIZ = 4
flags = Foo::BAR | Foo::BAZ # flags = 3

Added 2021-01-17

If you are passing the enum value around (for example, storing it in a database) and you need to be able to translate the value back into the symbol, there's a mashup of both approaches

  currency: 1,
  investment: 2,

def commodity_type_string(value)


This approach inspired by andrew-grimm's answer

I'd also recommend reading through the rest of the answers here since there are a lot of ways to solve this and it really boils down to what it is about the other language's enum that you care about

How do I check to see if a value is an integer in MySQL?

I have tried using the regular expressions listed above, but they do not work for the following:

SELECT '12 INCHES' REGEXP '^(-|\\+){0,1}([0-9]+\\.[0-9]*|[0-9]*\\.[0-9]+|[0-9]+)$' FROM ...

The above will return 1 (TRUE), meaning the test of the string '12 INCHES' against the regular expression above, returns TRUE. It looks like a number based on the regular expression used above. In this case, because the 12 is at the beginning of the string, the regular expression interprets it as a number.

The following will return the right value (i.e. 0) because the string starts with characters instead of digits

SELECT 'TOP 10' REGEXP '^(-|\\+){0,1}([0-9]+\\.[0-9]*|[0-9]*\\.[0-9]+|[0-9]+)$' FROM ...

The above will return 0 (FALSE) because the beginning of the string is text and not numeric.

However, if you are dealing with strings that have a mix of numbers and letters that begin with a number, you will not get the results you want. REGEXP will interpret the string as a valid number when in fact it is not.

Converting a Uniform Distribution to a Normal Distribution

I would use Box-Muller. Two things about this:

  1. You end up with two values per iteration
    Typically, you cache one value and return the other. On the next call for a sample, you return the cached value.
  2. Box-Muller gives a Z-score
    You have to then scale the Z-score by the standard deviation and add the mean to get the full value in the normal distribution.

How do I dump the data of some SQLite3 tables?

Any answer which suggests using grep to exclude the CREATE lines or just grab the INSERT lines from the sqlite3 $DB .dump output will fail badly. The CREATE TABLE commands list one column per line (so excluding CREATE won't get all of it), and values on the INSERT lines can have embedded newlines (so you can't grab just the INSERT lines).

for t in $(sqlite3 $DB .tables); do
    echo -e ".mode insert $t\nselect * from $t;"
done | sqlite3 $DB > backup.sql

Tested on sqlite3 version 3.6.20.

If you want to exclude certain tables you can filter them with $(sqlite $DB .tables | grep -v -e one -e two -e three), or if you want to get a specific subset replace that with one two three.

Best way to convert pdf files to tiff files

Required ghostscript & tiffcp Tested in Ubuntu

import os

def pdf2tiff(source, destination):
    idx = destination.rindex('.')
    destination = destination[:idx]
    args = [
    '-q', '-dNOPAUSE', '-dBATCH',
    '-r600', '-sPAPERSIZE=a4',
    '-sOutputFile=' + destination + '__%03d.tiff'
    gs_cmd = 'gs ' + ' '.join(args) +' '+ source
    args = [destination + '__*.tiff', destination + '.tiff' ]
    tiffcp_cmd = 'tiffcp  ' + ' '.join(args)
    args = [destination + '__*.tiff']
    rm_cmd = 'rm  ' + ' '.join(args)
pdf2tiff('abc.pdf', 'abc.tiff')

What are the uses of "using" in C#?

Things like this:

using (var conn = new SqlConnection("connection string"))

    // Execute SQL statement here on the connection you created

This SqlConnection will be closed without needing to explicitly call the .Close() function, and this will happen even if an exception is thrown, without the need for a try/catch/finally.

Getting all types in a namespace via reflection

You won't be able to get all types in a namespace, because a namespace can bridge multiple assemblies, but you can get all classes in an assembly and check to see if they belong to that namespace.

Assembly.GetTypes() works on the local assembly, or you can load an assembly first then call GetTypes() on it.

Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming?

You could try using Insight a graphical front-end for gdb written by Red Hat Or if you use GNOME desktop environment, you can also try Nemiver.

How to vertically align elements in a div?

A technique from a friend of mine:


<div style="height:100px; border:1px solid;">
    <p style="border:1px dotted;">I'm vertically centered.</p>


div:before {content:" "; display:inline-block; height:100%; vertical-align:middle;}
div p {display:inline-block;}

DEMO here

How to get the file path from HTML input form in Firefox 3

Actually, just before FF3 was out, I did some experiments, and FF2 sends only the filename, like did Opera 9.0. Only IE sends the full path. The behavior makes sense, because the server doesn't have to know where the user stores the file on his computer, it is irrelevant to the upload process. Unless you are writing an intranet application and get the file by direct network access!

What have changed (and that's the real point of the bug item you point to) is that FF3 no longer let access to the file path from JavaScript. And won't let type/paste a path there, which is more annoying for me: I have a shell extension which copies the path of a file from Windows Explorer to the clipboard and I used it a lot in such form. I solved the issue by using the DragDropUpload extension. But this becomes off-topic, I fear.

I wonder what your Web forms are doing to stop working with this new behavior.

[EDIT] After reading the page linked by Mike, I see indeed intranet uses of the path (identify a user for example) and local uses (show preview of an image, local management of files). User Jam-es seems to provide a workaround with nsIDOMFile (not tried yet).

How do the PHP equality (== double equals) and identity (=== triple equals) comparison operators differ?

Difference between == and ===

The difference between the loosely == equal operator and the strict === identical operator is exactly explained in the manual:

Comparison Operators

¦ Example  ¦ Name      ¦ Result                                                    ¦
¦$a ==  $b ¦ Equal     ¦ TRUE if $a is equal to $b after type juggling.            ¦
¦$a === $b ¦ Identical ¦ TRUE if $a is equal to $b, and they are of the same type. ¦

Loosely == equal comparison

If you are using the == operator, or any other comparison operator which uses loosely comparison such as !=, <> or ==, you always have to look at the context to see what, where and why something gets converted to understand what is going on.

Converting rules

Type comparison table

As reference and example you can see the comparison table in the manual:

Loose comparisons with ==

¦         ¦ TRUE  ¦ FALSE ¦   1   ¦   0   ¦  -1   ¦  "1"  ¦  "0"  ¦ "-1"  ¦ NULL  ¦ array() ¦ "php" ¦  ""   ¦
¦ 0       ¦ FALSE ¦ TRUE  ¦ FALSE ¦ TRUE  ¦ FALSE ¦ FALSE ¦ TRUE  ¦ FALSE ¦ TRUE  ¦ FALSE   ¦ TRUE  ¦ TRUE  ¦

Strict === identical comparison

If you are using the === operator, or any other comparison operator which uses strict comparison such as !== or ===, then you can always be sure that the types won't magically change, because there will be no converting going on. So with strict comparison the type and value have to be the same, not only the value.

Type comparison table

As reference and example you can see the comparison table in the manual:

Strict comparisons with ===

¦         ¦ TRUE  ¦ FALSE ¦   1   ¦   0   ¦  -1   ¦  "1"  ¦  "0"  ¦ "-1"  ¦ NULL  ¦ array() ¦ "php" ¦  ""   ¦

How can I concatenate two arrays in Java?

You can try this method which concatenates multiple arrays:

public static <T> T[] concatMultipleArrays(T[]... arrays)
   int length = 0;
   for (T[] array : arrays)
      length += array.length;
   T[] result = (T[]) Array.newInstance(arrays.getClass().getComponentType(), length) ;

   length = 0;
   for (int i = 0; i < arrays.length; i++)
      System.arraycopy(arrays[i], 0, result, length, arrays[i].length);
      length += arrays[i].length;

   return result;

How to match all occurrences of a regex

To find all the matching strings, use String's scan method.

str = "A 54mpl3 string w1th 7 numb3rs scatter36 ar0und"
#=> ["54", "3", "1", "7", "3", "36", "0"]

If you want, MatchData, which is the type of the object returned by the Regexp match method, use:

str.to_enum(:scan, /\d+/).map { Regexp.last_match }
#=> [#<MatchData "54">, #<MatchData "3">, #<MatchData "1">, #<MatchData "7">, #<MatchData "3">, #<MatchData "36">, #<MatchData "0">]

The benefit of using MatchData is that you can use methods like offset:

match_datas = str.to_enum(:scan, /\d+/).map { Regexp.last_match }
#=> [2, 4]
#=> [7, 8]

See these questions if you'd like to know more:

Reading about special variables $&, $', $1, $2 in Ruby will be helpful too.

How to Truncate a string in PHP to the word closest to a certain number of characters?

I would use the preg_match function to do this, as what you want is a pretty simple expression.

$matches = array();
$result = preg_match("/^(.{1,199})[\s]/i", $text, $matches);

The expression means "match any substring starting from the beginning of length 1-200 that ends with a space." The result is in $result, and the match is in $matches. That takes care of your original question, which is specifically ending on any space. If you want to make it end on newlines, change the regular expression to:

$result = preg_match("/^(.{1,199})[\n]/i", $text, $matches);

Visual Studio opens the default browser instead of Internet Explorer

If you're running an MVC 3 application - in your solution explorer click the show all files icon and then under the Global.asax file there should be a file called YourProjectName.Publish.XML right-click it and then click "Browse With..." and select your favorite browser as the default.

What and where are the stack and heap?

Thank you for a really good discussion but as a real noob I wonder where instructions are kept? In the BEGINNING scientists were deciding between two architectures (von NEUMANN where everything is considered DATA and HARVARD where an area of memory was reserved for instructions and another for data). Ultimately, we went with the von Neumann design and now everything is considered 'the same'. This made it hard for me when I was learning assembly because they talk about registers and stack pointers.

Everything above talks about DATA. My guess is that since an instruction is a defined thing with a specific memory footprint, it would go on the stack and so all 'those' registers discussed in assembly are on the stack. Of course then came object oriented programming with instructions and data comingled into a structure that was dynamic so now instructions would be kept on the heap as well?

How to convert local time string to UTC?

if you prefer datetime.datetime:

dt = datetime.strptime("2008-09-17 14:04:00","%Y-%m-%d %H:%M:%S")
utc_struct_time = time.gmtime(time.mktime(dt.timetuple()))
utc_dt = datetime.fromtimestamp(time.mktime(utc_struct_time))
print dt.strftime("%Y-%m-%d %H:%M:%S")

A regex for version number parsing

Keep in mind regexp are greedy, so if you are just searching within the version number string and not within a bigger text, use ^ and $ to mark start and end of your string. The regexp from Greg seems to work fine (just gave it a quick try in my editor), but depending on your library/language the first part can still match the "*" within the wrong version numbers. Maybe I am missing something, as I haven't used Regexp for a year or so.

This should make sure you can only find correct version numbers:


edit: actually greg added them already and even improved his solution, I am too slow :)

Is it possible to print a variable's type in standard C++?

In C++11, we have decltype. There is no way in standard c++ to display exact type of variable declared using decltype. We can use boost typeindex i.e type_id_with_cvr (cvr stands for const, volatile, reference) to print type like below.

#include <iostream>
#include <boost/type_index.hpp>

using namespace std;
using boost::typeindex::type_id_with_cvr;

int main() {
  int i = 0;
  const int ci = 0;
  cout << "decltype(i) is " << type_id_with_cvr<decltype(i)>().pretty_name() << '\n';
  cout << "decltype((i)) is " << type_id_with_cvr<decltype((i))>().pretty_name() << '\n';
  cout << "decltype(ci) is " << type_id_with_cvr<decltype(ci)>().pretty_name() << '\n';
  cout << "decltype((ci)) is " << type_id_with_cvr<decltype((ci))>().pretty_name() << '\n';
  cout << "decltype(std::move(i)) is " << type_id_with_cvr<decltype(std::move(i))>().pretty_name() << '\n';
  cout << "decltype(std::static_cast<int&&>(i)) is " << type_id_with_cvr<decltype(static_cast<int&&>(i))>().pretty_name() << '\n';
  return 0;

How do I kill a VMware virtual machine that won't die?

If you are using Windows, the virtual machine should have it's own process that is visible in task manager. Use sysinternals Process Explorer to find the right one and then kill it from there.

Where do I find the current C or C++ standard documents?

C99 is available online. Quoted from

The lastest publically available version of the standard is the combined C99 + TC1 + TC2 + TC3, WG14 N1256, dated 2007-09-07. This is a WG14 working paper, but it reflects the consolidated standard at the time of issue.

What IDE to use for Python?


Spreadsheet version

spreadsheet screenshot

Alternatively, in plain text: (also available as a a screenshot)

                         Bracket Matching -.  .- Line Numbering
                          Smart Indent -.  |  |  .- UML Editing / Viewing
         Source Control Integration -.  |  |  |  |  .- Code Folding
                    Error Markup -.  |  |  |  |  |  |  .- Code Templates
  Integrated Python Debugging -.  |  |  |  |  |  |  |  |  .- Unit Testing
    Multi-Language Support -.  |  |  |  |  |  |  |  |  |  |  .- GUI Designer (Qt, Eric, etc)
   Auto Code Completion -.  |  |  |  |  |  |  |  |  |  |  |  |  .- Integrated DB Support
     Commercial/Free -.  |  |  |  |  |  |  |  |  |  |  |  |  |  |  .- Refactoring
   Cross Platform -.  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |     
Atom              |Y |F |Y |Y*|Y |Y |Y |Y |Y |Y |  |Y |Y |  |  |  |  |*many plugins
Editra            |Y |F |Y |Y |  |  |Y |Y |Y |Y |  |Y |  |  |  |  |  |
Emacs             |Y |F |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |  |  |  |
Eric Ide          |Y |F |Y |  |Y |Y |  |Y |  |Y |  |Y |  |Y |  |  |  |
Geany             |Y |F |Y*|Y |  |  |  |Y |Y |Y |  |Y |  |  |  |  |  |*very limited
Gedit             |Y |F |Y¹|Y |  |  |  |Y |Y |Y |  |  |Y²|  |  |  |  |¹with plugin; ²sort of
Idle              |Y |F |Y |  |Y |  |  |Y |Y |  |  |  |  |  |  |  |  |
IntelliJ          |Y |CF|Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |
JEdit             |Y |F |  |Y |  |  |  |  |Y |Y |  |Y |  |  |  |  |  |
KDevelop          |Y |F |Y*|Y |  |  |Y |Y |Y |Y |  |Y |  |  |  |  |  |*no type inference
Komodo            |Y |CF|Y |Y |Y |Y |Y |Y |Y |Y |  |Y |Y |Y |  |Y |  |
NetBeans*         |Y |F |Y |Y |Y |  |Y |Y |Y |Y |Y |Y |Y |Y |  |  |Y |*pre-v7.0
Notepad++         |W |F |Y |Y |  |Y*|Y*|Y*|Y |Y |  |Y |Y*|  |  |  |  |*with plugin
Pfaide            |W |C |Y |Y |  |  |  |Y |Y |Y |  |Y |Y |  |  |  |  |
PIDA              |LW|F |Y |Y |  |  |  |Y |Y |Y |  |Y |  |  |  |  |  |VIM based
PTVS              |W |F |Y |Y |Y |Y |Y |Y |Y |Y |  |Y |  |  |Y*|  |Y |*WPF bsed
PyCharm           |Y |CF|Y |Y*|Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |*JavaScript
PyDev (Eclipse)   |Y |F |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |Y |  |  |  |
PyScripter        |W |F |Y |  |Y |Y |  |Y |Y |Y |  |Y |Y |Y |  |  |  |
PythonWin         |W |F |Y |  |Y |  |  |Y |Y |  |  |Y |  |  |  |  |  |
SciTE             |Y |F¹|  |Y |  |Y |  |Y |Y |Y |  |Y |Y |  |  |  |  |¹Mac version is
ScriptDev         |W |C |Y |Y |Y |Y |  |Y |Y |Y |  |Y |Y |  |  |  |  |    commercial
Spyder            |Y |F |Y |  |Y |Y |  |Y |Y |Y |  |  |  |  |  |  |  |
Sublime Text      |Y |CF|Y |Y |  |Y |Y |Y |Y |Y |  |Y |Y |Y*|  |  |  |extensible w/Python,
TextMate          |M |F |  |Y |  |  |Y |Y |Y |Y |  |Y |Y |  |  |  |  |    *PythonTestRunner
UliPad            |Y |F |Y |Y |Y |  |  |Y |Y |  |  |  |Y |Y |  |  |  |
Vim               |Y |F |Y |Y |Y |Y |Y |Y |Y |Y |  |Y |Y |Y |  |  |  |
Visual Studio     |W |CF|Y |Y |Y |Y |Y |Y |Y |Y |? |Y |? |? |Y |? |Y |
Visual Studio Code|Y |F |Y |Y |Y |Y |Y |Y |Y |Y |? |Y |? |? |? |? |Y |uses plugins
WingIde           |Y |C |Y |Y*|Y |Y |Y |Y |Y |Y |  |Y |Y |Y |  |  |  |*support for C
Zeus              |W |C |  |  |  |  |Y |Y |Y |Y |  |Y |Y |  |  |  |  |
   Cross Platform -'  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |     
     Commercial/Free -'  |  |  |  |  |  |  |  |  |  |  |  |  |  |  '- Refactoring
   Auto Code Completion -'  |  |  |  |  |  |  |  |  |  |  |  |  '- Integrated DB Support
    Multi-Language Support -'  |  |  |  |  |  |  |  |  |  |  '- GUI Designer (Qt, Eric, etc)
  Integrated Python Debugging -'  |  |  |  |  |  |  |  |  '- Unit Testing
                    Error Markup -'  |  |  |  |  |  |  '- Code Templates
         Source Control Integration -'  |  |  |  |  '- Code Folding
                          Smart Indent -'  |  |  '- UML Editing / Viewing
                         Bracket Matching -'  '- Line Numbering

Acronyms used:

 L  - Linux
 W  - Windows
 M  - Mac
 C  - Commercial
 F  - Free
 CF - Commercial with Free limited edition
 ?  - To be confirmed

I don't mention basics like syntax highlighting as I expect these by default.

This is a just dry list reflecting your feedback and comments, I am not advocating any of these tools. I will keep updating this list as you keep posting your answers.

PS. Can you help me to add features of the above editors to the list (like auto-complete, debugging, etc.)?

We have a comprehensive wiki page for this question

Submit edits to the spreadsheet

Difference between BYTE and CHAR in column datatypes

Let us assume the database character set is UTF-8, which is the recommended setting in recent versions of Oracle. In this case, some characters take more than 1 byte to store in the database.

If you define the field as VARCHAR2(11 BYTE), Oracle can use up to 11 bytes for storage, but you may not actually be able to store 11 characters in the field, because some of them take more than one byte to store, e.g. non-English characters.

By defining the field as VARCHAR2(11 CHAR) you tell Oracle it can use enough space to store 11 characters, no matter how many bytes it takes to store each one. A single character may require up to 4 bytes.

How do I set up access control in SVN?

In your svn\repos\YourRepo\conf folder you will find two files, authz and passwd. These are the two you need to adjust.

In the passwd file you need to add some usernames and passwords. I assume you have already done this since you have people using it:


Then you want to assign permissions accordingly with the authz file:

Create the conceptual groups you want, and add people to it:

allaccess = user1
someaccess = user2

Then choose what access they have from both the permissions and project level.

So let's give our "all access" guys all access from the root:

@allaccess = rw

But only give our "some access" guys read-only access to some lower level project:

@someaccess = r

You will also find some simple documentation in the authz and passwd files.

Most efficient way to increment a Map value in Java

There are a couple of approaches:

  1. Use a Bag alorithm like the sets contained in Google Collections.

  2. Create mutable container which you can use in the Map:

    class My{
        String word;
        int count;

And use put("word", new My("Word") ); Then you can check if it exists and increment when adding.

Avoid rolling your own solution using lists, because if you get innerloop searching and sorting, your performance will stink. The first HashMap solution is actually quite fast, but a proper like that found in Google Collections is probably better.

Counting words using Google Collections, looks something like this:

    HashMultiset s = new HashMultiset();
    System.out.println(""+s.count("word") );

Using the HashMultiset is quite elegent, because a bag-algorithm is just what you need when counting words.

How to move the cursor word by word in the OS X Terminal

If you check Use option as meta key in the keyboard tab of the preferences, then the default emacs style commands for forward- and backward-word and ?F (Alt+F) and ?B (Alt+B) respectively.

I'd recommend reading From Bash to Z-Shell. If you want to increase your bash/zsh prowess!

How can I view the allocation unit size of a NTFS partition in Vista?

Open an administrator command prompt, and do this command:

fsutil fsinfo ntfsinfo [your drive]

The Bytes Per Cluster is the equivalent of the allocation unit.

Converting an integer to a hexadecimal string in Ruby

Just in case you have a preference for how negative numbers are formatted:

p "%x" % -1   #=> "..f"
p -1.to_s(16) #=> "-1"

Is there a macro to conditionally copy rows to another worksheet?

The way I would do this manually is:

  • Use Data - AutoFilter
  • Apply a custom filter based on a date range
  • Copy the filtered data to the relevant month sheet
  • Repeat for every month

Listed below is code to do this process via VBA.

It has the advantage of handling monthly sections of data rather than individual rows. Which can result in quicker processing for larger sets of data.

    Sub SeperateData()

    Dim vMonthText As Variant
    Dim ExcelLastCell As Range
    Dim intMonth As Integer

   vMonthText = Array("January", "February", "March", "April", "May", _
 "June", "July", "August", "September", "October", "November", "December")


    RowCount = ThisWorkbook.Worksheets("Sharepoint").UsedRange.Rows.Count
'Forces excel to determine the last cell, Usually only done on save
    Set ExcelLastCell = ThisWorkbook.Worksheets("Sharepoint"). _
'Determines the last cell with data in it

        Range("A1").FormulaR1C1 = "Month No."
        Range("A2").FormulaR1C1 = "=MONTH(RC[1])"
        Range("A3:A" & ExcelLastCell.Row).Select
        Application.CutCopyMode = False
    'Insert a helper column to determine the month number for the date

        For intMonth = 1 To 12
            Selection.AutoFilter Field:=1, Criteria1:="" & intMonth
            ThisWorkbook.Worksheets("" & vMonthText(intMonth - 1)).Select
            Columns("A:A").Delete Shift:=xlToLeft
            Application.CutCopyMode = False
        Next intMonth
    'Filter the data to a particular month
    'Convert the month number to text
    'Copy the filtered data to the month sheet
    'Delete the helper column
    'Repeat for each month

        Columns("A:A").Delete Shift:=xlToLeft
 'Get rid of the auto-filter and delete the helper column

    End Sub

How do I use WPF bindings with RelativeSource?

If you want to bind to another property on the object:

{Binding Path=PathToProperty, RelativeSource={RelativeSource Self}}

If you want to get a property on an ancestor:

{Binding Path=PathToProperty,
    RelativeSource={RelativeSource AncestorType={x:Type typeOfAncestor}}}

If you want to get a property on the templated parent (so you can do 2 way bindings in a ControlTemplate)

{Binding Path=PathToProperty, RelativeSource={RelativeSource TemplatedParent}}

or, shorter (this only works for OneWay bindings):

{TemplateBinding Path=PathToProperty}

Setting the default ssh key location

man ssh gives me this options would could be useful.

-i identity_file Selects a file from which the identity (private key) for RSA or DSA authentication is read. The default is ~/.ssh/identity for protocol version 1, and ~/.ssh/id_rsa and ~/.ssh/id_dsa for pro- tocol version 2. Identity files may also be specified on a per- host basis in the configuration file. It is possible to have multiple -i options (and multiple identities specified in config- uration files).

So you could create an alias in your bash config with something like

alias ssh="ssh -i /path/to/private_key"

I haven't looked into a ssh configuration file, but like the -i option this too could be aliased

-F configfile Specifies an alternative per-user configuration file. If a configuration file is given on the command line, the system-wide configuration file (/etc/ssh/ssh_config) will be ignored. The default for the per-user configuration file is ~/.ssh/config.

Curl command line for consuming webServices?

If you want a fluffier interface than the terminal, is awesome.

Remove spaces from std::string in C++

If you want to do this with an easy macro, here's one:

#define REMOVE_SPACES(x) x.erase(std::remove(x.begin(), x.end(), ' '), x.end())

This assumes you have done #include <string> of course.

Call it like so:

std::string sName = " Example Name ";
printf("%s",sName.c_str()); // requires #include <stdio.h>

How do I call a SQL Server stored procedure from PowerShell?

Here is a function that I use (slightly redacted). It allows input and output parameters. I only have uniqueidentifier and varchar types implemented, but any other types are easy to add. If you use parameterized stored procedures (or just parameterized sql...this code is easily adapted to that), this will make your life a lot easier.

To call the function, you need a connection to the SQL server (say $conn),

$res=exec-storedprocedure -storedProcName 'stp_myProc' -parameters @{Param1="Hello";Param2=50} -outparams @{ID="uniqueidentifier"} $conn

retrieve proc output from returned object

$ #dataset containing the datatables returned by selects

$res.outputparams.ID #output parameter ID (uniqueidentifier)

The function:

function exec-storedprocedure($storedProcName,  
        [hashtable] $parameters=@{},
        [hashtable] $outparams=@{},

        function put-outputparameters($cmd, $outparams){
            foreach($outp in $outparams.Keys){
                $cmd.Parameters.Add("@$outp", (get-paramtype $outparams[$outp])).Direction=[System.Data.ParameterDirection]::Output
        function get-outputparameters($cmd,$outparams){
            foreach($p in $cmd.Parameters){
                if ($p.Direction -eq [System.Data.ParameterDirection]::Output){

        function get-paramtype($typename,[switch]$help){
            switch ($typename){
                'uniqueidentifier' {[System.Data.SqlDbType]::UniqueIdentifier}
                'int' {[System.Data.SqlDbType]::Int}
                'xml' {[System.Data.SqlDbType]::Xml}
                'nvarchar' {[System.Data.SqlDbType]::NVarchar}
                default {[System.Data.SqlDbType]::Varchar}
        if ($help){
            $msg = @"
    Execute a sql statement.  Parameters are allowed.  
    Input parameters should be a dictionary of parameter names and values.
    Output parameters should be a dictionary of parameter names and types.
    Return value will usually be a list of datarows. 

    Usage: exec-query sql [inputparameters] [outputparameters] [conn] [-help]
            Write-Host $msg
        $close=($conn.State -eq [System.Data.ConnectionState]'Closed')
        if ($close) {

        $cmd=new-object system.Data.SqlClient.SqlCommand($sql,$conn)
        foreach($p in $parameters.Keys){

        put-outputparameters $cmd $outparams
        $ds=New-Object system.Data.DataSet
        $da=New-Object system.Data.SqlClient.SqlDataAdapter($cmd)
        if ($close) {
        get-outputparameters $cmd $outparams

        return @{data=$ds;outputparams=$outparams}

How can I extract a predetermined range of lines from a text file on Unix?

sed -n '16224,16482p;16483q' filename > newfile

From the sed manual:

p - Print out the pattern space (to the standard output). This command is usually only used in conjunction with the -n command-line option.

n - If auto-print is not disabled, print the pattern space, then, regardless, replace the pattern space with the next line of input. If there is no more input then sed exits without processing any more commands.

q - Exit sed without processing any more commands or input. Note that the current pattern space is printed if auto-print is not disabled with the -n option.


Addresses in a sed script can be in any of the following forms:

number Specifying a line number will match only that line in the input.

An address range can be specified by specifying two addresses separated by a comma (,). An address range matches lines starting from where the first address matches, and continues until the second address matches (inclusively).

Reading PDF documents in .Net

You could look into this: It's not completely free, but it looks very nice.


What's wrong with foreign keys?

Like many things, it's a tradeoff. It's a question of where you want to do the work to verify the data integrity:

(1) use a foreign key (a single point to configure for a table, feature is already implemented, tested, proven to work)

(2) leave it to the users of the database (possible multiple users/apps updating the same table (s) meaning more potential points of failure and increased complexity in testing).

It's more efficient for the database to do (2), easier to maintain and less risk with (1).

Why not use tables for layout in HTML?

Tools that use table layouts can become extraordinarily heavy due to the amount of code required to create the layout. SAP's Netweaver Portal by default uses TABLE to layout their pages.

The production SAP portal at my current gig has a home page whose HTML weighs over 60K and goes seven tables deep, three times within the page. Add in the Javascript, the misuse of 16 iframes with similar table issues inside of them, overly heavy CSS etc, and the page weighs over 5MB.

Taking the time to lower the page weight so you can use your bandwidth to do engaging activities with users is worth the effort.

ORA-03113: end-of-file on communication channel after long inactivity in ASP.Net app

This error message can be thrown in the application logs when the actual issue is that the oracle database server ran out of space.

After correcting the space issue, this particular error message disappeared.

Before and After Suite execution hook in jUnit 4.x

Provided that all your tests may extend a "technical" class and are in the same package, you can do a little trick :

public class AbstractTest {
  private static int nbTests = listClassesIn(<package>).size();
  private static int curTest = 0;

  public static void incCurTest() { curTest++; }

  public static void closeTestSuite() {
      if (curTest == nbTests) { /*cleaning*/ }             

public class Test1 extends AbstractTest {
   public void check() {}
public class Test2 extends AbstractTest {
   public void check() {}

Be aware that this solution has a lot of drawbacks :

  • must execute all tests of the package
  • must subclass a "techincal" class
  • you can not use @BeforeClass and @AfterClass inside subclasses
  • if you execute only one test in the package, cleaning is not done
  • ...

For information: listClassesIn() => How do you find all subclasses of a given class in Java?

How to list the tables in a SQLite database file that was opened with ATTACH?

The .tables, and .schema "helper" functions don't look into ATTACHed databases: they just query the SQLITE_MASTER table for the "main" database. Consequently, if you used

ATTACH some_file.db AS my_db;

then you need to do

SELECT name FROM my_db.sqlite_master WHERE type='table';

Note that temporary tables don't show up with .tables either: you have to list sqlite_temp_master for that:

SELECT name FROM sqlite_temp_master WHERE type='table';

How do I check whether a file exists without exceptions?

Prefer the try statement. It's considered better style and avoids race conditions.

Don't take my word for it. There's plenty of support for this theory. Here's a couple:

Convert DOS line endings to Linux line endings in Vim

:g/Ctrl-v Ctrl-m/s///

CtrlM is the character \r, or carriage return, which DOS line endings add. CtrlV tells Vim to insert a literal CtrlM character at the command line.

Taken as a whole, this command replaces all \r with nothing, removing them from the ends of lines.

Can you use Microsoft Entity Framework with Oracle?

Oracle have announced a "statement of direction" for and the Entity Framework:

In summary, ODP.Net beta around the end of 2010, production sometime in 2011.

svn over HTTP proxy

In /etc/subversion/servers you are setting http-proxy-host, which has nothing to do with svn:// which connects to a different server usually running on port 3690 started by svnserve command.

If you have access to the server, you can setup svn+ssh:// as explained here.

Update: You could also try using connect-tunnel, which uses your HTTPS proxy server to tunnel connections:

connect-tunnel -P -T

Then you would use

svn checkout svn://localhost:10234/path/to/trunk

How do I use sudo to redirect output to a location I don't have permission to write to?

A trick I figured out myself was

sudo ls -hal /root/ | sudo dd of=/root/test.out

Why is using the JavaScript eval function a bad idea?

It's not necessarily that bad provided you know what context you're using it in.

If your application is using eval() to create an object from some JSON which has come back from an XMLHttpRequest to your own site, created by your trusted server-side code, it's probably not a problem.

Untrusted client-side JavaScript code can't do that much anyway. Provided the thing you're executing eval() on has come from a reasonable source, you're fine.

Does C# have an equivalent to JavaScript's encodeURIComponent()?

I tried to do full compatible analog of javascript's encodeURIComponent for c# and after my 4 hour experiments I found this

c# CODE:

string a = "!@#$%^&*()_+ some text here ??? ??????? ????";
a = System.Web.HttpUtility.UrlEncode(a);
a = a.Replace("+", "%20");

the result is: !%40%23%24%25%5e%26*()_%2b%20some%20text%20here%20%d0%b0%d0%bb%d0%b8%20%d0%bc%d0%b0%d0%bc%d0%b5%d0%b4%d0%be%d0%b2%20%d0%b1%d0%b0%d0%ba%d1%83

After you decode It with Javascript's decodeURLComponent();

you will get this: !@#$%^&*()_+ some text here ??? ??????? ????

Thank You for attention

How do I upload a file to an SFTP server in C# (.NET)?

Unfortunately, it's not in the .NET Framework itself. My wish is that you could integrate with FileZilla, but I don't think it exposes an interface. They do have scripting I think, but it won't be as clean obviously.

I've used CuteFTP in a project which does SFTP. It exposes a COM component which I created a .NET wrapper around. The catch, you'll find, is permissions. It runs beautifully under the Windows credentials which installed CuteFTP, but running under other credentials requires permissions to be set in DCOM.

What’s the best way to reload / refresh an iframe?

For debugging purposes one could open the console, change the execution context to the frame that he wants refreshed, and do document.location.reload()

Select current date by default in ASP.Net Calendar control

DateTime.Now will not work, use DateTime.Today instead.

How can I get Git to follow symlinks?

With Git 2.3.2+ (Q1 2015), there is one other case where Git will not follow symlink anymore: see commit e0d201b by Junio C Hamano (gitster) (main Git maintainer)

apply: do not touch a file beyond a symbolic link

Because Git tracks symbolic links as symbolic links, a path that has a symbolic link in its leading part (e.g. path/to/dir/file, where path/to/dir is a symbolic link to somewhere else, be it inside or outside the working tree) can never appear in a patch that validly applies, unless the same patch first removes the symbolic link to allow a directory to be created there.

Detect and reject such a patch.

Similarly, when an input creates a symbolic link path/to/dir and then creates a file path/to/dir/file, we need to flag it as an error without actually creating path/to/dir symbolic link in the filesystem.

Instead, for any patch in the input that leaves a path (i.e. a non deletion) in the result, we check all leading paths against the resulting tree that the patch would create by inspecting all the patches in the input and then the target of patch application (either the index or the working tree).

This way, we:

  • catch a mischief or a mistake to add a symbolic link path/to/dir and a file path/to/dir/file at the same time,
  • while allowing a valid patch that removes a symbolic link path/to/dir and then adds a file path/to/dir/file.

That means, in that case, the error message won't be a generic one like "%s: patch does not apply", but a more specific one:

affected file '%s' is beyond a symbolic link

How do I ignore files in Subversion?

(This answer has been updated to match SVN 1.8 and 1.9's behaviour)

You have 2 questions:

Marking files as ignored:

By "ignored file" I mean the file won't appear in lists even as "unversioned": your SVN client will pretend the file doesn't exist at all in the filesystem.

Ignored files are specified by a "file pattern". The syntax and format of file patterns is explained in SVN's online documentation: "File Patterns in Subversion".

Subversion, as of version 1.8 (June 2013) and later, supports 3 different ways of specifying file patterns. Here's a summary with examples:

1 - Runtime Configuration Area - global-ignores option:

  • This is a client-side only setting, so your global-ignores list won't be shared by other users, and it applies to all repos you checkout onto your computer.
  • This setting is defined in your Runtime Configuration Area file:
    • Windows (file-based) - C:\Users\{you}\AppData\Roaming\Subversion\config
    • Windows (registry-based) - Software\\Subversion\Config\Miscellany\global-ignores in both HKLM and HKCU.
    • Linux/Unix - ~/.subversion/config

2 - The svn:ignore property, which is set on directories (not files):

  • This is stored within the repo, so other users will have the same ignore files. Similar to how .gitignore works.
  • svn:ignore is applied to directories and is non-recursive or inherited. Any file or immediate subdirectory of the parent directory that matches the File Pattern will be excluded.
  • While SVN 1.8 adds the concept of "inherited properties", the svn:ignore property itself is ignored in non-immediate descendant directories:

    cd ~/myRepoRoot                             # Open an existing repo.
    echo "foo" > "ignoreThis.txt"                # Create a file called "ignoreThis.txt".
    svn status                                  # Check to see if the file is ignored or not.
    > ?    ./ignoreThis.txt
    > 1 unversioned file                        # is NOT currently ignored.
    svn propset svn:ignore "ignoreThis.txt" .   # Apply the svn:ignore property to the "myRepoRoot" directory.
    svn status
    > 0 unversioned files                       # ...but now the file is ignored!
    cd subdirectory                             # now open a subdirectory.
    echo "foo" > "ignoreThis.txt"                # create another file named "ignoreThis.txt".
    svn status
    > ?    ./subdirectory/ignoreThis.txt        # ...and is is NOT ignored!
    > 1 unversioned file

    (So the file ./subdirectory/ignoreThis is not ignored, even though "ignoreThis.txt" is applied on the . repo root).

  • Therefore, to apply an ignore list recursively you must use svn propset svn:ignore <filePattern> . --recursive.

    • This will create a copy of the property on every subdirectory.
    • If the <filePattern> value is different in a child directory then the child's value completely overrides the parents, so there is no "additive" effect.
    • So if you change the <filePattern> on the root ., then you must change it with --recursive to overwrite it on the child and descendant directories.
  • I note that the command-line syntax is counter-intuitive.

    • I started-off assuming that you would ignore a file in SVN by typing something like svn ignore pathToFileToIgnore.txt however this is not how SVN's ignore feature works.

3- The svn:global-ignores property. Requires SVN 1.8 (June 2013):

  • This is similar to svn:ignore, except it makes use of SVN 1.8's "inherited properties" feature.
  • Compare to svn:ignore, the file pattern is automatically applied in every descendant directory (not just immediate children).
    • This means that is unnecessary to set svn:global-ignores with the --recursive flag, as inherited ignore file patterns are automatically applied as they're inherited.
  • Running the same set of commands as in the previous example, but using svn:global-ignores instead:

    cd ~/myRepoRoot                                    # Open an existing repo
    echo "foo" > "ignoreThis.txt"                       # Create a file called "ignoreThis.txt"
    svn status                                         # Check to see if the file is ignored or not
    > ?    ./ignoreThis.txt
    > 1 unversioned file                               # is NOT currently ignored
    svn propset svn:global-ignores "ignoreThis.txt" .
    svn status
    > 0 unversioned files                              # ...but now the file is ignored!
    cd subdirectory                                    # now open a subdirectory
    echo "foo" > "ignoreThis.txt"                       # create another file named "ignoreThis.txt"
    svn status
    > 0 unversioned files                              # the file is ignored here too!

For TortoiseSVN users:

This whole arrangement was confusing for me, because TortoiseSVN's terminology (as used in their Windows Explorer menu system) was initially misleading to me - I was unsure what the significance of the Ignore menu's "Add recursively", "Add *" and "Add " options. I hope this post explains how the Ignore feature ties-in to the SVN Properties feature. That said, I suggest using the command-line to set ignored files so you get a feel for how it works instead of using the GUI, and only using the GUI to manipulate properties after you're comfortable with the command-line.

Listing files that are ignored:

The command svn status will hide ignored files (that is, files that match an RGA global-ignores pattern, or match an immediate parent directory's svn:ignore pattern or match any ancesor directory's svn:global-ignores pattern.

Use the --no-ignore option to see those files listed. Ignored files have a status of I, then pipe the output to grep to only show lines starting with "I".

The command is:

svn status --no-ignore | grep "^I"

For example:

svn status
> ? foo                             # An unversioned file
> M modifiedFile.txt                # A versioned file that has been modified

svn status --no-ignore
> ? foo                             # An unversioned file
> I ignoreThis.txt                  # A file matching an svn:ignore pattern
> M modifiedFile.txt                # A versioned file that has been modified

svn status --no-ignore | grep "^I"
> I ignoreThis.txt                  # A file matching an svn:ignore pattern


How do I create a folder in VB if it doesn't exist?

If Not Directory.Exists(somePath) then
End If