Dates can be converted to HTTP valid dates (RFC 1123) by using the &quot;r&quot; format string in .Net. HTTP dates need to be GMT / not offset - this can be done using the ToUniversalTime() method.

So, in C# for example:

    string HttpDate = SomeDate.ToUniversalTime().ToString(&quot;r&quot;);

Right now, that produces HttpDate = &quot;Sat, 16 Aug 2008 10:38:39 GMT&quot;

See [Standard Date and Time Format Strings][1] for a list of .Net standard date &amp; time format strings.

See [Protocol Parameters][2] for the HTTP date specification, and background to other valid (but dated) RFC types for HTTP dates.


  [1]: http://msdn.microsoft.com/en-us/library/az4se3k1.aspx
  [2]: http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html

In .NET there are two version numbers available when building a project, File Version and Assembly Version. How are you using these numbers?  Keeping them the same?  Auto-incrementing one, but manually changing the other?

Also what about the `AssemblyInformationalVersion` attribute?

I&#39;d found this support Microsoft Knowledge Base (KB) article that provided some help:  [How to use Assembly Version and Assembly File Version][1].

  [1]: http://support.microsoft.com/kb/556041


How best to use File Version and Assembly Version?

I&#39;m downloading an entire directory from a web server. It works OK, but I can&#39;t figure how to get the file size before download to compare if it was updated on the server or not. Can this be done as if I was downloading the file from a FTP server?

    import urllib
    import re

    url = &quot;http://www.someurl.com&quot;

    # Download the page locally
    f = urllib.urlopen(url)
    html = f.read()
    f.close()

    f = open (&quot;temp.htm&quot;, &quot;w&quot;)
    f.write (html)
    f.close()

    # List only the .TXT / .ZIP files
    fnames = re.findall(&#39;^.*&lt;a href=&quot;(\w+(?:\.txt|.zip)?)&quot;.*$&#39;, html, re.MULTILINE)

    for fname in fnames:
        print fname, &quot;...&quot;

        f = urllib.urlopen(url + &quot;/&quot; + fname)

        #### Here I want to check the filesize to download or not #### 
        file = f.read()
        f.close()

        f = open (fname, &quot;w&quot;)
        f.write (file)
        f.close()

---

@Jon: thank for your quick answer. It works, but the filesize on the web server is slightly less than the filesize of the downloaded file. 

Examples:

    Local Size  Server Size
     2.223.533	2.115.516
       664.603	  662.121

It has anything to do with the CR/LF conversion?

Get size of a file before downloading in Python

How does one convert a .Net DateTime into a valid HTTP-formatted date string?

How do I convert a date to a HTTP-formatted date in .Net / C#

<p>How does one convert a .Net DateTime into a valid HTTP-formatted date string?</p>


I need to validate an integer to know if is a valid enum value.

What is the best way to do this in C#?

Validate Enum Values

I&#39;ve been looking for some good genetic programming examples for C#. Anyone knows of good online/book resources? Wonder if there is a C# library out there for Evolutionary/Genetic programming?

Genetic Programming in C#

I have a structure which I need to populate and write to disk (several actually).

An example is:

    byte-6    
    bit0 - original_or_copy  
    bit1 - copyright  
    bit2 - data_alignment_indicator  
    bit3 - PES_priority  
    bit4-bit5 - PES_scrambling control.  
    bit6-bit7 - reserved  

In C I might do something like the following:

    struct PESHeader  {
        unsigned reserved:2;
        unsigned scrambling_control:2;
        unsigned priority:1;
        unsigned data_alignment_indicator:1;
        unsigned copyright:1;
        unsigned original_or_copy:1;
    };


Is there any way to do this in C# that would enable me to access the bits using the struct dereferencing dot operator? 

For a couple of structures, I can just do bit shifting wrapped in an accessor function.

I have loads of structures to handle in this way, so I&#39;m looking for something that&#39;s easier to read and quicker to write.


Bit fields in C#

Normally I would just use:

    HttpContext.Current.Server.UrlEncode(&quot;url&quot;);

But since this is a console application, `HttpContext.Current` is always going to be `null`.

Is there another method that does the same thing that I could use?

UrlEncode through a console application?

What is the best way to disable &lt;kbd&gt;Alt&lt;/kbd&gt; + &lt;kbd&gt;F4&lt;/kbd&gt; in a c# win form to prevent the user from closing the form?

I am using a form as a popup dialog to display a progress bar and I do not want the user to be able to close it.

How to Disable Alt + F4 closing form?

The main web application of my company is crying out for a nifty set of libraries to make it in some way maintainable and scalable, and one of my colleagues has suggested CSLA. So I&#39;ve bought the book but as :

&gt; _programmers don&#39;t read books anymore_

 I wanted to gauge the SOFlow community&#39;s opinion of it.

So here are my questions:

 1. How may people are using CSLA?
 2. What are the pros and cons?
 3. Does CSLA really not fit in with TDD?
 4. What are my alternatives?
 5. If you have stopped using it or decided against why?

Does anyone have any real-world experience of CSLA?

Is there a free or open source library to read Excel files (.xls) directly from a C# program? 

It does not need to be too fancy, just to select a worksheet and read the data as strings. So far, I&#39;ve been using Export to Unicode text function of Excel, and parsing the resulting (tab-delimited) file, but I&#39;d like to eliminate the manual step.


Reading Excel files from C#

I have a small utility that I use to download an MP3 file from a website on a schedule and then builds/updates a podcast XML file which I&#39;ve added to iTunes.

The text processing that creates/updates the XML file is written in Python. However, I use wget inside a Windows `.bat` file to download the actual MP3 file. I would prefer to have the entire utility written in Python.

I struggled to find a way to actually download the file in Python, thus why I resorted to using `wget`.

So, how do I download the file using Python?

How to download a file over HTTP?

What&#39;s the best way to specify a proxy with username and password for an http connection in python?

How to specify an authenticated proxy for a python http connection?

Are square brackets in URLs allowed?

I noticed that [Apache commons HttpClient][1] (3.0.1) throws an IOException, wget and Firefox however accept square brackets.

URL example:

    http://example.com/path/to/file[3].html

  [1]: http://hc.apache.org/httpclient-3.x/index.html

My HTTP client encounters such URLs but I&#39;m not sure whether to patch the code or to throw an exception (as it actually should be).

Are square brackets permitted in URLs?

Our investigations have shown us that not all browsers respect the HTTP cache directives in a uniform manner.

For security reasons we do not want certain pages in our application to be cached, **ever,** by the web browser. This must work for at least the following browsers:

  - Internet Explorer 6+
  - Firefox 1.5+
  - Safari 3+
  - Opera 9+
  - Chrome

Our requirement came from a security test. After logging out from our website you could press the back button and view cached pages.



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

I am writing a little application to download files over http (as, for example, described [here][1]).

I also want to include a little download progress indicator showing the percentage of the download progress.

Here is what I came up with:
&lt;pre&gt;
    sys.stdout.write(rem_file + &quot;...&quot;)    
    urllib.urlretrieve(rem_file, loc_file, reporthook=dlProgress)

    def dlProgress(count, blockSize, totalSize):
      percent = int(count*blockSize*100/totalSize)
      sys.stdout.write(&quot;%2d%%&quot; % percent)
      sys.stdout.write(&quot;\b\b\b&quot;)
      sys.stdout.flush()
&lt;/pre&gt;

Output: MyFileName... 9%

Any other ideas or recommendations to do this? 

One thing that&#39;s somewhat annoying is the blinking cursor in the terminal on the first digit of the percentage. Is there a way to prevent this? Is there a way to hide the cursor?

**EDIT:**

Here a better alternative using a global variable for the filename in dlProgress and the &#39;\r&#39; code:

&lt;pre&gt;
    global rem_file # global variable to be used in dlProgress

    urllib.urlretrieve(rem_file, loc_file, reporthook=dlProgress)

    def dlProgress(count, blockSize, totalSize):
      percent = int(count*blockSize*100/totalSize)
      sys.stdout.write(&quot;\r&quot; + rem_file + &quot;...%d%%&quot; % percent)
      sys.stdout.flush()
&lt;/pre&gt;

Output: MyFileName...9% 

And the cursor shows up at the END of the line. Much better.

  [1]: https://stackoverflow.com/questions/22676/how-do-i-download-a-file-over-http-using-python#22776

Content Type	Original Author	Original Content on Stackoverflow
Question	Gareth Jenkins	View Question on Stackoverflow
Solution 1 - C#	Gareth Jenkins	View Answer on Stackoverflow

How do I convert a date to a HTTP-formatted date in .Net / C#

C# Problem Overview

C# Solutions

Solution 1 - C#

Get size of a file before downloading in Python

How best to use File Version and Assembly Version?

Attributions