Here’s how you do it.

NSString to char*

NSString* nsstr = @"My NSString" ;
const char * cstr = [ nsstr cStringUsingEncoding:ASCIIEncoding ] ;

// There's also
const char * cstr2 = [ nsstr UTF8String ] ;

These are covered in the docs page for NSString, basically.

char * to NSString

// Here you simply want to use one of the static method constructors
const char * cstyleString = "HELLO!!" ;
NSString * nsstr = [ NSString stringWithUTF8String:cstyleString ] ;

Or an instance method
NSString * nsstr2 = [[ NSString alloc ] initWithUTF8String:cstyleString ]

(( just a note that any methods labelled with + method are static methods and methods labelled with - are instance methods ))

sprintf() for NSString

Use initWithFormat

[ [ NSString alloc ] initWithFormat:@"%s is %d years old", "Bobby", 45 ]

This seems to be a trivial and is an inherently subjective question but I want to know what the best practice is __with reasons__.

I used to write

    char * var ;

But I started writing

    char* var ;

Because I thought that the type of var is simply char* so the * pointer should be stuck to the type so its read in “one eyeful.”

THEN I ran into a bug recently where I didn’t notice that I had declarations

    char* var1, var2 ;

And I actually didn’t realize that var2 was type char, not char*. Hmm. Then I thought, well, this way makes the most sense then:

    char *var1, *var2 ;

Currently I’m thinking the last way is the correct way now.

“End of the football.”

http://www.youtube.com/watch?v=aVhYN7NTIKU

this isn’t just funny to watch, its _real_!

this isn’t funny in an “aha look at him sort” of way,

look at her expression at 1:00, and his answers to some of the questions is quite hilarious.

You can use mplayer as follows:

1. Download mplayer from here if you’re on a windows machine. If that stops working, pick another installer package from this list. If you’re not on windows start here, you may choose to build from source if you’re a masochist.

mplayer -dumpstream -dumpfile stream.wmv mms://lang.stanford.edu/courses/ee380/050216-ee380-100.wmv

from here

Right now i’m not able to rip the stream the connection keeps timing out thouhg

Sufficient condition

An event A is said to be a sufficient condition for an event B iff

The truth/occurrence of event A guarantees the truth/occurrence of event B

Necessary condition

An event A is said to be necessary for an event B
iff the falsity/nonoccurrence of event A GUARANTEES
the falsity/nonoccurrence of event B.

Barycentric coordinates

Plane plane = new Plane( a, b, c ) ;

float areaABC = Vector3.Dot( plane.Normal, Vector3.Cross( b - a, c - a ) ) ;
float areaPBC = Vector3.Dot( plane.Normal, Vector3.Cross( b - P, c - P ) ) ;
float areaPCA = Vector3.Dot( plane.Normal, Vector3.Cross( c - P, a - P ) ) ;

float alpha = areaPBC / areaABC ;
float beta = areaPCA / areaABC ;
float gamma = 1.0f - alpha - beta ;

“watching nonprogrammers trying to run software companies is like watching someone who doesn’t know how to surf trying to surf”

I read that, and i’m like THANK YOU

LOL!! joel refers to the 1984 mac commercial on page 32. He starts to point at how the whole MAC thing.. macusers have a distinct groovy personality from pc users. or something.

Instead of fighting with libcurl you could just use WinInet for your http needs if you are married to the Windows platform.

A quick example follows, great article, and as usual pretty difficult to navigate msdn docs

#include <windows.h>
#include <wininet.h>

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

#pragma comment ( lib, "Wininet.lib" )

int main()
{
  HINTERNET hInternet = InternetOpenA("InetURL/1.0", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0 );

  HINTERNET hConnection = InternetConnectA( hInternet, "mohammad.appspot.com", 80, " "," ", INTERNET_SERVICE_HTTP, 0, 0 );

  HINTERNET hData = HttpOpenRequestA( hConnection, "GET", "/", NULL, NULL, NULL, INTERNET_FLAG_KEEP_CONNECTION, 0 );

  char buf[ 2048 ] ;

  HttpSendRequestA( hData, NULL, 0, NULL, 0 ) ;

  DWORD bytesRead = 0 ;
  DWORD totalBytesRead = 0 ;
  // http://msdn.microsoft.com/en-us/library/aa385103(VS.85).aspx
  // To ensure all data is retrieved, an application must continue to call the
  // InternetReadFile function until the function returns TRUE and the
  // lpdwNumberOfBytesRead parameter equals zero.
  while( InternetReadFile( hData, buf, 2000, &bytesRead ) && bytesRead != 0 )
  {
    buf[ bytesRead ] = 0 ; // insert the null terminator.

    puts( buf ) ;          // print it to the screen.

    printf( "%d bytes read\n", bytesRead ) ;

    totalBytesRead += bytesRead ;
  }

  printf( "\n\n END -- %d bytes read\n", bytesRead ) ;
  printf( "\n\n END -- %d TOTAL bytes read\n", totalBytesRead ) ;

  InternetCloseHandle( hData ) ;
  InternetCloseHandle( hConnection ) ;
  InternetCloseHandle( hInternet ) ;

}

google app engine

index.py

class Person( db.Model ) :
  name = db.StringProperty()

class TPerson( webapp.RequestHandler ) :
  def get( self ) :

    # run once
    '''
    people = [ 'John Hopkins', 'Bob Jordan', 'Mike Bobs' ]

    for person in people :
      p = Person()
      p.name = person
      p.put()
    '''

    people = db.GqlQuery( 'select * from Person' ).fetch( 1000 ) 

    # if you don't .fetch(), then the addition of dynamic
    # properties won't work here.
    for person in people :
      person.shortname = person.name[ 0:2 ]

    self.response.out.write( template.render( 'TPerson.html', { 'people' : people } ) )

application = webapp.WSGIApplication([

  ( '/TPerson', TPerson ),

  ], debug=True )

def main():
  run_wsgi_app(application)

if __name__ == "__main__":
  main()

TPerson.html

{% for p in people %}
<p>{{ p.name }}</p>
<p>{{ p.shortname }}</p>
{% endfor %}

I got this error in my google app engine application

it says something to the effect of

<type ‘exceptions.ImportError’> Python 2.5.4: c:\python25\python.exe
Wed Sep 09 12:29:14 2009
A problem occurred in a Python script. Here is the sequence of function calls leading up to the error, in the order they occurred.

c:\program files (x86)\google\google_appengine\google\appengine\tools\dev_appserver.py in _HandleRequest(self=)
2921 infile,
2922 outfile,
2923 base_env_dict=env_dict)
2924 finally:
2925 self.module_manager.UpdateModuleFileModificationTimes()
base_env_dict undefined, env_dict = {‘APPLICATION_ID’: ‘mohammad’, ‘CURRENT_VERSION_ID’: ‘1.1′, ‘REMOTE_ADDR’: ‘127.0.0.1′, ‘REQUEST_METHOD’: ‘GET’, ‘SERVER_NAME’: ‘localhost’, ‘SERVER_PORT’: ‘8080′, ‘SERVER_PROTOCOL’: ‘HTTP/1.0′, ‘SERVER_SOFTWARE’: ‘Development/1.0′}

Really the problem was I has put a leading slash in my app.yaml where one should not be

- url: /home
  script: /home/index.py

Really this should be

- url: /home
  script: home/index.py

So there was no leading slash on script: EVER.