V8 JavaScript Engine getting started 3-a simple V8 Application

After compiling the hello World program, you can't help but use V8 and V8 JavaScript Engine as a powerful JavaScript parsing engine. What functions can it provide for us?
Let's take a closer look at the hello World Program:

... // Create a string containing the JavaScript source code. Handle <string> source = string: New ("'hello' + ', world! '"); // Compile the source code. handle <SCRIPT> script = Script: Compile (source); // run the script to get the result. handle <value> result = script-> Run ();
    // Convert the result to an ASCII string and print it.    String::AsciiValue ascii(result);    printf("%s/n", *ascii);    return 0;
The annotation is very clear: Use string: New to generate the source code, use Script: Compile to compile the source code, and execute script-> Run () to get the result.
      
In addition, the script execution result can be converted into an ASCII string. And string: New accepts an ASCII string as the parameter.
Therefore, although we do not know any basic concepts of V8, we only need to modify the hello World program to implement a simple JavaScript decryption program!
A simple JavaScript decryption program function: encrypts the criptcode into the input.txt file, and the decryption result is generated into the output.txt file.
Key code:
/*************************************** *********************************/
    
/* Function name: v8_decryt
    
/* Skill: Get the execution result of a piece of JavaScript code, which can be used to decrypt Javascript
    
/* Return value: the number of characters in the result string.
    
/* Note: the memory of the returned string presult is cleared by the caller.
    
/*************************************** *********************************/
  
Unsigned int v8_decryt (const char * pexpression, // string containing JavaScript code
    
Char * & presult // output parameter, returns a string containing the JavaScript code execution result
    
)
  
{
// Create a stack-allocated handle scope.
    
V8: handlescope handle_scope;
// Create a new context.
    
V8: Persistent <V8: context> context = V8: Context: New ();
// Enter the created context for compiling and
    
// Running the hello World script.
    
V8: Context: Scope context_scope (context );
// Create a string containing the JavaScript source code.
    
V8: handle <V8: String> source = V8: String: New (pexpression );
  
// Compile the source code.
    
V8: handle <V8: SCRIPT> script = V8: Script: Compile (source );
// Run the script to get the result.
    
V8: handle <V8: value> result = script-> Run ();
// Dispose the persistent context.
    
Context. Dispose ();
// Convert the result to a two-byte string.
    
V8: String: asciivalue ASCII (result );
// Todo: add extra codes here
    
Unsigned int size = ASCII. Length ();
  
If (size! = 0)
  
{
  
Presult = (char *) malloc (size + 1 );
  
Memset (presult, 0, size + 1 );
  
Memcpy_s (presult, size, * ASCII, size );
  
}
  
Return size;
  
}
Test example:
View eval Encryption
eval(function(p,a,c,k,e,d){e=function(c){return c.toString(36)};if(!''.replace(/^/,String)){while(c--){d[c.toString(a)]=k[c]||c.toString(a)}k=[function(e){return d[e]}];e=function(){return'//w+'};c=1};while(c--){if(k[c]){p=p.replace(new RegExp('//b'+e(c)+'//b','g'),k[c])}}return p}('9 a(){8();7 0=4.5(/'6/');0.b(/'#c#i/');4.f(0);d{0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1);0.2(/'3/',1)}h(e){}1.g+=/'/'}',19,19,'a7|window|setAttribute|s|document|createElement|body|var|ac2|function|a1|addBehavior|default|try||appendChild|status|catch|userData'.split('|'),0,{}))
Remove the evalfile to the input.txtfile (retain the left and right character numbers). Run the command output.txt
function a1(){ac2();var a7=document.createElement('body');a7.addBehavior('#default#userData');document.appendChild(a7);try{a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window);a7.setAttribute('s',window)}catch(e){}window.status+=''}
Decrypted successfully!
Complete code (only one. cpp in vs2010 can be easily converted to your vs Version)
Http://download.csdn.net/source/2718386