Online Compilers

Two cool online compilers for code snippets:
http://codepad.org and http://ideone.com

I tried this C++ Fibonacci function and the compiler worked:

#include <iostream>
 
int fib(int n)
{
     if ( n == 0 ) return 0;
     if ( n == 1 ) return 1;
 
     return fib(n-1) + fib(n-2);
}
 
int main(){
 printf("Fib Val: %i", fib(7));
 return 0;
}

.NET C# Get Byte array from a file

public static byte[] GetBytesFromFile(string file)

{

try

{

// check if this is a file name;

if (file == null)

return null;

if (file.Trim().Length == 0)

return null;

// get the size of the buffer

int bufferSize = (int)(new System.IO.FileInfo(file).Length);

// check if the file has anything.

if (bufferSize == 0)

return null;

// create the buffer with the proper size

byte[] buffer = new byte[bufferSize];

// create the stream

System.IO.FileStream fs =  new System.IO.FileStream(file, System.IO.FileMode.Open);

// create the reader of the stream

System.IO.BinaryReader reader = new System.IO.BinaryReader(fs);

// populate the buffer

buffer = reader.ReadBytes(bufferSize);

// Close the stream

fs.Close();

fs.Dispose();

// close the reader

reader.Close();

fs.Dispose();

return buffer;

}

catch (Exception ex)

{

System.Windows.Forms.MessageBox.Show("Please Make sure that the file is valid or is not in use. Details:\r\n" + ex.Message);

return null;

}

}

.NET C# Create a file and open it using Default Application Type

public static void OpenFileWithDefaultApplication(string fullfileLocationAndName, byte[] data)

{

try

{

System.IO.FileStream fs =   new System.IO.FileStream(fullfileLocationAndName, System.IO.FileMode.Create, System.IO.FileAccess.ReadWrite);

fs.Write(data, 0, data.Length - 1);

fs.Close();

fs.Dispose();

System.Diagnostics.Process.Start(fullfileLocationAndName);

}

catch (Exception ex)

{

MessageBox.Show("There was an error opening the file: " + ex.Message);

}

}

JAVA Write to a file

// Write x to file
public void writeFile(String x, String file){
    try{
        // Create file
        FileWriter fstream = new FileWriter(file);
        // Create Writer
        BufferedWriter out = new BufferedWriter(fstream);
        // Write x to the file        
        out.write(x);
        //Close the output stream
        out.close();
    }catch (Exception e){
        //Catch exception if any
        System.err.println("Error: " + e.getMessage());
    }
}

JAVA Date and time formatting

public static String getDateNow(){
  DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date date = new Date();
return (dateFormat.format(date))+"";
}

JAVA Manipulate a String using regular expressions

// Example 1, remove all instances of a word with another in a String.

// Example 2, remove all white spaces from a String

public static String manipulateString(String s){

  String result = s;

  

  //1 replace all instances of the word foo with the word bee 

  result = result.replaceAll("(?:foo)", "bee");

  // remove all white space

  result = result.replaceAll("\\s+", "");

   

  return result;

}

JAVA Open a file using the default application editor.

// Example Foo.xls will be opened with Excel
// Make sure to import the class java.awt.Desktop

public static void OpenFile(String filename){
  try{
    // Check if class 'Desktop' is supported on the platform 
    if (Desktop.isDesktopSupported()) {
      Desktop.getDesktop().open(new File(filename));
    }else{
      System.out.println("Class Desktop is unsupported");
    }
  } catch (Exception ex){
    System.out.println("Error opening "+ filename);
  }
}

.NET C# Write to a file

public static bool WriteToFile(string fileName, string fileContent)
{
    fileName = fileName;
    System.IO.TextWriter tw;
    try
    {
        tw = new System.IO.StreamWriter(fileName, true);
        tw.WriteLine(fileContent);
        tw.Close();
        return true;
    }
    catch{}
    return false;
} 

.NET C# Read from a file

public static string ReadFromFile(string fileName)
{
    string ret = "";
    System.IO.StreamReader sr;
    try
    {
        sr = new System.IO.StreamReader(fileName);           
        ret = sr.ReadToEnd();
        sr.Close();
        return ret;
    }
    catch{ return null; }
}