Size: 1 byte(s)
Size: 6 byte(s)
65 = 01000001 = 'A'
32 = 00100000 = ' '
32 = 00100000 = ' '
32 = 00100000 = ' '
32 = 00100000 = ' '
122 = 01111010 = 'z'

class LogFile : IDisposable
{
    private readonly FileStream fs;
    private bool disposed = false;
    public void Dispose()
    { Dispose(true); GC.SuppressFinalize(this); }
    protected virtual void Dispose(bool disposing)
    {
        if (disposed) return;
        if (disposing) fs.Dispose();
        disposed = true;
    }
    ~LogFile() { Dispose(false); }
}

Read only : CanRead=True CanWrite=False CanSeek=True
Read write: CanRead=True CanWrite=True CanSeek=True

fs.WriteByte(65);
fs.WriteByte(66);

Position=0 Length=0
Position=1 Length=1
Position=2 Length=2
File now holds: AB

ReadByte on a Write-only stream:
  NotSupportedException
WriteByte on a Read-only stream:
  NotSupportedException
Append with FileAccess.Read:
  ArgumentException
Append, then Seek back to 0:
  IOException

data = new byte[fs.Length];
int numBytesToRead = (int)fs.Length;
int numBytesRead = 0;
while (numBytesToRead > 0)
{
    int n = fs.Read(data, numBytesRead, numBytesToRead);
    if (n == 0) break;     // end of the file
    numBytesRead += n;
    numBytesToRead -= n;
}

Read 10 bytes:
67 35 32 115 116 114 101 97 109 115 
copy.txt holds: C# streams

var w = new StreamWriter(fs);  // fs: note.txt
w.Write("Hello");      // size?
w.Flush();             // size?
w.WriteLine(" OS");    // size?
w.Close();             // size?

After Write : file size = 0
After Flush : file size = 5
After WriteLine: file size = 5
After Close : file size = 10

sr.BaseStream.Seek(0, SeekOrigin.Begin);
string str = sr.ReadLine();
while (str != null)
{
    Console.WriteLine(str);
    str = sr.ReadLine();
}

1: Streams
2: and
3: Directories
ReadLine returned null after line 3

Characters read: 25
File size: 25 bytes

dataout = new BinaryWriter(
    new FileStream("data", FileMode.Create));
dataout.Write(20);            // int
dataout.Write(101.50);        // double
dataout.Write(true);          // bool
dataout.Write(12.2 * 15.5);   // double
dataout.Close();

File size: 21 bytes
First 4 bytes (the int 20): 20 0 0 0
Byte 12 (the bool true): 1

site
    about.txt       48 bytes
    work.txt        13 bytes
    images
        logo.bin   300 bytes
    wiki
        home.txt    19 bytes
        week1.txt   25 bytes
        old
            week0.txt  13 bytes

var dir = new DirectoryInfo(source);
DirectoryInfo[] dirs = dir.GetDirectories();
if (!Directory.Exists(dest))
    Directory.CreateDirectory(dest);
foreach (FileInfo file in dir.GetFiles())
    file.CopyTo(Path.Combine(dest, file.Name), false);
if (copySubDirs)
    foreach (DirectoryInfo subdir in dirs)
        DirectoryCopy(subdir.FullName,
            Path.Combine(dest, subdir.Name), copySubDirs);

create site-2
  copy site-2\about.txt
  copy site-2\work.txt
create site-2\images
  copy site-2\images\logo.bin
create site-2\wiki
  copy site-2\wiki\home.txt
  copy site-2\wiki\week1.txt
create site-2\wiki\old
  copy site-2\wiki\old\week0.txt
Copying finished
Files in site-2: 6

string line = sr.ReadLine();
while (line != null)
{
    count++;
    if (line.Length > longest.Length)
        longest = line;
    line = sr.ReadLine();
}

Lines: 5
Longest: Windows (7 characters)
File size: 41 bytes

static long PrintTree(DirectoryInfo dir, string indent)
{
    long total = 0;
    Console.WriteLine(indent + dir.Name + "/");
    foreach (FileInfo f in dir.GetFiles())
    {
        Console.WriteLine(indent + "    " + f.Name
            + " (" + f.Length + ")");
        total += f.Length;
    }
    foreach (DirectoryInfo sub in dir.GetDirectories())
        total += PrintTree(sub, indent + "    ");
    return total;
}

site/
    about.txt (48)
    work.txt (13)
    images/
        logo.bin (300)
    wiki/
        home.txt (19)
        week1.txt (25)
        old/
            week0.txt (13)
Total: 418 bytes
wiki: 57 bytes

foreach (var directory in Directory.GetDirectories(sDir))
{
    foreach (var filename in Directory.GetFiles(directory))
    {
        // read it, lower-case it,
        // add it if it contains "stream"
    }
    DirSearch(directory);
}

foreach (var filename in Directory.GetFiles(sDir))
    using (var sr = new StreamReader(filename))
        if (sr.ReadToEnd().ToLower().Contains(SearchText))
            FilesFound.Add(filename);
foreach (var directory in Directory.GetDirectories(sDir))
    FileSearch(directory);

DirSearch: files containing the word stream
   site\wiki\week1.txt
FileSearch: files containing the word stream
   site\about.txt
   site\wiki\week1.txt