7.Файлове и потоци

Файлове и потоци

File – something (a resource) that stores information
-	Located on a storage device
-	Has name, size, extension and contents
-	Stores information as series of bytes

Two file types – text and binary
Text files contain text information
-	Store text differently according to the encoding. E.g.:
o	in ASCII a character is represented by 1 byte,
o	in UTF8 a character is represented by 1-4 bytes
Binary files – store raw sequence of bytes
-	can contain any data (images, sounds, multimedia, etc.)
-	not human-readable

Stream – the natural way to transfer data in the computer world
Streams are ordered sequences of bytes – provide consecutive access to its elements


По default повечето хард дискове четат по 4 kB наведнъж (на операция), така че 4 kB е оптималния вариант при четене на байтове

Different types of streams are available to access different data sources – file access, network access, memory streams and others

Base streams:
FileStream – чете и пише във файлове
MemoryStream – чете и пише в паметта
NetworkStream – чете и пише по мрежата

.NET supports special streams
-	they work just like normal streams but provide additional functionality. E.g.:
o	CryptoStream – encrypts when writing, decrypts when reading
o	GzipStream – compresses, decompresses data

File is a static class that provides methods for quick and easy manipulation of files

Празните файлове и папки не заемат никава памет на твърдия диск. Заемат памет само във файловата система