Information Technology Reference
In-Depth Information
Multiple data streams
For traditional files, the file's data is a single logical sequence of bytes, and each byte
can be identified by its offset from the start of the sequence (e.g., byte 0, byte 999, or
byte 12481921 of a file.)
Some file systems support multiple sequences of bytes per file. For example, Ap-
ple's MacOS Extended file system supports multiple forks per file—a data fork for the
file's basic data, a resource fork for storing additional attributes for the file, and multiple
named forks for application-defined data. Similarly, Microsoft's NTFS supports alternate
data streams that are similar to MacOS's named forks.
In these systems, when you open a file to read or write its data, you specify not only
the file but also the fork or stream you want.
/
bin
exec
echo
exec
ls
home
mike
tom
Music
Work
Docs
Class
OS
Lorem ipsum dolor sit amet, consectetur adipiscing
elit. Donec aliquam scelerisque tincidunt. Curabitur
sed augue nibh, nec dapibus urna. Vestibulum sit amet
leo vitae neque dictum adipiscing.
Cras aliquam, risus quis fringilla malesuada, leo felis convallis
felis, tincidunt eleifend turpis sem sit amet massa. Nunc eu
felis vitae risus hendrerit rhoncus ac a neque. Donec
accumsan, lorem sed imperdiet convallis, arcu urna rutrum
mi, sollicitudin vestibulum tellus lectus vulputate mauris.
hw1.txt
Figure11.2: Example of a hierarchical organization of files using directories.
