LINUX
COMMANDS
Contents | Previous
| Next
A. Further Help
What's a filesystem, directory, and file?
Think of a file as a piece of paper. Words and pictures
can be stored on this piece of paper.
To organise all these bits of paper, they're stored in
folders. Each folder is a directory. Folders can
be stored inside other folders to become subdirectories.
The folder that holds all other folders (the root
(/) directory in Linux) is for all purposes, the
filesystem.
What's a current and parent directory?
The current directory (or current working directory)
is the directory you're in.
The parent directory is the directory the current
directory is stored in.
Bytes, kilobytes, megabytes, gigabytes?
Computers are stupid. They only know two things, on and
off. On is represented by a 1 and off is represented
by a 0. These we call bits.
By clumping together eight bits you get a byte.
Here's an example:
01001100
This notation is called binary. It's not as complicated
as it looks. If the number above were in denary (base 10)
notation, you would know this number to represent 1,001,100
(one million, eleven hundred).
But because it's in binary (base 2), each of the columns
represents:
128 64 32 16 8 4 2 1
0 1 0 0 1 1 0 0
Which is 64 + 8 + 4 = 76.
Fortunately the computer deals with all this and you can
quite happily forget about it.
What you do need to know, is that there are 1024 bytes
in a kilobyte (k or Kb), 1024 kilobytes in a megabyte
(M or Mb), and 1024 megabytes in a gigabyte (G or
Gb).
What's an absolute and relative path?
A path is the route taken to get to a file or directory.
Absolute path means it starts from the root (/)
directory, e.g.:
/home/john/mywork/report.txt
A relative path means just that, that it's relative
to the current directory, e.g.:
mywork/report.txt
You can always tell a relative path because it never starts
with a: /
Contents | Previous
| Next
