Operation Manual

The Linux Command Line

155

Notes:

Lesson 6.2: Command syntax and ﬁle structure

Commands take the form:

In guides, such as this one, the brackets “<” and “>” are often used to indicate

the place a command would take in a string of text being typed into the CLI.

The horizontal line “|” is used to denote “or”. Confused? Okay, let’s look at the

example above. We would read that as saying that commands can be used by

themselves OR they can be used with:

• Switches: single letters, preceded by a hyphen, that adjust what the

command does

• Parameters: things that the command needs to know in order to work

• A target: the thing (such as a ﬁle) that the command will be applied to

Let’s look at an example. We’ll start with the “ls” command, which you can use to

see a list of a folder’s contents.

ls -l /home/brian

This command tells the command line to list, in long format, the contents of the

directory “/home/brian”. The command is “ls”; the switch “-l” tells Linux that you

want the list in long format; and the target of this command is the directory

“/home/brian”. In this example, there are no parameters, so that part of the

command is just skipped.

Lists the contents of directories.

For a slightly more detailed example, let’s look at the “mount” command, which

tells Linux to incorporate a new ﬁle system (such as a CD or DVD) into its own ﬁle

system structure so that you can browse it.

mount -F smbfs //workgroup;fred:foo@192.168.1.99/homes /mnt/net

This command tells the operating system to use the username “fred”

and password “foo” (parameters) to make the shared drive called “homes” on

the Windows server at 192.168.1.99 (parameter) appear in the directory tree at

the point “/mnt/net” (target) using the Server Message Block Filing System

(the -F switch).

mount

Makes a ﬁle structure available at a new location.

Command Switch Target

Command Switch Parameters Target