The
$
symbol is the shell's prompt; don't type it or the space that
follows
. Type what's shown in the
bold fixed-width typeface
. Press Return when you complete each line. The response you get back (if any) follows, shown in
fixed-width typeface
but not bold. In this example, you type two commands,
sudo renice -15 25132
and
ps -xc -O pri,nice grep iPhoto
, pressing Return at the end of each command.
Sometimes you're required to give your administrator's password before a command can be executed, as shown on the second line of the example. Type your password and press Return, and don't worry when nothing is
echoed
back as you type. If you are not an administrator, you won't be able to issue such commands.
The output from a command is included in the code extract unless the command line is being illustrated without the need for example output. Sometimes a
$
is shown at the end of the results to
emphasize
that no (more) output is expected. Sometimes the prompt is shown as
#
which means you should be running as the root
user
(superuser).
Mostly, output shown in the examples is as you see it in the Terminal. Sometimes it's curtailed, or sections are chopped from the middle, because it's too long and not of great interest.
The book uses an ellipsis (...) to indicated omitted output.
$ top -o cpu
...
PID COMMAND %CPU TIME #TH #PRTS #MREGS RPRVT ...
15931 top 26.4% 0:29.98 1 18 22 1.04M...
14631 Microsoft 20.5% 6:00:56 4 96 368 23.2M...
10898 Terminal 7.3% 20:17.01 8 105 193 3.37M...
14140 Safari 1.3% 38:12.23 7 291 412 24.0M...
69 WindowServ 1.3% 4:29:47 2 882 2914 34.8M...
...
A Terminal window is usually 80 or more characters wide, but typographical limitations mean that examples in the book are only 60
characters
wide. It has been necessary, therefore, to edit long lines by using any of four techniques. Where possible, padding (white space) is removed, so the output shown in the book looks more squashed than you'd see in the Terminal. Sometimes lines are truncated, indicated by an ellipsis.
$
top
Processes: 125 total, 3 running, 122 sleeping, 391 thre...
Load Avg: 0.93, 0.62, 0.46 CPU usage: 24.7% user,...
Sometimes the middle part is chopped because the end is important.
$
ps -acux
USER PID %CPU %MEM ... TIME COMMAND
root 18670 11.0 0.1 ... 0:00.29 sshd
saruman 10898 8.5 1.5 ... 22:58.57 Terminal
Finally, sometimes output is wrapped to cover two lines where you'd see it all on one line in the Terminal.
Commands that you type should be on a single line. Where command lines are too long for the width of the book, they are shown broken, but they must be entered as one line. Where a command line has to be broken for layout reasons, the special symbol
is used, and the rest of the command follows on the
next
line, indented four spaces.
$
ipfw add 3010 allow tcp from any to any dst ¬
1024-65535 in
It's very important to note whether a space appears before the
symbol and to include it on your command line. Type the line shown above as
ipfw add 3010 allow tcp from any to any dst 1024-65535 in
Where no space should be typed, none is shown before the
symbol. For example, type the following line
$
ditto -rsrc User\ Template/¬
English.lproj/ /Users/jan
as:
ditto -rsrc User\ Template/English.lproj/ /Users/jan
In the main text, command names, arguments, options, files, directory
names
, and whatever you type at the command line is shown in
fixed-width typeface
.
