Unix is case sensitive. This means that Unix distinguishes between
uppercase and lowercase letters, i.e. Biff and biff
don't mean the same thing to Unix.
There are a number of different "flavors" of Unix available today.
By different "flavors" I mean different command interpreters (called
shells) which handle your input in their own unique way.
This manual covers the C shell only. Many of the things found here will
be identical with other shells, but don't count on it. It is possible
to determine which shell is in use by typing echo $SHELL. The
response for the C shell is /bin/csh which is what you should
get. One other popular shell is the Bourne shell which would respond
Unix commands begin with a command name, often followed by flags and
arguments some of which are optional. The generic syntax is:
command [flags] argument1 argument2 ...
Normally the flags are preceded by a hyphen to prevent them from being
interpreted as a filename. For example, in the command line
ls -l avhrr
ls is the program called, -l is the flag, and avhrr
is the argument. This command tells the computer to list (in long
format) the file called avhrr or, if avhrr is
a directory, to list all the files in the directory avhrr.
There are three tools to destroy typos that occur on the command line.
<DEL> Erases the previous character.
<ctrl-W> Erases the previous word.
<ctrl-U> Erases the whole command line.
If output scrolls up on your terminal screen faster than you can read
it, you can suspend it by typing <ctrl-S>. To resume
the display, type <ctrl-Q>. The
will discuss how to pass output through a paging program that will
automatically display only one screen at a time. While I'm at it,
<ctrl-C> will abort a process, and
<ctrl-O> will discard the output until another
<ctrl-O> is entered. Be sure to note that although
the output doesn't appear, the process is still running.
<ctrl-Z> suspends the current program. You can
see its job number by typing jobs. You can resume the
suspended program by giving the fg (foreground) command, or
resume it in the background with bg.
|Controlling your terminal output|
1 A couple of notes on notation here. The
delete key varies from keyboard to keyboard. Your delete key
may be labeled DEL, DELETE, BACKSPACE, RUB, or
RUBOUT. Also, <ctrl-W> means
holding down the <ctrl> key and pressing
W. Control <ctrl> character commands
are not case sensitive, i.e. <ctrl-w>
is equivalent to <ctrl-W>.
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© 1993-2001 Christopher C. Taylor