introduction(9)

introduction(9)

Logging In

To log in you must have a valid user name and password, which can be obtained from your system adminis- trator.

When a connection has been established, the system displays login: on your terminal. Type your user name and press the Return key. Enter your password (it is not echoed by the system) and press Return.

A list of copyright notices and a message-of-the-day may greet you before the ®rst prompt.

It is important that you type your login name with lowercase letters, if possible. If you type uppercase letters, HP-UX assumes that your terminal cannot generate lowercase letters, and treats subsequent uppercase input as lowercase.

When you log in successfully, the system starts your login shell. The default is the POSIX shell, /usr/bin/sh . The POSIX shell (and its predecessors, the Korn and Bourne shells) use $ as the default prompt. The C shell uses %.

See login(1) for more on login, passwd(1) to change your password, chsh(1) to change your login shell.

Logging Out

You can log out of the shells by typing an exit command or the eof (end-of-®le) character (see the Special Interactive Characters subsection below). The shell terminates and the login: prompt appears again. (If you are using the C, Korn, or POSIX shells, respectively, see csh(1), ksh(1), or sh-posix(1) for information about the ignoreeof special command.)

How to Communicate Through Your Terminal

HP-UX gathers keyboard input characters and saves them in a buffer. The accumulated characters are not passed to the shell or other program until you type Return.

HP-UX terminal input/output is full-duplex. It has full read-ahead, which means that you can type at any time, even while a program is printing on your display or terminal. Of course, if you type during output, the output display will have the input characters interspersed in it. However, whatever you type will be saved and interpreted in the correct sequence. There is a limit to the amount of read-ahead, but it is generous and not likely to be exceeded unless the system is severely overloaded or operating abnormally. When the read-ahead limit is exceeded, the system throws away all the saved characters.

stty(1) tells you how to describe the characteristics of your terminal to the system. pro®le(4) explains how to accomplish this task automatically every time you log in.

Special Interactive Characters

A number of special characters are used to control the input and output of your terminal. These characters have defaults and can be rede®ned with the stty command (see stty(1)).

stty

Default At Login

Common

Name

Character (ASCII Name; Key Names)

Rede®nition

eof

^D (EOT)

 

erase

#

^H (BS; Backspace)

kill

@

^U (NAK), ÃX (CAN)

intr

Ã? (DEL; Delete, Rub, Rubout)

^C (ETX)

quit

Ã\ (FS)

 

start

ÃQ (DC1; X-ON)

 

stop

ÃS (DC3; X-OFF)

 

The eof character terminates "®le" input from the terminal, as read by programs and scripts. By exten- sion, eof can also terminate the shell (see the Logging Out subsection above).

The kill character deletes all characters typed before it on a terminal input line. The erase character erases the last character typed. Successive uses of erase will erase characters back to, but not beyond, the beginning of the input line.

The intr character generates an interrupt signal that bypasses the input buffer. This signal generally causes whatever program you are running to terminate. It can be used to stop a long printout that you don't want. However, programs can arrange either to ignore this signal altogether, or to be noti®ed when it happens (instead of being terminated). For example, the vi editor catches interrupts and stops what it is doing, instead of terminating, so that an interrupt can be used to halt an editing operation without losing

Introduction−4

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HP-UX Release 11i: December 2000