HELP(1) BSD Reference Manual HELP(1)NAMEhelp - help for new users and administrators
DESCRIPTION
This document is meant to familiarize new users and system administrators
with OpenBSD and, if necessary, UNIX in general.
Firstly, a wealth of information is contained within the system manual
pages. In UNIX, the man(1) command is used to view them. Type man man for
instructions on how to use it properly. Pay especially close attention to
the -k option.
Other OpenBSD references include the FAQ (Frequently Asked Questions) lo-
cated at http://www.openbsd.org/faq, which is mostly intended for ad-
ministrators and assumes the reader possesses a working knowledge of
UNIX. There are also mailing lists in place where questions are fielded
by OpenBSD developers and other users; see
http://www.openbsd.org/mail.html.
System administrators should have already read the afterboot(8) man page
which explains a variety of tasks that are typically performed after the
first system boot. When configuring any aspect of the system, first con-
sider any possible security implications your changes may have.
The Unix shell
After logging in, some system messages are typically displayed, and then
the user is able to enter commands to be processed by the shell program.
The shell is a command-line interpreter that reads user input (normally
from a terminal) and executes commands. There are many different shells
available; OpenBSD ships with csh(1), ksh(1), and sh(1). Each user's
shell is indicated by the last field of their corresponding entry in the
system password file (/etc/passwd).
Basic Unix commands
man Interface to the system manual pages. For any of the commands
listed below, type man <command> for detailed information on what
it does and how to use it.
pwd Print working directory. Files are organized in a hierarchy (see
hier(7)) called a tree. This command will indicate in which
directory you are currently located.
cd Change working directory. Use this command to navigate throughout
the file hierarchy. For example, type cd / to change the working
directory to the root.
ls List directory contents. Type ls -l for a detailed listing.
cat Although it has many more uses, cat filename will print the con-
tents of a plain-text file to the screen.
mkdir Make a directory. For example, mkdir foobar.
rmdir Remove a directory.
rm Remove files. Files are generally only removable by their owners.
See the chmod(1) command for information on file permissions.
chmod Change file modes, including permissions. It is not immediately
obvious how to use this command; please read its manual page
carefully, as proper file permissions, especially on system
files, are vital in maintaining security and integrity.
cp Copy files.
mv Move and rename files.
ps List active processes. Most UNIX-based operating systems, includ-
ing OpenBSD, are multitasking, meaning many programs share system
resources at the same time. A common usage is ps -auxw, which
will display information about all active processes.
kill Kill processes. Used mostly for terminating run-away/unresponsive
programs, but also used to signal programs for requesting certain
operations (i.e., re-read their configuration).
date Print the current system date and time.
mail Access mailbox.
logout Log out of the system.
When a command is entered, it is first checked to see if it is built-in
to the shell. If not, the shell looks for the command in any directories
contained within the PATH environment variable (see environ(7)). If the
command is not found, an error message is printed. Otherwise, the shell
runs the command, passing it any arguments specified on the command line.
SEE ALSOman(1), whatis(1), whereis(1), afterboot(8)HISTORY
This manual page was written by Aaron Campbell <aaron@openbsd.org> and
first appeared in OpenBSD 2.6.
MirOS BSD #10-current October 17, 1999 1
