.\" $OpenBSD: help.1,v 1.11 2012/08/12 17:01:36 schwarze Exp $ .\" .\" Copyright (c) 1999 Aaron Campbell .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR .\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES .\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. .\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, .\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, .\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY .\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" .Dd $Mdocdate: August 12 2012 $ .Dt HELP 1 .Os .Sh NAME .Nm help .Nd help for new users and administrators .Sh DESCRIPTION This document is meant to familiarize new users and system administrators with .Ox and, if necessary, .Ux in general. .Pp Firstly, a wealth of information is contained within the system manual pages. In .Ux , the .Xr man 1 command is used to view them. Type .Ic man man for instructions on how to use it properly. Pay especially close attention to the .Fl k option. .Pp Other .Ox references include the FAQ (Frequently Asked Questions) located at .Lk http://www.openbsd.org/faq , which is mostly intended for administrators and assumes the reader possesses a working knowledge of .Ux . There are also mailing lists in place where questions are fielded by .Ox developers and other users; see .Lk http://www.openbsd.org/mail.html . .Pp System administrators should have already read the .Xr 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 consider any possible security implications your changes may have. .Ss 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; .Ox ships with .Xr csh 1 , .Xr ksh 1 , and .Xr sh 1 . Each user's shell is indicated by the last field of their corresponding entry in the system password file .Pf ( Pa /etc/passwd ) . .Ss Basic Unix commands .Bl -tag -width "chmodXXX" .It Cm man Interface to the system manual pages. For any of the commands listed below, type .Ic man for detailed information on what it does and how to use it. .It Cm pwd Print working directory. Files are organized in a hierarchy (see .Xr hier 7 ) called a tree. This command will indicate in which directory you are currently located. .It Cm cd Change working directory. Use this command to navigate throughout the file hierarchy. For example, type .Ic cd / to change the working directory to the root. .It Cm ls List directory contents. Type .Ic ls -l for a detailed listing. .It Cm cat Although it has many more uses, .Ic cat filename will print the contents of a plain-text file to the screen. .It Cm mkdir Make a directory. For example, .Ic mkdir foobar . .It Cm rmdir Remove a directory. .It Cm rm Remove files. Files are generally only removable by their owners. See the .Xr chmod 1 command for information on file permissions. .It Cm 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. .It Cm cp Copy files. .It Cm mv Move and rename files. .It Cm ps List active processes. Most .Ux Ns -based operating systems, including .Ox , are multitasking, meaning many programs share system resources at the same time. A common usage is .Ic ps -auxw , which will display information about all active processes. .It Cm kill Kill processes. Used mostly for terminating run-away/unresponsive programs, but also used to signal programs for requesting certain operations (e.g., re-read their configuration). .It Cm date Print the current system date and time. .It Cm mail Access mailbox. .It Cm exit Log out of the system. .El .Pp 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 .Ev PATH environment variable (see .Xr 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. .Pp Shell built-in commands do not have their own manual page, so it's necessary to read the manual page for the user's shell. Tools such as .Xr which 1 and .Dq whence , a .Xr ksh 1 built-in command, can be used to see what commands are being executed. .Sh SEE ALSO .Xr csh 1 , .Xr ksh 1 , .Xr man 1 , .Xr whatis 1 , .Xr whereis 1 , .Xr which 1 , .Xr afterboot 8 .Sh HISTORY This manual page was written by .An Aaron Campbell Aq aaron@openbsd.org and first appeared in .Ox 2.6 .