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Finding Help From Within the Shell

Note: Please look further down about help facilities specific to SDF, like the FAQ!

While the UNIX shell may seem a bit daunting and cold with cryptic two-letter commands, dozens of command line switches, and no animated paper clips to show you the way, there are several different ways of getting help from the system.

Using Manpages

The Definitive Guide to RTFMing

The easiest and most comprehensive way of getting help is reading the manpage. You've probably heard RTFM (Read The Fscking Manual) somewhere throughout your computer use, well, this is that Manual. Manpages are the standard form of documentation for every UNIX. Learn to use them. Learn to love them.

Where can you find them? It's pretty simple. Think of a command. (ls, rm, chmod, kill, grep) or a program (vi, mutt, snarf, majordomo) So go ahead, type

% man command

command being the name of the command you want to learn about. As you can see, manpages are broken down into sections. We'll use mkdir as an example.

% man mkdir
MKDIR(1)                NetBSD General Commands Manual                

     mkdir - make directories

     mkdir [-p] [-m mode] directory_name ...

     mkdir creates the directories named as operands, in the order specified,
     using mode rwxrwxrwx (0777) as modified by the current umask(2).

     The options are as follows:

     -m      Set the file permission bits of the final created directory to
             the specified mode.  The mode argument can be in any of the for-
             mats specified to the chmod(1) utility.  If a symbolic mode is
             specified, the operation characters ``+'' and ``-'' are inter-
             preted relative to an initial mode of ``a=rwx''.

     -p      Create intermediate directories as required.  If this option is
             not specified, the full path prefix of each operand must already
             exist.  Intermediate directories are created with permission bits
             of rwxrwxrwx (0777) as modified by the current umask, plus write
             and search permission for the owner.  Do not consider it an error
             if the argument directory already exists.

     The user must have write permission in the parent directory.
     mkdir exits 0 if successful, and >0 if an error occurred.

     chmod(1), rmdir(1), mkdir(2), umask(2)

     The mkdir utility is expected to be IEEE Std 1003.2 (``POSIX.2'') compat-

NetBSD 2.0.2                   January 25, 1994                   NetBSD 

For our mkdir command, the man page displayed has six sections: NAME, SYNOPSIS, DESCRIPTION, EXIT STATUS, SEE ALSO, and STANDARDS. The NAME section simply shows the name of the command and a terse description of its function. The SYNOPSIS gives a brief outline of the command syntax, so you can see what the command you enter should look like. Items in square brackets [ ] are optional. The DESCRIPTION section provides a detailed description of how the command works, including information on the various options or modes of the command. The EXIT STATUS section describes what status codes are generated by the command when it completes (successfully or unsuccessfully). These codes can be read by programs (such as a shell script) to determine how to react to the command's result. SEE ALSO provides cross referencing information for related commands or others which may be helpful. And finally, the STANDARDS section lists information on which standards this particular command complies with.

The manual is divided up into nine sections:

  1. User commands.
  2. System calls and error numbers.
  3. Functions in the C libraries.
  4. Device drivers.
  5. File formats.
  6. Games and other diversions.
  7. Miscellaneous information.
  8. System maintenance and operation commands.
  9. Kernel developers.

In some cases, the same topic will appear on more than one section of the manual. For example, there is a chmod user command and a chmod() system call. How would you find the appropriate manpage? You can tell man which section you'd like to look under. If you wanted to find the user command you would type:

% man 1 chmod

This would display the manpage for the user command chmod. References to the specific sections are traditionally placed in parenthesis after the command name like so: chmod(1)

Well, this is all fine and good if you know the name of the command, but what if you can't remember the name? 'man -k' can be used to search for keywords in the command descriptions. So, if you want to find a mail program you would type:

% man -k editor

A list of commands with the keyword “editor” in their descriptions will be presented on the screen.

The GNU Info system

For programs of the GNU Project, you may also use the info command. If you know the name of a program, give it as an argument (like with man). In fact, you can use info as an alias to man, because the info reader will simply display the man page if it cannot find an info entry (but you cannot specify the manpage section).

However, navigation is different in the standard info reader, as it is based on the emacs text editor. Quick key help (for more, consult info info):

SPACE, BACKSPACEpage forward, backward
TABplace cursor onto next menu item or link (info files are hyperlinked)
RETURNjump to the place where the link the cursor is sitting on points to
l (the letter ell)get back to the spot from where last jump started
u n pup, next, previous node (info files are hierarchically structured)
qquit the info reader

With most terminals, you can also move around using the cursor keys (arrows).

SDF specific help

There are also a number of tools at SDF that you can use to get more help. Enter the following commands at a shell prompt.

Command Description
helpThe SDF help system. After launching the 'help' reader by typing help at the shell prompt, navigate by the letter commands in brackets
faqA collection of frequently asked questions. After starting the FAQ reader, type 'g ' to enter a topic, 'l' to list the questions in the topic, and 't ' to read the FAQ. You can also view an HTML version of the FAQ on the SDF website.
helpdeskIf you cannot find your answer in the man pages, help, faq, or googling post a question to the helpdesk and a friendly member of the community will answer your question. Any member with ARPA status can login as an attendent to answer questions. Please note: in helpdesk you should only post questions directly related to SDF's systems, but not about general UNIX, programming or gardening - these belong to the bboard!
bboardTo enter the SDF Bulletin Board System (BBOARD), type bboard at the command line. Help on using BBOARD may be found by typing h and ? at the bboard Command: prompt or at the bboard tutorial. If you have a general question about using the SDF system, post in <HELPDESK>. If you have a question that requires intervention from an admin 1) (e.g., software requests or membership queries), post in <REQUESTS>. Admins 2) don't read the other boards.
comCom and bboard are meeting places for the SDF community. You could also pose your question there. Bboard and faq have the same interface. See COM is not IRC for how to use com.

SDF Specific Commands

Informative Commands

Command Description 3)
addressprints out an address & paypal information for sending money to SDF; used by some other commands
arpaprints out information about the ARPA membership level
bbsgives information about purchasing a BBS documentary DVD set from SDF; seems to be a bit outdated
commandsprints out a list of basic Unix commands; also available as “unix”
dbaprints out information about the DBA membership
dialupgives information on SDF's dialup internet service
downtimedisplays the reason(s) for recent server downtime
dslrefers the user to “” to find out about the availability of SDF DSL in one's area
editorsdisplays the list of text editors from FAQ BASICS #09
faqinteractive command for viewing the SDF Frequently Asked Questions (and their answers); uses the same command set as bboard
gallerylists some of the commands that users can use to contribute to the SDF galleries (see below)
gamesprints a list of some of the games installed on SDF
getdialuplists dialup internet services available in your area code
helpa small interactive program listing useful commands from certain categories. Note that this program is located at /usr/pkg/bin/help and is not to be confused with the help command built into most shells.
howgives an overview of the types of memberships available
maxusersdisplays the current record for the maximum number of users logged into SDF at once
metaprints out information about the MetaARPA membership level
milgives information on how the validation process can be waived for those on active military duty
musicprints out information about purchasing the SDF music compilations
orderoutdated command; now consists of a pointer to the store on SDF's website
softwarelists the software packages available to the various membership levels
stickerprints information on obtaining an SDF bumper sticker
twenexprints out summaries of (most of) the user-contributed software in /sys/sdf/bin
unixsame as commands
vhostprints out information about the VHOST membership
vpnprints out information about the VPN membership

Inter-User Communication & Social Networking

Command Description 4)
bboardbulletin board system for SDF
com (a.k.a. commode)inter-user chat system for SDF
guestbooksign or view the guestbook
happeningsubmit an anonymous journal entry or view a random entry
helpdeskrequest help from & give help to other SDF users
mesgsend messages to other users
notesleave urgent notes for other users
profilesset up a profile for viewing by other SDF users

Account Management Commands

Command Description 5)
addlinkpublish your website; invoked by mkhomepg
bkspset your backspace key
greylisttoggle greylisting for your e-mail address(es) (VPM membership required)
maintchange your password, shell, & contact information
mdnsassign a domain name to a dynamic IP address (MetaARPA membership required); also available as “udns”
metaarrayFor MetaARPA members. This will first generate a random login password for your MetaArray account followed by a random database password sent via local e-mail, if you have a DBA membership. If you ever forget your MetaArray password or your MetaArray MySQL password, this will reset it.
mkcronset up & manage cronjobs (MetaARPA 6) membership required)
mkfingercontrol what information to display for finger requests from remote hosts
mkgopherset up a gopherspace on SDF
mkhomepgset up a website on SDF
mkvhostcreate & maintain DNS and/or VHOST membership features
mkvpmmanage virtual POP3 mailboxes (VPM membership required)
motdmanage MOTD membership
mypasswdchange your MySQL password.
phloglist (or delist) your Gopher blog on SDF's registry of phlogs
reset-mysqlresets your MySQL password and sends you a new one via local mail.
setdialupmanage DIALUP membership
setgrpadd & remove users to & from your personal group (MetaARPA membership required)
setvmailtoggle e-mail addresses at various SDF domains (MetaARPA 7) membership required)
setvpnconfigure your PPTP VPN login on SDF (VPN membership required)
startsqlset up a MySQL database (DBA membership required)
tweakredistribute your file storage quotas (TWEAK membership required)
udnssame as mdns
vpmclearclear out a virtual POP3 mailbox (VPM membership required)

Account Information

Command Description 8)
diskdisplay filesystem usage for your home directory, mail spool, gopherspace, & webspace
domainslist the SDF domains available to you for webhosting & e-mail addresses
duesgive details on your membership dues
expireshow how long until your account expires (pre-validated users only)
vpmstatdisplay information about your virtual POP3 mailboxes (VPM membership required)
vpnstatsview VPN usage statistics (VPN membership required)
webquotashow web transfer quotas for your website

User Information

Command Description 9)
onlineprints the amount of time that the given user (or yourself, if none is given) has spent logged in today; does not work correctly
sentryprints notices of logins & logouts on the system
uinfoprint the date & time when the given user joined SDF & the various membership levels
urlprint the URL at which the given SDF user's website is located
Command Description 10)
artgalleryadd photography & artwork to the SDF art gallery
astrogalleryadd astronomical photographs to the astro gallery
deskshotsadd a picture of your computer desktop to the deskshots gallery
patchesadd pictures of SDF 20th anniversary patches to the patches gallery
sdfersadd a picture of yourself to the SDF member photos gallery
stickersadd pictures of SDF stickers to the SDF stickers gallery
vintageadd a picture of a vintage computer to the vintage computers gallery


Command Description 11)
due (delete, undelete, expunge) two-step file deletion for Unix machines. Currently, this program doesnot actually seem to be installed, but its source is available in /sys/sdf/src/due.
freeircallows non-ARPA members to use IRC on the weekend
game-reviewsubmit a review for a game on
instructmanage student shell accounts (INSTRUCTOR membership required)
mkgalleryproduce a thumbnail gallery page for the given images
mudtelnet to SDFmud
nospamdefers obvious spam messages to separate files; run nospam -i for more information
onelinerprint a random line by another SDF member, or add your own
pledgeplease pledge money to the SDF Public Access UNIX System
pshthe restricted shell used by pre-validated SDF accounts
quotedisplay the current price for a given stock; does not seem to currently be working properly
smjprint a random quote from the SDF sysadmin
surlSDF's URL shortening service
teachfill out a survey about virtual classes taught on SDF machines
thxmooa MOO based around the world of THX-1138
uinfoaccount information for a given user or yourself
uploadwrapper around rz for uploading files
urlshow the url for yourself or a given user
votevote on a currently open SDF ballot (ARPA membership required)
Much of this SDF Specific Commands list was pulled from jwodder's reference,; he deserves a huge thanks for putting this list together.

And of course there are the online tutorials that you are reading right now!

Finding help and SDF Specific Commands - traditional links (using RCS)
This wiki page was reviewed with the Plan 9 abaco, and mothra, browsers.

1) , 2)
The admin pseudonym‚ for members′ home‚ is SDF Membership.
3) , 4) , 5) , 8) , 9) , 10) , 11)
The table was merged from SDF Specific Commands.
Use 'crontab -e' to edit your crontab.
Put '$' in your .forward on the SDF Cluster.
finding_help.txt · Last modified: 2024/02/25 22:16 by hc9