This FAQ has been partitally, but not completely, updated for the new system.
Grex is a public-access computer conferencing system in Ann Arbor, Michigan, USA. It is cooperatively owned and operated, and is supported entirely by donations from users. All staff members are volunteers.
Grex is not an acronym. It is a Latin word meaning "flock". It is the root of a number of familiar English words such as aggregate, congregate, and gregarious.
Grex provides all of the following services for free.
However, Grex does not provide any of the following services at all:
And there are a few things you can only do if you are a member (who has made a donation and sent ID). These are
For the first 13 years of it's life, Grex ran on second-hand Sun computers, using Sun's proprietary version of Unix. Recently Grex took a leap into the 21st century by purchasing the first new computer we have ever owned, a 2800MHz Athlon system with has 1.5GB of RAM and 135GB of hard disk space. We have replaced our old SunOS operating system with OpenBSD. Like Linux, OpenBSD is a completely open-source operating system. It's developers focus strongly on security issues. There are a lot of details about Grex's configuration available in the Grex staff notes on the web. http://www.grex.org/staffnote/ Follow the link to Grex's Hardware and software.
A computer conference is an area set aside for discussion on some general topic, such as computers, politics, or gardening. In such an area, people can read what other people have posted, and can introduce new subtopics or add responses to existing ones. On many systems, conferences are called "forums". Grex has many conferences. For a complete list, see http://cyberspace.org/cgi-bin/backtalk/pistachio/conflist.
Grex's conferences are accessible by a text-based terminal interface or by the World Wide Web. To access the text-based interface, either dial direct or telnet to Grex and run the "bbs" command. (This command is run automatically every time you log in if you choose the "bbs shell" when you create your account.) World Wide Web access is provided by Grex's "Backtalk" conferencing software. Please see http://cyberspace.org/cgi-bin/backtalk for details on using Backtalk.
Cyberspace Communications functions as an online democracy, with policies set by its users. The Co-op Conference is open to all users and provides a forum for discussing policy issues. The Board of Directors, elected by the members, is the formal governing body and uses consensus in the Co-op Conference as its primary guide for making decisions. Any member of Grex who can attend the monthly meetings, held in Ann Arbor, Michigan, is eligible to run for the Board of Directors. In addition, any member can call a binding vote by the membership on any policy issue. The Articles of Incorporation and Bylaws can be viewed online.
Any user can have a voice in Grex governance by joining the Co-op conference and participating in the discussions there. If you wish to be eligible to vote in Grex elections and to run for the Board of Directors, you can become a Grex member. Membership dues are US$6/month or US$60/year. To find out how to make membership payments, please see http://www.grex.org/member.html. Membership donations are Grex's primary source of financing.
Yes!
You can change any of these properties of your account with the "change" command. If you are using a menu or if you are at a bbs (Ok) prompt, type "!change" If you are in lynx, type "!" (an exclamation point) to get to a shell prompt first. At a shell prompt, type "change" and follow the menu-based instructions.
You can't change it. Instead, you have to create a new account with the login ID that you wish. Once you have done that, you can copy the files that you need from your old account to your new one. When you no longer need your old account, you can ask to have it deleted by sending a request from your old account to help@grex.org.
There is a completely separate FAQ for all questions related to the Grex web server. Please see http://www.grex.org/local/grex/wwwfaq.html.
Unless you are a paying member, you can't use IRC because the protocol is blocked for free accounts. For more detailed information about this, see the Grex Eggdrop Page from the Grex Staff Notes.
If you are a guest user, you cannot access IRC. You can chat on-line within the Grex community by using "party" (see chatting, below). Paying members just need to type "irc" to run the ircii client program, which is installed for this purpose.
Grex has six ways of chatting:
vi (pronounced vee-eye) is a powerful text editor, but it has a steep learning curve at first. You can usually tell that you are in vi when you have a vertical line of squiggles (tildes) on the left of your screen. If you are trapped in vi, remember to type the escape key and then :q! (colon-q-exclamation point) followed by a return. The pico editor is a much friendlier editor for less experienced users.
Grex does not maintain its own base of Usenet news, because this requires too much space and too much of our internet link. So there is no usenet client program on Grex. However, you can access Usenet via the "lynx" web browser. Just connect to http://dejanews.com/.
Grex does not support graphical interfaces such as X-windows. This service requires many more resources than the text-based service that Grex provides. It would use far too much CPU time and bandwidth for Grex to be able to support it.
We can't do that. We just don't have time. Grex makes regular backups onto tape, but this is an enormously time consuming process. The purpose of these backup tapes is to protect the system from disaster. Unfortunately, there is not enough time to honor requests from individual users to restore files from these tapes. Grex is not a good place to keep any file that you cannot afford to lose. If you have an important file on Grex, it is your responsibility to keep a backup of it on your own computer.
There are so many Unix commands that we recommend that users who are not familiar with Unix use the "menu" command to explore Grex. The most common commands are available there. If you really want a list, then run the Grex command "listcommands" to print a list of most Unix commands on Grex. (Built-in shell commands are not included). This will take a long time to run.
The Unix operating system is amazingly powerful and flexible, with thousands of commands. Unix can be a challenge to get started with, but if you are interested in learning Unix, Grex is a good place to start, since we do give you access to almost all commands. For a good introduction to basic Unix and VI usage, see Christopher Taylor's witty tutorial Unix is a Four Letter Word, or the University of Edinburgh's UNIXhelp for Users pages.
Online reference information about most commands can be called up via the "man" command. For example, for information about the date command, type
man date
The book "Unix for Dummies" is pretty good.
There are numerous howto's and tutorials on the web (try tldp.org, The Linux Documentation Project).
You cannot access Hotmail from Grex. This is because the folks who run Hotmail have decided that lynx is not an acceptable browser for use with their service. According to the Hotmail FAQ, Lynx is not supported by Hotmail, because it does not meet their requirements. This is not a problem with Grex. Please complain to MSN Hotmail, use a graphical browser, or use a different web-based email provider.
For security reasons, you should not keep the same password for too long. Grex passwords expire when they have not been changed for a whole year. All you have to do is run the "change" program to change your password, and you will stop getting nagged when you log in. Please remember to write your new password down when you change it, so you won't forget it.
When someone tries to log in to your account but does not know the password, Grex keeps count of failed login attempts. In general if there are only two or three of them, it probably means someone made a typo at the login prompt. This happens most often for accounts with very short user IDs and those with popular names, such as "ken". Less commonly, login failures may occur when someone runs telnet with the option to pass along the account name from another system. If it is a different account name, but matches yours, this will produce a failed login attempt for your account every time this person telnets to Grex.
If there are 25 or 30 failed login attempts, or if the last successful login to your account wasn't yours, then it could mean that someone is trying to break in to your account. In general, most failed login attempts are from other people's typing errors and are not malicious. If you still suspect malicious activity, change your password (don't forget to write it down) and let the staff know so that they can investigate.
Contact the Grex staff. Send mail from another site if you have access to email at another site. Send messages about access problems to help@grex.org. Remember to specify which account is the one you lost the password for.
You can also log in to Grex as "trouble" without a password, which will send a message to the staff. Be sure to provide a postal address, an e-mail address, or a local telephone number, so that the staff can contact you in return.
This means that your account has been deleted. Accounts on Grex are deleted if no one logs in for more than 3 months. There is not enough room on Grex to keep old unused accounts. To avoid losing your account, you should log in every month or two. Accessing your web page, or having your mail get forwarded does not count, but conferencing over the web using your account and password in Backtalk does count as logging in for this purpose.
If your account has been deleted, it usually cannot be recovered or restored. Please feel free to recreate the account.
If you don't want to wait until your account expires, you have to log in one last time and send a message to help@grex.org from the account that you want deleted. In your message, ask for it to be deleted.
When creating an account by telnet, you are asked to provide the characters you wish to use for various purposes. People using Macintosh NCSA Telnet have experienced the behavior that when they type ^C, the program exits rather than accepting the ^C as the designated control character.
This is caused by undesirable preferences within that program and is easy to fix. Look at the "Session" menu, at the "Setup Keys" menu item (or hit command-S). You will probably find that you have a setting for "interrupt process" which is set to ^C. If so, NCSA Telnet is honoring this setting and sending the "interrupt process" signal (part of the time-worn telnet protocol) whenever you type ^C. Blank this setting out and then save your telnet set in a file. If you start telnetting by double clicking on the saved settings, you won't have to remember to clear it each time.
We don't recommend the use of NCSA Telnet. For a better telnet client for the Mac, see the Grex Telnet information page.
Grex does not display your password as you type it. This is to keep it secret from anybody who might be looking over your shoulder. Type your password anyway. Even though you don't see it, Grex will register it and, if you typed it correctly, you will be logged in.
Passwords on Grex expire after a year. If you telnet in, Grex will give you warnings to tell you that this expiration is coming, and then when the year is up it will force you to change your password. Ssh isn't smart enough to participate in this, so it doesn't give any warnings, and then after a year it simply stops letting you log in. You'll need to use telnet to connect Grex and change your password to a temporary password, then login in via ssh with the temporary password, and change it again.
Use the "change" command. Just type "change" at a shell prompt or "!change" at any other prompt. This will invoke a menu that allows you to change almost any setting on your account, including the mail forwarding option. There are certain restrictions on the use of forwarding, so make sure you are following the rules..
Probably because it is not world readable. .forward files must be world readable in order to be valid on Grex. If you are looking for a way to forward your mail to an anonymous place, you need to find an anonymous remailer system. Grex doesn't do this. To make your .forward file world readable, change to your home directory (type: cd) and then issue this command:
chmod 644 .forwardYour home directory must also be world accessible; type:
chmod 755 .or use 711 instead of 755 if you don't want other people to be able to scan your directory.
You can't. If you have forwarding enabled, the address must appear in the finger command. There is no way to hide the address that you are forwarding to. Grex does not wish to provide anonymous remailing services. You may wish to make use of one of the anonymous remailers listed on the Yahoo page http://dir.yahoo.com/Computers_and_Internet/Security_and_Encryption/Anonymous_Mailers/.
You can't. Those are POP clients, and Grex doesn't run a POP server. This is because Grex is intended to be an on-line community, and having a POP server would encourage people to use Grex as a mail drop instead, never logging on, and so never having a chance to become part of the Grex community. You must log in to Grex in order to read your mail.
Spam (unwanted mail) is unfortunately very common on the internet.
For the time being, Grex is not doing any spam filtering. We hope to change this soon.
Grex's old mail transport system had numerous filters to reduce spam, but it did not eliminate it. The Grex staff may or may not be able to help you reduce the spam you are getting. The proper way to report spam is to forward a copy of one of the offending messages to uce@grex.org. Do not send multiple messages.
The message you send MUST be accompanied by the full mail headers, so that we can determine its true origin. The origin of spam is often hidden, and may require detailed examination of these headers. If you use pine, you can view these headers with the "H" command.
The "uce" account will not send you a reply. Forwarded spam collects there until someone on staff can go through it and look for patterns to add to Grex's anti-spam blocks. For more information, you can run the command "finger uce@grex.org"
This usually happens when the sending site is not configured properly. Problems in mail configuration can often lead to mail that has an invalid return address. Grex's mail system tries very hard to detect and reject invalid sending addresses, in order to reduce the amount of spam (unwanted mail) on Grex. If your mail looks like spam, then Grex will reject it. If you think this is happening to your legitimate mail, send a rejected copy of it to grex-staff@hvcn.org, and be sure to include all of the mail headers.
Other common reasons for mail to Grex to be rejected are that it may be too large (over 100k) or your mailbox may have grown too large (over 600k). Mail will be rejected in these cases.
Actually, that is probably just a faulty error message. For new accounts, it only means that you haven't received any mail yet. Once you receive some mail, the message should go away forever. We are working on getting rid of this error message.
This feature is turned off on Grex by default, because lots of new users were accumulating vast files of old mail without ever knowing that they were doing it. You're quite welcome to create the folder, as long as you keep an eye on your disk usage so that you don't exceed Grex's 1 megabyte limit for your account. To create your saved-mail folder, go into the pine configuration screen and look for the setting for "default-fcc". Set it to "saved-mail" or whatever name you would like to use. You need to use quotation marks around the file name.
Please do not send large attachments. If you have a small one, so that your mail remains under 100 K bytes in size, then you can send attachments from Grex.
First move the file into your home directory on Grex, then when composing a message in pine, put the file name on the attachments line. Please remember to delete the file after sending it as an attachment, so that you do not fill up your allotted disk space.
Any file that ends with ".doc" is probably a Microsoft Word file. There is no way to view such a file on Grex. You will have to download that file to a computer that has Microsoft Word or some other word processor that can import such files.
In Pine on Grex, you can't set the "From:" field. This is disabled because there were too many problems with people setting invalid addresses, which caused their outgoing mail to bounce to the postmaster whenever it was undeliverable.
You can't. We're sorry, but this is not permitted. You can only forward mail to a single site elsewhere on the internet. Mailing lists are too resource intensive for Grex to support. You may wish to try using an advertising-based free mailing list service. The Free Center maintains a rated list of free mailing list providers, and groups.yahoo.com offers free mailing lists with lots of features.
Yes, but you must do it correctly.
It is a extremely risky to attempt to transfer your mail spool file directly off of Grex by FTP. You risk losing some or all of your collected mail, because the FTP daemon does not participate in the locking scheme used by the mail delivery programs on Grex. In addition, your account may appear to be abandoned because FTP connections do not update the date of last login. This could result in loss of your account if it is the only way you use Grex.
Instead, we recommend telnetting to Grex and running a mail client program. These all do participate in the locking mechanism for the mail spool. Collect all of your mail into a file in your home directory, and then log out. You may now safely fetch that file in your home directory by FTP. Please remember to delete it once it has been safely transferred.
The most likely reason is that you have not told procmail how to find your mail spool file. In order to improve performance on a system with this many users, Grex uses a pair of hierarchical levels of directory structure based on the first two letters of your login ID to hold users' spool files. This means that your spool file will not be where procmail expects to find it by default. To find your spool file, type
echo $MAIL.Procmail will work if you make this the first line of the .procmailrc file:
MAIL=PATH-TO-YOUR-INBOXFor example, the first line of a .procmailrc file used by Staff member John Remmers (remmers) would be:
MAIL=/var/spool/mail/r/e/remmers
Yes. Try the vacation program. Type "vacation" to run it.
The short answer is to dial (734) 761-3000 with your terminal software set to 8-N-1. This process is described in detail in Grex's dial-up access information page. Note that if it is a long distance call for you, the telephone company's charges to you may add up to be very expensive.
We try very hard to keep all of the modems working properly, but sometimes, you may encounter a failure. Grex's phone lines are all configured so that if one modem doesn't answer after 3 rings, you are automatically transferred to the next line in the trunk hunt. If there happens to be a stuck modem, you need to wait at least 4 rings before a second one gets a chance to work. If there are two bad modems, then 7 rings are required.
No. Grex used to publicize other numbers in the interior of the hunt group, but there is no longer any advantage to calling any other number, because of this automatic stepping feature. Even if Grex is down, the phone should pick up once it steps past any bad modems. If it is down for an extended period, you should receive a short explanation from the terminal server. If the terminal server has failed, or the power to Grex's building has failed, the phones will not answer, but these conditions are very rare.
Probably because you don't have a modem cable that is capable of handling hardware flow control, or your modem doesn't support it or has the feature turned off.
When you look up your own user information, you can always see it, even if it is set up so that nobody else on the system can see it. To see what other people see, ask for the info about "youraccount@grex.org" instead of just "youraccount".
This is considered public information on Grex. The only way to hide it is not to log on.
You can adjust the chat settings for your account with the "change" command. To run it, type "change" at a shell prompt, or "!change" from a menu or from bbs. Then choose "W) Write settings" and follow the menus from there. You can: turn off all chat requests, accept all chat requests, or select which users can and cannot chat with you.
Grex is a very open system, so directories are open to the public unless the owner decides to make them private. E-mail, however, is automatically saved in private files that the world cannot see.
To permit a file so that it can be seen by others, type
chmod a+r file-nameTo permit a directory, type
chmod a+rx dir-nameTo hide a file or directory, type
chmod ou-rx file-or-dir-nameIf you hide your home directory completely, neither mail forwarding nor web hosting will be available to you. You may make your directory accessible without allowing it to be scanned. This is how:
chmod 711 dir-name
No. PGP is not available on Grex for a number of reasons. The two most compelling reasons are that it would not be legal, and it would not offer you the protection you seek. We would like to see it be legally available to all, but in order to be effective, PGP must be installed on your own computer, not on Grex. Encrypting or decrypting a message on Grex would mean that the message would have to travel over an insecure network in plaintext before encryption or after decryption, and this is not the way to protect your message.
In order to install PGP on your home computer, North American users should go to the MIT PGP Distribution Site at http://web.mit.edu/network/pgp.html, and all other users should use the international PGP home page at http://www.pgpi.org/.
Yes, we do. Secure shell (ssh) is a good way to connect because your session is encrypted, so that passwords cannot be intercepted by sniffers.
To compile a C program named foo.c, type gcc foo.c -o foo This compiles foo.c and creates an executable program named foo. To run it, type ./foo Likewise, to compile a C++ program named foo.cpp, type g++ foo.cpp -o foo Please check with the Grex staff before compiling programs you bring in from the net. Most of the useful programs are already installed here, and many others will not run on Grex, but compiling them on Grex wastes a lot of bandwidth and cpu time — resources that Grex is short on.
Probably you are using the wrong C compiler. Grex has two compilers installed. cc is only used for building certain system executables. It is not ANSI standard, and it lacks certain standard include files. You need to use gcc instead. This is a fairly recent version of the Gnu C compiler. It is ANSI standard and very complete.
Usually this is because the program is not on your path. Unlike a DOS or Windows system, on Unix the current directory is not automatically placed on your path. So if you compile a program named foo, you cannot run it by just typing "foo". You need either to place the executable somewhere on your path, or to precede its name with ./ (dot-slash) so you would type "./foo".
No. These are all servers, daemons, or programs that remain running after you have logged out. No program run by users is allowed to run after you log out. See the Grex Eggdrop Page from the Grex Staff Notes.
At one time or another, the possibility of our installing some of these as official services has been discussed in the "coop" conference. We have never yet decided to do so, but if you are interested in pursuing this possibility, the Grex coop conference is the place to make your request.
Yes, you can find out more about newuser, including availability, on this web page: http://www.grex.org/~mdw/newuser.html.
Yes, you can find out more about write/chat/tel, including availability, on this web page: http://unixpapa.com/write.html.
Yes, you can find out more about party, including availability, on this web page: http://unixpapa.com/party.html.
We're looking into it.
You need to configure your browser to find your telnet application program. The exact instructions for doing this vary widely depending upon both your operating system and your browser. In Netscape 3 this setting can be found in "Options"/"General preferences"/"Applications". Select the telnet application that came with your system, or one you downloaded from the internet. For more details about telnet applications, see the Grex Telnet Information page at http://www.grex.org/telnet.html.
There are several things that can go wrong.
These tools are not available on Grex. Vandals were using them to attack other sites. This is a ludicrous thing to do from Grex, because Grex is so tiny that its CPU and net connection become overloaded long before any other system would even begin to notice that it was being attacked. But people were doing it anyway, and hurting Grex. Regrettably, the actions of a few thoughtless people has forced Grex to disable these potentially valuable network analysis tools.
You may be able to use a remote traceroute server on the web. See http://www.traceroute.org/.
At the time this answer was last updated, the IP address of Grex was 216.86.77.194, but IP addresses may change at any time. In general we have little control over changes to our IP address. You should always use the hostname, because if the IP address does change, the DNS (Domain/Name Service) lookup of the hostname should produce the new IP address. If you unsure if a problem is due to DNS, you can test to see if you can connect using our IP address. However, if you can, it is strongly recommended that you resolve the problem you are having with DNS, so that you do not have to rely on inherently unreliable IP addresses.
That is because this information is stored in a file (utmp) which only permits 16 characters of storage for this information. If the IP address exceeds 16 characters when converted to text form, then it is stored (and reported) only in its numeric form. This affects other commands besides the "who" command, such as the "finger" and "last" commands.
The disk quota on grex is two megabytes, enforced by the 'quota' system. You can find out how much disk space you are using (in kilobytes) by running the following command in your home directory:
du -skThe number that comes back is the number of kilobytes of disk you are using. If you are using more than 2048, please remove files.
The command
quotawill show your quota and usage on the current file system. The command
quota -vwill show your quota and usage on all the file systems you have "write" access.
If you are thinking of putting something big in your account, please talk to the Grex staff (help@grex.org) first. There aren't many good reasons to put big things in your Grex account: Grex doesn't allow multimedia files on its web pages (not even gifs and jpegs), and most of the useful programs that will actually run on Grex are already installed on Grex. So please talk to the staff first.
If you exceed the 2 megabyte disk quota or have multimedia files, big downloaded program packages, or vandal tools, in your account, a member of the Grex staff will delete the files and quite likely lock your account. The Grex staff spent way too much time policing this and was usually quite crabby about the whole topic. So the current Grex computer has automated disk quotas, which will notify you when you go over quota and prevent your creating new files if you stay over quota.
This is because Grex is running a real sh, and that is a feature not supported by sh. What some Unix systems call sh is actually bash, an enhanced version of the sh shell which does this. If you would like to use bash instead, you should change your shell on Grex to bash. You can do that by running the change command.
Bash, ksh and tcsh do support previous line editing. It may not be working the way you expect because a different default editing mode is in use. To change the default editing mode to the style of emacs or vi, the command you must use depends upon your shell. For ksh and bash, use one of the following commands:
set -o emacsThe equivalents in tcsh are:
set -o vi
bindkey -eAfter that, you should be able to edit your command line in a way that is familiar to you. If you prefer to preserve this setting so you don't have to execute it every time you log in, then place it in .profile (ksh and bash) or .login (tcsh).
bindkey -v
This happens when Grex doesn't know how many rows of text are on your screen. The easiest way to set this correctly is to run the "change" program on Grex. It will count rows for you and display the correct number at the top of your screen (sometimes it can take some fiddling to figure out whether your screen has 48 or 49 or 50 rows), and make the necessary changes to your startup files so that your settings will be right in the future. To run the change program, type "change" at a shell prompt, or "!change" from a menu or bbs. Then select "change terminal type" and follow the menus from there.
Same problem. Wrong number of lines in the setting. See solution above.
Grex runs a special daemon that kills all user processes when a user logs out. This prevents users from running servers or robots of any kind. It also prevents them from using the reconnect feature of screen (although the other features work fine). The reason for this policy is to prevent users from consuming our limited resources while not logged in.
Nothing really. This is a file that gets created if a program fails (crashes). It is intended to help the programmer find whatever bug caused the failure. If not renamed, these files will be deleted automatically in a day or two. You can delete it if you wish. By the way, a core file usually doesn't take up as much space on the disk as it appears to, because it is "sparse" (full of empty space).
Grex uses a hierarchical arrangement of home directories to keep the directory sizes from growing too large and thus becoming inefficient. So, on Grex, home directories are always located by a path of this form:
/x/y/z/usernameThe x is the disk letter, the y is the first letter of the username, and the z is the second letter of the username. Currently we have two disks that user accounts occupy, /a and /c (/b was not available). The choice of disk is determined when your account is created. This choice is switched back and forth manually by the staff to keep the available disk space balanced.
The environment variable $HOME should always be set to the full path of your home directory. The ~ symbol may also be used as a shorthand for your home directory, as long as your shell supports it. (The Bourne Shell does not.)
You might want to try out Grex's party program. See the Party Question in this FAQ.
Color listings are available with many terminal types, but whether or not they show up depends on which terminal emulator you're using. See http://www.grex.org/telnet.html for more information on telnet programs. You also need to turn on color listing. This involves two steps. You will need to run dircolors for you shell. If your shell is a sh-like shell (sh, bash, ksh), you will run the following command: eval `dircolors -b` otherwise, if your shell is a csh like shell (csh, tcsh) you will run the following command: eval `dircolors -c` Then, if you use ls with the --color=auto option, it will use colors. You can add the following alias to your .profile file of startup commands (for bash-type shells, or your .login file for csh-type shells): alias ls='/usr/local/bin/ls --color=auto' to always get color listings when your terminal emulator can support it.
We are always delighted to have new volunteers One of the things that Grex needs most urgently is more people to answer "write help" requests. It is recommended that you check out the helpers conference. To turn on your helper flag, run the Unix command "mesg -h y".
Also you should read the Grex Staff Note on the topic of volunteering to be on the Grex staff.
Last updated June 8, 2003 (vm)
Return to the welcome page.