Testing IMP

only for RuBoard - do not distribute or recompile

To test IMP, you will need to set up some user accounts to send mail from and to. I will walk you through the process, and give you some additional things to consider as you think about the use of your IMP system.

Setting Up User Accounts

The Red Hat system provides several command-line programs for basic user maintenance. Whenever you add a user to the system, that user is automatically allowed to send and receive email. The user's password is the same password used to log on using IMP.

NOTE

For the X Window environment, you can use the linuxconf program. It works well, but is not my personal favorite. It allows the root user to add a user to the system. However, you still must set the password using the command-line passwd utility in a terminal screen.

The adduser command adds a user to the system. No password is set for the user at that time. You must run the passwd command to do that. Only root can set the initial password for the user.

If you give the user shell logon ability, the user can change several identifying items by running one of several utilities. The user's real name is set using the chfn utility. The chsh utility allows the user to change the default logon shell. To execute these functions, a user must be logged in to your system. The root user can change these items for the user.

Here is an example where the user test is entered, with the password test. Note how the system complains about the password. It is never, ever, a good idea to give the user a password that is the same as the logon name. The user's real name is also changed by the root user:

 [root@wmaxlaptop /root]# adduser test [root@wmaxlaptop /root]# passwd test

Output

 Changing password for user test New UNIX password: test BAD PASSWORD: it is too short Retype new UNIX password: test passwd: all authentication tokens updated successfully [root@wmaxlaptop root]# chfn test Changing finger information for test. Name []: Test User Office []: Office Phone []: Home Phone []: [root@wmaxlaptop root]# tail /etc/passwd ......[various lines]... test:x:503:503:Test User:/home/test:/bin/bash  [root@wmaxlaptop root]#

The information shown in italics at the passwd command is not echoed to the screen. If you look in the /home directory, you will see a test directory. In the /etc/passwd file, you will see an entry for user test. This file controls the login directory and user name. In the /etc/groups file you will find another entry for user test. This is the group that the user is in.

EXCURSION: User IDs, Group Numbers, and Security

Linux provides a standardized way of controlling access to files. The root user arbitrarily assigns all users to one or more groups. All users have a unique user ID. Each file is owned by a single user. With these three facts, a good security system has been created.

A file or directory has three basic attributes: read ability, write ability, and execute ability. The security system in Linux assigns these abilities to the owner of the file, the group the file is in, and anyone else, known as other.

Using chmod to change these settings, you can make a file readable or unreadable by the owner(!), users in the group the file belongs to, or others. You can also add or remove write and execute privileges from any of the above. Either the owner of a file or the root user is always allowed to restore any privileges to a file, unless the file has been made immutable using the chattr function.

Files can have their owner changed using chown. The group that files are in can be changed using chgrp. Only the owner of a file or the root user can successfully run these functions on files.

TIP

To find out more about commands listed in this book, use the man command. The man program prints out the manual pages for a command.

For example, to print out the manual page for chown, start an xterm in X windows , and enter the following:

man chown

The manual page for chown will be shown. It might take a little while to understand what the manual pages are telling you. After you get used to them, they are invaluable.

You can have a situation where parts of a mail folder become read-only for a user. If so, check to see that the root user does not own the user's mail directory or any files in the mail directory. This happened to me when I edited a file as the root user to fix a problem. The user could no longer save sent mail!

Connecting to IMP

IMP will normally be used over a network. You can set IMP up on your computer and run it locally. This is an easy way to initially test IMP.

In most cases, you will be connecting to your Web server using Windows machines. You can use any computer system that has network access and a Web browser that runs JavaScript. In the following sections, I will cover the most popular options for connecting to IMP.

Logging On from Your Red Hat

At the time of this writing, if you are using Netscape to connect to IMP, it must be Netscape browser version 4 or later. Earlier versions of Netscape don't support JavaScript.

NOTE

If you are using Internet Explorer on a Windows machine, you must use version 3.02 or later. Most of the Web browser illustrations are taken while using Internet Explorer Version 4 under Windows to connect to IMP running on a Red Hat server.

A new commercial Web browser called Opera may work. It is currently in the beta test stage.

If the IMP you are testing resides on the same machine you are running the X Window System on, you can enter this URL: http://127.0.0.1/ horde /imp. You will be taken to the logon screen.

Logging On from Another Machine on the Network

You have multiple choices when logging on from other machines. Depending on the operating system, you will be able to use Netscape, Internet Explorer, Opera (still in beta), or other Web browsers that support Java script. Many of the examples will be shown using Internet Explorer running under Windows. (After all, most of your customers will use Windows. They don't have to know what platform IMP is running on!)

You must be able to ping the computer that contains IMP by name or IP number from another machine on the network. To ping the IMP machine by name, the name must be correctly entered in a DNS server or in the hosts file in your computer.

For example, let's suppose the name of the IMP server is imp. If I can type ping imp from a command prompt, then I would be able to connect to the imp server by using this URL: http://imp/horde/imp.

If you are running Windows 98, you could also do the following from the command line:

 C:\WINDOWS>ping imp

Output

 Pinging imp [10.101.168.47] with 32 bytes of data: Reply from 10.101.168.47: bytes=32 time=2ms TTL=254 Reply from 10.101.168.47: bytes=32 time=2ms TTL=254 Reply from 10.101.168.47: bytes=32 time=2ms TTL=254 Reply from 10.101.168.47: bytes=32 time=2ms TTL=254 Ping statistics for 10.101.168.47:     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds:     Minimum = 2ms, Maximum =  2ms, Average =  2ms C:\WINDOWS>start http://imp/horde/imp

only for RuBoard - do not distribute or recompile