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linux-unix130.linux.and.unix.ebooks130 linux and unix ebookslinuxLearning Linux - Collection of 12 E

like <TT>elm</TT>.

<H4 ALIGN="CENTER"><A NAME="Heading6<FONT COLOR="#000077">sendmail</FONT></H4>

<P>The <TT>sendmail</TT> program is quite popular with small Linux installations.

It is included with the Slackware distribution of Linux.</P>

<P>If you are running a UUCP-only site and you want to use <TT>sendmail</TT> instead

of <TT>smail</TT> when you have both on your system, you should make sure that all

files from <TT>smail</TT> are removed to prevent conflicts (you can use <TT>whereis</TT>

and <TT>find</TT> to locate <TT>smail</TT> files).</P>

<P>To configure <TT>sendmail</TT>, change to the <TT>/etc</TT> directory and edit

the <TT>sendmail.cf</TT> file. This file has enough information to help you determine

which lines to replace with your system values. Usually you will edit the hostname,

aliases, and smarthost settings.

<H4 ALIGN="CENTER"><A NAME="Heading7<FONT COLOR="#000077">Local Delivery Agents</FONT></H4>

<P>Unlike most UNIX versions, Linux does not have a mail-delivery package built in.

Mail- delivery packages send the received mail to the proper user. One of the most

widely used is called deliver.</P>

<P>In most cases, you don't have to do anything to install and configure deliver.

When you installed the mail software using the Linux installation routine, the necessary

software was installed and configured properly.

<H4 ALIGN="CENTER"><A NAME="Heading8<FONT COLOR="#000077">Mail User Agents</FONT></H4>

<P>Mail user agents are the mailreaders you use to see your e-mail. Many newsreaders

are available. Your choice of mailreader is more a personal preference than a feature-based

decision.</P>

<P><TT>Elm</TT> is probably the most widely used mailreader with Linux. It uses the

configuration file <TT>/usr/lib/elm.rc</TT> to provide basic information about the

machine name and its connections. You should edit the <TT>elm.rc</TT> file to replace

the names with proper values.</P>

<P>Another popular mailreader is <TT>Mailx</TT>, which has been available for UNIX

systems for many years. Versions of <TT>Mailx</TT> are available for Linux on many

archive sites. Make sure you get version 5.3b or higher because there are security

problems in version 5.3a.</P>

<P>Other interesting and popular mailreaders are <TT>Pine</TT> and <TT>Metamail</TT>,

both of which are freely available from Linux archive sites and user groups.

<H3 ALIGN="CENTER"><A NAME="Heading9<FONT COLOR="#000077">News</FONT></H3>

<P>Usenet is a service provided over the Internet. It's composed of more than 9,000

newsgroups on every subject imaginable. If you want to set your system to download

the entire day's news, you must dedicate a lot of money to hardware and telephone

lines. Such a connection is beyond the scope of most users.</P>

<P>However, accessing newsgroups from another machine that downloads them is quite

easy, using software provided with Linux.</P>

<P>There are two parts to the News software: the server and the client. The server

is the software that controls the newsgroups and handles delivering articles to other

machines. The client or newsreader software is the user interface.</P>

<P>You do not have to hook up to the Internet to use <TT>News</TT>. You can run <TT>News</TT>

locally (on your own machine for all the users) or across a small network. In this

case, you don't have to worry about connecting to the Internet's Usenet newsfeed,

which generally is expensive and very time- consuming.

<H4 ALIGN="CENTER"><A NAME="Heading10<FONT COLOR="#000077">News Transport Software</FONT></H4>

<P>News transport software, as its name implies, carries the news to your system

and its newsreaders and helps your users post news to Usenet. Two main news transport

software packages are used with Linux: <TT>Cnews</TT> and <TT>INN</TT>. The two should

not be mixed. Use one or the other, or major hassles will result!</P>

<P>If you plan to use News locally only, much of the configuration required for connecting

to the Internet or other newsfeed can be ignored. News normally is stored in the

directory <TT>/usr/spool/news</TT>, so all the news transport and client software

should be set to point to this location.</P>

<P>The most popular news transport software is <TT>Cnews</TT>, which has been available

for almost a decade. <TT>Cnews</TT> runs on many different machines, and many people

understand it very well, providing technical resources should you need them. <TT>Cnews</TT>

is designed primarily for capturing news over a UUCP connection and a standard telephone

modem, so it requires additional software to provide access to the Internet. This

additional software is called NNTP (Network News Transfer Protocol). NNTP isn't necessary

for local news support.</P>

<P>Installing <TT>Cnews</TT> is straightforward, as long as you follow the directions

in the accompanying documentation files. Configuration involves editing several files,

which usually reside in <TT>/usr/ lib/news</TT>. The files of primary interest are

listed here:



<UL>

	<LI><TT>active</TT>: The active file

	<P>

	<LI><TT>batchparms</TT>: Batch parameters

	<P>

	<LI><TT>explist</TT>: Article expiration

	<P>

	<LI><TT>mailname</TT>: Header names for mailed replies

	<P>

	<LI><TT>mailpaths</TT>: Path to mail-moderated postings

	<P>

	<LI><TT>organization</TT>: Your company name

	<P>

	<LI><TT>sys</TT>: Controls what you take and feed

	<P>

	<LI><TT>whoami</TT>: Your hostname

</UL>



<P>Most of <TT>Cnews</TT> is configured with shell scripts or utility programs (such

as <TT>addgroup</TT> to change the active file and <TT>addfeed</TT> to change newsfeed

information). Again, check the documentation for complete information.</P>

<P>To download news automatically, <TT>cron</TT> makes an excellent choice. A sample

<TT>cron</TT> entry for the <TT>Cnews</TT> newsfeed is</P>

<PRE><FONT COLOR="#0066FF">20 * * * * /usenet/sw/news/bin/input/newsrun

0 * * * * /usenet/sw/news/bin/batch/sendbatches feedsite

59 0 * * * /usenet/sw/news/bin/expire/doexpire

10 5 * * * /usenet/sw/news/bin/newsdaily

00 5 * * * /usenet/sw/new/bin/newswatch

</FONT></PRE>

<P>This sample does things every hour, which is fine for a large site but considerable

overkill for a small network or single machine to which you might want to connect

only once a day. Modify the files as necessary to meet your requirement.

<H4 ALIGN="CENTER"><A NAME="Heading11<FONT COLOR="#000077">InterNetNews (INN)</FONT></H4>

<P><TT>INN</TT> is newer than <TT>Cnews</TT> but is faster and has NNTP built in,

making it easier to use for direct newsfeeds. Unfortunately, it is a little harder

to install and configure than <TT>Cnews</TT>. <TT>INN</TT> uses a daemon (sometimes

two) that runs continually, whereas <TT>Cnews</TT> is invoked by the user (or <TT>cron</TT>).

Novices to Linux should probably stick with <TT>Cnews</TT> at the beginning until

they gain more experience.</P>

<P>Installation is a little more complex than with <TT>Cnews</TT>, but following

the documentation helps. <TT>INN</TT> is very particular about its file permissions,

so make sure you set them properly. Configuration is a matter of making sure all

of the site information is correct. Once correctly installed and configured, though,

<TT>INN</TT> requires virtually no maintenance.

<H4 ALIGN="CENTER"><A NAME="Heading12<FONT COLOR="#000077">Newsreaders</FONT></H4>

<P>Many newsreaders are available for Linux. A newsreader presents the messages in

a newsgroup and lets you step through them or reply to them, as well as create new

messages. Some of the most popular newsreaders are <TT>tin</TT>, <TT>trn</TT>, and

<TT>nn</TT>.</P>

<P>Choosing a newsreader is essentially a personal choice. Experiment with several

and stay with the one you find easiest to work with and that offers the features

you need. They all have some slight twist that gives you different methods of looking

at news or moving through newsgroups.

<H3 ALIGN="CENTER"><A NAME="Heading13<FONT COLOR="#000077">Summary</FONT></H3>

<P>Both e-mail and news extend the Linux system into a full-featured UNIX implementation,

and make your machine part of a much larger network. Even if you are using your Linux

machine only for yourself and have no interest in connecting to the outside world,

e-mail is simple and easy to install, configure, and use. Once you've used e-mail,

you'll probably never go back to the paper-based kind!</P>



<P>If you have several users on your Linux system or plan to connect to a network,

News is a great way to get discussions and information flowing among the users. On

top of that, News is just plain fun!









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