ch14.htm

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

of giant bulletin boards for you to select topics from and post messages to. The

number of subjects available can be quite overwhelming at times, since there are

more than 13,000 newsgroup topics to choose from. (A newsgroup is one of the bulletin

boards.) Newsgroups offer the best example of free speech and a forum for discussing

just about any topic imaginable.</P>

<P>Topics range from the serious to the absurd. In the serious category you can talk

about computer communications (<TT>comp.dcom.telecom</TT>), astronomy (<TT>sci.astro</TT>),

and so forth. In the absurd corner you have such choices as <TT>alt.tasteless</TT>,

<TT>alt.barney.dinosaur.die.die.die</TT>, and <TT>alt.fan.oj-simpson.drive.faster</TT>.</P>

<P>Usenet was started at Duke University in 1979 by two students, Tom Truscott and

Jim Ellis, as an experiment to connect two computers between Duke and the University

of North Carolina. From these two news sites in 1980, the number of news sites has

grown to hundreds of thousands of sites in the 1990s, with millions of subscribers

worldwide.</P>

<P>There are several news readers for Linux. I will cover two: <TT>nn</TT> and <TT>tin</TT>.

<CENTER>

<H4><A NAME="Heading30<FONT COLOR="#000077">nn</FONT></H4>

</CENTER>

<P>The <TT>nn</TT> news reader stands for Net News. When you use <TT>nn</TT>, you

decide which of the many news groups you are interested in. You unsubscribe those

that do not interest you any more. <TT>nn</TT> lets you read all articles in each

of the groups you subscribe to, using a menu-based article selection prior to reading

the articles in the news group.</P>

<P>When you enter a newsgroup in <TT>nn</TT>, you are presented with a screen that

lists the most recent unread articles. Each item on this list contains at least the

sender and subject. You are now in selection mode. You can select using the A through

Z and 0 through 9 keys. When you select an article, it is displayed in a highlight

color. If you press the spacebar, you go into read mode.</P>

<P>In read mode, <TT>nn</TT> presents you with each article. Press the spacebar to

get to the next page of each article. If you are at the end of an article, the spacebar

takes you to the next article.</P>

<P>When you have read all the selected articles in the current group, pressing the

spacebar takes you to the next group.</P>

<P>Here are some of the other commands in <TT>nn</TT>:



<UL>

	<LI><TT>?</TT> or help gives a one-page overview of the commands available in the

	current mode. This is perhaps the most used command for beginners. The best way to

	learn about <TT>nn</TT> is by using this command.

	<P>

	<LI>Ctrl-L or Ctrl-R redraws the screen.

	<P>

	<LI>Ctrl-P shows the previous message.

	<P>

	<LI><TT>!</TT> is the shell escape command. You are prompted for a command if you

	do not type one after the <TT>!</TT>.

	<P>

	<LI><TT>Q</TT> quits <TT>nn</TT>.

	<P>

	<LI><TT>V</TT> prints release and version information (for debug).

	<P>

	<LI><TT>:command</TT> executes the command by name. This is used to invoke any of

	<TT>nn</TT>'s commands, including those that cannot be bound to a key.

</UL>



<P>The <TT>nn</TT> man pages provide about 600 lines of very detailed information

about all the options and commands available to you. You do not have to use all of

them--just use as many as necessary to customize your own environment.

<CENTER>

<H4><A NAME="Heading31<FONT COLOR="#000077">tin</FONT></H4>

</CENTER>

<P><TT>tin</TT> is a screen-oriented Net News reader. It can read news locally (<TT>/usr/spool/news</TT>)

or remotely (<TT>rtin</TT> or <TT>tin -r</TT> option) via an NNTP (Network News Transport

Protocol) server. <TT>tin</TT> is based on the <TT>tass</TT> newsreader, which was

developed by Rich Skrenta in March 1991. <TT>tass</TT> was itself heavily influenced

by NOTES, which was developed at the University of Illinois by Ray Essick and Rob

Kolstad in 1982. The most relevant author to date is Iain Lea (<TT>[e-mail]</TT>).

Check the long list of contributors in the man pages.



<DL>

	<DT></DT>

</DL>





<DL>

	<DD>

<HR>

<A NAME="Heading32<FONT COLOR="#000077"><B>TIP:</B> </FONT>Use the <TT>h</TT>

	(help) command to view a list of the commands available at any level.

<HR>



</DL>



<P>On startup, <TT>tin</TT> shows a list of the newsgroups found in <TT>$HOME/.newsrc</TT>.

An arrow (<TT>-&gt;</TT>) or highlighted bar points to the first newsgroup. Move

to a group by using the terminal arrow keys or j and k. Use Page Up and Page Down

or Ctrl-U and Ctrl-D to page up and down. Select a newsgroup to read from by pressing

Enter.</P>



<P>The Tab key advances to the next newsgroup that has unread articles and enters

it.</P>

<P>To start and run <TT>tin</TT>, export NNTPSERVER to the address of your remote

news server. Use the command<FONT COLOR="#0066FF"></FONT>

<PRE><FONT COLOR="#0066FF">$ export NNTPSERVER=news.your.provider.com

</FONT></PRE>

<P>Then run <TT>tin</TT> with the <TT>-r</TT> option to connect to this remote server.</P>

<P>A sample <TT>tin</TT> session is shown in Listing 14.8. It shows two newsgroups

that I have subscribed to: <TT>alt.humor</TT> and <TT>tx.jobs</TT>.</P>

<P>When you select a message to read from and press either the right arrow or Enter

key, you are shown the message itself, as shown in Listing 14.9.

<CENTER>

<H3><A NAME="Heading33<FONT COLOR="#000077">Listing 14.8. A sample tin session.</FONT></H3>

</CENTER>

<PRE><FONT COLOR="#0066FF">

                     Group Selection (news.neosoft.com  2)            h=help

       1   571  alt.humor

  u    2   398  tx.jobs





       &lt;n&gt;=set current to n, TAB=next unread, /=search pattern, c)atchup,

    g)oto, j=line down, k=line up, h)elp, m)ove, q)uit, r=toggle all/unread,

      s)ubscribe, S)ub pattern, u)nsubscribe, U)nsub pattern, y)ank in/out

</FONT></PRE>



<PRE><FONT COLOR="#0066FF">

Group tx.jobs (`q' to quit)...

</FONT></PRE>

<CENTER>

<H3><A NAME="Heading35<FONT COLOR="#000077">Listing 14.9. Another sample tin

session.</FONT></H3>

</CENTER>

<PRE><FONT COLOR="#0066FF">

                          tx.jobs (368T 401A 0K 0H R)                   h=help



   171  +    US-TX-Dallas    MicroFocus Cobol Contract       Mark Allen

   172  +    CA-CLARIS HR, WINDOWS DEVELOPMENT POSITIONS A   CLARIS HR

   173  +    CA-CLARIS HR, DIRECTOR OF WORLDWIDE PRODUCT D   CLARIS HR

   174  +    CA-CLARIS HR, INTERNATIONAL WINDOWS ENGINEER    CLARIS HR

   175  +    CA, CLARIS CORP - TELECOMMUNICATIONS ANALYST    CLARIS HR

   176  +    CA- CLARIS HR, SYBASE PROGRAMMER/ANALYST AT C   CLARIS HR

   177  +    CA-CLARIS HR, DOCUMENTATION CONTROL SPECIALIST  CLARIS HR

   178  +    CA-CLARIS, SUPERVISOR, DIRECT ACCOUNT SERVICE   CLARIS HR

   179  +    CA-DEVELOPERS &amp; TEST ENGINEERS - JAPANESE PRO   CLARIS HR

   180  +    CA-CLARIS HR, DATABASE INTERNALS ENGINEER POS   CLARIS HR

   181  +    CA, CLARIS CORPORATION - PRICING ANALYST        CLARIS HR

   182  +    WA-CLARIS HR, MAC &amp; WINDOWS DEV'RS/ INTERFACE   CLARIS HR

   183  +    USA-TX-DALLAS -   Informix 4GL/ESQL             imi

   184  +    USA-TX-DALLAS - SONET Telephany Engineers       imi

   185  +    USA-TX-DALLAS - PowerBuilder                    imi

   186  +    USA-TX-DALLAS - Oracle DBAs                     imi

   187  +    USA-TX-DALLAS - CICS, Cobol, JCL, VSAM (ALC +   imi



    &lt;n&gt;=set current to n, TAB=next unread, /=search pattern, ^K)ill/select,

  a)uthor search, c)atchup, j=line down, k=line up, K=mark read, l)ist thread,

</FONT></PRE>

<PRE><FONT COLOR="#0066FF">

    |=pipe, m)ail, o=print, q)uit, r=toggle all/unread, s)ave, t)ag, w=post

</FONT></PRE>

<P>In Listing 14.9, you see a list of subject headers and their index numbers. The

+ sign indicates that you have not read this message. For example, the SONET job

for Dallas, Texas, has an index of 184 and is unread. To read this message, use the

arrow keys to move to it, and then press Enter. Command-Line Options <TT>tin</TT>

has several command-line options, some of which are listed in Table 14.2. <BR>



<CENTER>

<P><FONT SIZE="4"><B>Table 14.2. tin's command-line options. </B></FONT>

<TABLE BORDER="0">

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><I>Option </I></TD>

		<TD ALIGN="LEFT"><I>Description </I></TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-c</TT> </TD>

		<TD ALIGN="LEFT">Creates or updates index files for every group in <TT>$HOME/.newsrc</TT> or every

			file specified by the <TT>-f</TT> option and marks all articles as read. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-f file</TT> </TD>

		<TD ALIGN="LEFT">Uses the specified file of subscribed newsgroups instead of </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT">			<P>

		</TD>

		<TD ALIGN="LEFT"><TT>$HOME/.newsrc</TT>. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-h</TT> </TD>

		<TD ALIGN="LEFT">A help listing of all command-line options. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-m dir</TT> </TD>

		<TD ALIGN="LEFT">The mailbox directory to use. The default is <TT>$HOME/Mail</TT>. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-n</TT> </TD>

		<TD ALIGN="LEFT">Loads only groups from the active file that are also subscribed to in the user's

			<TT>.newsrc</TT>. This enables a noticeable speedup when connecting via a slow line.

					</TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-p program</TT> </TD>

		<TD ALIGN="LEFT">Prints program with options. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-q quick</TT> </TD>

		<TD ALIGN="LEFT">Starts without checking for new newsgroups. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-r read</TT> </TD>

		<TD ALIGN="LEFT">News specified in the environment variable <TT>NNTPSERVER</TT> or contained in the

			file <TT>/etc/nntpserver</TT>. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-R read</TT> </TD>

		<TD ALIGN="LEFT">News saved by <TT>-S</TT> option (not yet implemented remotely from the default NNTP

			server). </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-s dir</TT> </TD>

		<TD ALIGN="LEFT">Saves articles to a directory. The default is <TT>$HOME/News</TT>. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>-v</TT> </TD>

		<TD ALIGN="LEFT">Verbose mode for the <TT>-c</TT>, <TT>-M</TT>, <TT>-S</TT>, <TT>-u</TT>, and <TT>-Z</TT>

			options. </TD>

	</TR>

</TABLE>

<BR>



</CENTER>

<P>To add a new group, type <TT>g</TT>groupname. For example, <TT>gmisc.invest</TT>

adds the newsgroup <TT>misc.invest</TT>.</P>



<P><TT>tin</TT> offers an <TT>emac</TT>s-style editing facility for entering messages.

The command strings include a history of commands to enable reuse of previous commands.

The man pages for <TT>tin</TT> list all the commands available to you for editing,

deleting, and removing messages.</P>

<P><TT>tin</TT> uses the following important environment variables: 

<TABLE BORDER="0">

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT"><TT>NNTPSERVER</TT> </TD>

		<TD ALIGN="LEFT">The default NNTP server to remotely read news from. This variable needs to be set

			only if the <TT>-r</TT> command-line option is specified and the file <TT>/etc/nntpserver</TT>

			does not exist. </TD>

	</TR>

	<TR ALIGN="LEFT" rowspan="1">

		<TD ALIGN="LEFT">





			<BLOCKQUOTE>

			<P><TT>VISUAL</TT>



			</BLOCKQUOTE>



			<P>

		</TD>

		<TD ALIGN="LEFT">





			<BLOCKQUOTE>

			<P>This variable overrides the default editor that is used in all editing operations

			within <TT>tin</TT>.



			</BLOCKQUOTE>



			<P>

		</TD>

	</TR>

</TABLE>

<TT>tin</TT> can pretty much be navigated by using the four arrow keys. The left

arrow key goes up a level; the right arrow key goes down a level; the up arrow key

goes up a line or page; and the down arrow key goes down a line or page. Most prompts

within <TT>tin</TT> can be aborted by pressing Esc.

<CENTER>

<H3><A NAME="Heading37<FONT COLOR="#000077">Using FTP</FONT></H3>

</CENTER>

<P>File transfer protocol (FTP) is a method of transferring files from one computer

to another. FTP provides the capability of transferring files to and from a remote

network site as well as means for sharing public files. In this section you go through