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<H1>Some Common Unix Commands</H1>
The purpose of this summary is to give a quick survey of the Unix
commands that most users find useful. These commands have many more
options -- alas, occasionally inconsistent from one computer to
another. For additional information see the Unix manual pages, using
the command <B><A HREF="#man">man</A></B>.
<P>For several commands whose descriptions would have been too
lengthy, only a brief description is given.
<P>
<B><a name="contents">Contents</a></B>
<P><UL>
<LI><a HREF="#file_dir">File and Directory Management</a>
<LI><a HREF="#text">Text Processing Commands</a>
<LI><a HREF="#graphics">Graphics Processing Commands</a>
<LI><a HREF="#system">System Commands</a>
<LI><a HREF="#network">Network Commands</a>
<LI><a HREF="#config">Some Configuration Files</a>
</UL>
<P><h2><a name="file_dir">File and Directory Management</a></h2>
<DL>
<P><DT><B>cat</B>
<DD>Concatenates file(s). By default, these are printed on the monitor
without pausing at the end of each page. To insert pauses, see the
first example.
<P><DD>Examples: <br><tt> cat chapter4 | more</tt> (or <tt>cat
chapter4 | less</tt>) <br>Displays the file chapter4 using the command
<B><A HREF="#more">more</A></B> (or <B><A HREF="#less">less</A></B>)
to insert pauses one screen at a time.
<P><tt> cat chapter1 chapter2 > book </tt>
<br>Concatenates the files named <tt>chapter1</tt> and <tt>chapter2</tt> in
the current directory and collects them in a file named <tt>book</tt> on
the current directory.
<P><tt> cat chapter12 | egrep broccoli > broccoli </tt> <br> Feeds
the contents of the file chapter12 to the <B><A
HREF="#grep">egrep</A></B> filter which then only keeps the lines
having the word <tt>broccoli</tt>. This is, in turn, saved in the file
named <tt>broccoli</tt>.
<P>
Remark: Blank spaces above just before or after > are unimportant, they
just make it easier to read.
<P><DT><B>cd</B>
<DD>Change directory
<P><DD>Examples:
<P><tt> cd Tex</tt>
<br>Change to the subdirectory (of the current directory) named <tt>Tex</tt>
<P><tt> cd Tex/mypapers </tt>
<br>Change to the sub-subdirectory (of the current directory) named
<tt>Tex/mypapers</tt>.
<P><tt> cd /Users</tt>
<br>Change to the subdirectory <tt>Users</tt> of the root directory.
<P><tt> cd</tt>
<br>Changes to your own home directory from any other directory.
<P><tt> cd ~ksmith/public_html/</tt>
<br>Changes to the user <tt>ksmith</tt>'s <tt>public_html</tt> directory.
<P><DT><B>chmod</B>
<DD>Change who has permission to read, write, or execute a file.
See the man page.
<P><DT><B>cp</B>
<DD>Copy file(s)
<P><DD>Examples:
<P><tt> cp .cshrc .cshrc3-24</tt>
<br>copies the file named <tt>.cshrc</tt> to the file named
<tt>.cshrc3-24</tt>
<P><tt> cp *.bak tmp/</tt>
<br>Copies all files whose names end <tt>.bak</tt> to the subdirectory
<tt>tmp</tt> of the current directory. The subdirectory <tt>tmp</tt> must
already exist.
<P><tt> cp -i *.bak tmp/ </tt>
<br>Same as above, but warns before overwriting a file with the same name.
<P><DT><B>crypt</B>
<DD>Encrypt a file using a key you specify. The key should not contain
whitespace (space or tab).
<P><DD>Example:
<P><tt> crypt F(x)=12 < exam1 > green </tt>
<br>Encrypts a file named <tt>exam1</tt> using the key <tt>F(x)=12</tt>. Here
the encrypted output file is named <tt>green</tt>.
<P><tt> crypt F(x)=12 < green > happy </tt>
<br>This deciphers the above file and saves the output in the file
<tt>happy</tt>. One must use the same key, but the output file need
not have the old name (you may not know the original name anyway).
<P><DT><B>find</B>
<DD>Finds files with specified names and then does something you request,
such as print their locations, or delete them, perhaps depending on when
they were last modified. This is a very powerful command; most people
use only its simplest abilities.
<P><DD>Example:
<P><tt> find /usr/local/ -name pico -print </tt>
<br>Find all files named <tt>pico</tt> in the directory <tt>/usr/local/</tt>
and its subdirectories. The list is printed on the monitor.
<P><A NAME="gzip"><DT><B>gzip, gunzip, zcat</B></A> <DD><B>gzip</B>
will compress a single file. Use the command <B>gunzip</B> to
uncompress. For a group of files, such as a complete subdirectory,
first use the program <B><A HREF="#tar">tar</A></B> to collect all of
these files into one longer file, which is then gzipped. <BR>Note:
this program is similar to the related program named <B>zip</B>, but
their files are not interchangeable. <B>gunzip</B> will, however,
uncompress any files compressed with either the <B>compress</B> or
<B>pack</B> commands--these files usually have a .Z or .z suffix,
respectively.
<P><DD>Examples:
<P><tt> gzip exam1.ps </tt>
<br>This creates the compressed file named <tt>exam1.ps.gz</tt> and deletes
the file <tt>exam1.ps</tt>
<P><tt> gunzip exam1.ps.gz </tt>
<br>Gives the original file <tt>exam1.ps</tt> and erases the compressed file
<tt>exam1.ps.gz</tt>
<P><a HREF="#contents">return to Table of Contents</a>
<P><A NAME="head"><DT><B>head</B></A>
<DD>Displays the first 10 lines of file(s). (See also <B><A
HREF="#tail">tail</A></B>).
<P><DD>Example:
<P><tt> head 141* | more </tt> <br>Displays the first 10 lines of the
files whose names begin with <tt>141</tt> and uses <B><A
HREF="#more">more</A></B> to display them one screen at a time.
<P><A NAME="less"><DT><B>less</B></A> <DD>Displays a file on the
screen, one page at a time. Many people prefer this to the older
program <B><A HREF="#more">more</A></B> since <B>less</B> has more
options.
<P><DD>Example:
<P><tt> less chapter1 </tt>
<br>This is equivalent to <tt> cat chapter1 | less</tt>
<P><DT><B>ln</B>
<DD>Link files, that is, have a filename in one directory refer to the
file located in another directory. See the man page.
<P><DT><B>ls</B>
<DD>List the directory contents.
<P><DD>Examples:
<P><tt> ls </tt>
<br>Alphabetical list of all the files in the current directory except
those whose names begin with a period . (thus, one frequently begins the
names of a configuration file with a period so it is hidden from a routine
directory listing).
<P><tt> ls -a </tt>
<br>Alphabetical list of all the files in the current directory, including
those whose names begin with a period.
<P><tt> ls -l</tt> (<I>or</I><tt> ls -al </tt>)
<br>Long directory listing (including size, date the file was last modified,
and who has permission to read, write or execute). The second version
also includes all files whose names begin with a period.
<br>If the directory has many items, it will not fit on one screen.
To avoid the listing scrolling off the screen one can either pipe the
output through the commands <B><A HREF="#more">more</A></B> or <B><A
HREF="#less">less</A></B>, as
<br><tt>ls -al | more </tt>
<P><tt> ls -lt *bak </tt>
<br>Long listing (ordered by the <I>time</I> the files was last modified)
of all files whose names end with <tt>bak</tt>.
<P><DT><B>mkdir</B>
<DD>Make a new directory.
<P><DD>Examples:
<P><tt> mkdir Tex </tt>
<br>Make a new subdirectory named <tt>Tex</tt> in the current directory.
<P><tt> mkdir Tex/classes </tt>
<br>Make a new subdirectory named classes in the directory <tt>Tex</tt>.
<P><tt> mkdir Tex/classes; cd Tex/classes </tt>
<br>Make a new subdirectory named classes in the directory <tt>Tex</tt>
and then immediately change to that directory.
<P><A NAME="more"><DT><B>more</B></A> <DD>Displays a file on the
screen, one page at a time. Many people prefer the program <B><A
HREF="#less">less</A></B>, since <B>less</B> has more options.
<P><DD>Examples:
<P><tt>more chapter1 </tt>
<br>This is equivalent to <tt> cat chapter1 | more</tt>
<P><DT><B>mv</B>
<DD>Move or rename a file.
<P><DD>Examples:
<P><tt> mv chapter1 chapter1.old </tt>
<br>Renames <tt> chapter1</tt> as <tt> chapter1.old </tt>
<P><tt> mv *.bak tmp/ </tt>
<br>Moves all the files in the current directory whose names end with
<tt>.bak</tt> to the directory <tt>tmp</tt>.
<P><tt> mv -i *.bak tmp/ </tt>
<br>Same as above but warns before overwriting a file that already exists.
<P><DT><B>rm</B>
<DD>Remove (= delete = erase) files(s).
<P><DD>Examples:
<P><tt> rm book *.dvi </tt>
<br>Removes the file <tt>book</tt> and all the files in the current directory
whose names end with <tt>.dvi</tt>.
<P><tt> rm -i book *.dvi </tt>
<br>Same as above but is interactive, prompting before removing each file.
<P><tt> rm -r book </tt>
<br>Recursively removes the directory book and all of its files and
subdirectories. <tt>rm -ri book</tt> is the interactive version.
<BR><I>Note: USE WITH CAUTION!</I>
<P><DT><B>rmdir</B>
<DD>Remove a directory (it must already be empty, but see <B>rm -r</B>).
<P><DD>Example:
<P><tt> rmdir math141 </tt>
<br> Removes the (already empty) directory math141.
<P><A NAME="tail"><DT><B>tail</B></A> <DD>Displays the last 10 lines
of a file. Also see <B><A HREF="#head">head</A></B>.
<P><A NAME="tar"><DT><B>tar</B></A> <DD>Collects a group of files into
one file. There is no command "untar"; instead one uses tar but with
different flags. By default, tar recursively includes all
sub-subdirectories and retains the subdirectory structure. One
frequently uses <B><A HREF="#gzip">gzip</A></B> to compress a file
after using <B>tar</B>. Files distributed on the network are
usually tarred and compressed or gzipped. This program is typically
used when archiving files.
<P><DD>Examples:
<P><tt> tar cvf letters1994.tar letters </tt> <br>Collects all of the
files in the subdirectory <TT>letters</TT> (and its subdirectories)
into one large file <tt>letters1994.tar</tt> in the current directory.
The original files are not deleted or changed. One might then use
<B><A HREF="#gzip">gzip</A></B> to compress the tar file:
<P><tt> gzip letters1994.tar </tt>
<br>
to create <tt>letters1994.tar.gz</tt> (and delete
<tt>letters1994.tar</tt>). One can combine these into one step with:
<P><tt> tar cf - letters | gzip > letters1994.tar.gz </tt>
<br>
<P><tt> tar xvf letters1994.tar </tt>
<br>Reverses the above and "untars". If needed, this creates the
subdirectory <tt>letters</tt> or any sub-subdirectories. The file
<tt>letters1994.tar</tt> is <I>not</I> erased.
<P><tt> zcat letters1994.tar.gz | tar xf - </tt>
<br>The <B><A HREF="#gzip">zcat</A></B> command uncompresses the
gzipped file which is then "untarred" by <tt>tar xf - </tt>
(note the final <tt>-</tt>). This avoids creating the file
<tt>letters1994.tar</tt>, which may use critical disk space. On some
computers the program <B><A HREF="#gzip">zcat</A></B> might be named
<B>gzcat</B>.
</DL>
<a HREF="#contents">return to Table of Contents</a>
<P><h2><a name="text">Text Processing Commands</a></h2>
In addition to the commands below one also has the commands <B>axe,
emacs, nedit, pico,</B> and <B>vi</B> to use various editors on
different computers.
<DL>
<P><DT><B>diff</B>
<DD>List the differences between two files.
<P><DD>Example:
<P><tt> diff chapter1 chapter1.old </tt>
<br>In the output, the lines beginning with "<" refer to
the first file, those beginning ">" refer to the second file.
<P><DT><B>dvips</B>
<DD>Print a TeX dvi file on a postscript printer. The command
<B>dvips</B> by itself lists a variety of options.
<P><DD>Examples:
<P><tt> dvips exam1.dvi</tt> (or just <tt> dvips exam1</tt>)
<br>Prints the file <tt>exam1.dvi</tt> on the default printer.
<P><tt> dvips -oexam1.ps exam1.dvi (<I>or</I> dvips -oexam1.ps exam1 )
</tt> <br>Processes the file <tt>exam1.dvi</tt> and saves the output
in the file <tt>exam1.ps</tt> rather than printing it immediately. At
a later time one can use the command <TT><A HREF="#lpr">lpr</A>
exam1.ps</tt> to print this.
<P><A NAME="grep"><DT><B>egrep, fgrep, grep</B></A>
<DD> Search file(s) for a pattern. <B>egrep</B> is recommended, as
it is typically faster than <B>grep</B> or <B>fgrep</B>. The grep
family of commands has many useful options.
<P><DD>Examples:
<P><tt> egrep Johnson chapt2 (<I>or</I> egrep -i johnson chapt2)</tt>
<br>
Display all the lines in the files <TT>chapt2</TT> that contain the word
<tt>Johnson</tt>. The case insensitive version using
<B>egrep -i</B> does the same but will also catch <I>JOHNSON,
JohnSon, johnson,</I> etc..
<P><DT><B>fmt</B>
<DD>Reformat a text file to include, say, in an email message, where
at most 80 columns are permitted. This breaks lines at white space (tab
or space). No hyphenations are introduced. Reformatting is useful
for files produced by editors such as <B>edit</B> on the NeXT,
where the lines may be very long.
<P><DD>Example:
<P><tt> fmt myfile</tt>
<br>Formats the text file <tt>myfile</tt> so that each line has at most (by
default) 72 columns.
<P><DT><B>latex2html</B>
<DD>Changes a LaTeX file into an <tt>html</tt> file that can be posted
on the World Wide Web. This processes the LaTeX file and makes each
mathematical formula in the document into a graphic file that can be
viewed by World Wide Web graphical browsers, such as Mosaic and Netscape.
One should avoid fancy LaTeX commands. One should also break the document
into sections, which are then treated as separate html files; these then
take less time to load in World Wide Web browsers.
<P><DD>Example:
<P><tt>latex2html homework3.tex</tt>
<br>This produces the subdirectory <tt>homework3</tt> containing the main
file <tt>homework3.html</tt> and other graphics and html files that that
file uses.
<P><a HREF="#contents">return to Table of Contents</a>
<P><DT><B>ispell</B>
<DD>Interactive spelling checker. One can use this by itself and also
within the editor <B>emacs</B>. [Within <B>emacs</B> on our system,
use <I>Ctrl C 3</I> to begin a spell check of the complete current
document].
<P><DD>Example:
<P><tt> ispell chapter1 </tt>
<br>Checks the spelling in the file chapter1.
<P><A NAME="lpq"><DT><B>lpq</B></A>
<DD>Lists all the jobs (and their job numbers) queued to be printed.
<P><DD>Examples:
<P><tt> lpq </tt>
<br>List the jobs queued to be printed on the default printer.
<P><tt> lpq -P4E1 </tt>
<br>Lists the jobs queued to be printed on the printer named 4E1.
<P><A NAME="lpr"><DT><B>lpr</B></A>
<DD>Print a file on the printer (for many years, a "line
printer" was used, whence the name <B>lpr</B>).
<P><DD>Examples:
<P><tt> lpr chapter1.ps </tt>
<br>Prints the file chapter1.ps on your default printer.
<P><tt> lpr -P4E1 chapter1.ps </tt>
<br>Prints the file chapter1.ps on the printer 4E1.
<P><A NAME="lprm"><DT><B>lprm</B></A>
<DD>Removes a job from the print queue. One first needs to run lpq to get
the job number. After removing a file from the print queue, you can run
lpq again to see if it was actually removed. You can only remove your own
files, not those of others.
<P><DD>Example:
<P><tt> lprm 235 </tt>
<br>Removes job 235 from the print queue.
<P><DT><B>sort</B>
<DD>Sort a file. There are many possibilities such as reversing the order
of a sort, and sorting by various fields in a line.
<P><DD>Examples:
<P><tt> sort file1 > file1.s </tt>
<br>Sorts the lines in <tt>file1</tt> by the characters at the beginning of
each line. Store the output in <tt>file1.s</tt>. ( <tt>>
file1.s</tt> is equivalent to <tt> -o file1.s</tt> ).
<P><tt> sort +2 file1 > file1.s </tt><br> As above, but sorts
beginning with the 3rd field; by default -- which can be changed -- fields
are separated by whitespace, i.e. spaces or tabs. The output is again
saved in file1.s
<P><DT><B>tex, latex, amstex</B>
<DD> Processes a TeX (or LaTeX or AMSTeX file), creating a dvi file.
<P><DD>Example:
<P><tt> tex exam1.tex (<I>or</I> tex exam1 ) </tt>
<br>Processes the file <tt>exam1.tex</tt> and creates <tt>exam1.dvi</tt>
<P><DT><B>xdvi</B>
<DD>Preview a TeX dvi file on an X-Terminal.
<P><DD>Example:
<P><tt> xdvi exam2.dvi & </tt>
<br>Displays the file exam2.dvi (the optional & at the end of the line
frees up that terminal window for subsequent commands without requiring
that you first exit from <B>xdvi</B>).
</DL>
<a HREF="#contents">return to Table of Contents</a>
<P><h2><a name="graphics">Graphics Processing</a></h2>
<DL>
<P><DT><B>ghostscript, ghostview</B>
<DD>Ghostview uses Ghostscript to view and modify PostScript files.
<P><DD>Example:
<P><tt>ghostview diagram1.ps</tt>
<br>Exhibits <tt>diagram1.ps</tt>. You can change such items as orientation,
and magnification.
<P><DT><B>grab</B>
<DD>On the NeXT computer, used to grab an image on the screen and capture
it as a tiff file. Documentation is in the application, which is located
in <tt>/NextApps/Grab.app </tt>. This image can be edited subsequently
using <tt>IconBuilder.app</tt> (see below) or changed to some other format
such as <I>gif</I> using <B><A HREF="#pbmplus">pbmplus</A></B>.
<P><DT><B>IconBuilder.app</B>
<DD>On the NeXT computers, used to edit images which are <I>tiff</I>
files, such as icons. Documentation is in the application, which is
located in <tt>/NextDeveloper/apps/IconBuilder.app</tt>. As an
alternate, one might prefer to edit the graphic using <tt>xpaint</tt>
on our X-Terminals. One may need to first use <B><A
HREF="#pbmplus">pbmplus</A></B> to change the format of the graphic.
<P><A NAME="pbmplus"><DT><B>pbmplus</B></A>
<DD>A family of programs that change a graphics file from one format
to another. One should presume that any change of format will result in a
loss of information and a degradation in quality.
<P><DD>Example:
<P><tt> tifftopnm touch.tiff | ppmtogif > touch.gif </tt>
<br>Changes the file <tt>touch.tiff</tt> to <tt>touch.gif</tt>.
<P><DT><B>xpaint</B>
<DD>An X-Windows program for making computer graphics. One can edit or
create a picture.
<P><DD>Example:
<P><tt>xpaint &</tt>
<br>This opens <tt>xpaint</tt>, which has both a <I>toolbox</I> and a
<I>canvas window</I>. Click on <I>File</I> to edit an existing picture
or icon.
<P><DT><B>xv</B>
<DD>An X-Windows program that displays many different file types, such
as <tt>gif</tt> and <tt>xbm</tt>. It can also grab (color) images
from your monitor and edit them as well as many additional
capabilities.
<P><DD>Example:
<P><tt>xv touch.gif</tt>
<br>Displays <tt>touch.gif</tt> which you can then process using
<tt>xv</tt>'s tools.
</DL>
<a HREF="#contents">return to Table of Contents</a>
<P><h2><a name="system">System Commands</a></h2>
<DL>
<P><DT><B>at</B> <DD>Executes a command line -- or a script -- at a
specified time. For instance, you may wish to print a long file at
4:30 in the morning (=04:30 on a 24 hour clock). Or you might want to
begin a long calculation in the middle of the night when the computer
is less busy. <br> Use <B>atq</B> (or <B>at -l</B>) to see the queue
of pending <B>at</B> commands. If desired, you can then delete jobs
from the queue with the command <B>atrm</B> (or <B>at -r</B>); the
procedure is similar to <B><A HREF="#lpq">lpq</A>, <A
HREF="#lprm">lprm</A></B> mentioned above.
<P><DD>Example:
<pre> at 0430
lpr myfile.ps
echo "myfile.ps was just printed"
[Ctrl D]</pre>
<DD>In the above, each line ends with a carriage return, and the last line
closes the file with the single character <I>Ctrl D</I>. After your
file is printed, you will be send an email message stating <tt>myfile.ps
was just printed</tt>.
<P><DT><B>date</B>
<DD>Prints the current system date and time on the screen.
<P><DD>Example:
<P><tt> date </tt>
<br>
<P><DT><B>du</B>
<DD>Prints a summary of the disk usage for the current directory and all
subdirectories. Careful: by default some computers use blocks of size 1024
bytes while others use blocks of size 512 bytes.
<P><DD>Example:
<P><tt> du </tt>
<br>Give size of each directory.
<P><tt> du -s </tt>
<br>Give summary total only.
<P><tt> du -a </tt>
<br>Give size of each file.
<P><DT><B>kill</B>
<DD>Terminate a process (i.e. terminate a computer program that is
running out of control). Killing a process may also kill all of its
"children". Thus, killing a shell (such as <B>csh</B>) may
kill all of the foreground and background processes started from that
shell. Killing a users login shell is equivalent to that person
logging out.
<br>For some types of severe problems, the easiest (and perhaps
<I>only</I>) way to kill a process or a whole login session is to
login to the same terminal from <I>another</I> terminal and then kill
the desired process(es). <br>Before using <B>kill</B> one needs to
run the command <B><A HREF="#ps">ps</A></B> to determine the process
number.
<P><DD>Examples:
<P><tt> kill 2765 </tt>
<br>Terminate process number 2765. This gently stops the process,
automatically closing all opened files and cleaning up. If this does not
kill the process, then use <tt>kill -9</tt> below.
<P><tt> kill -9 2765 </tt>
<br>Terminate process number 2765. Not gentle. You may need to do your own
cleanup, but at least you almost always get the process to stop. If this
doesn't work, ask an expert.
<P><a HREF="#contents">return to Table of Contents</a>
<P>
<A NAME="man"><DT><B>man, TkMan, xman</B></A>
<DD>Use this to read the Unix manual page on a command. On an X-Terminal
you may prefer to use <B>xman</B> (or, better yet, <B>tkman</B>).
<P><DD>Examples:
<P><tt> man man </tt>
<br> Use this to read the Unix man page on the command man itself.
<P><tt> man ls </tt>
<br> This gives the Unix man page for the command ls.
<P><tt> man -k print </tt>
<br> This gives a list of all the Unix commands concerning
"printing$quot;.
<P><A NAME="ps"><DT><B>ps</B></A>
<DD>List all the processes running. Before killing a process (=program)
you'll need this to get the process id number. The switches on this
depend on which computer you are using.
<P><DD>Examples:
<P><tt> ps -aef | egrep jsmith</tt> (System V Unix, recent SGI or Sun
computers)
<P><tt> ps -aux | egrep jsmith</tt> (BSD Unix, on all NeXT computers)
<br>
List all of the processes running that have the word <tt>jsmith</tt> in
their description. In practice, the user jsmith will use this to find all
the processes she is running.
<P><DT><B>pwd</B>
<DD>Print (on the screen) the complete pathname of the current working
directory.
<P><DD>Example:
<P><tt> pwd </tt>
<br>
<P><DT><B>stty</B>
<DD>Set or display the current terminal settings. For instance, set the
number or rows, columns, and the delete key.
<P><DD>Examples:
<P><tt> stty </tt>
<br>Display the current terminal settings.
<P><tt> stty rows 49 </tt>
<br>Set the screen size to 49 rows.
<P><DT><B>which</B>
<DD>Which command is being used. The command must be in your PATH.
<P><DD>Example:
<P><tt> which emacs </tt>
<br>Gives the full pathname to the emacs command, including any shell aliases
being used.
<P><DT><B>who</B>
<DD>Who is currently logged in this computer.
<P><DD>Example:
<P><tt> who </tt>
<br>Gives a list of the userids of those currently logged in.
</DL>
<a HREF="#contents">return to Table of Contents</a>
<P><h2><a name="network">Network Commands</a></h2>
<DL>
<P><DT><B> electronic mail (E-mail)</B>
<DD>There are a variety of commands: <B>elm</B> or <B>Mail</B> work on
all of our computers. In addition, while sitting at the console of
our networked computers, each have their own E-mail program. Finally
<B>procmail</B> is the standard program used to filter and pre-process
mail, say depending on who it is from or the subject -- although the
simple <B>filter</B> program is frequently adequate. One can also
have mail automatically forwarded, or automatically send your
correspondents a message that you are out of town. <br>One uses MIME
to include non-text material (binary files, graphics, sound) in an
email message.
<P><DT><B>ftp</B>
<DD>Transfer files to or from a remote computer on the Internet.
Some computers permit anonymous ftp that is accessible to
anyone on the network, even if you don't have an account on
that computer. In this case, when asked for the userid, type
ftp and then give your true E-mail address as your password.
<P><DD>Example:
<P><tt> ftp math.berkeley.edu </tt>
<br> To initiate a file transfer with the computer math.berkeley.edu
<P>After connecting, one gives various file transfer commands, such
as:<pre>
get file2 to get (receive) file2
mget chapter* (multiple) get all files whose names begin
with <tt>chapter</tt>.
put, file1 to put (send) file1
mput *.tex (multiple) put all files whose names end
with <tt>.tex</tt> </pre>
<DD> By default, files are assumed to be text files. To send binary files
(including compressed files), first use the command: <tt>bin</tt>
<P><DT><B>kermit</B> <DD>Transfer files between two computers, usually
when one is not on the network but only connected via modem. Slow.
<A HREF="#zmodem">ZMODEM transfer</A> is usually faster if available
on your other computer (for instance, ProcommPlus supports this).
<P><DD>Example:
<P><tt> kermit </tt>
<br>
After starting kermit one uses the commands <pre>
send chapter1 sends chapter1 to the remote computer
receive receive files from the remote computer;
you then transfer control to the other
computer and tell it what files to send
</pre>
<DD>In addition first one must set the file type for binary or text files
(<tt>set file type binary</tt> or <tt>set file type text</tt>). The
default is usually set for text files.
<P><DT><B> Reading News</B> <DD> The standard newsreader we use is
<B>tin</B> (just give the command <B>tin</B>), but there are many
others such as <B>rn</B> or (on the NeXT) NewsGrazer. The first time
you read mail you will need to decide which newsgroups you wish to
read. <br>One can also read some news groups from various World Wide
Web browsers.
<P><DT><B>rlogin</B>
<DD>Remotely login to a Unix computer. This automatically sets certain
variables, such as which terminal (keyboard) you are using. Unless
specified otherwise, the same userid is assumed.
<P><DD>Examples:
<P><tt> rlogin mail.sas.upenn.edu </tt>
<P><tt> rlogin mail.sas </tt>
<br>You can use this shorter name if you are currently on another
computer also in <tt>upenn.edu</tt>
<P><DT><B>telnet</B>
<DD>Remotely login to a computer.
<P><DD>Examples:
<P><tt> telnet mail.sas.upenn.edu </tt>
<P><tt> telnet archimedes.math </tt>
<br>You can use this shorter name if you are currently on another
computer also in <tt>upenn.edu</tt>
<P><DT><B>World Wide Web</B> <DD>Our computers use the graphical World
Wide Web browsers <B>netscape</B> for hans.math), and <B>OmniWeb</B>
for the NeXTs. In addition one can use the browser <B>lynx</B> that
does not offer graphics.
<P><A NAME="zmodem"><DT><B>zmodem (rz, sz)</B></A>
<DD>Transfer files between two computers, usually when one is not on the
network but only connected via modem. Much faster than Kermit.
<P><DD>Examples:
<P><tt> sz *.tex </tt>
<br>Send all files in the current directory whose names end with
<tt>.tex</tt>
<P><tt> rz -b </tt>
<br>Prepare to receive binary files from the other computer (the
<tt>-b</tt> means <I>binary</I>). You must then use the other computer,
perhaps at home, to specify which files are to be sent.
</DL>
<a HREF="#contents">return to Table of Contents</a>
<P><h2><a name="config">Some Configuration Files</a></h2>
There are a number of configuration files: several for the operating
system as well as special files for separate programs. Here are some.
Many of these are initially set with defaults that will be correct for
most users. You may customize these -- and others -- yourself
(<I>caveat emptor</I>).
<pre>
shell: .cshrc .login .logout .profile .plan
X: .chestrc .sgisession .Xdefaults
editors: .emacs .neditrc
mail: .mailrc .elm/elmrc .elm/aliases.text .forward .vacation
netnews: .newsrc .tin/tinrc
</pre>
<p>
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