Unix Sig
By Christopher J. Fearnley

@SH = Next Month's Meeting

We will have two member presentations: Steve Beuret will present some
useful awk scripts; and Gordon Fink will present an introduction to perl.
[The UNIX SIG meets from 11-1 pm in M408.]

@SH = An ftp Tutorial

Ftp stands for file transfer protocol. If you have a net account that
supports ftp, this is a powerful way to get informational files, and free or
shareware programs. We will use a sample session to download the PARI/gp
advanced programmable calculator and its "readme" files. To begin the ftp
program type "ftp" from the command prompt. [The ftp site given in my
example is in France, so one should not ftp there during French working
hours (when their system is most taxed). Since France is several hours
ahead of us, I think mid-afternoon to mid-evening in Philadelphia would be
appropriate.] Then type "open megrez.ceremab.u-bordeaux.fr" (if your system
does not know this name, you can use the IP address 147.210.16.17 instead). 
Once the ftp connection is established, enter the user name "anonymous". 
Give your email address for the password. You can use the command "ls" or
"dir" to see the contents of the current directory. The command "pwd" will
give the name of the current directory. To get to the directory with the
PARI/gp program type "cd pub/pari". If you will be compiling the program
under UNIX, type "cd unix". First, You should get the readme file, so type
"get README" [Note: file and directory names are case sensitive]. This
command may not work, because many ftp programs only support files of the
form *.*. In this case try using the optional second argument of the get
command which gives the ftp program the name to use on your system. So try
"get README read.me". Next, we should get the program itself. When we give
the command "ls -l" we notice that all the other files end in ".gz", which
means they are compressed with GNU's gzip program [try "man gzip" or ask
your system administrator how you can get it]. Compiled or compressed
progams must be retrieved in binary mode (use the "bin" command to enter
binary mode); normal text files must be transferred in text mode (use
"ascii"). So type "bin" to enter binary mode. Now we can retrieve the
source for the calculator with the command "get pari-1.38.tar.gz
pari138.tgz". [Note: perhaps on your system you will not need the second
argument. Also the other files in the unix subdirectory are for various
flavors of UNIX or older versions of the program. If you want to run
the calculator on one of those systems, you should get those files (see the
README file for details).] We should "close" the connection as soon as we
are finished. Then type "quit" to get back to the system prompt.
 
One of the best places to find out about ftp sites is in the FAQs
(Frequently Asked Questions) posted in the newsgroup news.answers. Also the
comp.sources newsgroup is a good way to find out what programs are available
and where they are located. There are many hundreds (thousands?) of ftp
sites around the world. There is much more material out there than any
single local BBS could possibly hold. Do Enjoy!