Level: Introductory Teodor Zlatanov (tzz@iglou.com), Programmer, Gold Software Systems
01 Mar 2001 After customizing tcsh, Enlightenment, Eterm, and Emacs for a Java and Perl-oriented programming environment, Teodor shows us the configuration of his desktop in Linux. It is optimized for a Java and Perl programming setup, but doubtless other programmers will find many useful tips.
A few years ago, I began building my programming environment in
UNIX. I'm still not done! What I present here is a snapshot of my
environment, but please understand that it is neither finished nor
perfect. You should never stop improving your computing environment. Tinkering is fun, and you will probably learn something new in the process. All the errors are mine, but I owe thanks to the many people who have helped me over the years. (There are too many to name.) If it weren't for their help, in person and on newsgroups, I wouldn't be writing the
following article. Getting started
This article is intended for the intermediate to advanced Linux user.
Perl 5.6.0, or at least 5.005, should be installed in order to do some
of the examples. The Emacs editor is mentioned and may need to be
installed if you want to try the Emacs examples. The Enlightenment
window manager is mentioned and may need to be installed together with
the Eterm terminal emulator, but most recent window managers and
terminal emulators have features similar to what Enlightenment and
Eterm provide in the context of this article. You should be comfortable with editing files, making system
modifications, installing Linux packages from source, and having fun
with Linux. If these tasks are unfamiliar to you, be doubly careful
with everything described here, and take care to back everything up.
(This is a good idea in any case.) For a refresher on installing Linux packages from source, check out the developerWorks tutorial Compiling and installing software from sources.
tcsh customization
I use tcsh as my primary login shell. It is easy to convert the
examples for use by bash, zsh, or another shell. The tcsh shell is
what I have used for years, but it is by no means perfect for
everyone. The tcsh shell uses several initialization (rc) files. In UNIX, rc
(pronounced: "ar cee") files are files read by a program upon initialization. The
rc moniker comes from the common "rc" suffix to the file name (for example, "tcshrc" for the tcsh shell, or "exrc" for the classic vi editor).
The rc files are also called "dot" files sometimes because they begin
with a dot in order to hide them from normal directory listings. The tcsh shell customization I have resides in the .cshrc, .login, and .logout files. Other people use .tcshrc instead of .cshrc, but unless you use the C (csh) shell as well (and you shouldn't; tcsh is much better), the difference is irrelevant. The .login file is the first thing executed for a login shell:
Listing 1: my .login file
stty erase \^?
echo TERM = $TERM
switch ($HOST)
case "workmachine":
fetchmail
breaksw
case "homemachine":
fortune
echo "---"
from | tail
mesg y
echo "---"
breaksw
default:
breaksw
endsw
|
The "stty erase" line sets the erase character to be the delete key.
I prefer this setting because I am used to the delete key erasing
backwards, but you may want to leave this out if the default suits
you. Then, an echo statement prints out the current terminal. I like this so I know if xterm capabilities are supported, but it is definitely not essential. A switch statement follows. It is similar in form to the C switch()
statement (which is after all where the C [csh] shell, and later the tcsh shell, gets its heritage). Depending on the host name, we either run fetchmail (I run this at my work machine in every login shell, since multiple copies of fetchmail don't interfere with each other), or some miscellaneous commands at home. The home machine commands are as follows: print a fortune (try it;
it's fun!); then a divisor ("---"); then the last few messages in my
mailbox; then turn on the paging permissions; then print another
divisor. There is also a default case for commands that should be run
everywhere. It is unused in my environment. After the .login file, the tcsh shell goes through the .cshrc file (it prefers the .tcshrc file, but it will take .cshrc if that's all that's available).
Listing 2: my .cshrc file, part 1: shell-specific settings
The code in Listing 2 is shell-specific, meaning that it doesn't directly carry over to any other shells. Generally, shell-specific settings are set with the "set" command, whereas environment settings are set with "setenv". The path is an exception because the tcsh shell maintains $PATH and $path synchronized, so you can use either set or setenv to set the path. It's a matter of personal preference. The opposite of set and setenv are unset and unsetenv. Only set or
setenv will print out a list of the shell and environment settings. Personally, I think that the distinction between environment and shell settings is the worst aspect of tcsh. I would use one or the other, but not both. The current design forces me to use both.
Listing 3: my .cshrc file, part 2: environment
# another switch statement
switch ($HOST)
case "homemachine":
# from home, I use my work machine's external network interface
setenv CVSROOT tzz@workmachine-external:/cvsroot
# of course, ssh is the only protocol allowed. rsh is insecure.
setenv CVS_RSH ssh
# my NNTP server at home
setenv NNTPSERVER nntp
# give Emacs a name, for Enlightenment positioning
alias emacs emacs -name workmachine-emacs
breaksw
case "homemachine-2":
# same as homemachine
setenv CVSROOT tzz@workmachine-external:/cvsroot
setenv CVS_RSH ssh
# but this is a Solaris machine, so use mailx (I could have used
# OSTYPE instead of $HOST for generality)
alias mail mailx
breaksw
default:
# default CVS root for all machine at work. Leave rsh as the
# default transport.
setenv CVSROOT tzz@workmachine:/cvsroot
breaksw
endsw |
The environment settings in Listing 3 are mainly concerned with setting the CVS repository root correctly. If you use CVS, this is a convenient way to set things up automatically so all CVS commands will work from any machine. Also, I give a name to the main Emacs window so that Enlightenment can position it correctly. I could have used $OSTYPE instead of $HOST, and set up a separate
switch() statement to handle Solaris; but all that for the sake of
aliasing mail to mailx seems a bit excessive to me.
Listing 4: my .cshrc file, part 3: aliases
To try out the aliases defined below, just type them in at the
prompt. The "abc" alias will print "foreach?" on a line by itself and
wait for your input. If you enter "echo $a" for example, and then
"end" at the next prompt, the "echo" command runs with 1
through 9, then A through Z, then a through z in $a. Finally, my .logout is pretty simple. It is the list of commands executed when a login tcsh shell exits, only on my home machine.
On all other machines it does nothing.
Listing 5: my .logout file
switch ($HOST)
case "homemachine":
# save the list of subscribed newsgroups, just in case:
# save only the first 2000 characters of each lines (the
# .newsrc file can have very long lines), then filter out the
# unsubscribed newsgroups, and save the output in ~/.subbed
cut -c 1-2000 ~/.newsrc | egrep -v "!" > ~/.subbed
# remove any dead letter files (/bin/mail generates them)
rm ~/dead.letter
breaksw
default:
breaksw
endsw |
Enlightenment and Eterm customization
My favorite window manager is Enlightenment. I like it and use it.
You may not like Enlightenment ("E" from now on), but, nevertheless, your window manager will probably support most of the features I like in E. It's harder to replicate the functionality of Eterm, though
the aterm program is similar in intent and effect. Both E and Eterm use themes. Themes are eye candy, rarely useful in
practice. I find them useful for Eterm, but for E I don't use themes
for programming support. The most important modification I made to E was to change the default keybindings with the e16keyedit program. I have Alt-F1 through
Alt-F12 mapped to go to desk 1 through 12, so I can switch between
different tasks quickly. I have aliased some desks to additional
keypresses -- for instance, Alt-Shift-M takes me to my mail desktop. Also, I have Ctrl-Alt-M start up a mail window (actually
"emacs -name gnus -f gnus" since I use Gnus to read my mail). In
similar fashion, I have Alt-Shift-Letter go to a specific desktop,
while Ctrl-Alt-Letter starts a program that is remembered to be on
that desktop. E can remember a program's location and command line invocation. This means that if a program has a unique name, E can restart it the next time you login, or just remember its position for the next time you start it. The name is the X name of the window, usually specified
with the -name parameter to the program. Eterm uses themes to specify custom behavior. You can try out the
default themes that come with Eterm (for example, "Eterm -t mutt" for a
mutt-oriented terminal, or "Eterm -t trans" for a transparent Eterm).
I find a transparent Eterm, set to stick in the layer below all other
windows, to be very useful in everyday work. It's always available
because it's sticky, it never obscures other windows, and provides
nice visual relief from black and white. You can write your own Eterm themes. Look at the Eterm documentation for further information.
Emacs customization
Emacs is more than an editor -- it's a complete editing environment,
file manager, Lisp compiler and virtual machine, and much more. I
like Emacs for the programming support it provides. Listings 6 and 7 are quite complex. They use a lot of Lisp code, so
you should have some understanding of Lisp before you attempt to
modify them to suit your own needs. (See the Resources for
Lisp help.)
Listing 6: The .emacs.gun.custom file
For help with all the settings in the emacs.gnu.custom file, use the Emacs help facility. Inside Emacs, press C-h v, then the name of the
variable you want to examine. You can even customize the variable's
value further from the window that comes up. The .emacs file invokes the custom file. The
.emacs file is rather large and complex, and it uses a lot of Lisp
modules not included with Emacs (which can be found in
Resources). I have included the majority in the Resources, but you may have to do some Web surfing to get some larger packages such as eshell.
Listing 7: The .emacs file
I have tried to comment the .emacs file thoroughly. Try to understand what each line does; use the Emacs help facility if you need help. C-h a invokes the apropos command, which will look up help based on a keyword. Also, see Resources for more information and help with Emacs. Most importantly, take only the pieces you like. If you don't use
footnotes or folding mode, that's OK. Maybe you like cycle-buffer and
align instead, or something in the emacs.gnu.custom file got your
attention. The Resources section will guide you further.
The rest: miscellaneous setup files
I use vim, a very powerful vi clone. Here's my vimrc file (see Resources for more information on vim and the vimrc file):
Listing 8: the .vimrc file
Below is a script I use to start up a new Emacs window. It can be
adapted to other uses, but I only need it to send Emacs a USR1 signal,
or start a new Emacs if one isn't running. You need the CPAN Proc::ProcessTable modules to use this script. Invoke it as "./getem.pl emacs".
Listing 9: getem.pl
#!/usr/bin/perl -w
use Proc::ProcessTable;
use strict;
# get the process name
my $name = shift @ARGV or die "You must provide a process name";
# get the PID to process
my $pid = get_pid ($name);
# if we got a PID...
if (defined $pid)
{
kill 'USR1', $pid or die "$pid - $!\n";
}
else # start a new process
{
system("$name &");
}
# find the PID from a process table, based on a name
sub get_pid
{
my $name = shift @_;
my $table = new Proc::ProcessTable;
foreach my $p (@{$table->table})
{
# this filters out getem.pl itself
return $p->pid if (defined $p->cmndline &&
$p->cmndline !~ /perl/ &&
$p->cmndline =~ /^$name/);
}
return undef;
} |
My XFree configuration uses xinerama with two video cards. Xinerama
is a module for the XFree server that provides multiple monitor
capability. This means that two monitors can be one display to the
computer. Enlightenment supports xinerama -- for instance, maximizing a window will maximize it to the monitor, not to the whole display, which may be multiple monitors. Unfortunately, XFree configuration files are not portable, so mine would not be useful to anyone. You have to read the documentation for XFree and create a configuration file for your own machine.
Looking ahead
I hope this cruise through my setup has helped you to improve your own
environment. It's really a matter of experimentation to find the
right environment, and as I already said, the experimentation should
never end. I also hope that you learned of some new programs from this tour. If you haven't, look through the Resources and I guarantee you will find something new. If you need help with any of the setups shown here, or need general
assistance, again, the Resources can help you. Your answer has almost
certainly been written already, and you just need to find it. If you
are stuck, look on Usenet newsgroups, Web forums, and the manuals for
the program in question.
Resources - Read Ted's other Perl articles in the "Cultured Perl" series on developerWorks.
- For Linux (and general UNIX) rc files, Dotfiles.com is a good resource.
- The best way to search the Usenet for past answers to your questions is to use Deja.com.
- For free reference cards for many programs and programming languages, try Refcards.com.
-
Internet FAQ archives provides frequently asked questions (with answers) for almost every Usenet newsgroup. Highly recommended.
- Perl news and other resources can be found at Use Perl, Perl User Groups, the main
Perl.org page, and CPAN among
others. The Perl Monks can offer extra wisdom. Perl documentation can be found at perldoc.com.
- For more information on CVS, see the CVS documentation at cvshome.org. It is a good starting point. Also see the developerWorks tutorial CVS for the developer or amateur.
- For information on Emacs:
- The Emacs JDE package is
simply the best Java environment available, in my opinion.
- The Gnus newsreader is an excellent newsreader
package for Emacs.
- The Free Software Foundation (which authored Emacs) publishes many
Emacs manuals and references.
-
O'Reilly and Associates publish manuals and reference guides on most of
the topics in this article.
- If you hate tcsh, look at the Advanced Bsh Scripting HOWTO, and read the developerWorks article "Bash by example, Part 2". You can do everything I've shown using tcsh with bash.
- The Jargon file is an
indispensable resource for the serious programmer.
- General Linux information can be found at Linux.org.
- Enlightenment's home page is at Enlightenment.org.
- Eterm's home page is at Eterm.org.
- XFree's home page is at XFree86.org.
- VIM's home page is at VIM.org.
- Here are the Emacs Lisp packages included with this article. (You can download them from their authors' Web sites as well. See inside each package for more information.)
About the author  | | | Teodor Zlatanov graduated with an M.S. in computer engineering from Boston University in 1999. He has worked as a programmer since 1992, using Perl, Java, C, and C++. His interests are in open source work on text parsing, 3-tier client-server database architectures, UNIX system administration, CORBA, and project management. Suggestions and corrections are welcome over e-mail. Contact Teodor at tzz@iglou.com. |
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