Linux : Java Glossary

Linux works fine on obsolete computers with slow CPUs and tight RAM. Consider installing it on one of your old boat anchors for experiments, rather than installing it via the more complex dual boot.

Sun supports Java on Linux. The independent Blackdown Java seems to have been abandoned.

This document is designed to help a naïve user install and get started with, Ubuntu, Red Hat Fedora Core 8 or Red Hat Enterprise Linux, especially if you have a Windows background. Since I originally wrote this essay, everything has changed for the better. All current distributions have vastly improved installers. You can now install in under an hour from a single DVD. This installation process will leave you with a working system connected to the Internet with a full set of development tools, databases, an office productivity suite and all the Internet utilities including Apache. To get to the comparable state with Windows can easily take several days. Windows requires many reboots and when you are done installing the OS, you still need to download and install all the applications.

Please take anything you read here with a large grain of salt. Please let me know of any errors or omissions. I had an exceedingly frustrating time getting Linux to work. Further, I have been overwhelmed by the sheer volume of documentation. Most of what I wrote here is what people told me. I did not do it from personal experience. I hope to make your way a little easier.

Introduction

1. I talked with various Linux users. They showed me how Linux had changed in the year last year and a half since I gave up on it as too nerdy. It is evolving about five times faster than Windows in terms of ease of use. It now has whiz bang wow-the-earthlings stuff like animated wallpaper. It runs Windows apps (Win 3.1 and Win95 with wine). It looks snazzy and modern. It has lost that klunky DOS look, even in the GUIs. KDE as GUI manager has made a world of difference. It runs many more devices than before. It can do simultaneous CPU-intensive tasks like Mp3 without even breathing hard. Caldera is no longer used.
2. Windows 2000 client retails for about  . If you have the patience, you can download Linux, along with all kinds of apps such as Star Office, free. Even if you buy the CD at full retail you will spend only to . Mr. Gates started out with DOS, an ersatz CPM-86. He blew away the competition not because his DOS was superior, but because it was much cheaper. I wonder if he has forgotten this.
3. I heard a report that a major US company had a server farm of 5000 servers, geographically distributed, all running NT server. About once every 60 seconds a server would fail and require a reboot. They switched to the much more stable and free Linux.

Terminology

distro

A Linux distribution. It would include pre-complied device drivers, OS, GUI, and applications, together with an installer. In the bad old days you had to collect source for all the pieces and compile and link them yourself, selecting from hundreds of variants. Now various groups do that work for you and present their easy-to-install products mostly from public domain sources.

KDE

KDE (K Desktop Environment) : A species of X-windowing system that manages your desktop. It is slightly more like Windows than GNOME.

GNOME

A species of X-windowing system that manages your desktop Originally it meant GNOME (Gnu Network Object Model Environment) but the current project has wandered so it now has little to do with networking.

grep

To search, particularly using a regex expression, a number of files.

RPM

RPM (Red Hat Program Manager). A scheme for distributing software bundles in an easy-to-install way. It was originally Red Hat’s invention and now nearly everyone supports it. You use an installer program such as UP2DATE, YUM (Yellowdog Updater, Modified) or AGET to unpack the bundle and install it. Must programs can install anywhere. The installer creates a symbolic link to them in /usr/bin, which has much the same effect at lower overhead as putting them on the path does in Windows.

Terminal

The command line interface. To get at the command line interface, click Applications ⇒ Accessories ⇒ Terminal. This strange name betrays Linux’s history when people typed commands at terminals connected to Unix mini computers.

Equivalents

Installation Hints

Installing Hard Disk Partitions

1. Live

   Using the Ubuntu or Knoppix CD. You boot and go, putting your data on your Windows partitions. You don’t install Linux on your hard disk. All your Linux apps are on the CD. This is fine for a trial, but you will probably want to install on hard disk for faster performance.

2. Automatic

   Let the installer figure out what partitions are needed, create them and format them. This might be reasonable for an all-Linux machine.

3. Manual partitioning

   This gives you fine control. You would likely want to use this method if you have other OS (Operating System) es already installed or if you want to leave room for future ones.

Manual Partitioning

• DOS ’s fdisk
• Windows Control Panel
• PartitionMagic: won’t be able to move or resize them.
• Boot-It Bare Metal
• Acronis Disk Director
• Other boot manager: won’t resize or format, but will slide and copy.
• Linux Fdisk, Disk Druid, GPart or GRUB.

Partitioning Gotches

• GRUB overwrites the master partition, i.e. Boot-It or at least bypasses it.
• You can only have 4 primary bootable partitions. Boot-It fakes 4 out of N, but when you boot from CD, you don’t see the deception, unless you boot from CD via Boot-It.
• All the Ubuntu partitions look unbootable to Boot-It, but they look bootable to Ubuntu.
• If you start Ubuntu via Boot-It with the wrong partition settings, it will happily treat your Windows partitions as free space.
• Partitions keep losing their labels. All you have is size to keep track of what is what. So make them slightly different sizes.

You can mount your DOS/Windows partition, either read-only or read-write. You don’t set it up during the sysgen. You add it later with a bit of fussing. You first need to mkdir a /windows directory as the mount point. Then you need to use the control-panel in X-Windows to add a new partition. Add, not edit! You need to set its type to vfat not DOS It will be added to the /etc/fstab the auto option, so it will be automatically remounted on any reboot. If you want to set it up before you get X-Windows working, you can edit the /etc/fstab to insert an entry of type vfat, mount point /win and options auto,noexec,nosuid,nouser,rw 0 0. You need to do one mount /dev/sda1 manually and from then on it seems to work automatically.

There are several jobstreams running during the install. You can flip back and forth with Alt-F1 Alt-F2 etc. or Ctrl-Alt-F1 if under X Windows. To get back to X-Windows use Alt-F7.

Installing Video and X-Windows

If you are a masochist, you will love Xfree86. It is almost like a build-it-yourself driver toolkit but more frustrating. If you want to spend less than a month of your life solving the problem of making the screen display something, use Red Hat 5.0 and the enclosed commercial Metro-X drivers and use configX. Be careful to fill in both panels one for the monitor and one for the video card and don’t touch the add button.

Use Xconfigurator to configure X-Windows and X or startx to start it. Once you have X working you can use the control-panel that you can access inside X to configure a second printer, configure ppp access, add users etc.

If Xconfigurator does not work, you may have to start over from scratch installing Linux or use RPM to make sure you have the right video driver. Look over all the choices, don’t just grab the first one that looks good. If X still does not work, try installing fewer video modes in particular leave out some of the higher resolution ones. I found the old xf86config line-oriented configuration program gave better results, though it was more awkward to use. Without it I could not get at the high resolution modes and I could not change modes with Ctrl-Alt-Keypad+ and Ctrl-Alt-Keypad-. If X hangs on fireup, hit Alt-F1 and you will be able see some error messages about why it failed. Use xvidtune within X-Windows to fine tune the configuration so that the image is sized and centered properly on the monitor in all modes. Not that xvidtune does not change your XF86Config file for you. It just displays settings you can manually add to it. It may be easier to use your monitor’s adjustments, then adjust other OS ’s to those settings.

The first entry on the modes line is the one your X-Windows will come up in. When you hit Ctrl-Alt-+, it should step through them in order.
Modes 640x480 800x600 1024x768 "1280x1024 "

You can control which colour depth your X-Windows comes up in with: startx -- -bpp 16

In theory you should by able to permanently configure this by creating a file in your home directory called .xserverrc with the line exec X :0 -bpp 16 in it. However, I have not got that to work myself.

To properly solve this configuration problem you have to have entries that exactly match the documented modes supported by your video bios. This may require setting up modes that are specific to a colour depth because your video card my require different rates for different colour depths with the same resolution. I have yet not found documentation on how to generate the required magic numbers.

After that is done, you can start thinking about configuring your .fvwmrc file to configure the menus etc.

Installing Internet Access

Installing Other Hardware

The standard install program ignores much of your hardware, e.g. tape backup, sound card, scanner. To use these devices you must generate a new kernel, or find a pre-built one that has the support you need. I’m told

CD /usr/src/linuxmake config

For a sound card you may want  commercial drivers from http://www.4front-tech.com.

More Shells Than You Can Shake A Shtick At

GUI s

I am a puzzled by the Unix folk having so many ways of handling the GUI. I have heard of Gnome 1 2 3, KDE, X-Windows, Xfce, Unify

Because we get a choice over the L&F. Everything uses X11, aka X-windows: that’s the underlying display technology for all graphical displays on UNIX/Linux but it doesn’t do window management/desktops. X-term is a non- graphical way of using X11 as a text-mode terminal — rather like a DOS box, but capable of talking to both local and remote hosts.

To do anything useful with X11 you use a window manager: all distros pick one to use as default and each has its own style of handling the desktop, decorating application windows, launching applications, etc. etc. — hence the religious wars and differences of opinion over them. The common ones are Gnome and KDE (the two commonest ones), Xfce (very basic, but lightweight. If you run up VNC (Virtual Network Computing), the default desktop for it is Xfce) and Unity (currently restricted to Ubuntu, introduced because they hate Gnome 3 but its reportedly disliked just as much). The true answer is even more complex, since the GUI is layered and you can mixed pieces together from different desktop environments, window managers and toolkits.

Gnome 1,2,3 are just versions of Gnome — think Java 2,3,4,5 6 …

Which does Java use?

None, but Swing has a limited ability provide the same look and feel as the native windows manager for the system the JVM (Java Virtual Machine) is installed on as well as Java’s cross-platform Metal look & feel, e.g. G3 buttons and text entry boxes have rounded corners, but Java doesn’t and its default button background gradient is different, as is the main menu bar though the appearance is fairly close. The title bar and its drop-down menus are, however, identical. AWT (Advanced Windowing Toolkit) uses GTK (the Gimp ToolKit). SWT (Standard Widget Toolkit) uses GTK.

When you write a C program do you have to pick a GUI manager? or do they share a common core API (Application Programming Interface)?

No, they have different APIs (Application Programming Interfaces). My distro uses Gnome by default but can support KDE. Almost all the apps I use are Gnome apps, but I do use one or two KDE apps. They run OK, but have a slightly different look & feel and drag in a whole bunch of KDE support libraries — but a decent package installer deals with that automatically. Package installers also differ: Red Hat distros such as Fedora and Red Hat clones use YUM, Ubuntu and the other Debian clones use APT.

Login Scripts

However, you often want to make changes that apply to all users. This used to be done by editing /etc/profile — something that needed to be redone after a reinstall. Now there’s a better way. /etc/profile shouldn’t need changing because its final act is to run every script it finds in /etc/profile.d. So, make a short script setting the customisations for everything to do with a particular program or package and drop it into /etc/profile.dand keep a copy in a safe place. That way after a clean install, you just drop this set of scripts into /etc/profile.d

Here is a Java customisation script, java.sh

• By default the JDK (Java Development Kit) will install in /usr/java, but by creating the directory /home/java and making /usr/java a symbolic link pointing to it, the JDK will install here instead. If /home is a separate partition that is never reformatted, the JDK will still be there after a Linux reinstall, so merely adding the symbolic link will reinstall the JDK and all the other Java packages.
• The third term in these definitions is a symbolic link pointing to the current version of that package. When you upgrade a package, you can simply unzip it into /home/java and then change the symbolic link so it points to the new version.

Re-Installing

Be very careful about copying files to and from a Windows partition. You will lose the owner, the attribute bits and files and directories beginning with . will not be copied. Files will be redated.

Naming Your Computer

Simply editing /etc/HOSTNAME is not sufficient. Change the name with the X Control Panel netconfig.

Your computer also has another name, localhost@localdomain with dummy IP (Internet Protocol) 127.0.0.1.

Gotchas

• Alt-F-X or Ctrl-C won’t get you out of very many programs. Linux has never heard of CUA. Each program wants to keep you trapped in there until you read the entire online manual looking for the magic escape sequence (other than Ctrl-Alt-Del to reboot). Hint:

  Program	How To Get Out
  emacs	Ctrl-G Ctrl-M Ctrl-C N yes
  less	Ctrl-Q Q
  man	Ctrl-Q Q
  vi	Esc : Q
  vim	Esc : Q

• Linux is case-sensitive. Linux programmers seem to take great delight in mixing case in names in inconsistent ways.
• Be careful in emacs. Using the arrow keys can add blank lines on the end of your document if you overshoot out the bottom.
• BS and Del don’t work consistently. The Linux folk still have not learned the difference. Backspace won’t work until you configure it to with:
  stty stop ^S start ^Q erase ^H
• The path traditionally excludes the current directory, at least for the root user. To execute something in the current directory you must say ./myProg to qualify it enough to be found.
• cp is not quite xcopy. * in a wildcard will not match files that begin with .. They have to be specially handled. cp usually seems to find a way to misread your intentions and create a new directory tree under the target rather than merging source files with the target’s similar directory structure. By default cp redates files. Do some experiments.
• There are no extensions. Linux examines the first few bytes of each file to figure out what type it is. Data files don’t appear to automatically launch the corresponding app when you run them. There is also an executable permission attribute bit (actually three separate ones) that must be set before you can execute a program.
• Wildcards of the form *xxx work in Linux, finding files ending in xxx. In DOS/Win they are uselessly equivalent to plain *. This is an ungotcha, a rare and precious event.
• X-Windows generates a virtual screen bigger than your physical screen. When you open a window, you might not see it. You have to scroll around to find it.
• In documentation, C-x means Control-x, M-x means Esc then x, or sometimes Alt-x.
• The default PATH given to root is different than for a normal user. root, by default does not get /usr/local/bin on his path. You have to add it in the .bash-profile.
• It is common for programs to come in source form only. Even you have no plans to develop software in C/C++, you still need the compilers installed to install software.
• If you let Linux write files in your Windows vfat partitions, it will use GMT (Greenwich Mean Time), not local time. Norton Disk Doctor will freak over these future dated files. It also may cause trouble trying to figure out which file are really more recent if you share files between OSes (Operating Systems).
• The RPM install package name is not the same as the uninstall package name. See notes under uninstall in the Windows equivalents table.
• If Linux gets it into its head that your CD-ROM drive is /dev/had when it should be /dev/hdb or vice versa, you set it straight by editing the symbolic link for cdrom in the /dev directory.
• if you don’t have write permissions for a file, you can still delete it — but only if you have write permissions for the directory the file is located in. The Linux people look at this very literally. When you delete the file, you don’t write to the file, you write to the directory. Every file has an owner and usually only the owner can touch that file. The root user can read, write or delete any files.
• If you create new script files, they are not accessible via unqualified names using the path until you have either logged out and in again, or used rehash.
• The control-panel program for adding new users will not automatically encrypt the passwords. They need to be encrypted before use. To encrypt them, click CHANGE; don’t just enter them in plain text in the slot marked password.
• Command line substitution is complex:

  code	meaning
  …	expand what is inside now.
  '…'	what is inside later.
  ${name}	expand name as a set parameter.
  $(name)	run the program name and expand with its output.
  $name	old way of doing ${name}
  `name`	old way of doing $(name)

Symbolic Links

• Creating aliases for files and directories.
• Putting a program on the path without adding extra directories to the path.
• Divvying up the directory tree over several partitions.
• Physically reordering the disk structure without changing any of the scripts that reference the files.
• Create a shorthand for long strings of directory names or long filenames.
• Letting a browser find a plug-in without needing its own private copy of the plug-in.

1. In some directory,
2. you put an alias name, a link to:
3. some other file or directory that exists elsewhere.

cd /B
ln -s A/x y

Installing Java

JAVA_HOME=/usr/local/java/jdk15
JDK_HOME=$JAVA_HOME
PATH=$JAVA_HOME/bin:$PATH

emacs

Emacs is designed solely for the convenience of advanced users. You might think if it as a suite of word processing LISP (List Processing language) functions. You edit a file by running in an interactive programming mode where you compose and execute a LISP program on the fly where each keystroke invokes one LISP function.

To begin to make it friendly, (bind home jump to start of line instead of start of file, bind end jump to end of line, bind ^@ behave like Shift-^@ and bind ^- to behave like ^C_) create a .emacs file in your $HOME directory like this:

Here is a table of the basic commands to get you started. M-x in Linux-speak means Alt-x, C-x means Ctrl-x and S-x means Shift-X.

Credits

Distributions

Books

Book referral for The Official Ubuntu Book (9th Edition)

	recommend book⇒The Official Ubuntu Book (9th Edition)
	by	Matthew Helmke, Elizabeth K. Joseph, Jose Antonio Rey	978-0-13-451342-3	paperback
	publisher	Prentice Hall	978-0-13-451249-5	eBook
	published	2016-07-30	B01IFCKT96	kindle
Aimed at first time users.
Online bookstores carrying The Official Ubuntu Book (9th Edition) abe books anz abe books.ca abe books.de amazon.ca amazon.de Chapters Indigo amazon.es Chapters Indigo eBooks iberlibro.com abe books.com abe books.fr amazon.com amazon.fr Barnes & Noble abe books.it Nook at Barnes & Noble amazon.it Kobo junglee.com Google play abe books.co.uk O’Reilly Safari amazon.co.uk Powells other stores
Greyed out stores probably do not have the item in stock. Try looking for it with a bookfinder.

Book referral for Running Linux, fifth edition

	recommend book⇒Running Linux, fifth edition
	by	Matthias Kalle Dalheimer, Matt Welsh	978-0-596-00760-7	paperback
	publisher	O’Reilly	978-0-613-91175-7	hardcover
	published	2005-12-29	978-0-596-55300-5	eBook
			B0043EWUNE	kindle
Good introduction to Linux and Unix in general
Online bookstores carrying Running Linux, fifth edition abe books anz abe books.ca abe books.de amazon.ca amazon.de Chapters Indigo amazon.es Chapters Indigo eBooks iberlibro.com abe books.com abe books.fr amazon.com amazon.fr Barnes & Noble abe books.it Nook at Barnes & Noble amazon.it Kobo junglee.com Google play abe books.co.uk O’Reilly Safari amazon.co.uk Powells other stores
Greyed out stores probably do not have the item in stock. Try looking for it with a bookfinder.

Book referral for Peter van der Linden’s Guide to Linux

	recommend book⇒Peter van der Linden’s Guide to Linux
	by	Peter van der Linden	978-0-13-187284-4	paperback
	publisher	Prentice Hall
	published	2005-08-18
Peter is fun to read. So many texts are so dry you have to force yourself to plod through. With Peter it is more like a good novel you can’t put down. This is a book for people wanting to get started with Linux written in standard English. Peter has a knack for bringing the esoteric down to earth and making it simple.
Online bookstores carrying Peter van der Linden’s Guide to Linux abe books anz abe books.ca abe books.de amazon.ca amazon.de Chapters Indigo amazon.es Chapters Indigo eBooks iberlibro.com abe books.com abe books.fr amazon.com amazon.fr Barnes & Noble abe books.it Nook at Barnes & Noble amazon.it Kobo junglee.com Google play abe books.co.uk O’Reilly Safari amazon.co.uk Powells other stores
Greyed out stores probably do not have the item in stock. Try looking for it with a bookfinder.