shell "set" and environment variables

If you type set at a Bash prompt you should see something like the following on your vt. These are your current environment variables and thier values.

BASH=/bin/bash
BASH_VERSION=1.14.7(1)
COLUMNS=80
EDITOR=pico -z
EUID=0
HISTFILE=/root/.bash_history
HISTFILESIZE=500
HISTSIZE=500
HOME=/root
HOSTNAME=BigBroot
HOSTTYPE=i386
.
.
.
.

Every unix process has an "environment". It's environment is the variables
that are visible to it. A shell is a process. The Bash builtin
command set will display all the variables know to the shell.




##########################
Here's the same thing, but the whole thing, the way mine is at the moment, 
with some annotation.......
	
BASH=/bin/bash
	The full pathname of your Bash shell.
	
BASH_VERSION=1.14.7(1)
	The version of Bash.
COLUMNS=80
	your terminal's width in characters.
EDITOR=pico -z
	A default editor, pico with ^z background switch enabled.
EUID=0
	Effective user ID. 0 is the superuser. 0 has all permissions.
HISTFILE=/root/.bash_history
	what you've been doing in Bash. Do   history   at a prompt.
HISTFILESIZE=500
	size of history ring buffer in lines.
HISTSIZE=500
HOME=/root
	where   ~   is an alias for, your home directory.
HOSTNAME=BigBroot
	Name of the box. See /etc/HOSTNAME
HOSTTYPE=i386
HUSHLOGIN=FALSE
	are we disabling the login message of the day?
HZ=100
	kernel jiffy clock frequency.
IFS= 	

	input field separator for .e.g. bash    read    builtin.
LESS=-MM
LESSOPEN=|lesspipe.sh %s
LINES=50
	visible lines on your vt.
LOGNAME=root
	who you logged in as.
MAIL=/var/spool/mail/root
	where your mail is kept. BigBroot doesn't do local mail.
MAILCHECK=60
	how often new email is checked for. not applicable.
MINICOM=-c on
OLDPWD=/
	your previous working directory.  cd -   will go there.
OPTERR=1
OPTIND=1
OSTYPE=Linux
	a digital penguin. Sharp beak.
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/usr/sbin:/bin:/usr/bin
	where the shell looks for commands.
PPID=1
	Process ID of the shell's parent process. 1 is init.
PS1=$   /dev/tty1  \u  \w  \s  \t\n$ 
	the usual Bash prompt. 
PS2=> 
	the secondary bash prompt.
PS4=+ 
PWD=/etc/rc.d
	your current directory.
SHELL=/bin/bash
	your shell. Bash is 99.44% Bourne script compaqtible, with many
	interactive niceties.
SHLVL=1
	shells can call shells. How often have we done that?
TERM=linux
        Terminal type, from termcap, "linux" is very vt102-like.
UID=0
	actual user ID.
USER=root
VISUAL=pico -z
	some programs check $VISUAL for what editor you prefer.
_=set
	the previous command you executed. I just did    set    to paste
	into this file.	
ignoreeof=10
	ASCI value of EOF, End Of File, I think. :o)