Ruby Basic environment variable settings and common interpreter commands Introduction to _ruby topics

Ruby Environment variables
The Ruby interpreter uses the following environment variables to control its behavior. The ENV object contains a list of all the currently set environment variables.

For Unix, use the ENV command to view a list of all environment variables.

Hostname=ip-72-167-112-17.ip.secureserver.net
rubypath=/usr/bin
shell=/bin/bash
TERM=xterm
histsize=1000
ssh_client=122.169.131.179 1742
ssh_tty=/dev/pts/1
user=amrood
jre_home=/usr/ Java/jdk/jre
j2re_home=/usr/java/jdk/jre
path=/usr/local/bin:/bin:/usr/bin:/home/guest/bin
MAIL =/var/spool/mail/guest
pwd=/home/amrood
inputrc=/etc/inputrc
java_home=/usr/java/jdk
LANG= C
home=/root
shlvl=2
jdk_home=/usr/java/jdk
logdir=/usr/log/ruby
logname=amrood
ssh_connection=122.169.131.179 1742 72.167.112.17
lessopen=|/usr/bin/lesspipe.sh%s
rubylib=/usr/lib/ Ruby
G_broken_filenames=1
_=/bin/env

Ruby Command line Options
Ruby is typically run from the command line as follows:

$ ruby [Options] [.] [Programfile] [Arguments ...]

The interpreter can be invoked with the following options to control the environment and behavior of the interpreter.

Given command-line options can be used in combination. The following two lines express the same meaning:

$ Ruby-ne ' Print if/ruby/'/usr/share/bin


$ ruby-n-E ' Print if/ruby/'/usr/share/bin