Difference between revisions of "CLI Variables"

From FreekiWiki
Jump to navigation Jump to search
Line 1: Line 1:
=== Assignment and Dereferencing ===
+
== Commands ==
 +
env  = Shows you the environment variables that are currently defined.
 +
echo = Displays a line of text.
 +
 
 +
== Examples ==
 +
=== Example #1 - Assignment ===
 
To assign a value to an environment variable you simply type the variable name, '=', then the value. For example,
 
To assign a value to an environment variable you simply type the variable name, '=', then the value. For example,
 
  FOO=Rob
 
  FOO=Rob
 
  BAR=Love
 
  BAR=Love
  
 +
=== Example #2 - Derefrencing ===
 
To get the value of the variable (i.e. dereference) you place a '$' before the variable name.
 
To get the value of the variable (i.e. dereference) you place a '$' before the variable name.
  
Line 11: Line 17:
 
  #Love
 
  #Love
  
=== Commands ===
+
== Quiz ==
env  = Shows you the environment variables that are currently defined.
 
echo = Displays a line of text.
 
 
 
=== Quiz ===
 
 
# What is the value of the "USER" environment variable?
 
# What is the value of the "USER" environment variable?
 
# What is the value of the "HOSTNAME" environment variable?
 
# What is the value of the "HOSTNAME" environment variable?
Line 23: Line 25:
 
# Using the GEEK environment variable, how would you echo the statement, "I think that FREE GEEK is the best!"?
 
# Using the GEEK environment variable, how would you echo the statement, "I think that FREE GEEK is the best!"?
 
# Can you tab-complete environment variables?
 
# Can you tab-complete environment variables?
 +
 +
== Instructor Notes ==
 +
There needs to be a little into paragraph and the examples could be flushed out more.
  
 
[[Category:CLI Quizes]]
 
[[Category:CLI Quizes]]
 
[[Category:Classes]]
 
[[Category:Classes]]

Revision as of 12:58, 19 April 2008

Commands

env  = Shows you the environment variables that are currently defined.
echo = Displays a line of text.

Examples

Example #1 - Assignment

To assign a value to an environment variable you simply type the variable name, '=', then the value. For example,

FOO=Rob
BAR=Love

Example #2 - Derefrencing

To get the value of the variable (i.e. dereference) you place a '$' before the variable name.

#echo $FOO
#Rob
#echo $BAR
#Love

Quiz

  1. What is the value of the "USER" environment variable?
  2. What is the value of the "HOSTNAME" environment variable?
  3. What is the value of the "PWD" environment variable?
  4. What is the value of the "HOME" environment variable?
  5. How would you create an environment variable named GEEK that has the contents- "FREE GEEK is the best!"?
  6. Using the GEEK environment variable, how would you echo the statement, "I think that FREE GEEK is the best!"?
  7. Can you tab-complete environment variables?

Instructor Notes

There needs to be a little into paragraph and the examples could be flushed out more.