Update III Control Statements in Bash Scripting.py

Author: ortizfram

Introduction to Bash Scripting/III Control Statements in Bash Scripting.py

@@ -2,3 +2,51 @@
  You’ll learn the differences between FOR, WHILE, IF, and CASE statements and how to use them in your Bash scripts.
  Armed with these new tools, you’ll be ready to create more advanced Bash scripts with conditional logic.
  """
+"""
+*** IF statements
+
+    *** sytax
+       >>>>>> if [ condition ]; then 
+                  # some code
+              else
+                  # some other code
+              fi   
+
+     # double parethesis structure
+     eg:     
+        if (($x > 5)); then
+            echo "$x is more than 5!"
+        fi    
+
+     # square brackets and arithmetic flags structure
+       >>>>>> -eq : 'equal to'
+       >>>>>> -ne : 'not equal to'
+       >>>>>> -lt : 'less than'
+       >>>>>> -le : 'less than or equal to'
+
+       eg: 
+          if [ $x -gt 5 ]; then
+              echo "$x is grater than 5!"
+          fi
+         
+   *** bash Conditional Flags
+       >>>>>> -e : 'file exists'
+       >>>>>> -s : 'if exists and it's grater than zero'
+       >>>>>> -r : 'if exists and readable'
+       >>>>>> -w : 'if exists and writable'
+       
+   *** AND OR in bash
+       >>>>>> && : 'and'
+       >>>>>> || : 'or'
+       
+       eg: 
+          # Simple-square notation 
+          if [ $x -gt 5 ] && [ $x -lt 11 ]; then
+              echo "$x more than 5, less than 11"
+          fi
+          
+          # Double-square notation
+          if [[  $x -gt 5 &&  ]]; then
+             echo "$x more than 5, less than 11"
+          fi
+"""