Shell Programming : 8 | Conditional statements

Hello.... Friends today we are going to discus about the conditional statements in the shell scripting . like in other languages the Shell Programming too have conditionals statements . Conditional executions means executing code when certain conditions met and during conditional executions we just simply executes our multiple commands one after the other.

Conditional statements are basically

• if/then
• else
• elif

Let's understand who & where we can use them. these are pretty Simple to use. So Let's understand them one by one.

• if/then 

 Syntax :

               if  [ condition ]   # when the condition is true then statement is executed or else it return.

                then  

                     statements

                fi

      Major things we have to remember the space after starting & before closing the Brackets. & closing of if statement with fi command. 

• else

Syntax :
                           if  [ condition ]           #  if the condition is true
                           then
                                 true statements    # statement is executed
                           else
                                false  statements   # statement is executed
                           fi


But if we want to make some more sense of the same script then we need to use else conditional statement too.

i e as we put false condition then it simply returns. but as we put else condition too then let's check what happened

• elif

Syntax :

                   if  [ condition ]                # if  condition is true

                   then

                          true  statement 

                  elif  [ either condition ]    # either different but true conditions

                          true  statement

                  else

                          false statement      # if all the conditions are false

                  fi

i think you will understand by this syntax where the elif statement is used so elif statement is generally for multiple true statements but we don't know the write one so to test the condition that which condition is meeting to our condition then we can use this elif  conditional statement. it will avoid the multiple if statement in our script.

let's clear it with our script 

if you have different OS then try this script in your shell. I hope it will provide you the write result as per your OS. 

thanks friends , Please leave your comments & like Tutorials it will help me in improving my quality.