#Ubuntu batch script example code#

If defined str1 echo 'Variable str1 is defined' Following is the general syntax of the statement.įollowing is an example of how the ‘if defined’ statement can be off

#Ubuntu batch script example code#

If the above code is saved in a file called test.bat and the program is executed asįollowing will be the output of the above program.Ī special case for the ‘if’ statement is the 'if defined', which is used to test for the existence of a variable.

If %3%=3 (echo 'The value is 3') else (echo 'Unknown value') If %2%=2 (echo 'The value is 2') else (echo 'Unknown value') If %1%=1 (echo 'The value is 1') else (echo 'Unknown value') The following example show how the ‘if’ statement can be used to check for the values of the command line off The ‘if else’ statement can also be used for checking of command line arguments. Since the condition of the second ‘if’ statement evaluates to false, the echo part of the statement will not be executed. If so, then it echo’s a string to the command prompt. The first ‘if’ statement checks if the value of the variable str1 contains the string “String1”.

If %str2%=String3 (echo 'The value of variable c is String3') else (echo 'Unknown value') If %str1%=String1 (echo 'The value of variable String1') else (echo 'Unknown value') The following example shows how the ‘if else’ statement can be used to off The same example can be repeated for strings. The above command produces the following output. In the second ‘if else’ statement, the else condition will be executed since the criteria would be evaluated to false. In the first ‘if else’ statement, the if condition would evaluate to true. If the brackets are not placed to separate the code for the ‘if and else’ code, then the statements would not be valid proper if else statements. The key thing to note about the above program is −Įach ‘if else’ code is placed in the brackets (). If %c%=10 (echo 'The value of variable c is 10') else (echo 'Unknown value') If %c%=15 (echo 'The value of variable c is 15') else (echo 'Unknown value')

The following example shows how the ‘if’ statement can be used for off The evaluation of the ‘if’ statement can be done for both strings and numbers. Just like the ‘if’ statement in Batch Script, the if-else can also be used for checking variables which are set in Batch Script itself. The following diagram shows the flow of the ‘if’ statement. If the condition is false, it then executes the statements in the else statement block and then exits the loop. If the condition is true, it then executes the statements thereafter and stops before the else condition and exits out of the loop. The general working of this statement is that first a condition is evaluated in the ‘if’ statement. If (condition) (do_something) ELSE (do_something_else) Following is the general form of this statement. The next decision making statement is the If/else statement.