if

---

examples/script/testing_variables.sh

if [ $# = 2 ]
then
   echo there are 2 parameters
else
   echo The number of parameters is $#
fi

$ ./examples/script/testing_variables.sh 
The number of parameters is 0

$ ./examples/script/testing_variables.sh one
The number of parameters is 1

$ ./examples/script/testing_variables.sh one two
there are 2 parameters

$ ./examples/script/testing_variables.sh one two three
The number of parameters is 3