La clause IF# #!/bin/bash printf "Enter your name: " read NAME echo "Hello $NAME !" printf "Please, enter a number: " read NUMBER if (( "$NUMBER" < "0" )); then echo "$NUMBER is negative !" elif (( "$NUMBER" == "0" )); then echo "$NUMBER is null !" else echo "$NUMBER is positive !" fi La clause IF..ELSE# #!/bin/bash printf "Enter your name: " read NAME echo "Hello $NAME !" printf "Please, enter a number: " read NUMBER if (( "$NUMBER" < "0" )); then echo "$NUMBER is negative !" elif (( "$NUMBER" == "0" )); then echo "$NUMBER is null !" else echo "$NUMBER is positive !" fi La clause IF..ELIF..ELSE# #!/bin/bash printf "Enter your name: " read NAME echo "Hello $NAME !" printf "Please, enter a number: " read NUMBER if (( "$NUMBER" < "0" )); then echo "$NUMBER is negative !" elif (( "$NUMBER" == "0" )); then echo "$NUMBER is null !" else echo "$NUMBER is positive !" fi