Of writing shell scripts Hello World

Shell first to write a script under Linux

// create a .sh file 
vi demo1.sh

 // Press i to enter edit mode 
echo " the Hello World! " 
// pressing the Shift + → esc : → WQ (save and exit)

 // first check ll 
ll

 // to just created a file executable permissions 
chmod + the X-demo1.sh

 // re-ll, you will find the script turned green, then state the script executable 
LL

 // execute the script 
. / demo1.sh
 // or 
SH demo1.sh

 / / can not use the second method to execute permissions to perform