Shell script in linux

Use vim or gedit or any editor to write shell script

syntax is : chmod permission your-script-name

for eg:
$ chmod +x your-scipt-name
$ chmod 755 your-script-name [will Read-write & execute for owner(7), while for group & other permission is read & execute(5)]

Executing the script:
$ bash bar(your-script-name)
$ sh bar(your-script-name)
$ ./bar(your-script-name)

. command-name
for example
$ .trollhard

Now try shell scripting
Open Gedit or Vim
type;

$ vi first
#
#My first shell script
#
clear
echo "Trolls are cute"

Save the script & run using below command using "Executing the script" commands given above.