4 Ways to Execute script
1)
#./script1
Script is to be made executable
From the login shell, a new shell is loaded into memory
which reads the commands from the script file, where as the login
shell is on hold
Note : The variables set in the login shell and variables
in the new shell are different and not retained.
2)
#sh script1
Similar to above, but the scripts is not required to be made executable
3)
#. script1
The commands in the scripts are executed by current shell
Variable set in the script are retained as it is executed b current shell
4)
#exec script1
execute the script and exit the session as soon as the
script execution is complete