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 |