172. We wrote a shell script in Unix but it is not doing anything. What
could be the reason?
After writing a shell script we have to give it execute permission so that it can be run in Unix shell.
We can use chmod command to change the permission of a file in Unix. In general we use chmod +x to give execute permission to users for
executing the shell script.
E.g. chmod +x abc.txt will give execute permission to users for executing the file abc.txt.
With chmod command we can also specify to which user/group the permission should be granted. The options are:
173. u is the owner user
174. g is the owner group
175. o is others
176. a is all users