[ubuntu-uk] Help needed with ssh

[John Matthews]

Ok, this is some good news, I have a question to ask, I need to change 
the permissions of a file in one of my folders, on my site, it has to be 
read only, as it is its 777.

I have gotten into the folder and have the list of files and their 
permissions, and I can see the file I need to change, but I am not sure 
of the command.

I know you have to chmod to something but I cannot work it out.

Can somebody help please?

John.