I have seen how this is done under Linux by appending a & after the command but I'm using Putty under Windows and I need to detach from the Linux process (PHP script) currently running. This script will need to remain running for several hours and I need to go home before that.
Ctrl+D sounds like the solution but it also sounds like it might stop the script as well.
EDIT | It seems the '&' would have worked under Windows too but unfortunately the script is already running via normal invocation so can I change the process while it's running the close the putty window?
I don't know about PuTTY, but in the linux shell, if you started a process and later decided to detach yourself, just press Ctrl+Z. Then you can control with bg, fg and jobs the program execution.
Detaching with & usually means, that if you close the terminal, the program will be also closed (it's a child process). So forking will be necessary.