I am trying to set up ssh, and I find different command line examples on the internet to help in my research. As I am learning CLI and scripting, can someone explain the following to me please? In a given directory, I typed in the following line. if [ ! -f authorized_keys ]; then touch authorized_keys ; chmod 600 authorized_keys ; fi It created the file authorized_keys and gave it the time stamp and changed the permission. I got that part. The only thing I don't understand is the very first boolean clause after the "if". What exactly does the exclamation mark signify? What also is the "-f" option? Thanks George -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org