Linux/Unix changing shell prompt

\u – Username
\h – Hostname
\w – Full path of the current working directory

$ pwd
/var/tmp

$ export PS1="# "
#

# hostname pats
export PS1="\h# "
pats#

pats# export PS1="\u@\h $ "
dennis@pats $

dennis@pats $  export PS1="\u@\h \w# "
dennis@pats ~#  cd /tmp
dennis@pats /tmp#