Inspired by LuRsT's hr, but written in Haskell instead, because why not?
Clone the repository, or obtain hr.hs by whatever other means, then in
the directory it's in, run
$ ghc --make hr.hs # you will, of course, require GHC for this $ cp hr ~/bin # ~/bin should be in your $PATH
To get a plain and simple line (repeats until terminal width, or 80 characters
if your system lacks tput):
$ hr ################################
For more interesting lines, you can give hr arguments, each of which is
used as a repeating pattern for one line:
$ hr - --------------------------------- $ hr - '#' - --------------------------------- ################################ --------------------------------- $ hr '-#-' -#--#--#--#--#--#--#--#--#--#--#- $ hr '.^._' .^._.^._.^._.^._.^._.^._.^._.^._.
And so on.