These functions are impure: they produce side-effects
writef(Fmt Args)
formatted write
as per the prolog writef/2
Example:
writef('hello ~w~n' [world])
writef(Fmt)
formatted write, no arguments
write(X)
write to screen
write(X)
write followed by newline
run(X)
run command in shell
X is first converted to a string using atom(X)
!X
syntactic sugar for run(X)
backquote(X)
opens a pipe and runs command X, collects standard out as an atom and returns it.
Syntactic sugar: You can instead enclode the command backquote character; e.g. `X`
The following example writes all files in a directory, on one line
