echo - (BSD) echo arguments
writes its arguments
separated by blanks and terminated by a
newline on the standard output.
is useful for producing diagnostics in shell programs and for
writing constant data on pipes. To send diagnostics to the standard error
file, do `echo ... 1>&2'.
It is recommended for portability that printf
(1) is used instead of
if backslashes are to be printed or if the trailing newline is to