| ECHO(1) | General Commands Manual | ECHO(1) | 
echo —
| echo | [ -n] [string ...] | 
echo utility writes any specified operands,
  separated by single blank (`` '') characters and followed by a newline
  (``\n'') character, to the standard output.
The following option is available:
-necho utility exits 0 on success,
  and >0 if an error occurs.
echo utility is expected to be IEEE
  Std 1003.2 (“POSIX.2”) compatible.
echo utility appeared in
  Version 2 AT&T UNIX.
| August 14, 2016 | NetBSD 9.4 |