echo writes each given string to standard output, with a space between each and a newline after the last one. Synopsis:
echo [option]... [string]...
Due to shell aliases and built-in echo functions, using an
unadorned echo interactively or in a script may get you
different functionality than that described here. Invoke it via
env echo ...) to avoid interference
from the shell.
The program accepts the following options. Also see Common options. Options must precede operands, and the normally-special argument ‘--’ has no special meaning and is treated like any other string.
If the POSIXLY_CORRECT environment variable is set, then when
echo's first argument is not -n it outputs
option-like arguments instead of treating them as options. For
echo -ne hello outputs ‘-ne hello’ instead of
POSIX does not require support for any options, and says that the behavior of echo is implementation-defined if any string contains a backslash or if the first argument is -n. Portable programs can use the printf command if they need to omit trailing newlines or output control characters or backslashes. See printf invocation.
An exit status of zero indicates success, and a nonzero value indicates failure.