echo
: Print a line of textecho
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
(i.e., env echo …
) to avoid interference
from the shell.
Due to historical and backwards compatibility reasons, certain bare option-like
strings cannot be passed to echo
as non-option arguments.
It is therefore not advisable to use echo
for printing unknown or
variable arguments. The printf
command is recommended as a more
portable and flexible replacement for tasks historically performed by
echo
. See printf
: Format and print data.
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.
Do not output the trailing newline.
Enable interpretation of the following backslash-escaped characters in each string:
alert (bell)
backspace
produce no further output
escape
form feed
newline
carriage return
horizontal tab
vertical tab
backslash
the eight-bit value that is the octal number nnn (zero to three octal digits), if nnn is a nine-bit value, the ninth bit is ignored
the eight-bit value that is the octal number nnn (one to three octal digits), if nnn is a nine-bit value, the ninth bit is ignored
the eight-bit value that is the hexadecimal number hh (one or two hexadecimal digits)
Disable interpretation of backslash escapes in each string. This is the default. If -e and -E are both specified, the last one given takes effect.
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
example, echo -ne hello
outputs ‘-ne hello’ instead of
plain ‘hello’. Also backslash escapes are always enabled.
To echo the string ‘-n’, one of the characters
can be escaped in either octal or hexadecimal representation.
For example, echo -e '\x2dn'
.
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 should use the printf
command instead.
See printf
: Format and print data.
An exit status of zero indicates success, and a nonzero value indicates failure.