ECHO(1) User Commands ECHO(1)

NAME

echo - echo arguments

SYNOPSIS

/usr/bin/echo [string]...

DESCRIPTION

The echo utility writes its arguments, separated by BLANKs and
terminated by a NEWLINE, to the standard output. If there are no
arguments, only the NEWLINE character is written.


echo is useful for producing diagnostics in command files, for
sending known data into a pipe, and for displaying the contents of
environment variables.


The C shell, the Korn shell, and the Bourne shell all have echo
built-in commands, which, by default, is invoked if the user calls
echo without a full pathname. See shell_builtins(1). sh's echo, ksh's
echo, ksh93's echo, and /usr/bin/echo understand the back-slashed
escape characters, except that sh's echo does not understand \a as
the alert character. In addition, ksh's and ksh93's echo does not
have an -n option. csh's echo and /usr/ucb/echo, on the other hand,
have an -n option, but do not understand the back-slashed escape
characters. sh and ksh determine whether /usr/ucb/echo is found
first in the PATH and, if so, they adapt the behavior of the echo
builtin to match /usr/ucb/echo.

OPERANDS

The following operand is supported:

string
A string to be written to standard output. If any operand
is "-n", it is treated as a string, not an option. The
following character sequences is recognized within any of
the arguments:

\a
Alert character.


\b
Backspace.


\c
Print line without new-line. All characters
following the \c in the argument are ignored.


\f
Form-feed.


\n
New-line.


\r
Carriage return.


\t
Tab.


\v
Vertical tab.


\\
Backslash.


\0n
Where n is the 8-bit character whose ASCII code is
the 1-, 2- or 3-digit octal number representing
that character.

USAGE

Portable applications should not use -n (as the first argument) or
escape sequences.


The printf(1) utility can be used portably to emulate any of the
traditional behaviors of the echo utility as follows:

o The Solaris 2.6 operating environment or compatible
version's /usr/bin/echo is equivalent to:

printf "%b\n" "$*"


o The /usr/ucb/echo is equivalent to:

if [ "X$1" = "X-n" ]

then

shift

printf "%s" "$*"

else

printf "%s\n" "$*"

fi


New applications are encouraged to use printf instead of echo.

EXAMPLES

Example 1: Finding how far below root your current directory is

located


You can use echo to determine how many subdirectories below the root
directory (/) is your current directory, as follows:


o Echo your current-working-directory's full pathname.

o Pipe the output through tr to translate the path's
embedded slash-characters into space-characters.

o Pipe that output through wc -w for a count of the names in
your path.

example% /usr/bin/echo $PWD | tr '/' ' ' | wc -w


See tr(1) and wc(1) for their functionality.


Below are the different flavors for echoing a string without a
NEWLINE:

Example 2: /usr/bin/echo

example% /usr/bin/echo "$USER's current directory is $PWD\c"

Example 3: sh/ksh shells

example$ echo "$USER's current directory is $PWD\c"

Example 4: csh shell

example% echo -n "$USER's current directory is $PWD"

Example 5: /usr/ucb/echo

example% /usr/ucb/echo -n "$USER's current directory is $PWD"

ENVIRONMENT VARIABLES

See environ(7) for descriptions of the following environment
variables that affect the execution of echo: LANG, LC_ALL, LC_CTYPE,
LC_MESSAGES, and NLSPATH.

EXIT STATUS

The following error values are returned:

0
Successful completion.


>0
An error occurred.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|CSI | Enabled |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|Standard | See standards(7). |
+--------------------+-------------------+

SEE ALSO

ksh93(1), printf(1), shell_builtins(1), tr(1), wc(1), echo(1B),
ascii(7), attributes(7), environ(7), standards(7)

NOTES

When representing an 8-bit character by using the escape convention
\0n, the n must always be preceded by the digit zero (0).


For example, typing: echo 'WARNING:\07' prints the phrase WARNING:
and sounds the "bell" on your terminal. The use of single (or double)
quotes (or two backslashes) is required to protect the "\" that
precedes the "07".


Following the \0, up to three digits are used in constructing the
octal output character. If, following the \0n, you want to echo
additional digits that are not part of the octal representation, you
must use the full 3-digit n. For example, if you want to echo "ESC 7"
you must use the three digits "033" rather than just the two digits
"33" after the \0.

2 digits Incorrect: echo "\0337" | od -xc
produces: df0a (hex)
337 (ascii)
3 digits Correct: echo "\00337" | od -xc
produces: lb37 0a00 (hex)
033 7 (ascii)


For the octal equivalents of each character, see ascii(7).

April 14, 2016 ECHO(1)