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(5) 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(5) for descriptions of the following attributes:


+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|CSI | Enabled |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|Standard | See standards(5). |
+--------------------+-------------------+

SEE ALSO


ksh93(1), printf(1), shell_builtins(1), tr(1), wc(1), echo(1B), ascii(5),
attributes(5), environ(5), standards(5)

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(5).


April 14, 2016 ECHO(1)