ECHO(1)ECHO(1)NAMEecho - echo arguments
SYNOPSIS
/usr/bin/echo [string]...
DESCRIPTION
The echo utility writes its arguments, separated by BLANKs and termi‐
nated 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 with‐
out 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. sh's echo and /usr/bin/echo have an -n option if the SYSV3
environment variable is set (see ENVIRONMENT VARIABLES below). 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 deter‐
mine 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 argu‐
ments:
\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 tradi‐
tional behaviors of the echo utility as follows:
o The Solaris 2.6 operating environment or compatible ver‐
sion'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.
SYSV3
This environment variable is used to provide compatibility
with INTERACTIVE UNIX System and SCO UNIX installation
scripts. It is intended for compatibility only and should not
be used in new scripts. This variable is applicable only for
Solaris x86 platforms, not Solaris SPARC systems.
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 ALSOksh93(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 pre‐
cedes 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).
Apr 8, 2008 ECHO(1)
