echo(1)echo(1)NAMEecho - Writes its arguments to standard output
SYNOPSISecho [-n] [string...]
[Tru64 UNIX] The -n option is valid only if the environment variable
CMD_ENV is set to bsd.
Note
The C shell has a built-in version of the echo command. If you are
using the C shell, and want to guarantee that you are using the command
described here, you must specify the full path /usr/bin/echo. See the
csh(1) reference page for a description of the built-in command.
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
echo: XCU5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
OPTIONS
[Tru64 UNIX] No newline is added to the output. The -n option is valid
only if the environment variable CMD_ENV is set to bsd. Otherwise any
-n operand is treated as a string rather than as a option. See the
printf(1) reference page for use in portable applications.
OPERANDS
The string to be displayed on standard output. The echo command recog‐
nizes the following special characters in the string: Displays an alert
character. Displays a backspace character. Suppresses the newline
character. All characters following \c in the arguments are ignored.
Displays a formfeed character. Displays a newline character. Displays
a carriage-return character. Displays a tab character. Displays a
vertical tab character. Displays a backslash character. Displays an
8-bit character whose value is the 1-, 2- or 3-digit octal number, num‐
ber. The first digit of number must be a 0 (zero).
DESCRIPTION
The echo command writes the specified string to standard output, fol‐
lowed by a newline character.
The arguments are separated by spaces. Use the echo command to produce
diagnostic messages in command files and to send data into a pipe. If
there are no arguments, the echo command outputs a newline character.
[Tru64 UNIX] The echo command described here is the program
/usr/bin/echo. Both csh and sh shells contain built-in echo subcom‐
mands, which do not necessarily work in the same way as the
/usr/bin/echo command.
EXIT STATUS
The following exit values are returned: Successful completion. An
error occurred.
EXAMPLES
To write a message to standard output, enter: echo Please insert
diskette . . . To display a message containing special characters as
listed in DESCRIPTION, enclose the message in quotes, as follows: echo
"\n\n\nI'm at lunch.\nI'll be back at 1 p.m."
This skips three lines and displays the message: I'm at lunch.
I'll be back at 1 p.m.
Note
You must enclose the message in quotation marks if it contains
escape sequences such as \n. Otherwise, the shell treats the
backslash (\) as an escape character. The previous command
example, entered without the quotes, results in the following
output: nnnI'm at lunch.nI'll be back at 1 p.m.
To use echo with pattern-matching characters, enter: echo The
back-up files are: *.bak
This displays the message The back-up files are: and then dis‐
plays the file names in the current directory ending with To add
a single line of text to a file, enter: echo Remember to set the
shell search path to $PATH. >>notes
This adds the message to the end of the file notes after the
shell substitutes the value of the PATH shell variable. To
write a message to the standard error output (sh only), enter:
echo Error: file already exists. >&2
Use this in shell procedures to write error messages. If the
>&2 is omitted, then the message is written to the standard out‐
put.
ENVIRONMENT VARIABLES
The following environment variables affect the execution of echo:
[Tru64 UNIX] This variable must set to bsd for the -n option to be
valid. Otherwise any -n operand is treated as a string member. Pro‐
vides a default value for the internationalization variables that are
unset or null. If LANG is unset or null, the corresponding value from
the default locale is used. If any of the internationalization vari‐
ables contain an invalid setting, the utility behaves as if none of the
variables had been defined. If set to a non-empty string value, over‐
rides the values of all the other internationalization variables.
Determines the locale for the interpretation of sequences of bytes of
text data as characters (for example, single-byte as opposed to multi‐
byte characters in arguments). Determines the locale for the format
and contents of diagnostic messages written to standard error. Deter‐
mines the location of message catalogues for the processing of LC_MES‐
SAGES.
SEE ALSO
Commands: csh(1), ksh(1), printf(1), Bourne shell sh(1b), POSIX shell
sh(1p)
Environment: environ(5)
Standards: standards(5)echo(1)