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echo - Writes its arguments to standard output
echo [-n] [string...]
[Tru64 UNIX] The -n option is valid only if the environment variable
CMD_ENV is set to bsd.
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
Interfaces documented on this reference page conform to industry standards
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
-n [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.
The string to be displayed on standard output. The echo command
recognizes the following special characters in the string:
\a Displays an alert character.
\b Displays a backspace character.
\c Suppresses the newline character. All characters following \c in
the arguments are ignored.
\f Displays a formfeed character.
\n Displays a newline character.
\r Displays a carriage-return character.
\t Displays a tab character.
\v 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, number. The first digit of number must be a 0
The echo command writes the specified string to standard output, followed
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 subcommands, which do not
necessarily work in the same way as the /usr/bin/echo command.
The following exit values are returned:
0 Successful completion.
>0 An error occurred.
1. To write a message to standard output, enter:
echo Please insert diskette . . .
2. 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.
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.
3. 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 displays the
file names in the current directory ending with .bak.
4. 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.
5. 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 output.
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.
Provides 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
variables contain an invalid setting, the utility behaves as if none of
the variables had been defined.
If set to a non-empty string value, overrides 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
multibyte characters in arguments).
Determines the locale for the format and contents of diagnostic
messages written to standard error.
Determines the location of message catalogues for the processing of
Commands: csh(1), ksh(1), printf(1), Bourne shell sh(1b), POSIX shell
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