ECHO(1) General Commands Manual ECHO(1)

echo — write arguments to standard output

echo [string ...]

The echo utility will write its arguments to standard output, followed by a newline character. If there are no arguments, only the newline character will be written.

The echo utility will not recognise the -- argument in the manner specified by Guideline 10 of the XBD specification, ; -- will be recognised as a string operand.

Implementations will not support any options.

The following operands are supported:

string
A string to be written to standard output. If any operand is -n, it will be treated as a string, not an option. The following character sequences will be recognised within any of the arguments:
Write an alert character.
Write a backspace character.
Suppress the newline character that otherwise follows the final argument in the output. All characters following the \c in the arguments will be ignored.
Write a form-feed character.
Write a newline character.
Write a carriage-return character.
Write a tab character.
Write a vertical-tab character.
\\
Write a backslash character.
Write an 8-bit value that is the zero-, one-, two- or three-digit octal number num .

Not used.

None.

The following environment variables affect the execution of echo :

Provide a default value for the internationalisation variables that are unset or null. If LANG is unset or null, the corresponding value from the implementation-dependent default locale will be used. If any of the internationalisation variables contains an invalid setting, the utility will behave as if none of the variables had been defined.
If set to a non-empty string value, override the values of all the other internationalisation variables.
Determine the locale for the interpretation of sequences of bytes of text data as characters (for example, single- as opposed to multi-byte characters in arguments).
Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error.
Determine the location of message catalogues for the processing of LC_MESSAGES .

Default.

The echo utility arguments will be separated by single space characters and a newline character will follow the last argument. Output transformations will occur based on the escape sequences in the input; see the OPERANDS section.

Used only for diagnostic messages.

None.

None.

The following exit values are returned:

Successful completion.
An error occurred.

Default.

It is not possible to use echo portably across all systems that are not XSI-conformant unless both -n (as the first argument) and escape sequences are omitted.

The printf utility can be used portably to emulate any of the traditional behaviours of the echo utility as follows:

  • The XSI echo is equivalent to: 
    printf "%b\n" "$*"
  • The BSD 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.

None.

None.

printf(1) .

February 1997 posix.fail