Section: POSIX Programmer's Manual (1P)
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
--- write arguments to standard output
utility writes its arguments to standard output, followed by a
If there are no arguments, only the
utility shall not recognize the
argument in the manner specified by Guideline 10 of the Base Definitions volume of POSIX.1-2017,
, Utility Syntax Guidelines;
shall be recognized as a string operand.
Implementations shall not support any options.
The following operands shall be supported:
A string to be written to standard output. If the first operand is
or if any of the operands contain a
character, the results are implementation-defined.
On XSI-conformant systems, if the first operand is
it shall be treated as a string, not an option. The following character
sequences shall be recognized on XSI-conformant systems within any of
that otherwise follows the final argument in the output. All
characters following the
in the arguments shall be ignored.
Write an 8-bit value that is the zero, one, two, or three-digit octal
The following environment variables shall affect the execution of
Provide a default value for the internationalization variables that are
unset or null. (See the Base Definitions volume of POSIX.1-2017,
Section 8.2, Internationalization Variables
for the precedence of internationalization variables used to determine
the values of locale categories.)
If set to a non-empty string value, override the values of all the
other internationalization variables.
Determine 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).
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 catalogs for the processing of
utility arguments shall be separated by single
characters and a
character shall follow the last argument.
Output transformations shall occur based on the escape sequences in
the input. See the OPERANDS section.
The standard error shall be used only for diagnostic messages.
The following exit values shall be returned:
An error occurred.
CONSEQUENCES OF ERRORS
The following sections are informative.
It is not possible to use
portably across all POSIX systems unless both
(as the first argument) and escape sequences are omitted.
utility can be used portably to emulate any of the traditional
behaviors of the
utility as follows (assuming that
has its standard value or is unset):
The historic System V
and the requirements on XSI implementations in this volume of POSIX.1-2017 are equivalent to:
is equivalent to:
if [ "X$1" = "X-n" ]
New applications are encouraged to use
utility has not been made obsolescent because of its extremely
widespread use in historical applications. Conforming applications that
wish to do prompting without
characters or that could possibly be expecting to echo a
should use the
utility derived from the Ninth Edition system.
writes its arguments in the simplest of ways. The two different
historical versions of
vary in fatally incompatible ways.
checks the first argument for the string
which causes it to suppress the
that would otherwise follow the final argument in the output.
The System V
does not support any options, but allows escape sequences within its
operands, as described for XSI implementations in the OPERANDS section.
utility does not support Utility Syntax Guideline 10 because historical
applications depend on
of its arguments, except for the
option in the BSD version.
The Base Definitions volume of POSIX.1-2017,
Chapter 8, Environment Variables,
Section 12.2, Utility Syntax Guidelines
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
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