xref: /illumos-gate/usr/src/man/man3c/strerror.3c (revision 66492cf01c4f0eb178cb6e056451d04be61a0374)

Sun Microsystems, Inc. gratefully acknowledges The Open Group for
permission to reproduce portions of its copyrighted documentation.
Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.

The Institute of Electrical and Electronics Engineers and The Open
Group, have given us permission to reprint portions of their
documentation.

In the following statement, the phrase ``this text'' refers to portions
of the system documentation.

Portions of this text are reprinted and reproduced in electronic form
in the SunOS Reference Manual, from IEEE Std 1003.1, 2004 Edition,
Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6,
Copyright (C) 2001-2004 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy
between these versions 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
http://www.opengroup.org/unix/online.html.

This notice shall appear on any product containing this material.

The contents of this file are subject to the terms of the
Common Development and Distribution License (the "License").
You may not use this file except in compliance with the License.

You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
or http://www.opensolaris.org/os/licensing.
See the License for the specific language governing permissions
and limitations under the License.

When distributing Covered Code, include this CDDL HEADER in each
file and include the License file at usr/src/OPENSOLARIS.LICENSE.
If applicable, add the following below this CDDL HEADER, with the
fields enclosed by brackets "[]" replaced with your own identifying
information: Portions Copyright [yyyy] [name of copyright owner]


Copyright 1989 AT&T
Copyright (c) 2001, The IEEE and The Open Group. All Rights Reserved.
Copyright (c) 2005, Sun Microsystems, Inc. All Rights Reserved.
Copyright 2015, Joyent, Inc.

STRERROR 3C "Aug 17, 2015"
NAME
strerror, strerror_r, strerror_l - get error message string
SYNOPSIS

#include <string.h>

char *strerror(int errnum);

int strerror_r(int errnum, char *strerrbuf, size_t buflen);

char *strerror_l(int errnum, locale_t loc);

DESCRIPTION

The strerror() function maps the error number in errnum to an error message string, and returns a pointer to that string. It uses the same set of error messages as perror(3C). The returned string should not be overwritten.

The strerror_r() function maps the error number in errnum to an error message string and returns the string in the buffer pointed to by strerrbuf with length buflen.

The strerror_l() function maps the error number in errnum to an error message string in the locale indicated by loc. The returned string should not be overwritten. If loc is passed the NULL pointer, then the locale of the calling thread's current locale will be used instead.

Because the strerror() and strerror_l() functions, return localized strings in the event of an unknown error, one must use the value of errno to detect an error. Callers should first set errno to 0 before the call to either function and then check the value of errno after the call. If the value of errno is non-zero then an error has occurred.

RETURN VALUES

Upon successful completion, strerror() and strerror_l() return a pointer to the generated message string. Otherwise, they set errno and returns a pointer to an error message string. They return the localized string "Unknown error" if errnum is not a valid error number.

Upon successful completion, strerror_r() returns 0. Otherwise it sets errno and returns the value of errno to indicate the error. It returns the localized string "Unknown error" in the buffer pointed to by strerrbuf if errnum is not a valid error number.

ERRORS

These functions may fail if: EINVAL

The value of errnum is not a valid error number.

The strerror_r() function may fail if: ERANGE

The buflen argument specifies insufficient storage to contain the generated message string.

USAGE

Messages returned from these functions are in the native language specified by the LC_MESSAGES locale category. See setlocale(3C) and uselocale(3C).

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Standard
MT-Level Safe
SEE ALSO

gettext(3C), perror(3C), setlocale(3C), uselocale(3C), attributes(5), standards(5)