STRERROR(P) POSIX Programmer's Manual STRERROR(P)PROLOG
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.
NAME
strerror, strerror_r - get error message string
SYNOPSIS
#include <string.h>
char *strerror(int errnum);
int strerror_r(int errnum, char *strerrbuf, size_t buflen);
DESCRIPTION
For strerror(): The functionality described on this reference page is
aligned with the ISO C standard. Any conflict between the requirements
described here and the ISO C standard is unintentional. This volume of
IEEE Std 1003.1-2001 defers to the ISO C standard.
The strerror() function shall map the error number in errnum to a
locale-dependent error message string and shall return a pointer to it.
Typically, the values for errnum come from errno, but strerror() shall
map any value of type int to a message.
The string pointed to shall not be modified by the application, but may
be overwritten by a subsequent call to strerror() or perror().
The contents of the error message strings returned by strerror() should
be determined by the setting of the LC_MESSAGES category in the current
locale.
The implementation shall behave as if no function defined in this vol‐
ume of IEEE Std 1003.1-2001 calls strerror().
The strerror() function shall not change the setting of errno if suc‐
cessful.
Since no return value is reserved to indicate an error, an application
wishing to check for error situations should set errno to 0, then call
strerror(), then check errno.
The strerror() function need not be reentrant. A function that is not
required to be reentrant is not required to be thread-safe.
The strerror_r() function shall map the error number in errnum to a
locale-dependent error message string and shall return the string in
the buffer pointed to by strerrbuf, with length buflen.
RETURN VALUE
Upon successful completion, strerror() shall return a pointer to the
generated message string. On error errno may be set, but no return
value is reserved to indicate an error.
Upon successful completion, strerror_r() shall return 0. Otherwise, an
error number shall be returned to indicate the error.
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 Insufficient storage was supplied via strerrbuf and buflen to
contain the generated message string.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSOperror() , the Base Definitions volume of IEEE Std 1003.1-2001,
<string.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 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 http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 STRERROR(P)
