mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-26 11:47:31 +00:00
125 lines
3.7 KiB
Groff
125 lines
3.7 KiB
Groff
.\" Copyright (c) 1980, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" This code is derived from software contributed to Berkeley by
|
|
.\" the American National Standards Committee X3, on Information
|
|
.\" Processing Systems.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)strerror.3 8.1 (Berkeley) 6/9/93
|
|
.\"
|
|
.Dd June 9, 1993
|
|
.Dt STRERROR 3
|
|
.Os BSD 4
|
|
.Sh NAME
|
|
.Nm perror ,
|
|
.Nm strerror ,
|
|
.Nm sys_errlist ,
|
|
.Nm sys_nerr
|
|
.Nd system error messages
|
|
.Sh SYNOPSIS
|
|
.Fd #include <stdio.h>
|
|
.Ft void
|
|
.Fn perror "const char *string"
|
|
.Vt extern char *sys_errlist[];
|
|
.Vt extern int sys_nerr;
|
|
.Fd #include <string.h>
|
|
.Ft char *
|
|
.Fn strerror "int errnum"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn strerror
|
|
and
|
|
.Fn perror
|
|
functions look up the error message string corresponding to an
|
|
error number.
|
|
.Pp
|
|
The
|
|
.Fn strerror
|
|
function accepts an error number argument
|
|
.Fa errnum
|
|
and
|
|
returns a pointer to the corresponding
|
|
message string.
|
|
.Pp
|
|
The
|
|
.Fn perror
|
|
function finds the error message corresponding to the current
|
|
value of the global variable
|
|
.Va errno
|
|
.Pq Xr intro 2
|
|
and writes it, followed by a newline, to the
|
|
standard error file descriptor.
|
|
If the argument
|
|
.Fa string
|
|
is
|
|
.Pf non- Dv NULL ,
|
|
it is prepended to the message
|
|
string and separated from it by
|
|
a colon and space
|
|
.Pq Ql \&:\ \& .
|
|
If
|
|
.Fa string
|
|
is
|
|
.Dv NULL ,
|
|
only the error message string is printed.
|
|
.Pp
|
|
If
|
|
.Fa errnum
|
|
is not a recognized error number,
|
|
the error message string will contain
|
|
.Dq Li "Unknown error:\0
|
|
followed by the error number in decimal.
|
|
.Pp
|
|
The message strings can be accessed directly using the external
|
|
array
|
|
.Fa sys_errlist .
|
|
The external value
|
|
.Fa sys_nerr
|
|
contains a count of the messages in
|
|
.Fa sys_errlist .
|
|
The use of these variables is deprecated;
|
|
.Fn strerror
|
|
should be used instead.
|
|
.Sh SEE ALSO
|
|
.Xr intro 2 ,
|
|
.Xr psignal 3
|
|
.Sh HISTORY
|
|
The
|
|
.Fn strerror
|
|
and
|
|
.Fn perror
|
|
functions first appeared in 4.4BSD.
|
|
.Sh BUGS
|
|
For unknown error numbers, the
|
|
.Fn strerror
|
|
function will return its result in a static buffer which
|
|
may be overwritten by subsequent calls.
|