NetBSD/lib/libc/stdio/strerror.3

113 lines
3.4 KiB
Groff
Raw Normal View History

1993-03-21 12:45:37 +03:00
.\" Copyright (c) 1980, 1991 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.
.\"
1993-08-01 11:42:49 +04:00
.\" from: @(#)strerror.3 6.9 (Berkeley) 6/29/91
.\" $Id: strerror.3,v 1.2 1993/08/01 07:44:49 mycroft Exp $
1993-03-21 12:45:37 +03:00
.\"
.Dd June 29, 1991
.Dt STRERROR 3
.Os BSD 4
.Sh NAME
.Nm perror ,
.Nm strerror ,
.Nm sys_errlist ,
.Nm sys_nerr
.Nd system error messages
.Sh SYNOPSIS
.Vt extern int errno;
.Vt extern char *sys_errlist[];
.Fd #include <stdio.h>
.Ft void
.Fn perror "const char *string"
.Ft char *
.Fn strerror "int errnum"
.Sh DESCRIPTION
The
.Fn strerror
and
.Fn perror
functions lookup the error message string affiliated with an
error number.
.Pp
The
.Fn sterror
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
and writes it, followed by a new-line, to the
.Em stderr .
If the argument
.Fa string
is
.Pf non- Dv NULL
it is pre-appended 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
The message strings can be accessed directly using the external
character 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 are
.Ud .