mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-16 10:20:30 +00:00
97 lines
2.4 KiB
Groff
97 lines
2.4 KiB
Groff
.\" Copyright (c) 1988 Massachusetts Institute of Technology,
|
|
.\" Student Information Processing Board. All rights reserved.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.TH COM_ERR 3 "22 Nov 1988" SIPB
|
|
.SH NAME
|
|
com_err \- common error display routine
|
|
.SH SYNOPSIS
|
|
.nf
|
|
#include <com_err.h>
|
|
.PP
|
|
void com_err (whoami, code, format, ...);
|
|
const char *whoami;
|
|
long code;
|
|
const char *format;
|
|
.PP
|
|
proc = set_com_err_hook (proc);
|
|
.fi
|
|
void (*
|
|
.I proc
|
|
) (const char *, long, const char *, va_list);
|
|
.nf
|
|
.PP
|
|
proc = reset_com_err_hook ();
|
|
.PP
|
|
void initialize_XXXX_error_table ();
|
|
.fi
|
|
.SH DESCRIPTION
|
|
.I Com_err
|
|
displays an error message on the standard error stream
|
|
.I stderr
|
|
(see
|
|
.IR stdio (3S))
|
|
composed of the
|
|
.I whoami
|
|
string, which should specify the program name or some subportion of
|
|
a program, followed by an error message generated from the
|
|
.I code
|
|
value (derived from
|
|
.IR compile_et (1)),
|
|
and a string produced using the
|
|
.I format
|
|
string and any following arguments, in the same style as
|
|
.IR fprintf (3).
|
|
|
|
The behavior of
|
|
.I com_err
|
|
can be modified using
|
|
.I set_com_err_hook;
|
|
this defines a procedure which is called with the arguments passed to
|
|
.I com_err,
|
|
instead of the default internal procedure which sends the formatted
|
|
text to error output. Thus the error messages from a program can all
|
|
easily be diverted to another form of diagnostic logging, such as
|
|
.IR syslog (3).
|
|
.I Reset_com_err_hook
|
|
may be used to restore the behavior of
|
|
.I com_err
|
|
to its default form. Both procedures return the previous ``hook''
|
|
value. These ``hook'' procedures must have the declaration given for
|
|
.I proc
|
|
above in the synopsis.
|
|
|
|
The
|
|
.I initialize_XXXX_error_table
|
|
routine is generated mechanically by
|
|
.IR compile_et (1)
|
|
from a source file containing names and associated strings. Each
|
|
table has a name of up to four characters, which is used in place of
|
|
the
|
|
.B XXXX
|
|
in the name of the routine. These routines should be called before
|
|
any of the corresponding error codes are used, so that the
|
|
.I com_err
|
|
library will recognize error codes from these tables when they are
|
|
used.
|
|
|
|
The
|
|
.B com_err.h
|
|
header file should be included in any source file that uses routines
|
|
from the
|
|
.I com_err
|
|
library; executable files must be linked using
|
|
.I ``-lcom_err''
|
|
in order to cause the
|
|
.I com_err
|
|
library to be included.
|
|
|
|
.\" .IR for manual entries
|
|
.\" .PP for paragraph breaks
|
|
|
|
.SH "SEE ALSO"
|
|
compile_et (1), syslog (3).
|
|
|
|
Ken Raeburn, "A Common Error Description Library for UNIX".
|