.\" .\" Copyright (c) 2000 Carnegie Mellon University. All rights reserved. .\" .\" 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. The name "Carnegie Mellon University" must not be used to .\" endorse or promote products derived from this software without .\" prior written permission. For permission or any other legal .\" details, please contact .\" Office of Technology Transfer .\" Carnegie Mellon University .\" 5000 Forbes Avenue .\" Pittsburgh, PA 15213-3890 .\" (412) 268-4387, fax: (412) 268-7395 .\" tech-transfer@andrew.cmu.edu .\" .\" 4. Redistributions of any form whatsoever must retain the following .\" acknowledgment: .\" "This product includes software developed by Computing Services .\" at Carnegie Mellon University (http://www.cmu.edu/computing/)." .\" .\" CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO .\" THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY .\" AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE .\" FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN .\" AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .\" Copyright (c) 1988 Massachusetts Institute of Technology, .\" Student Information Processing Board. All rights reserved. .\" .\" $Header: /cvs/repository/iservers/Servers/cyrus/cyrus_imap/et/com_err.3,v 1.5 2005/03/05 00:36:41 dasenbro Exp $ .\" .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".