1.\" $NetBSD: core.5,v 1.5 1997/07/10 04:37:22 mikel Exp $ 2.\" 3.\" Copyright (c) 1980, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)core.5 8.3 (Berkeley) 12/11/93 35.\" 36.Dd December 11, 1993 37.Dt CORE 5 38.Os BSD 4 39.Sh NAME 40.Nm core 41.Nd memory image file format 42.Sh SYNOPSIS 43.Fd #include <sys/param.h> 44.Sh DESCRIPTION 45A small number of signals which cause abnormal termination of a process 46also cause a record of the process's in-core state to be written 47to disk for later examination by one of the available debuggers. 48(See 49.Xr sigaction 2 . ) 50This memory image is written to a file named 51.Nm programname.core 52in the working directory; 53provided the terminated process had write permission in the directory, 54and provided the abnormality did not cause 55a system crash. 56(In this event, the decision to save the core file is arbitrary, see 57.Xr savecore 8 . ) 58.Pp 59The maximum size of a 60.Nm programname.core 61file is limited by 62.Xr setrlimit 2 . 63Files which would be larger than the limit are not created. 64.Pp 65The 66.Nm programname.core 67file consists of the 68.Fa u . 69area, whose size (in pages) is 70defined by the 71.Dv UPAGES 72manifest in the 73.Aq Pa sys/param.h 74file. The 75.Fa u . 76area starts with a 77.Fa user 78structure as given in 79.Aq Pa sys/user.h . 80The remainder of the 81.Nm programname.core 82file consists of the data pages followed by 83the stack pages of the process image. 84The amount of data space image in the 85.Nm programname.core 86file is given (in pages) by the 87variable 88.Fa u_dsize 89in the 90.Fa u . 91area. 92The amount of stack image in the core file is given (in pages) by the 93variable 94.Fa u_ssize 95in the 96.Ar u . 97area. 98The size of a ``page'' is given by the constant 99.Dv NBPG 100(also from 101.Aq Pa sys/param.h ) . 102.Sh SEE ALSO 103.Xr gdb 1 , 104.Xr sigaction 2 , 105.Xr setrlimit 2 106.Sh HISTORY 107A 108.Nm core 109file format appeared in 110.At v6 . 111