1.\" $OpenBSD: core.5,v 1.8 2000/10/26 00:37:04 aaron Exp $ 2.\" $NetBSD: core.5,v 1.4 1994/11/30 19:31:11 jtc Exp $ 3.\" 4.\" Copyright (c) 1980, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)core.5 8.3 (Berkeley) 12/11/93 36.\" 37.Dd December 11, 1993 38.Dt CORE 5 39.Os 40.Sh NAME 41.Nm core 42.Nd memory image file format 43.Sh SYNOPSIS 44.Fd #include <sys/param.h> 45.Sh DESCRIPTION 46A small number of signals which cause abnormal termination of a process 47also cause a record of the process's in-core state to be written 48to disk for later examination by one of the available debuggers (see 49.Xr sigaction 2 ) . 50This memory image is written to a file named 51.Pa programname.core 52in the working directory, provided the terminated process had write 53permission in the directory, and provided the abnormality did not cause 54a system crash. 55(In this event, the decision to save the core file is arbitrary, see 56.Xr savecore 8 . ) 57.Pp 58The maximum size of a 59.Pa programname.core 60file is limited by 61.Xr setrlimit 2 . 62Files which would be larger than the limit are not created. 63.Pp 64The 65.Pa programname.core 66file consists of the 67.Fa u . 68area, whose size (in pages) is defined by the 69.Dv UPAGES 70manifest in the 71.Aq Pa sys/param.h 72file. 73The 74.Fa u . 75area starts with a 76.Fa user 77structure as given in 78.Aq Pa sys/user.h . 79The remainder of the 80.Pa programname.core 81file consists of the data pages followed by the stack pages of the 82process image. 83The amount of data space image in the 84.Pa programname.core 85file is given (in pages) by the variable 86.Fa u_dsize 87in the 88.Fa u . 89area. 90The amount of stack image in the core file is given (in pages) by the variable 91.Fa u_ssize 92in the 93.Ar u . 94area. 95The size of a 96.Dq page 97is given by the constant 98.Dv NBPG 99(also from 100.Aq Pa sys/param.h ) . 101.Sh SEE ALSO 102.Xr gdb 1 , 103.Xr setrlimit 2 , 104.Xr sigaction 2 105.Sh HISTORY 106A 107.Nm 108file format appeared in 109.At v6 . 110