core.5 (19dd549aca1ca3021af4c353fe0f5df4dc7a761f) core.5 (aa81f3a9d85a26b38316d07ae140c02adf2cb066)
1.\" Copyright (c) 1980, 1991, 1993
2.\" The Regents of the University of California. All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.

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25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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31.\"
32.\" @(#)core.5 8.3 (Berkeley) 12/11/93
1.\" Copyright (c) 1980, 1991, 1993
2.\" The Regents of the University of California. All rights reserved.
3.\"
4.\" Redistribution and use in source and binary forms, with or without
5.\" modification, are permitted provided that the following conditions
6.\" are met:
7.\" 1. Redistributions of source code must retain the above copyright
8.\" notice, this list of conditions and the following disclaimer.

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25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30.\" SUCH DAMAGE.
31.\"
32.\" @(#)core.5 8.3 (Berkeley) 12/11/93
33.\" $Id: core.5,v 1.5 1997/02/22 13:25:57 peter Exp $
33.\" $Id: core.5,v 1.6 1998/05/11 03:41:51 steve Exp $
34.\"
35.Dd December 11, 1993
36.Dt CORE 5
37.Os BSD 4
38.Sh NAME
39.Nm core
40.Nd memory image file format
41.Sh SYNOPSIS
42.Fd #include <sys/param.h>
43.Sh DESCRIPTION
44A small number of signals which cause abnormal termination of a process
45also cause a record of the process's in-core state to be written
46to disk for later examination by one of the available debuggers.
47(See
48.Xr sigaction 2 . )
34.\"
35.Dd December 11, 1993
36.Dt CORE 5
37.Os BSD 4
38.Sh NAME
39.Nm core
40.Nd memory image file format
41.Sh SYNOPSIS
42.Fd #include <sys/param.h>
43.Sh DESCRIPTION
44A small number of signals which cause abnormal termination of a process
45also cause a record of the process's in-core state to be written
46to disk for later examination by one of the available debuggers.
47(See
48.Xr sigaction 2 . )
49This memory image is written to a file named
49This memory image is written to a file named by default
50.Nm programname.core
51in the working directory;
52provided the terminated process had write permission in the directory,
53and 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
50.Nm programname.core
51in the working directory;
52provided the terminated process had write permission in the directory,
53and 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.Nm programname.core
60file is limited by
58The maximum size of a core file is limited by
61.Xr setrlimit 2 .
62Files which would be larger than the limit are not created.
63.Pp
59.Xr setrlimit 2 .
60Files which would be larger than the limit are not created.
61.Pp
64The
65.Nm programname.core
66file consists of the
62The name of the file is controlled via the
63.Xr sysctl 8
64variable
65.Va kern.corefile .
66The contents of this variable describes a filename to store
67the core image to. This filename can be absolute, or relative (which
68will resolve to the current working directory of the program
69generating it). Any sequence of
70.Em \&%N
71in this filename template will be replaced by the process name,
72.Em \&%P
73by the processes PID, and
74.Em \&%U
75by the UID. The name defaults to
76.Em \&%N.core ,
77yielding the traditional FreeBSD behaviour.
78.Pp
79The core file consists of the
67.Fa u .
68area, whose size (in pages) is
69defined by the
70.Dv UPAGES
71manifest in the
72.Aq Pa sys/param.h
73file. The
74.Fa u .
75area starts with a
76.Fa user
77structure as given in
78.Aq Pa sys/user.h .
80.Fa u .
81area, whose size (in pages) is
82defined by the
83.Dv UPAGES
84manifest in the
85.Aq Pa sys/param.h
86file. The
87.Fa u .
88area starts with a
89.Fa user
90structure as given in
91.Aq Pa sys/user.h .
79The remainder of the
80.Nm programname.core
92The remainder of the core
81file consists of the data pages followed by
82the stack pages of the process image.
93file consists of the data pages followed by
94the stack pages of the process image.
83The amount of data space image in the
84.Nm programname.core
95The amount of data space image in the core
85file is given (in pages) by the
86variable
87.Fa u_dsize
88in the
89.Fa u .
90area.
91The amount of stack image in the core file is given (in pages) by the
92variable
93.Fa u_ssize
94in the
95.Ar u .
96area.
97The size of a ``page'' is given by the constant
98.Dv PAGE_SIZE
99(also from
100.Aq Pa sys/param.h ) .
96file is given (in pages) by the
97variable
98.Fa u_dsize
99in the
100.Fa u .
101area.
102The amount of stack image in the core file is given (in pages) by the
103variable
104.Fa u_ssize
105in the
106.Ar u .
107area.
108The size of a ``page'' is given by the constant
109.Dv PAGE_SIZE
110(also from
111.Aq Pa sys/param.h ) .
112.Sh EXAMPLES
113In order to store all core images in per-user private areas under
114.Pa /var/coredumps ,
115the following
116.Xr sysctl 8
117command can be used:
118.Pp
119.Dl sysctl -w kern.corefile="/var/coredumps/\&%U/\&%N.core"
101.Sh SEE ALSO
102.Xr gdb 1 ,
103.Xr kgdb 1 ,
104.Xr setrlimit 2 ,
120.Sh SEE ALSO
121.Xr gdb 1 ,
122.Xr kgdb 1 ,
123.Xr setrlimit 2 ,
105.Xr sigaction 2
124.Xr sigaction 2 ,
125.Xr sysctl 8
106.Sh HISTORY
107A
108.Nm core
109file format appeared in
110.At v6 .
126.Sh HISTORY
127A
128.Nm core
129file format appeared in
130.At v6 .