V7/usr/man/man5/core.5

.TH CORE 5 
.SH NAME
core \- format of core image file
.SH DESCRIPTION
UNIX
writes out a core image of a terminated
process when any of various errors occur.
See
.IR signal (2)
for the list of reasons;
the most common are memory violations, illegal
instructions, bus errors, and user-generated
quit signals.
The core image is called `core' and is written in the process's
working directory (provided it can be; normal
access controls apply).
.PP
The first 1024 bytes of the core image
are a copy of the system's per-user
data for the process, including the registers
as they were at the time of the fault;
see the system listings for the format of this area.
The
remainder represents the actual contents of
the user's core area when the core image
was written.
If the text segment
is write-protected and shared,
it is not dumped; otherwise the entire
address space is dumped.
.PP
In general the debugger
.IR adb (1)
is sufficient to deal with core images.
.SH "SEE ALSO"
adb(1), signal(2)