NAME

core − format of core image file

DESCRIPTION

The UNIX System writes out a core image of a terminated process when any of various errors occur.  See 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).  A process with an effective user ID different from the real user ID will not produce a core image. 

The first section of the core image is a copy of the system’s per-user data for the process, including the registers as they were at the time of the fault.  The size of this section depends on the parameter USIZE , which is defined in /usr/include/sys/param.h.  The remainder represents the actual contents of the user’s core area when the core image was written.  If the text segment is read-only and shared, or separated from data space, it is not dumped. 

The format of the information in the first section is described by the user structure of the system, defined in /usr/include/sys/user.h.  The locations of the registers are outlined in /usr/include/sys/reg.h. 

SEE ALSO

setuid(2), signal(2). 

Version 2.5  —  April 22, 1987