core dumped

Cause

A core(4) file contains an image of memory at the time of software failure, and is used by programmers to find the reason for the failure.

Action

To see which program produced a core(4) file, run either the file(1) command or the adb(1)(1) command. The following examples show the output of the file(1) and adb(1) commands on a core file from the dtmail program.

$ file core
core: ELF 32-bit MSB core file SPARC Version 1, from `dtmail'

$ adb core
core file = core -- program `dtmail'
SIGSEGV  11: segmentation violation
^D      (use Control-d to quit the program)

Technical Notes

Some signals, such as SIGQUIT, SIGBUS, and SIGSEGV, produce a core dump. See the signal(5) man page for a complete list.

If you have the source code for the program, you can try compiling it with cc -g, and debugging it yourself using dbx or a similar debugger. The where directive of dbx provides a stack trace.

On mixed networks, it can be difficult to discern which machine architecture produced a particular core dump, since adb(1) on one type of system generally cannot read a core(4) file from another type of system, and will produce an "unrecognized file" message. Run adb(1) on various machine architectures until you find the right one.

The term "core" is archaic-- ferrite core memory was supplanted by silicon RAM in the 1970s, although spaceships still employ core memory for its imperviousness to radiation.

See Also

For information on saving and viewing crash information see the System Administration Guide, Volume II. If you are using the AnswerBook, "system crash" is a good search string.