файл дампа ядра (core dump file)
Примечание (Note)
The gdb(1) gcore command can be used to obtain a core dump of a
running process.
In Linux versions up to and including 2.6.27, if a multithreaded
process (or, more precisely, a process that shares its memory
with another process by being created with the CLONE_VM
flag of
clone(2)) dumps core, then the process ID is always appended to
the core filename, unless the process ID was already included
elsewhere in the filename via a %p specification in
/proc/sys/kernel/core_pattern. (This is primarily useful when
employing the obsolete LinuxThreads implementation, where each
thread of a process has a different PID.)