CORE(5) File Formats Manual CORE(5) NAME core – memory image file format SYNOPSIS #include <sys/param.h> DESCRIPTION A small number of signals which cause abnormal termination of a process also cause a record of the process's in-core state to be written to disk for later examination by one of the available debuggers. (See sigaction(2).) This memory image is written to a file named by default core.pid, where pid is the process ID of the process, in the /cores directory, provided the terminated process had write permission in the directory, and the directory existed. The maximum size of a core file is limited by setrlimit(2). Files which would be larger than the limit are not created. The core file consists of the Mach-O(5) header as described in the ⟨mach-o/loader.h⟩ file. The remainder of the core file consists of various sections described in the Mach-O(5) header. NOTE Core dumps are disabled by default under Darwin/macOS. To re-enable core dumps, do one of the following * For subsequent processes spawned by launchd and their child processes, a privileged user can issue the command # launchctl limit core unlimited * For susequent processes spawned by a shell, use ulimit(1) or limit(1) depending upon the shell. % ulimit -c unlimited or % limit coredumpsize unlimited To disable core dumps, set the limit to 0 using one of the aforementioned ways. SEE ALSO lldb(1), setrlimit(2), sigaction(2), launchd.conf(5), launchd.plist(5), Mach-O(5), sysctl(8) HISTORY A core file format appeared in Version 1 AT&T UNIX. macOS 15.2 December 22, 2020 macOS 15.2