gcore —
get core images of running process
  
    | gcore | [ -ccorename]
      pid [pid ...] | 
gcore creates a core image of the specified processes
  suitable for use with gdb(1). By
  default, the core is written to the file
  “<progname>.core”, where
  “⟨progname⟩” is the
  program name of the process corresponding to the pid that is given on the
  command line. This filename can be changed by supplying the
  -c corename argument, or setting
  “proc.<pid>.corename” with
  sysctl(8).
  - <progname>.core
- The core image.
gcore appeared in 4.2BSD,
  disappeared in NetBSD 1.2, and reappeared in
  NetBSD 2.0.