gcore [-o filename] pid
Generate a core dump of a running program with process ID pid.
Produced file is equivalent to a kernel produced core file as if the process
crashed (and if ulimit -c were used to set up an appropriate core dump
limit). Unlike after a crash, after
gcore the program remains
running without any change.
The optional argument filename specifies the file name where to put the core dump. If not specified, the file name defaults to core.pid, where pid is the running program process ID.