GCORE(1)

NAME
gcore - Generate a core file of a running program

SYNOPSIS
gcore [-v | --version] [-h | --help] [-a] [-o prefix] [-d directory]
      pid1 [pid2...pidN]

DESCRIPTION
Generate core dumps of one or more running programs with process IDs pid1, pid2, etc. A core file produced by gcore is equivalent to one produced by the kernel when the process crashes (and when "ulimit -c" was used to set up an appropriate core dump limit). However, unlike after a crash, after gcore finishes its job the program remains running without any change.

OPTIONS

-a  Dump all memory mappings. The actual effect of this option depends on the Operating System. On GNU/Linux, it will disable "use-coredump-filter" and enable "dump-excluded-mappings".

-o prefix
    The optional argument prefix specifies the prefix to be used when composing the file names of the core dumps. The file name is composed as prefix.pid, where pid is the process ID of the running program being analyzed by gcore. If not specified, prefix defaults to core.

-g gdb
    Use gdb as the executable binary to invoke GDB for running the gcore command. This argument is optional, and defaults to invoking the GDB binary that is installed alongside gcore.

-d directory
    Use directory as the data directory when invoking GDB for running the gcore command. This argument is optional.

--help
-h  List all options, with brief explanations.

--version
-v  Print version information and then exit.

ENVIRONMENT

SEE ALSO
The full documentation for GDB is maintained as a Texinfo manual. If the "info" and "gdb" programs and GDB's Texinfo documentation are properly installed at your site, the command

        info gdb

should give you access to the complete manual.

Using GDB: A Guide to the GNU Source-Level Debugger, Richard M. Stallman and Roland H. Pesch, July 1991.

COPYRIGHT
Copyright (c) 1988-2026 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being "Free Software" and "Free Software Needs Free Documentation", with the Front-Cover Texts being "A GNU Manual," and with the Back-Cover Texts as in (a) below.

(a) The FSF's Back-Cover Text is: "You are free to copy and modify this GNU Manual. Buying copies from GNU Press supports the FSF in developing GNU and promoting software freedom."