---
name: "gcore"
section: "1"
platform: "linux"
package: "gdb"
version: "18.1-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/gcore"
---

# gcore(1)

Generate a core file of a running program

## 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."