GCORE(1) GNU Development Tools GCORE(1)

# [NAME](#NAME)

gcore - Generate a core file of a running program

# [SYNOPSIS](#SYNOPSIS)

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

# [DESCRIPTION](#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](#OPTIONS)

[**-a**](#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*](#o)

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*](#g)

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*](#d)

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

[**--help**](#help)

[**-h**](#h)

List all options, with brief explanations.

[**--version**](#version)

[**-v**](#v)

Print version information and then exit.

# [ENVIRONMENT](#ENVIRONMENT)

# [SEE ALSO](#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)

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."

2026-09-25 gdb-18.1

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Document: gcore(1) from gdb 18.1-r0 (Chainguard OS)
Source: https://gitlab.com/gnutools/binutils-gdb.git