GCORE(1)

💅 GCORE(1) — the GNU Development Tools one, bestie

okay so this is gcore from the GNU Development Tools corner of the universe, and no cap, it's lowkey one of the most useful little gremlins in your toolbox 🫶

✨ NAME ✨

gcore — generate a core file of a running program. yes. of a running program. it's giving "screenshot but for memory" 📸

🦋 SYNOPSIS 🦋

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

🌸 DESCRIPTION 🌸

So the whole vibe: you give it one or more process IDs — pid1, pid2, etc. — and it generates core dumps of those running programs. Iconic behaviour honestly.

A core file produced by gcore is equivalent to the one the kernel makes when the process crashes (and when "ulimit -c" was used to set up an appropriate core dump limit). Same energy, same artifact. 💯

But here's the main character twist: unlike after a crash, after gcore finishes its job the program remains running without any change. No murder. No interruption. It just... takes the snapshot and leaves. Obsessed. 🧚‍♀️

Fr fr, that's the whole sell: core dump, but nobody dies.

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💅 OPTIONS 💅

• -a — dump all memory mappings. The actual effect depends on your Operating System, so like, read the room. On GNU/Linux, it will disable "use-coredump-filter" and enable "dump-excluded-mappings". Slay, but OS-dependent 💀
• -o prefix — this optional argument specifies the prefix 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 you don't specify it, 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. iykyk 🌈
• -d directory — use directory as the data directory when invoking GDB for running the gcore command. This argument is optional. that's it, that's the whole thing ✨
• --help, -h — list all options, with brief explanations. the "what does this even do" button 🫶
• --version, -v — print version information and then exit. bye bestie 👋

🎀 ENVIRONMENT 🎀

literally nothing here. it's an empty section. not a single environment variable. we love a minimalist queen who knows when to say nothing 💜

🔥 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. go get your reading done 📚

Also, there's this book: Using GDB: A Guide to the GNU Source-Level Debugger, Richard M. Stallman and Roland H. Pesch, July 1991. vintage. iconic. retro royalty 👑

👑 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."

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okay that's the whole page, mwah 💋 this lil beauty is gdb-18.1, dated 2026-09-25 — so yes, she's fresh, she's current, she's the moment ⭐ 🦋 💖