Elf Inspection

When you're staring at an `undefined reference` error or wondering why your binary is 50MB, this skill walks you through the ELF inspection toolkit: `readelf`, `objdump`, `nm`, and `ldd`. It covers the practical stuff like checking shared library dependencies, hunting down missing symbols, analyzing section bloat, and verifying security features like PIE and RELRO. The workflow is structured around real diagnostic scenarios rather than just listing tool flags. If you've ever needed to understand what's actually inside a Linux binary or debug a dynamic linking mess, the cheatsheet format here beats hunting through man pages.

skills.sh installs: 702
GitHub stars: 279
last updated: Aug 21, 2026

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Install

$ npx -y skills add mohitmishra786/low-level-dev-skills --skill elf-inspection --agent claude-code

Installs into .claude/skills of the current project.

Files

ELF Inspection

Purpose

Guide agents through inspecting Linux ELF binaries: symbol tables, section layout, dynamic linking, debug info, and diagnosing linker errors.

Triggers

"What libraries does this binary depend on?"
"Why is this binary so large?"
"I have an undefined reference or symbol not found at runtime"
"How do I check if debug info is in this binary?"
"How do I find what symbols a library exports?"
"How do I check if a binary is PIE / has RELRO?"

Workflow

1. Quick overview: `file` and `size`

file prog                    # type, arch, linkage, stripped or not
size prog                    # section sizes: text, data, bss
size --format=sysv prog      # detailed per-section breakdown

2. Dynamic dependencies: `ldd`

ldd ./prog                   # show all shared lib dependencies
ldd -v ./prog                # verbose: include symbol versions

# Check why a library is loaded
ldd ./prog | grep libssl

# For a library (not an executable)
ldd ./libfoo.so

If ldd shows not found, the shared library is missing from LD_LIBRARY_PATH or /etc/ld.so.conf.

Fix:

SKILL.md on GitHub