dyld_info(1)

🎀 dyld_info — the General Commands Manual page, but make it group chat

okay so this is dyld_info, straight out of the General Commands Manual, and she is literally here to spill all the dyld tea. 💅

🌸 NAME

dyld_info — displays information used by dyld in programs and dylibs. that's the whole assignment, and she ate.

✨ SYNOPSIS

dyld_info [-arch arch-name] [-platform] [-segments] [-linked_dylibs]
          [-inits] [-exports] [-imports] [-objc] [-fixups]
          [-fixup_chains] [-fixup_chain_details] [-function_starts]
          [-symbolic_fixups] [-opcodes] [-uuid] [-dlopens] [-dlsyms]
          [-disassemble] [-section segment-name section-name]
          [-all_sections] [-section_bytes segment-name section-name]
          [-all_sections_bytes] [-validate_only] [-no_validate] file(s)

💖 DESCRIPTION

okay bestie, the dyld_info tool will display information that dyld uses from binaries. she supports fixups information encoded as opcode based or as chained fixups — both flavors, no cap. 🔥

if the tool is run with no options, it defaults to the common options: -platform, -segments, -linked_dylibs. fr fr, zero options = those three, automatic.

and yes, the tool can be run with paths to dylibs that are in the dyld cache and not on disk. cache-only dylibs are welcome here, bestie. 🫶

the options are as follows — every single one, because we do not skip:

• -arch arch — only display the specified architecture. other architectures in a universal image are ignored. bye to the rest, honestly.
• -platform — display the platform (e.g. macOS, iOS) that the binary was built for.
• -segments — display all segments and sections with size info.
• -linked_dylibs — display all dylibs that the binary is linked against.
• -inits — display all static initializers and Objective-C +load methods.
• -exports — display all exported symbols.
• -imports — display all imported symbols.
• -objc — display the Objective-C classes and categories defined.
• -fixups — display a simple table of fixup locations and what dyld will set them to.
• -fixup_chains — if the binary uses chained fixups, displays the format of the chains and the starts.
• -fixup_chain_header — display the fixup chains header fields.
• -fixup_chain_details — display a table of all the raw fixup chain bits and their meanings.
• -symbolic_fixups — display all fixups, grouped by data symbol.
• -shared_region — displays split-seg information from dylib files that may be placed in the dyld cache.
• -function_starts — display the offset of all functions starts and their name.
• -opcodes — display all the opcodes used to generate the rebase and binding information.
• -load_commands — display the load commands in the binary.
• -uuid — display the UUID of the binary.
• -function_variants — display info about function variants in the binary.
• -dlopens — display calls to dlopen() in the binary and if possible the path string used.
• -dlsyms — display calls to dlsym() in the binary and if possible the symbol string used.
• -disassemble — display a disassemble of all code sections.
• -section segment-name section-name — display content of specified section. content is formatted if the content type is known.
• -all_sections — display content of all sections. content is formatted if the content type is known.
• -section_bytes segment-name section-name — display content of specified section as hex bytes.
• -all_sections_bytes — display content of all sections as hex bytes.
• -validate_only — display nothing if binary is valid, or information about what parts are malformed.
• -no_validate — skip validation before inspecting binary.

bestie PSA: -no_validate skips validation before inspecting binary. that's literally the whole vibe, no extra lore. 🙈

• -all_dir directory — will start at specified directory, recursively scan, and run dyld_info on each file found.
• -all_dyld_cache — will run dyld_info on every dylib in the dyld cache.

🧚 SEE ALSO

otool(1), nm(1) — go give them a little kiss, they're icons too. 💋

okay bye bestie — this page is from Darwin, dated May 5, 2025, and it's dyld_info(1). mwah 💖✨