Objdump

{{Short description|Program for displaying information about object files}} {{lowercase title|title=objdump}} {{more citations needed |date=April 2025}} {{Infobox software | name = objdump | logo = | screenshot = | screenshot size = | caption = | author = | developer = | released = | latest release version = | latest release date = | operating system = Unix and Unix-like | genre = Command | license = GNU GPL | website = }} '''objdump''' is a command-line program for displaying various information about object files on Unix-like operating systems. For instance, it can be used as a disassembler to view an executable in assembly form. It is part of the GNU Binutils for fine-grained control over executables and other binary data. objdump uses the BFD library to read the contents of object files. Similar utilities are Borland TDUMP, Microsoft DUMPBIN and readelf.

On certain platforms (e.g. macOS), the objdump binary may actually be a link to LLVM's objdump, with different command-line options and behavior.{{Citation needed|date=July 2023}} '''otool''' and nm perform analogous functions for Mach-O files.<ref>{{cite web |url=https://developer.apple.com/forums/thread/715385 |title=An Apple Library Primer |publisher=Apple Developer Forums}}</ref><ref>{{cite web |url=https://llvm.org/docs/CommandGuide/llvm-otool.html |title=llvm-otool - Mach-O dumping tool |publisher=LLVM Reference}}</ref>

==Example== For example,

$ objdump -D -M intel file.bin

This disassembles the file <code>file.bin</code>, showing its assembly code in Intel syntax.

Example output: <syntaxhighlight lang="objdump-nasm"> 4004ed <main>: 4004ed: 55 push rbp 4004ee: 48 89 e5 mov rbp,rsp 4004f1: c7 45 ec 00 00 00 00 mov DWORD PTR [rbp-0x14],0x0 4004f8: c7 45 f0 01 00 00 00 mov DWORD PTR [rbp-0x10],0x1 4004ff: c7 45 f4 02 00 00 00 mov DWORD PTR [rbp-0xc],0x2 400506: c7 45 f8 03 00 00 00 mov DWORD PTR [rbp-0x8],0x3 40050d: c7 45 fc 04 00 00 00 mov DWORD PTR [rbp-0x4],0x4 400514: c7 45 ec 00 00 00 00 mov DWORD PTR [rbp-0x14],0x0 40051b: eb 13 jmp 400530 <main+0x43> 40051d: 8b 05 15 0b 20 00 mov eax,DWORD PTR [rip+0x200b15] # 601038 <globalA> 400523: 83 e8 01 sub eax,0x1 400526: 89 05 0c 0b 20 00 mov DWORD PTR [rip+0x200b0c],eax # 601038 <globalA> 40052c: 83 45 ec 01 add DWORD PTR [rbp-0x14],0x1 400530: 8b 05 02 0b 20 00 mov eax,DWORD PTR [rip+0x200b02] # 601038 <globalA> 400536: 39 45 ec cmp DWORD PTR [rbp-0x14],eax 400539: 7c e2 jl 40051d <main+0x30> 40053b: 5d pop rbp 40053c: c3 ret </syntaxhighlight>

==See also== {{Portal|Computer programming}} * GNU Binutils

==References== {{Reflist}}

==External links== * {{man|1|objdump|die.net}} * {{man|1|readelf|die.net}} * [https://metacpan.org/pod/Binutils::Objdump Binutils::Objdump] - Perl interface to objdump

Category:Unix programming tools Category:Disassemblers