Objdump

Last updated
objdump
Operating system Unix and Unix-like
Type Command
License GNU GPL

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.

Contents

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 ]otool and nm perform analogous functions for Mach-O files. [1] [2]

Example

For example,

$ objdump -D -M intel file.bin | grep main.: -A20

This performs disassembly on the file «file.bin», with the assembly code shown in Intel syntax. We then redirect it to grep, which searches the main function and displays 20 lines of its code.

Example output:

  4004ed <main>:4004ed:55 pushrbp4004ee:48 89 e5 movrbp,rsp4004f1:c7 45 ec 00 00 00 00 movDWORDPTR[rbp-0x14],0x04004f8:c7 45 f0 01 00 00 00 movDWORDPTR[rbp-0x10],0x14004ff:c7 45 f4 02 00 00 00 movDWORDPTR[rbp-0xc],0x2400506:c7 45 f8 03 00 00 00 movDWORDPTR[rbp-0x8],0x340050d:c7 45 fc 04 00 00 00 movDWORDPTR[rbp-0x4],0x4400514:c7 45 ec 00 00 00 00 movDWORDPTR[rbp-0x14],0x040051b:eb 13 jmp400530<main+0x43>40051d:8b 05 15 0b 20 00 moveax,DWORDPTR[rip+0x200b15]# 601038 <globalA>400523:83 e8 01 subeax,0x1400526:89 05 0c 0b 20 00 movDWORDPTR[rip+0x200b0c],eax# 601038 <globalA>40052c:83 45 ec 01 addDWORDPTR[rbp-0x14],0x1400530:8b 05 02 0b 20 00 moveax,DWORDPTR[rip+0x200b02]# 601038 <globalA>400536:39 45 ec cmpDWORDPTR[rbp-0x14],eax400539:7c e2 jl40051d<main+0x30>40053b:5d poprbp40053c:c3 ret40053d:0f 1f 00 nopDWORDPTR[rax]

See also


Free and open-source software logo (2009).svg

This free and open-source software article is a stub. You can help Wikipedia by expanding it.

  1. ↑ "An Apple Library Primer". Apple Developer Forums.
  2. ↑ "llvm-otool - Mach-O dumping tool". LLVM Reference.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.