nm_objdump

A simple implementation of GNU shell commands: Nm and Objdump.

• These commands disassemble executable files, relocatable object files, core files, and shared objects in a Unix environnement
• These are very useful tools for programmers working on compiling tools
• Or for programmers working on binary security.

Nm command

GNU nm lists the symbols from object files objfile…. If no object files are listed as arguments, nm assumes the file a.out.

For each symbol, nm shows:

• The symbol value, in the radix selected by options (see below), or hexadecimal by default
• The symbol type. At least the following types are used; others are, as well, depending on the object file format. If lowercase, the symbol is usually local; if uppercase, the symbol is global (external). There are however a few lowercase symbols that are shown for special global symbols (u, v and w)
• The symbol name

See man nm for more informations.

Objdump command

GNU objdump displays information about one or more object files.

• Display summary information from the overall header of each of the objfile files
• Display the full contents of any sections requested. By default all non-empty sections are displayed

See man objdump for more informations.

Format

These tools use the C ELF structure (Executable and Linking Format). See man elf.

x86-64 and i386 architecture are both supported.

Compile

compiling:

make

cleaning obj files:

make clean

cleaning binary files:

make fclean

cleaning all and compile:

make re

How to use it

For nm:

./my_nm YOUR_OBJ_FILE

or if you have a a.out file

./my_nm

For objdump:

./my_objdump YOUR_OBJ_FILE

or if you have a a.out file

./my_objdump