How do you use the GNU Binutils tools to inspect and manipulate binary files and object files?

4 Editing object files

The objedit tool can edit object files in place. You can use it to change the values of symbols, relocate sections, or patch instructions. For example, to change the value of a symbol named foo in an object file named hello.o, you can run:

objedit --change-symbol foo=0x1234 hello.o        

This will modify the value of foo to 0x1234 in the object file.

5 Linking object files

The ld tool can link object files into a binary file. You can use it to specify the entry point, the libraries, the output format, and the linker script of the program. For example, to link two object files named hello.o and world.o into a binary file named hello_world, you can run:

ld -o hello_world hello.o world.o        

This will create a binary file that can be executed by the operating system.

6 Archiving object files

The ar tool can create and manipulate static libraries. Static libraries are archives of object files that can be linked into a binary file at compile time. You can use ar to create, extract, list, or update static libraries. For example, to create a static library named libhello.a from two object files named hello.o and world.o, you can run:

ar rcs libhello.a hello.o world.o        

This will create a library file that can be used by other programs.

The GNU Binutils tools are powerful and versatile tools that can help you work with binary files and object files in GNU/Linux. You can learn more about them by reading their man pages or online documentation.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?