How do I find symbols in a object file?


The command nm displays symbols in an object file.  nm is a command that
extracts the name list of object files, archives(libraries) and executables.
Here we run it on a object file.

	$ cat a.c
	#include <stdio.h>

	int main()
	{
		printf("hello world\n");
	}

	$ cc -c a.c
	$ nm a.o

 
	Symbols from a.o:

	Name                    Value   Scope  Type    Subspace

	M$2                 |1073741824|static|data   |$DATA$
	main                |         0|extern|entry  |$CODE$
	printf              |          |undef |code   |
	$ 

As expected nm shows there is a function main and a reference to printf.
nm can also be used to track missing symbols.  For example, during a
build if you see the error 

ld: Unsatisfied symbols: