given a function identifier, is there a command line program or a library function providing the address as stored in the elf file

Question

I am looking for a command or library function that returns the address of a function, the opposite of addr2line.

Currently, I use the following command:

readelf -s ./a.out|grep "\<main\>"|uniq
>    451: 000000000001967f   148 FUNC    GLOBAL DEFAULT   14 main

What's wrong with the command you currently use? See also `man nm`. — Employed Russian, Mar 25 '18 at 16:03
I want to get the address of the function without having to parse the output from readelf or nm — Remy, Mar 25 '18 at 16:57
I'm going to check out libbfd from GNU binutils, it looks like it is the answer I'm looking for. — Remy, Mar 25 '18 at 18:19
`libbfd` is a *horrible* library, choke-full of macros. You should use `libelf` instead. — Employed Russian, Mar 25 '18 at 18:32

score 1 · Answer 1 · answered Mar 25 '18 at 15:12

1

You could also use gdb for this, info address prints the address of the given symbol, so something like this should work: gdb ./a.out -ex 'info address main'

answered Mar 25 '18 at 15:12

mnistic

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Employed Russian · Accepted Answer · 2018-03-25T18:47:40.890

You could use libelf.

Alternatively, this question and answer shows how to do what nm does.

You could easily modify the code there to go in reverse: iterate over all symbols until you find the right symbol name, then return the address of that symbol.

If you need to perform lookups over multiple symbol names, you could of course iterate over all symbols once, and build a name -> address map, so subsequent lookups are fast.

given a function identifier, is there a command line program or a library function providing the address as stored in the elf file

2 Answers2