Get ELF build-id w/ pyelftools

elf-build-id.py

#!/usr/bin/python3
# encoding: utf-8
# SPDX-FileCopyrightText: 2024 FC (Fay) Stegerman <[email protected]>
# SPDX-License-Identifier: GPL-3.0-or-later

from typing import Optional

from elftools.elf.elffile import ELFFile
from elftools.elf.sections import NoteSection


class Error(Exception):
    pass


def elf_build_id(elffile: str) -> Optional[str]:
    with open(elffile, "rb") as fh:
        for section in ELFFile(fh).iter_sections():     # type: ignore[no-untyped-call]
            if isinstance(section, NoteSection):
                for note in section.iter_notes():       # type: ignore[no-untyped-call]
                    if note["n_type"] == "NT_GNU_BUILD_ID":
                        return note["n_desc"]           # type: ignore[no-any-return]
    return None


def main() -> None:
    import argparse
    parser = argparse.ArgumentParser(prog="elf-build-id.py", description="Get ELF build-id.")
    parser.add_argument("elffiles", metavar="ELF", nargs="+")
    args = parser.parse_args()
    for elffile in args.elffiles:
        if build_id := elf_build_id(elffile):
            print(f"{elffile!r}:\n  0x{build_id}")
        else:
            print(f"{elffile!r}:\n  Could not find build-id.")


if __name__ == "__main__":
    main()

# vim: set tw=80 sw=4 sts=4 et fdm=marker :