code: def _parse_ld_musl_from_elf(f: IO[bytes]) -> Optional[str]:
      """Detect musl libc location by parsing the Python executable.
  
      Based on: https://gist.github.com/lyssdod/f51579ae8d93c8657a5564aefc2ffbca
      ELF header: https://refspecs.linuxfoundation.org/elf/gabi4+/ch4.eheader.html
      """
      f.seek(0)
      try:
          ident = _read_unpacked(f, "16B")
      except struct.error:
          return None
      if ident[:4] != tuple(b"\x7fELF"):  # Invalid magic, not ELF.
          return None
      f.seek(
          struct.calcsize("HHI"), 1
      )  # Skip file type, machine, and version.
  
      try:
          # e_fmt: Format for program header.
          # p_fmt: Format for section header.
          # p_idx: Indexes to find p_type, p_offset, and p_filesz.
          e_fmt, p_fmt, p_idx = {
              1: ("IIIIHHH", "IIIIIIII", (0, 1, 4)),  # 32-bit.
              2: ("QQQIHHH", "IIQQQQQQ", (0, 2, 5)),  # 64-bit.
          }[ident[4]]
      except KeyError:
          return None
      else:
          p_get = operator.itemgetter(*p_idx)
  
      # Find the interpreter section and return its content.
      try:
          _, e_phoff, _, _, _, e_phentsize, e_phnum = _read_unpacked(
              f, e_fmt
          )
      except struct.error:
          return None
      for i in range(e_phnum + 1):
          f.seek(e_phoff + e_phentsize * i)
          try:
              p_type, p_offset, p_filesz = p_get(
                  _read_unpacked(f, p_fmt)
              )
          except struct.error:
              return None
          if p_type != 3:  # Not PT_INTERP.
              continue
          f.seek(p_offset)
          interpreter = os.fsdecode(f.read(p_filesz)).strip("\0")
          if "musl" not in interpreter:
              return None
          return interpreter
      return None
  
file_path: catboost/contrib/python/packaging/py3/packaging/_musllinux.py
imports: import contextlib
  import functools
  import operator
  import os
  import re
  import struct
  import subprocess
  import sys
  from typing import IO, Iterator, NamedTuple, Optional, Tuple
label_desc: Use image node_id 2 for calling a global function with example usage: _parse_ld_musl_from_elf(f) and returns: None, None, interpreter, None, None, None, None, None