print_appinfo_field_name_table.py

print_appinfo_field_name_table.py

# Licensed under Creative Commons Zero
#
# Prints the list of field names stored at the end of the `appinfo.vdf` file
# which is needed to parse the binary VDF segments in the same file.
# This list can then be provided to `vdf.binary_load` as the `field_names` kwarg.
from pathlib import Path
import struct

appinfo_path = Path.home() / ".steam" / "steam" / "appcache" / "appinfo.vdf"

with appinfo_path.open("rb") as file_:
    # Read the offset in appinfo.vdf
    file_.seek(8)
    table_offset = struct.unpack("<L", file_.read(4))[0]

    file_.seek(table_offset)

    # Retrieve the number of field names
    field_name_count = struct.unpack("<L", file_.read(4))[0]

    field_names = []

    # Retrieve each null-terminated string
    for _ in range(0, field_name_count):
        field_name = bytearray()
        while True:
            field_name += file_.read(1)

            if field_name[-1] == 0:
                field_name = field_name[0:-1]
                field_name = field_name.decode("utf-8")

                field_names.append(field_name)
                break


print(field_names)