#!/usr/local/bin/python3.12
import sys
import struct
def read_gguf_metadata(filepath):
ctx_val, blocks_val = None, None
try:
with open(filepath, "rb") as f:
# 1. Verify Magic Header "GGUF"
magic = f.read(4)
if magic != b"GGUF":
return None, None
# 2. Read Version (uint32) - Extracts the integer out of the unpack tuple
version = struct.unpack("<I", f.read(4))[0]
if version not in set((2, 3)):
return None, None
# 3. Read metadata counts safely using version boundaries
tensor_count = struct.unpack("<Q" if version == 3 else "<I", f.read(8 if version == 3 else 4))[0]
kv_count = struct.unpack("<Q" if version == 3 else "<I", f.read(8 if version == 3 else 4))[0]
# 4. Iterate over key-value metadata blocks
for _ in range(kv_count):
key_len = struct.unpack("<Q" if version == 3 else "<I", f.read(8 if version == 3 else 4))[0]
key = f.read(key_len).decode("utf-8", errors="ignore")
val_type = struct.unpack("<I", f.read(4))[0]
# Helper closure to skip or evaluate values based on GGUF type IDs
def skip_value(t):
# 0=uint8, 1=int8, 7=bool
if t in set((0, 1, 7)):
f.seek(1, 1)
# 2=uint16, 3=int16
elif t in set((2, 3)):
f.seek(2, 1)
# 4=uint32, 5=int32, 6=float32
elif t in set((4, 5, 6)):
val = struct.unpack("<I", f.read(4))[0]
return val
# 8=string
elif t == 8:
s_len = struct.unpack("<Q" if version == 3 else "<I", f.read(8 if version == 3 else 4))[0]
f.seek(s_len, 1)
# 9=array
elif t == 9:
arr_type = struct.unpack("<I", f.read(4))[0]
arr_len = struct.unpack("<Q" if version == 3 else "<I", f.read(8 if version == 3 else 4))[0]
for _ in range(arr_len):
skip_value(arr_type)
# 10=uint64, 11=int64, 12=float64, 13=uint64, 14=int64
elif t in set((10, 11, 12, 13, 14)):
f.seek(8, 1)
return None
res = skip_value(val_type)
# 5. Capture context size and block layers out of matching keys
if "context_length" in key and res is not None:
ctx_val = res
elif "block_count" in key and res is not None:
blocks_val = res
# Break loop immediately if both core targets are gathered
if ctx_val is not None and blocks_val is not None:
break
except Exception:
pass
return ctx_val, blocks_val
if __name__ == "__main__":
if len(sys.argv) > 1:
# Pass index 1 to isolate the path argument string
ctx, blocks = read_gguf_metadata(sys.argv[1])
ctx_str = str(ctx) if ctx else "Unknown"
blocks_str = str(blocks) if blocks else "Unknown"
print(f"{ctx_str} {blocks_str}")
