How to get the minor and major device numbers with os.stat ?

[Alain Tesio]

Hi, I can't manage to get the major or minor device numbers
with os.stat :

~ $ll /dev/xda7 /dev/xda8
brw-rw---- 1 root disk 13, 7 Nov 30 2000 /dev/xda7
brw-rw---- 1 root disk 13, 8 Nov 30 2000 /dev/xda8

~ $python
Python 2.2.2 (#4, Oct 15 2002, 04:21:28)
[GCC 2.95.4 20011002 (Debian prerelease)] on linux2
Type "help", "copyright", "credits" or "license" for more information.

import os
os.stat("/dev/xda7") (25008, 17383L, 5643L, 1, 0, 6, 0L, 1007270448, 975597764, 1007270448) os.stat("/dev/xda8") (25008, 17384L, 5643L, 1, 0, 6, 0L, 1007270448, 975597764, 1007270448) 17384 / 256 , 17384 % 256

(67, 232)
I expected major*256+minor, I've tried a lot of combinations at random
and couldn't manage to get 17383 from (13,7)

Any idea ?

Thanks
Alain

[Erik Max Francis]

Alain Tesio wrote:

I expected major*256+minor, I've tried a lot of combinations at random
and couldn't manage to get 17383 from (13,7)

For the answer to this, you should really be looking at man stat. The
values here are implementation defined; Python's just mimicking whatever
the underlying OS is doing. What you want is st_rdev:

import os
os.system('ls -l /dev/ttyS0') crw-rw---- 1 root uucp 4, 64 Jul 17 1994 /dev/ttyS0
0 s = os.stat('/dev/ttyS0')
tuple(s) (8624, 9064L, 769L, 1, 0, 14, 0L, 1058628788, 774488935, 1058628789) s.st_rdev 1088 divmod(1088, 256)

(4, 64)

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