pythonfilesetuidstat

Check if a file is setuid root in Python


I'm trying to check if a file has the setuid bit in Python.

The stat doc mentions a S_ISUID function but it only works with os.chmod(), not to actually read the setuid bit. It also lists S_IMODE, but I have no idea how to interpret it.

How can I easily check if a file as the setuid root bit set?


Solution

  • stat.S_ISUID is the mode bit for 'setuid'. You compare the stat result's mode to see if it contains that bit:

    >>> import os
    >>> import stat
    
    >>> ping = os.stat('/bin/ping')
    >>> ping.st_mode & stat.S_ISUID
    2048
    >>> echo = os.stat('/bin/echo')
    >>> echo.st_mode & stat.S_ISUID
    0