SUGGEST: os.getuser()

[Michael P. Reilly]

Gerrit Holl <gerrit.holl at pobox.com> wrote:
: Fredrik Lundh wrote on 948044608:
:> Gerrit Holl wrote:
:> > may I suggest this function for in the posix module:
:> > 
:> > def getuser():
:> >     import pwd
:> >     return pwd.getpwuid(getuid())[0]
:> 
:> you'll find a more complete implementation of that
:> function in the getpass module:

: The code of that getuser() is:

: def getuser():
:         """Get the username from the environment or password database.

:         First try various environment variables, then the password
:         database.  This works on Windows as long as USERNAME is set.

:         """

:         import os

:         for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'):
:                 user = os.environ.get(name)
:                 if user:
:                         return user

:         # If this fails, the exception will "explain" why
:         import pwd
:         return pwd.getpwuid(os.getuid())[0]

: So the user can mislead the program. I think the other way would be better:

: ...
: try:
:     import pwd
:     return pwd.getpwuid(os.getuid())[0]
: except ImportError:
:     import os
:     for name in ('LOGNAME', 'USER', 'LNAME', 'USERNAME'):
:         user = os.environ.get(name)
:         if user:
:             return user
:     return None

And this can mislead the program.  getpwuid() usually only stops at the
first entry matching the given userid.  There are a lot of systems
which have multiple accounts with the same userid, for legitimate
reasons.  If the user has changed the environment variable, there is
usually a reason.  If your program is so paranoid, then you probably
want your own mechanism.

Not to mention that in some ways, it is far easier to "fake" out
accounts on a MS box than it is on a UNIX box.  And then there are Mac
"accounts".

  -Arcege