os.getlogin should use the DISPLAY and not the tty

[snoiraud]

BPO	1750013
Nosy	@loewis

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

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GitHub fields:

assignee = None
closed_at = <Date 2007-07-10.08:45:31.000>
created_at = <Date 2007-07-08.20:02:21.000>
labels = ['invalid']
title = 'os.getlogin should use the DISPLAY and not the tty'
updated_at = <Date 2007-07-10.08:45:31.000>
user = 'https://bugs.python.org/snoiraud'

bugs.python.org fields:

activity = <Date 2007-07-10.08:45:31.000>
actor = 'loewis'
assignee = 'none'
closed = True
closed_date = None
closer = None
components = ['None']
creation = <Date 2007-07-08.20:02:21.000>
creator = 'snoiraud'
dependencies = []
files = []
hgrepos = []
issue_num = 1750013
keywords = []
message_count = 2.0
messages = ['32463', '32464']
nosy_count = 2.0
nosy_names = ['loewis', 'snoiraud']
pr_nums = []
priority = 'normal'
resolution = 'not a bug'
stage = None
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue1750013'
versions = []

[snoiraud]

Hi,

I have the following with gramps on kubuntu ( KDE ).
My terminals are "konsole". They don't register their pty
in utmp and I think they are correct. We are already logged. so if we register again for each konsole, we have a bad user count.

In these case, os.getlogin() return :
OSError: [Errno 2] No such file or directory

I think getlogin should use the DISPLAY instead of the tty when we get this error.

to correct this problem I use :

try:
user=os.getlogin()
except:
user=os.environ.get("USER")

but I'm not sure os.environ.get return the good value on every OSes ...

I have tested too :
except:
user = pwd.getpwuid(os.getuid())[0]

What is the best solution to this problem.

I looked at all bugs about getlogin and I saw we should avoid this function.
What is in this case the function we should use and which works correctly on every OS ( Linux, Unices, Windows, MAC OS/X, ... )

[loewis]

os.getlogin is a wrapper around the getlogin(3) POSIX function. It is important that Python exposes the function as-is, rather than trying to be more clever than the operating system designers. getlogin(3) is specified as "getlogin() returns a pointer to a string containing the name of the user logged in on the controlling terminal of the process, or a null pointer if this information cannot be determined." See the man page for the precise list of error conditions; ENOENT is returned if there is no utmp entry.

Whether konsole is correct in not listing the controlling terminal in utmp, I don't know. Notice that xterm (which should be considered an authority in such matters) *does* create an utmp entry.

It's not clear to me how DISPLAY could be used at all, but even if it could, using it here would be incorrect.

Closing as invalid.