.\" Copyright (c) 1989, 1991 The Regents of the University of California.
.\" %sccs.include.redist.roff%
.\" @(#)getlogin.2 6.3 (Berkeley) %G%
.Fn setlogin "const char *name"
returns the login name of the user associated with the current session,
The name is normally associated with a login shell
at the time a session is created,
and is inherited by all processes descended from the login shell.
(This is true even if some of those processes assume another user ID,
sets the login name of the user associated with the current session to
This call is restricted to the super-user, and
is normally used only when a new session is being created on behalf
(for example, at login time, or when a remote shell is invoked).
succeeds, it returns a pointer to a null-terminated string in a static buffer.
If the name has not been set, it returns
succeeds, a value of 0 is returned. If
fails, a value of -1 is returned and an error code is
placed in the global location
The following errors may be returned by these calls:
pointed to a string that was too long.
Login names are limited to
characters, currently 12.
The caller tried to set the login name and was not the super-user.
Login names are limited in length by
However, lower limits are placed on login names elsewhere in the system
In earlier versions of the system,
failed unless the process was associated with a login terminal.
The current implementation (using
allows getlogin to succeed even when the process has no controlling terminal.
In earlier versions of the system, the value returned by
could not be trusted without checking the user ID.
Portable programs should probably still make this check.