getlogin.3

<B>Digital的Unix操作系统VAX 4.2源码</B>

.\" SCCSID: @(#)getlogin.3	8.1	9/11/90
.TH getlogin 3 
.SH Name
getlogin \- get login name
.SH Syntax
.B char *getlogin()
.SH Description
.NXR "getlogin subroutine"
.NXR "login name" "getting"
The
.PN getlogin
subroutine
returns a pointer to the login name as found in 
.PN /etc/utmp .
It may be used in conjunction with
.PN getpwnam
to locate the correct password file entry when the same userid
is shared by several login names.
.PP
If
.PN getlogin
is called within a process that is not attached to a
typewriter, it returns NULL.
The correct procedure for determining the login name is to first call
.PN getlogin
and if it fails, to call
.PN getpw 
( 
.PN getuid
).
.SH Restrictions
The return values point to static data
whose content is overwritten by each call.
.SH Return Values
Returns NULL (0) if name not found.
.SH Files
/etc/utmp
.SH See Also
getgrent(3), getpw(3), getpwent(3), utmp(5)