GETLOGIN(3)                          BSD                           GETLOGIN(3)



NAME
     getlogin, getlogin_r - get log-in name

SYNOPSIS
     char *getlogin()

     int getlogin_r (name, namelen)
     char *name;
     int namelen;

DESCRIPTION
     getlogin returns a pointer to the log-in name as found in /etc/utmp.  It
     may be used in conjunction with getpwnam to locate the correct password
     file entry when the same user ID is shared by several login names.

     If getlogin is called within a process that is not attached to a
     terminal, or if there is no entry in /etc/utmp for the process' terminal,
     getlogin returns a NULL pointer (0).  A reasonable procedure for
     determining the log-in name is to first call getlogin and, if it fails,
     to call getpwuid(getuid()).

     getlogin_r is the reentrant version of the getlogin function and can be
     used in a multiple-thread environment. It places the login name in a
     user-supplied buffer and returns a non-zero value if it fails.

FILES
     /etc/utmp

WARNINGS
     /etc/utmp can be an unreliable source of login information.  /etc/utmp is
     written by the most recently executed /bin/login, which is not
     necessarily the same as the current login.

SEE ALSO
     getuid(2), getpwent(3), utmp(5), ttyslot(3)

DIAGNOSTICS
     Returns a NULL pointer (0) if name is not found.

BUGS
     The return values point to static data whose content is overwritten by
     each call.