GETLOGIN(3C)                         SysV                         GETLOGIN(3C)



NAME
     getlogin, getlogin_r - get login name

SYNOPSIS
     char *getlogin (void);

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

DESCRIPTION
     getlogin returns a pointer to the login 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, it returns a NULL pointer.  The correct procedure for
     determining the login name is to call cuserid, or to call getlogin and if
     it fails to call getpwuid.

     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), cuserid(3S), getgrent(3C), getpwent(3C), getpwuid(3C),
     utmp(4).

DIAGNOSTICS
     Returns the NULL pointer if name is not found.

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