Le 31/05/2010 13:22, Andy Koppe a écrit :
<snip>
Posix defines LOGNAME, but regarding USER it only says that it is
"unwise to conflict with certain variables that are frequently
exported by widely used command interpreters and applications".
(http://opengroup.org/onlinepubs/007908799/xbd/envvar.html)
FYI only, in short :
historically, USER is the bsd variant of the sysv LOGNAME.
long...
sunos, login(1) both set USER and LOGNAME using pwd->pw_name
also, logname(1) uses cuserid(3) instead of getlogin(3)
cuserid(3) does getpwuid(geteuid()) || getlogin() || NULL
funny, logname(3) does getenv("LOGNAME") in libxpg !
solaris, login(1) only set LOGNAME
logname(1) does getlogin(3)
in both case, getlogin(3) does an utmp lookup using
a kind of ttyslot() * sizeof(struct utmp) || NULL
sys5r4, same as solaris, but
getlogin(3) does an utmp lookup using a kind
of a while getsid(0) != utmp.ut_pid loop
cuserid(3) does a getlogin(3) || getpwuid(getuid()) || NULL
irix, login(1) and logname(1) does as sunos
getlogin(2) does an utmp lookup using a kind
of a while ttyname(0||1||2) == utmp.ut_line
cuserid(3) does as sys5r4
osf1, login(1) does as sunos, logname(1) as solaris
getlogin(1) does a syscall _getlogin(2)
cuserid(3) does as getpwuid(getuid()) || NULL
Regards,
Cyrille Lefevre
--
mailto:cyrille.lefevre-li...@laposte.net
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