.\" Hey Emacs! This file is -*- nroff -*- source.
.\"
.\" Copyright 1995  James R. Van Zandt <jrv@vanzandt.mv.com>
.\"
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.\" manual provided the copyright notice and this permission notice are
.\" preserved on all copies.
.\"
.\" Permission is granted to copy and distribute modified versions of this
.\" manual under the conditions for verbatim copying, provided that the
.\" entire resulting derived work is distributed under the terms of a
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.\" Since the Linux kernel and libraries are constantly changing, this
.\" manual page may be incorrect or out-of-date.  The author(s) assume no
.\" responsibility for errors or omissions, or for damages resulting from
.\" the use of the information contained herein.  The author(s) may not
.\" have taken the same level of care in the production of this manual,
.\" which is licensed free of charge, as they might when working
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.\" Formatted or processed versions of this manual, if unaccompanied by
.\" the source, must acknowledge the copyright and authors of this work.
.\"
.\" Changed Tue Sep 19 01:49:29 1995, aeb: moved from man2 to man3
.\"  added ref to /etc/utmp, added BUGS section, etc.
.\" modified 2003 Walter Harms, aeb - added getlogin_r, note on stdin use
.\"
.\" Japanese Version Copyright (c) 1998 NAKANO Takeo all rights reserved.
.\" Translated 1998-03-01, NAKANO Takeo <nakano@apm.seikei.ac.jp>
.\" Updated & Modified 1999-08-21, NAKANO Takeo <nakano@apm.seikei.ac.jp>
.\" Updated & Modified 2005-03-18, Akihiro MOTOKI <amotoki@dd.iij4u.or.jp>
.\"
.TH GETLOGIN 3 2007-07-26 "GNU" "Linux Programmer's Manual"
.SH ̾
getlogin, getlogin_r, cuserid \- 桼̾
.SH 
.B #include <unistd.h>
.sp
.B "char *getlogin(void);"
.br
.BI "int getlogin_r(char *" buf ", size_t " bufsize );
.sp
.B #include <stdio.h>
.sp
.BI "char *cuserid(char *" string );
.sp
.in -4n
glibc εǽޥ׷
.RB ( feature_test_macros (7)
):
.in
.sp
.BR getlogin_r ():
_REENTRANT || _POSIX_C_SOURCE\ >=\ 199506L
.br
.BR cuserid ():
_XOPEN_SOURCE
.SH 
.BR getlogin ()
ϡߤΥץü˥󤷤Ƥ桼̾ʸؤ
ݥ󥿤֤桼̾Ǥʤ null ݥ󥿤֤
ʸŪΰ˳ƤƤꡢθǤδؿ
.BR cuserid ()
ƤӽФ줿ݤ˾񤭤뤳Ȥ롣
.PP
.BR getlogin_r ()
ϡ嵭Ʊ桼̾礭
.I bufsize

.I buf
֤
.PP
.BR cuserid ()
ϡߤΥץμ¸桼ID б桼̾
ʸؤΥݥ󥿤֤
\fIstring\fP  null ݥ󥿰ʳξ硢\fIstring\fP ϾʤȤ
\fBL_cuserid\fP ʸݻǤǤʤФʤʤ
\fIstring\fP  null ݥ󥿤ξˤϡŪΰ֤줿ʸؤ
ݥ󥿤֤롣ʸŪΰ˳ƤƤꡢ
δؿ
.BR getlogin ()
ƤӽФ줿ݤ˾񤭤뤳Ȥ롣
.PP
ޥ \fBL_cuserid\fP  integer ǡ桼̾ݻ뤿
ɬפĹ򼨤 \fBL_cuserid\fP  \fBstdio.h\fP 
롣
.PP
δؿȤȡץ¹ԤƤ桼
.RB ( cuserid ())

Υå˥󤷤Ƥ桼
.RB ( getlogin ())
Τꤹ뤳ȤǤ
( set-user-ID ץǤϡ㤦Ȥ⤢)
.PP
ƤŪǤϡ桼ˤϴĶѿ \fBLOGNAME\fP Ĵ
ۤǤ롣LOGNAME ѿϥ桼ͳǤΤ
бǽˤʤ롣
.SH ֤
.BR getlogin ()
ϥ桼̾ؤΥݥ󥿤֤Ԥ NULL ֤
.BR getlogin_r ()
 0 ֤Ԥ 0 ʳ֤
.SH 顼
POSIX ǤϰʲΥ顼ꤵƤ:
.TP
.B EMFILE
ƤӽФץץ󤷤ƤեǤ˥ץ
¤ãƤ롣
.TP
.B ENFILE
ƥΤǥץ󤷤ƤեǤ˾¤ãƤ롣
.TP
.B ENXIO
ƤӽФץˤüʤ
.TP
.B ERANGE
(getlogin_r)
(ü NULL ХȤޤ᤿) 桼̾Ĺ
.I bufsize
Ĺ
.LP
Linux/glibc ˤϰʲΥ顼⤢롣
.TP
.B ENOENT
utmp եб륨ȥ꤬ʤä
.TP
.B ENOMEM
passwd ¤ΤƤΤ˽ʬʥ꤬ʤ
.SH ե
.TP
\fI/etc/passwd\fP
ѥɥǡ١Υե
.TP
\fI/var/run/utmp\fP
(Ūˤ \fI/etc/utmp\fP ȤƤ;
libc ˤ \fI/var/adm/utmp\fP ȤΤ⤢)
.SH 
.BR getlogin ()

.BR getlogin_r ()
 POSIX.1-2001 ǵꤵƤ롣

System V ˤ
.BR cuserid ()
뤬
ϼ¸桼 ID ǤϤʤ¥桼 ID Ѥ롣
.BR cuserid ()
ؿ 1988 ǯǤ POSIX ˤϴޤޤƤ
1990 ǯǤǤϺ줿
SUSv2 ¸ߤPOSIX.1-2001 Ǻ줿
.LP
OpenBSD ˤ
.BR getlogin ()

.BR setlogin ()
ꡢ
åб桼̾롣üʤ
åξǤäƤ⡢б桼̾롣
.SH Х
ǰʤ顢
.BR getlogin ()
ޤΤϤۤ񤷤ȤǤϤʤ̤Υץब utmp ե
ƤޤȡưʤȤ⤢롣ޤ̾κǽ 8 ʸ
֤ʤȤ¿ޤץ椷Ƥ tty 
ߥ󤷤Ƥ桼ϡץ¹Ԥ
桼Ǥʤ⤢롣
ƥӤˤ
.BR getlogin ()
Ѥ٤ǤϤʤ
.LP
glibc  POSIX ͤˤϽäƤ餺
.I /dev/tty
ǤϤʤ
.I "ɸ (stdin)"
ȤϥХǤ롣
(SunOS 5.8  HP-UX 11.11  FreeBSD 4.8 Ȥä¾κǶΥƥϤ⡢
.I ɸ
쥯Ȥ줿Ǥ֤̾)
.LP
.BR cuserid ()
ԤäƤΤºݤΤȤΤäƤԤï⤤ʤ;
ܿץǤ
.BR cuserid ()
ϻȤ٤ǤϤʤ
ȤɤʥץǤȤ٤ǤϤʤ:

.I getpwuid(geteuid())
Ѥ٤Ǥ
(줬տޤƤ뤳ȤʤС)
.BR cuserid ()
ϡֻȤʤפȡ
.SH Ϣ
.BR geteuid (2),
.BR getuid (2)