getlogin.3

来自「操作系统设计与实现源码」· 3 代码 · 共 46 行

.\"	@(#)getlogin.3	6.2 (Berkeley) 5/9/86
.\"
.TH GETLOGIN 3  "May 9, 1986"
.AT 3
.SH NAME
getlogin \- get login name
.SH SYNOPSIS
.nf
.ft B
#include <unistd.h>

char *getlogin(void)
.fi
.SH DESCRIPTION
.B Getlogin
returns a pointer to the login name as found in
.BR /etc/utmp .
It may be used in conjunction with
.B getpwnam
to locate the correct password file entry when the same user ID
is shared by several login names.
.PP
If
.B getlogin
is called within a process that is not attached to a
terminal, or if there is no entry in
.B /etc/utmp
for the process's terminal,
.B getlogin
returns a null pointer.
A reasonable procedure for determining the login name is to first call
.B getlogin
and if it fails, to call
.BR getpwuid ( getuid ()).
.SH FILES
/etc/utmp
.SH "SEE ALSO"
.BR getpwent (3),
.BR utmp (5),
.BR ttyslot (3)
.SH DIAGNOSTICS
Returns a null pointer if the name cannot be found.
.SH BUGS
The return values point to static data
whose content is overwritten by each call.