getuid.2

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 2 代码 · 共 61 行

.\" SCCSID: @(#)getuid.2	8.1	9/11/90
.\" Last modified by BAM on 2-Aug-85  1000  
.\"
.TH getuid 2
.SH Name
getuid, geteuid \- get user identity
.SH Syntax
.nf
.B #include <sys/types.h>
.B #include <unistd.h>
.PP
.B uid = getuid()
.B uid_t uid;
.sp
.B euid = geteuid()
.B uid_t euid;
.fi
.SH Description
.NXR "getuid system call"
.NXR "geteuid system call"
.NXR "real group ID" "getting"
.NXR "effective group ID" "getting"
.NXR "real user ID" "getting"
.NXR "effective user ID" "getting"
The
.PN getuid
system call returns the real user ID of the current process,
.PN geteuid
the effective user ID.
.PP
The real user ID identifies the person who is logged in.
The effective user ID
gives the process additional permissions during
execution of \*(lqset-user-ID\*(rq mode processes, which use
.PN getuid
to determine the real-user-id of the process which
invoked them.
.SH Environment
.SS System Five
Differs from the System V definition in that
the return values are of type
.I int,
instead of 
.I unsigned short.
.SS POSIX
When your program is compiled in POSIX mode,
the
.PN getuid
and
.PN geteuid
functions return a value of type 
.I uid_t.
The
.PN getgid
and
.PN getegid
functions return a value of type 
.I gid_t.
.SH See Also
getgid(2), setreuid(2)