setuid.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 99 行

.\" SCCSID: @(#)setuid.3	8.1	9/11/90
.\"
.TH setuid 3
.SH Name
setuid, seteuid, setruid, setgid, setegid, setrgid \- set user and group ID
.SH Syntax
.nf
.B #include <\fIsys/types.h\fP>
.B #include <\fIunistd.h\fP>
.PP
.B setuid(\fIuid\fP)
.B uid_t \fIuid\fP;
.B seteuid(\fIeuid\fP)
.B uid_t \fIeuid\fP;
.B setruid(\fIruid\fP)
.B uid_t \fIruid\fP;
.PP
.B setgid(\fIgid\fP)
.B gid_t \fIgid\fP;
.B setegid(\fIegid\fP)
.B gid_t \fIegid\fP;
.B setrgid(\fIrgid\fP)
.B gid_t \fIrgid\fP;
.fi
.SH Description
.NXR "setuid subroutine"
.NXR "seteuid subroutine"
.NXR "setruid subroutine"
.NXR "setgid subroutine"
.NXR "setegid subroutine"
.NXR "setrgid subroutine"
.NXR "real user ID" "setting"
.NXR "effective user ID" "setting"
.NXR "real group ID" "setting"
.NXR "effective group ID" "setting"
The
.PN setuid
subroutine sets both the real and effective
user ID of the current process to the ID specified.
Likewise, the
.PN setgid
subroutine sets the real and effective
group ID of the current process to the ID specified.
.PP
The
.PN seteuid
subroutine sets the effective user ID of the current process,
while the
.PN setegid
subroutine sets the effective group ID of the current process.
.PP
The
.PN setruid
subroutine sets the real user ID of the current process,
while the
.PN setrgid
subroutine sets the real group ID of the current process.
.PP
These calls are only permitted to the super-user
or if the argument is the real or effective ID.
.SH Environment
.PP 
.B POSIX
.br
.B SYSTEM_FIVE
.br
When your program is compiled in POSIX or System V mode the following semantics
apply when using the
.PN setuid
or
.PN setgid
functions:
.PP 
If the process is the super-user the real, effective, and saved
set (as described in
.MS execve 2 )
user/group ID are set to
.I uid.
.PP 
If the process is not the super-user, but
.I uid
is equal to the real or the saved set user/group ID, the
effective user/group ID is set to
.I uid.
The real and saved set user/group ID remain unchanged.
.PP 
.B POSIX
.br 
In POSIX mode, the
.PN setuid
function returns a value of type uid_t. The
.PN setgid
function returns a value of type gid_t.
.SH Return Values
Zero is returned if the user ID or group ID is set;
\-1 is returned otherwise.
.SH See Also
setreuid(2), setregid(2), getuid(2), getgid(2)