Minix2.0/man/man2/setuid.2

.\" Copyright (c) 1980 Regents of the University of California.
.\" All rights reserved.  The Berkeley software License Agreement
.\" specifies the terms and conditions for redistribution.
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.\"	@(#)setreuid.2	6.1 (Berkeley) 5/9/85
.\"
.TH SETUID 2 "May 9, 1985"
.UC 4
.SH NAME
setuid, setgid \- set user or group ID's
.SH SYNOPSIS
.nf
.ft B
#include <sys/types.h>

int setuid(uid_t \fIuid\fP)
int setgid(gid_t \fIgid\fP)
.ft R
.fi
.SH DESCRIPTION
.B Setuid
sets the real and effective user ID's of the
current process to
.IR uid .
Unprivileged users may only change both user ID's
to the real user ID; only the super-user may
make other changes.
.B Setgid
does the same for the real and effective group ID's.
.PP
Minix-vmd
allows an unprivileged user to change ID's to the original real or effective
ID as they were at the time the process was executed.
.B Setgid
may also set the group ID's to any of the additional group ID's.
If one of the
remembered user ID's was 0 then any user or group ID may be chosen.
.SH "RETURN VALUE
Upon successful completion, a value of 0 is returned.  Otherwise,
a value of \-1 is returned and \fBerrno\fP is set to indicate the error.
.SH "ERRORS
.TP 15
[EPERM]
The current process is not the super-user and a change
other than one of the allowed changes was attempted.
.SH "SEE ALSO"
.BR getuid (2),
.BR getgid (2).