Section: POSIX Programmer's Manual (3P)
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
--- set effective user ID
int seteuid(uid_t uid);
is equal to the real user ID or the saved set-user-ID, or if the
process has appropriate privileges,
shall set the effective user ID of the calling process to
the real user ID and saved set-user-ID shall remain unchanged.
function shall not affect the supplementary group list in any way.
Upon successful completion, 0 shall be returned; otherwise, -1 shall
be returned and
set to indicate the error.
function shall fail if:
The value of the
argument is invalid and is not supported by the implementation.
The process does not have appropriate privileges and
does not match the real user ID or the saved set-user-ID.
The following sections are informative.
Refer to the RATIONALE section in
The Base Definitions volume of POSIX.1-2017,
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
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