SETGID(3P) POSIX Programmer's Manual SETGID(3P)PROLOG
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.
NAMEsetgid — set-group-ID
SYNOPSIS
#include <unistd.h>
int setgid(gid_t gid);
DESCRIPTION
If the process has appropriate privileges, setgid() shall set the real
group ID, effective group ID, and the saved set-group-ID of the calling
process to gid.
If the process does not have appropriate privileges, but gid is equal
to the real group ID or the saved set-group-ID, setgid() shall set the
effective group ID to gid; the real group ID and saved set-group-ID
shall remain unchanged.
The setgid() function shall not affect the supplementary group list in
any way.
Any supplementary group IDs of the calling process shall remain
unchanged.
RETURN VALUE
Upon successful completion, 0 is returned. Otherwise, −1 shall be
returned and errno set to indicate the error.
ERRORS
The setgid() function shall fail if:
EINVAL The value of the gid argument is invalid and is not supported by
the implementation.
EPERM The process does not have appropriate privileges and gid does
not match the real group ID or the saved set-group-ID.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
Refer to the RATIONALE section in setuid().
FUTURE DIRECTIONS
None.
SEE ALSO
exec, getegid(), geteuid(), getgid(), getuid(), setegid(), seteuid(),
setregid(), setreuid(), setuid()
The Base Definitions volume of POSIX.1‐2008, <sys_types.h>, <unistd.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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 http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 SETGID(3P)
