setgid (3)

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.

NAME

setgid --- 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 Electrical 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 www.unix.org/online.html .
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