setgid(2)
NAME
setgid - set group identity
SYNOPSIS
#include <sys/types.h> #include <unistd.h> int setgid(gid_t gid);
DESCRIPTION
setgid() sets the effective group ID of the calling process. If the
caller is the superuser, the real GID and saved set-group-ID are also
set.
Under Linux, setgid() is implemented like the POSIX version with the
_POSIX_SAVED_IDS feature. This allows a set-group-ID program that is
not set-user-ID-root to drop all of its group privileges, do some unprivileged work, and then reengage the original effective group ID in a
secure manner.
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is
set appropriately.
ERRORS
- EPERM The calling process is not privileged (does not have the
- CAP_SETGID capability), and gid does not match the real group ID or saved set-group-ID of the calling process.
CONFORMING TO
SVr4, POSIX.1-2001.
SEE ALSO
getgid(2), setegid(2), setregid(2), capabilities(7), credentials(7)
COLOPHON
- This page is part of release 3.25 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.