setgroups.2 (2010 09)

setgroups(2) setgroups(2)

NAME

setgroups - set group access list

SYNOPSIS

#include <unistd.h>

int setgroups(int ngroups, const gid_t *gidset);

DESCRIPTION

setgroups() sets the group access list of the current user process according to the array gidset . The

parameter ngroups indicates the number of entries in the array and must be no more than

sysconf(_SC_NGROUPS_MAX)

Only a user with the

CHSUBJIDENT privilege can set new groups by adding to the group access list of the

current user process; any user can delete groups from it.

Security Restrictions

Some or all of the actions associated with this system call require the

CHSUBJIDENT privilege.

Processes owned by the superuser have this privilege. Processes owned by other users may have this

privilege, depending on system conﬁguration. See privileges (5) for more information about privileged

access on systems that support ﬁne-grained privileges.

RETURN VALUE

Upon successful completion,

setgroups() returns 0; otherwise it returns − 1 and sets errno to indi-

cate the error.

ERRORS

setgroups() fails if any of the following conditions are encountered:

[EPERM] The caller is not a user with the

CHSUBJIDENT privilege and has attempted to set

new groups.

[EFAULT] The address speciﬁed for gidset is outside the process address space. The reliable

detection of this error is implementation dependent.

[EINVAL] ngroups is greater than

sysconf(_SC_NGROUPS_MAX)

or not positive.

[EINVAL] An entry in gidset is not a valid group ID.

AUTHOR

setgroups() was developed by the University of California, Berkeley.