initgroups(3) Library Functions Manual initgroups(3) initgroups - (libc -lc) #include #include int initgroups(const char *user, gid_t group); glibc ( feature_test_macros(7)): initgroups(): glibc 2.19: _DEFAULT_SOURCE glibc 2.19 : _BSD_SOURCE initgroups() /etc/group user . group . user (non-NULL). initgroups() 0 . -1 errno . ENOMEM . EPERM . setgroups(2). /etc/group attributes(7). +----------------------+------------------------------------+---------------------------------------------------------------------------------------------+ | | | | +----------------------+------------------------------------+---------------------------------------------------------------------------------------------+ |initgroups() | | (locale) (MT-Safe) | +----------------------+------------------------------------+---------------------------------------------------------------------------------------------+ . SVr4, 4.3BSD. getgroups(2), setgroups(2), credentials(7) 3 . . : . 6.18 8 2026 initgroups(3)