getgrnam(3) Library Functions Manual getgrnam(3) getgrnam, getgrnam_r, getgrgid, getgrgid_r - (libc -lc) #include #include struct group *getgrnam(const char *name); struct group *getgrgid(gid_t gid); int getgrnam_r(size_t size; const char *restrict name, struct group *restrict grp, char buf[restrict size], size_t size, struct group **restrict result); int getgrgid_r(size_t size; gid_t gid, struct group *restrict grp, char buf[restrict size], size_t size, struct group **restrict result); glibc ( feature_test_macros(7)): getgrnam_r(), getgrgid_r(): _POSIX_C_SOURCE || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE getgrnam() ( /etc/group NIS LDAP) name. getgrgid() gid. group : struct group { char *gr_name; /* */ char *gr_passwd; /* */ gid_t gr_gid; /* */ char **gr_mem; /* NULL */ }; group(5). getgrnam_r() getgrgid_r() getgrnam() getgrgid() group grp. group buf size. ( ) NULL ( ) *result. sysconf(_SC_GETGR_R_SIZE_MAX) -1 errno buf. ( ERANGE (caller) .) getgrnam() getgrgid() group NULL . errno . errno . getgrent(3) getgrgid() getgrnam(). ( free(3).) getgrnam_r() getgrgid_r() *result grp. 0 NULL *result. NULL *result. 0 ENOENT ESRCH EBADF EPERM ... name gid . EINTR signal(7). EIO /. EMFILE . ENFILE . ENOMEM group. ERANGE . /etc/group attributes(7). +----------------------+------------------------------------+----------+ | | | | +----------------------+------------------------------------+----------+ |getgrnam() | | MT-Unsafe | | | | race:grnam | | | | locale | +----------------------+------------------------------------+----------+ |getgrgid() | | MT-Unsafe | | | | race:grgid | | | | locale | +----------------------+------------------------------------+----------+ |getgrnam_r(), | | | |getgrgid_r() | | (locale) | | | | | | | | | | | | | | | | (MT-Safe) | +----------------------+------------------------------------+----------+ " " POSIX.1. " " errno . . POSIX errno . UNIX : 0 ENOENT EBADF ESRCH EWOULDBLOCK EPERM . POSIX.1-2008. POSIX.1-2001 SVr4 4.3BSD. endgrent(3), fgetgrent(3), getgrent(3), getpwnam(3), setgrent(3), group(5) 3 . . : . 6.18 8 2026 getgrnam(3)