Other UNIX® system interfaces, not in POSIX.1-2024, or deprecated:

    _longjmp			(SUSv4)
    _setjmp			(SUSv4)
    _tolower			(SUSv4)
    _toupper			(SUSv4)
    acl_add_perm		(POSIX.1e draft)
    acl_calc_mask		(POSIX.1e draft)
    acl_check			(libacl)
    acl_clear_perms		(POSIX.1e draft)
    acl_cmp			(libacl)
    acl_copy_entry		(POSIX.1e draft)
    acl_copy_ext		(POSIX.1e draft)
    acl_copy_int		(POSIX.1e draft)
    acl_create_entry		(POSIX.1e draft)
    acl_delete_def_file		(POSIX.1e draft)
    acl_delete_entry		(POSIX.1e draft)
    acl_delete_perm		(POSIX.1e draft)
    acl_dup			(POSIX.1e draft)
    acl_entries			(libacl)
    acl_equiv_mode		(libacl)
    acl_error			(POSIX.1e draft)
    acl_extended_fd		(libacl)
    acl_extended_file		(libacl)
    acl_extended_file_nofollow	(libacl)
    acl_free			(POSIX.1e draft)
    acl_from_mode		(libacl)
    acl_from_text		(POSIX.1e draft)
    acl_get_entry		(POSIX.1e draft)
    acl_get_fd			(POSIX.1e draft)
    acl_get_fd_np		(FreeBSD, NetBSD)
    acl_get_file		(POSIX.1e draft)
    acl_get_link_np		(FreeBSD, NetBSD)
    acl_get_perm		(libacl)
    acl_get_perm_np		(FreeBSD, NetBSD)
    acl_get_permset		(POSIX.1e draft)
    acl_get_qualifier		(POSIX.1e draft)
    acl_get_tag_type		(POSIX.1e draft)
    acl_init			(POSIX.1e draft)
    acl_is_trivial_np		(FreeBSD, NetBSD)
    acl_set_fd			(POSIX.1e draft)
    acl_set_fd_np		(FreeBSD, NetBSD)
    acl_set_file		(POSIX.1e draft)
    acl_set_link_np		(FreeBSD, NetBSD)
    acl_set_permset		(POSIX.1e draft)
    acl_set_qualifier		(POSIX.1e draft)
    acl_set_tag_type		(POSIX.1e draft)
    acl_size			(POSIX.1e draft)
    acl_strip_np		(FreeBSD, NetBSD)
    acl_to_any_text		(libacl)
    acl_to_text			(POSIX.1e draft)
    acl_valid			(POSIX.1e draft)
    atoff			(AIX)
    bcmp			(POSIX.1-2001, SUSv3)
    bcopy			(SUSv3)
    bzero			(SUSv3)
    chroot			(SUSv2 - see the section called “Implementation Notes”)
    clock_setres		(QNX, VxWorks - see the section called “Implementation Notes”)
    cuserid			(POSIX.1-1988, SUSv2)
    ecvt			(SUSv3)
    endutent			(XPG2)
    fcvt			(SUSv3)
    ftime			(SUSv3)
    ftw				(SUSv4)
    gcvt			(SUSv3)
    getcontext			(SUSv3)
    gethostbyaddr		(SUSv3)
    gethostbyname		(SUSv3)
    gethostbyname2		(first defined in BIND 4.9.4)
    getitimer			(SUSv4 - see the section called “Implementation Notes”)
    getpass			(SUSv2)
    gets			(SUSv4)
    gettimeofday		(SUSv4)
    getutent			(XPG2)
    getutid			(XPG2)
    getutline			(XPG2)
    getw			(SVID)
    getwd			(SUSv3)
    h_errno			(SUSv3)
    index			(SUSv3)
    ioctl			(SUSv4)
    isascii			(SUSv4)
    makecontext			(SUSv3)
    mallinfo			(SVID)
    mallopt			(SVID)
    mktemp			(SUSv3)
    on_exit			(SunOS)
    pthread_attr_getstackaddr	(SUSv3)
    pthread_attr_setstackaddr	(SUSv3)
    pthread_continue		(XPG2)
    pthread_getconcurrency	(SUSv4)
    pthread_getsequence_np	(Tru64)
    pthread_setconcurrency	(SUSv4)
    pthread_suspend		(XPG2)
    pthread_yield		(POSIX.1c drafts)
    pututline			(XPG2)
    putw			(SVID)
    rand_r			(SUSv4)
    rindex			(SUSv3)
    scalb			(SUSv3)
    setcontext			(SUSv3)
    setitimer			(SUSv4 - see the section called “Implementation Notes”)
    setpgrp			(SUSv4)
    setutent			(XPG2)
    sighold			(SUSv4)
    sigignore			(SUSv4)
    siginterrupt		(SUSv4)
    sigpause			(SUSv4 - see the section called “Implementation Notes”)
    sigrelse			(SUSv4)
    sigset			(SUSv4)
    stime			(SVID)
    swapcontext			(SUSv3)
    sys_errlist			(BSD)
    sys_nerr			(BSD)
    sys_siglist			(BSD)
    tempnam			(SUSv4)
    toascii			(SUSv4)
    ttyslot			(SUSv2)
    ualarm			(SUSv3)
    usleep			(SUSv3)
    utime			(SUSv4)
    utmpname			(XPG2)
    vfork			(SUSv3 - see the section called “Implementation Notes”)