my Gentoo updating script
update [options]
-h,--help show this help message and exit
-u update @world
-U update @world and the kernel
-b update @world with --emptytree
-B update @world with --emptytree and update the kernel
-j,--jobs override kernel build job count (Default is in make.conf)
-s,--sync sync portage before updating
-k,--kernel rebuild the current kernel
-N,--no-GRUB call bootloader.sh instead of grub-mkconfig
-m,--menuconfig call make menuconfig before building the kernel
-i,--no-initramfs do not call dracut after building the kernel
-D,--defconfig call make defconfig instead of make olddefconfig
-K,--custom-kernel-building call ckb.sh instead of building the kernel via build_rest
-a,--add-repo name=<repo-name> url=<repo-url> [Sync=<sync type>] :
name=<repo-name> name of repo locally
url=<repo-url> link to repo
Sync=<sync-type> how to sync, defaults to git