mysqldump --all-databases >name.sql

mysqldump -u root -p database --ignore-table tablename >name.sql

mysqldump -system=all >name.sql

mysqldump -system=user >name.sql

/etc/init.d/mysql stop

mysqld_safe --user=mysql --skip-grant-tables --skip-networking &

mysql_upgrade

kill mysqld_safe

/etc/init.d/mysql start

backup system disk with boot disk  using zstd

tar cpf /mnt/data/gentoo.tar.zst --zstd  /boot/ --exclude /var/lib/docker/ --exclude /var/db/repos/ --exclude /var/cache/ --exclude /var/log/ --one-file-system /

tar xpf  gentoo.tar.zst --zstd -C /

openssl genrsa -out cakey.pem 2048

openssl req -new -x509 -days 3650 -key cakey.pem -out cacert.pem

openssl genrsa -out c1.key 2048

openssl req -new -key c1.key -out c1.csr

#commonName = optional
openssl ca -in c1.csr -out c1.crt -days=3650 -create_serial

openssl pkcs12 -export -clcerts -in c1.pem -out c1.p12

1. make a sparseimage or sparsebundle file using Disk Utility
 //hdiutil create -size 1000g -type SPARSEBUNDLE -nospotlight -volname "Name" -fs "Journaled HFS+" -verbose file.sparsebundle

2. copy the file to a samba dir

3. mount the disk image file

4. sudo tmutil setdestination /Volumes/DiskImageMountPoint

5. now the disk is available in time machine

#!/bin/bash
echo -n "Enter Pass:"
read -s my_pass
cmd_name="/bin/somecmd"

expect << EOF
set timeout 100
spawn "$cmd_name"
expect {
    "Enter password:" { send "$my_pass\r";exp_continue }
}
EOF

//simulate terminal input

#include <sys/ioctl.h>
#include <termios.h>
#include <stdio.h>
#include <stdlib.h>

python2 -m SimpleHTTPServer

python -m http.server

python2 -c "import socket,SocketServer,CGIHTTPServer;SocketServer.TCPServer.address_family=socket.AF_INET6;CGIHTTPServer.test()" 8000

download stage3

tar xpvf stage3-*.tar.bz2 --xattrs-include='*.*' --numeric-owner
###copy whole system to another disk
###tar cpf - --exclude=="/mnt/" --one-file-system  / | tar xpf - --xattrs-include='*.*' --numeric-owner

GENTOO_MIRRORS="http://mirrors.sohu.com/gentoo/"

cp --dereference /etc/resolv.conf /mnt/gentoo/etc/

mount --types proc /proc /mnt/gentoo/proc

mount --rbind /sys /mnt/gentoo/sys

mount --make-rslave /mnt/gentoo/sys

wg genkey | tee server.key | wg pubkey > server.pub

PEER_A_PUB=key_string
PEER_Endpoint="endpoint ip:9902" #maybe empty
PEER_A_IP=10.1.0.2
MY_IP=10.1.0.1/24
MY_PORT=9901
ip link del wg0 ip link add dev wg0 type wireguard
ip addr add $MY_IP dev wg0
wg set wg0 listen-port $MY_PORT private-key /etc/wireguard/server.key
wg set wg0 peer $PEER_A_PUB $PEER_Endpoint allowed-ips $PEER_A_IP/32
ip link set wg0 up

in dir /etc/wireguard