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* Change the column property
    ALTER TABLE table_name MODIFY COLUMN column_name VARCHAR(50);

* Create table from exist table
    CREATE TABLE table_name LIKE exist_table;  //empty table with same structure
    CREATE TABLE table_name AS SELECT * FROM exist_table;  //copy the whole table

* Estimate rough row number of a database
    SELECT TABLE_NAME,TABLE_ROWS FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=table_schema; // this is only an estimate,not the exact one!!!!!

oilbeater

#!/bin/bash -x

# To count row number of each table in a schema
# Example: echo 127.0.0.1 root rootpassword rootdatabase | ./count_database.sh 2>/dev/null

while read host username password schema; 
    do
        mysql -h$host -u$username -p$password -Ne "select table_name from information_schema.tables where table_schema='${schema}'"|
        while read table;
            do

oilbeater

#Batch move
ls | head -n 50 | xargs -i mv {} mvdir/

#Batch files replace
sed -i "s/older/newser/g" `grep -li older *`

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// use shell command
import subprocess
output = subprocess.check_output('dir', shell=True)
print(output)

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ref = 'https://docs.python.org/3/library/functools.html'

@lru_cache(maxsize=None)
def fib(n):
    if n < 2:
        return n
    return fib(n-1) + fib(n-2)

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#!/usr/bin/env python
"""
Very simple HTTP server in python.

Usage::
    ./dummy-web-server.py [<port>]

Send a GET request::
    curl http://localhost

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#!/bin/bash

while :
do
    address=`ifconfig bond0 | grep inet | grep -v inet6|awk '{print $2}'`
    echo $address

    ip route | grep cali | grep -v src | while read -r line ;
    do
        ip route replace $line src $address

oilbeater

8.2.3. HTTP log format
----------------------

The HTTP format is the most complete and the best suited for HTTP proxies. It
is enabled by when "option httplog" is specified in the frontend. It provides
the same level of information as the TCP format with additional features which
are specific to the HTTP protocol. Just like the TCP format, the log is usually
emitted at the end of the session, unless "option logasap" is specified, which
generally only makes sense for download sites. A session which matches the
"monitor" rules will never logged. It is also possible not to log sessions for

oilbeater

edit /etc/sysconfig/network-scripts/ifcfg-eth0

it will looks like

TYPE=Ethernet
PROXY_METHOD=none
BROWSER_ONLY=no
BOOTPROTO=none
DEFROUTE=yes

oilbeater

package main

import (
        "net/http"

        "github.com/prometheus/client_golang/prometheus/promhttp"
)

func main() {
        http.Handle("/metrics", promhttp.Handler())