June 2020

To check if a port is reachable on Linux This is tested using nc version 7.50 (package nmap-ncat) on Amazon Linux. nc -vz localhost 22Connection read more

Use watch with -n to watch a command ever 2 seconds. e.g. To watch top command with first 12 lines every 2 seconds:watch -n 2  read more

Using rpm We can use rpm on Centos/RHEL/Amazon Linux based system to file which package provides a specific file. e.g. rpm -q -f /usr/bin/watchprocps-3.2.8-45.16.amzn1.x86_64 Alternatively read more

csvkit can be used to extract and process fields from a csv file on Linux or Mac. Install python3 if not installed already. The command read more

To replace comma of any other character with newline on Linux or Mac, the following tr command can be used tr ‘,’ ‘\n’ filename or read more

The steps to enable mysql query logs on Mysql 5.7 (should work on other versions also) on Linux Edit /etc/my.cnf and add the followinggeneral_log=1general_log_file=/var/log/mysqlquery.log Ensure read more

The query to find recently created tables in mysql select table_schema, table_name, create_timefrom information_schema.TABLESwhere table_schema not in (‘information_schema’, ‘mysql’)order by CREATE_TIME desc

Steps to install php 7.3 or higher versions on Amazon Linux 3 Install many remi repos remi-php74, remi-php74, etc. (but keep them disabled)sudo yum install read more

Steps to install and enable httpd/apache 2.4 on Amazon Linux 2. sudo yum install httpd sudo systemctl start httpd sudo systemctl enable httpd

Linux Yum handy commands for Amazon Linux, Centos, RHEL Linux Show Repository listsudo yum repolistsudo yum repolist all (includes disabled also) List all packages from read more

A random root password is generated and logged in log /var/log/mysqld.log sudo cat /var/log/mysqld.log | grep -i password2020-06-02T17:39:23.434297Z 1 [Note] A temporary password is generated read more

Steps to install mysql 5.7 on Amazon Linux 2 Install Extra Packages for Enterprise Linux (EPEL)sudo yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm(you can alternatively use sudo amazon-linux-extras install read more