$ mail -s “Subject: Test email from linux server” info@test.com

Press the “Return” key

Enter the body part of the email

Press ctrl + D

Enter a CC email if you would like (e.g. info2@test.com)

Press ctrl + D again

Then check the mail box to see if the mail has arrived.

Method 2:

$ echo “Enter the body part of the email” | mail -s “Subject: Test email from linux server” info@test.com -c info2@test.com

For example,

$ dig -x 217.83.122.34

;; ANSWER SECTION:

34.122.83.217.in-addr.arpa. 66372 IN PTR mail.example.com.

$ dig mail.example.com

;; ANSWER SECTION:

mail.example.com. 900 IN A 217.83.122.34

Check the IP address that is getting resolved matches the name that is getting returned back.

$ php -version

Check Linux Version

$ cat /etc/*-release (or redhat-release)

Create a repo file with the content given below. As you can note, we are looking for package upgrade related to php only.

$ vi /etc/yum.repos.d/CentOS-phpupgrade.repo

# CentOS5-Upgrade:
# This repository is a proving grounds for packages on their way to CentOSPlus and CentOS Extras.
# They may or may not replace core CentOS packages, and are not guaranteed to function properly.
# These packages build and install, but are waiting for feedback from testers as to
# functionality and stability. Packages in this repository will come and go during the
# development period, so it should not be left enabled or used on production systems without due
# consideration.
[cent5-upgrade]
name=CentOS5 Upgrade
baseurl=http://dev.centos.org/centos/$releasever/testing/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://dev.centos.org/centos/RPM-GPG-KEY-CentOS-testing
includepkgs=php*

Update the repository

$ yum update

Restart Apache server

$ service http restart

Check the PHP version that is installed

$ php -version

Check the package repository

$ rpm -qa | grep php

To see if SELinux is set, type

$ sestatus

To list all port, try the semanage command

$ semanage port -l

To check for a specific port that is opened

$ semanage port -l | grep 8085

To allow access to a specific port

$ semanage port -a -t http_port_t -p tcp 8085

Following command should help you set/change MySQL password

$ mysql -u root -p

mysql> use mysql;
mysql> show tables;
mysql> desc user;
mysql> update user set password=PASSWORD(‘mypassword’) where User=’root’;
mysql> flush privileges;
mysql> \q

Now you need to enter the new password for the user ‘root’ to gain access to mysql.

Point to note:

Prior to MySQL 4.1 PASSWORD function returns 16 byte string and in later versions it returns 41 byte string. In later versions, passwords begin with “*”. When users migrate databases from one version to other there are chances for the application to break if this factor is not considered. In later versions, if users want to still use the old form of password hashing there is a function “OLD_PASSWORD” available to them.

$/etc/init.d/mysqld start
$/etc/init.d/mysqld restart
$/etc/init.d/mysqld stop

In windows, mysql runs as a service.
C:> net stop mysql
C:> net start mysql

In such scenarios when a database call is made after the application migration happens, users often run into errors which can send them in circles between the migration servers.

Solution to this problem is to add a single line of text under my.cnf (MySQL configuration file) under [mysqld]