ubuntu_notes.sh

# How can I determine if Apache is installed on a system?
dpkg --get-selections | grep apache
# echo -----------------------
# apache2                install
# apache2-doc            install
# apache2-mpm-prefork    install
# apache2-utils          install
# apache2.2-bin          install
# apache2.2-common       install
# libapache2-mod-php5    install
# libapache2-svn         install

# Check busy port, to find any running HTTP daemon on the default port would be:
sudo lsof -nPi | grep ":80 (LISTEN)"
# echo -----------------------
# apache2    1026     root    4u  IPv6    3739      0t0  TCP *:80 (LISTEN)
# apache2    3966 www-data    4u  IPv6    3739      0t0  TCP *:80 (LISTEN)
# apache2    4014 www-data    4u  IPv6    3739      0t0  TCP *:80 (LISTEN)
# apache2    4015 www-data    4u  IPv6    3739      0t0  TCP *:80 (LISTEN)
# apache2    4016 www-data    4u  IPv6    3739      0t0  TCP *:80 (LISTEN)

# How to find the Process ID (PID) of a running terminal program
ps ax | grep firefox
# echo -----------------------
# 2222 ?         S      0:00 /bin/sh /usr/lib/firefox-3.6.9/firefox
# 2231 ?         Sl   514:36 /usr/lib/firefox-3.6.9/firefox-bin
# 30290 pts/2    S+     0:00 grep --color=auto firefox <- this is self process terminal, exclude this line, just ignore

# Installing specific version  PHP 5.3 in Ubuntu 14.04
sudo -i
wget http://in1.php.net/distributions/php-5.3.29.tar.bz2
tar -xvf php-5.3.29.tar.bz2
cd php-5.3.29
./configure
make
make install

# apache restart
sudo service apache2 restart