Application can't be opened because it is from an unidentified developer.

Lot of times when you are installing applications which are from an unidentified developer, you get following error:

"{application_name} can't be opened because it is from an unidentified developer."

E.g.

It is usual in MacOSX since Mountain Lion in Mac to get such an error message.

To fix this, you need to go to "System Preferences => Security & Privacy". You will see a screen like following:

See the settings "Allow apps downloaded from:". It is by default set to "Mac App Store and identified developers."

Go ahead and change it to "Anywhere" like following:

Now you are good to go and install applications from anywhere :)

Note: It's not a good idea to install applications from anywhere unless you already know the application you are installing is safe to install. 

Install the Command Line Developer Tools from Terminal

Open terminal and execute following command:

xcode-select --install

You will see alert like:

Now, click on Install button and there you go :)

Find files by name on Mac Terminal

Use following command to find files by name on Mac OS Terminal:
find -name

Examples:

Find files named with 'test' on my mac:
find / -name test


Find files named with 'test' on current folder/directory:
find . -name test

Reinstall mysql using brew:

Remove mysql installation and cleanup using brew:

brew remove mysql

brew cleanup

unload homebrew.mxcl.mysql.plist if already loaded and remove it:

launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

rm ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

Install mysql using brew:

brew install mysql

Set up databases to run AS YOUR USER ACCOUNT with:

unset TMPDIR

mysql_install_db --verbose --user=`whoami` --basedir="$(brew --prefix mysql)" --datadir=/usr/local/var/mysql --tmpdir=/tmp

Start the mysql server:

mysql.server start

Set the root password

/usr/local/Cellar/mysql/5.5.19/bin/mysqladmin -u root password 'new-password'

Setting the root password ensures that nobody can log into the MySQL

root user without the proper authorisation.

Alternatively you can run following command and follow the steps:

/usr/local/Cellar/mysql/5.5.19/bin/mysql_secure_installation

which will also give you the option of removing the test databases and anonymous user created by default.  This is strongly recommended for production servers. See the manual for more instructions.

To launch on startup:

* if this is your first install:

    mkdir -p ~/Library/LaunchAgents

    cp /usr/local/Cellar/mysql/5.5.19/homebrew.mxcl.mysql.plist ~/Library/LaunchAgents/

    launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

* if this is an upgrade and you already have the homebrew.mxcl.mysql.plist loaded:

    launchctl unload -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

    cp /usr/local/Cellar/mysql/5.5.19/homebrew.mxcl.mysql.plist ~/Library/LaunchAgents/

    launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist

You may also need to edit the plist to use the correct "UserName".