Xampp Won't Startup MySQL server on Mac OSX?

you can check if any instance of mysql is running by executing in the terminal

sudo ps aux | grep mysql

this will list any processes that have mysql in their name.

_mysql          18943   0,0  0,5  2514608  20340 s008  S+    5:46am   0:00.07   /opt/local/libexec/mysqld --basedir=/opt/local --datadir=/opt/local/var/db/mysql5 --  user=_mysql --log-error=/opt/local/var/db/mysql5/Max-NB.local.err --pid-  file=/opt/local/var/db/mysql5/Max-NB.local.pid
root            18900   0,0  0,1  2439964   2592 s008  S+    5:46am   0:00.15 /bin/sh   /opt/local/bin/mysqld_safe5
root            18899   0,0  0,1  2439396   2616 s008  S+    5:46am   0:00.02 sudo   mysqld_safe5

you may then terminate the process by executing

sudo killall mysqld_safe5

you should replace "mysqld_safe5" by the name of your mysql process. It is most likely "mysqld".

After that you could try to restart your server and check if it works.

chmod -R 777 /Applications/XAMPP/xamppfiles/var

fixed the problem for me. Refer - StackOverflow question

However do not do this in production servers, you may need to change the owner or group (chown or chgrp to resolve the problem.