Uly.me

cloud engineer

Archives for September 2019

Get Directory Size

Here’s how to get the size of a directory.

du -sh /var/www

Output:

2.1GB    /var/www

Size of the directories and files one level down.

du -sh /var/www/*

Sort with biggest files from top to bottom.

du -sh /var/www/* | sort -rh

Top 5 biggest files from top to bottom.

du -sh /var/www/* | sort -rh | head -5

Git Diff Head

Here’s how to check what’s changed in your local Git repo vs the master repo.

Git Status tells you what file has changed, but not to the level of detail such as what lines or what code was changed.

git diff HEAD

Diff Between Two Directories

Here’s how to get the differences between two directories using diff.

  • -q display only files when they differ
  • -r recursive to all sub-directories
diff -qr /directory-1 /directory-2

Recover MySQL Root Password

How to recover a MySQL root password without a password.

  1. Stop MySQL.
  2. Start MySQL Safe Mode.
  3. Login to MySQL as root without password.
  4. Change root password.

# Stop MySQL.
service mysql stop
# MySQL Safe Mode.
mysqld_safe --skip-grant-tables &
# Login to MySQL without password. Set new password.
mysql -u root -p
use mysql;
# For MySQL 5.6 or lower
UPDATE mysql.user SET Password=PASSWORD('newpassword') WHERE User='root';
# For MySQL 5.7 or higher
SET PASSWORD FOR 'root'@'localhost' = PASSWORD("newpassword");
FLUSH PRIVILEGES;
exit;
# Kill mysqld
killall mysqld
# Restart MySQL
service mysql start

I ran into issues running MySQL Safe mode. I got a “UNIX socket file don’t exists” error. Here’s the fix.

mkdir -p /var/run/mysqld
chown mysql:mysql /var/run/mysqld