‘undo’ ssh-add

  • List all available keys.
  • Remove a key.
  • List all available keys.

MySQL won’t start automatically during system startup

  • P: The MySQL service does not automatically start during system startup.

  • A:
    1. Purge and redo startup scripts:
    2. Change bind-address to 0.0.0.0: Find bind-address = 127.0.0.1 and change it to bind-address = 0.0.0.0
    3. Check /etc/init/mysql.override: This file might override your startup settings. In case it looks like this
      $ less /etc/init/mysql.override
      manual
      
      Execute the following:
    4. Done.

change file encoding recursively

Good: Bad: The second one will only work if find will not descend into sub directories, since the directory tree inside of converted will not be created on demand, as it would be the case e.g. for mkdir -p. The result will be a ‘file or directory not found’ error.

mv: do not override destination file that is newer than source file (update move)

mv does not support the update option, unlike rsync and cp. If your version of coreutils does support it, using cp (followed by rm) is the easiest way to perform an update move operation:

Install Oracle Java 8

count words in a PDF file

Exemplary output: tr -d '.' removes single dots (such as from the TOC).