Install macOS 10.15 using a bootable installer

by
    1. Get an external hard drive that has at least 12 GB of available storage and plug it in your Mac.
    2. Launch the Disk Utility app and erase your hard drive selecting Mac OS Extended format.
    3. Open Terminal (Applications > Utilities).
    4. Paste this command and press Enter:
  1. sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume
  2. If prompted, enter your administrator password and press Enter again.
  3. When Terminal says “done”, your hard drive should have the same name as the installer you downloaded (for example, Install macOS Catalina).
  4. Open System Preferences > Startup Disk. Choose your bootable installer as a startup disk and press Restart.
  5. Your Mac should start up to macOS Recovery.
  6. Make sure your Mac has an internet connection to download firmware updates (you can use the Wi-Fi menu in the menu bar).
  7. In the Utilities window, select Install macOS.
  8. Your Mac will then start installing macOS Catalina and will restart when it’s done.

How to find all files containing specific text on Linux?

by

Do the following:

grep -rnw '/path/to/somewhere/' -e 'pattern'

-r or -R is recursive,
-n is line number, and
-w stands for match the whole word.
-l (lower-case L) can be added to just give the file name of matching files.

Along with these, –exclude, –include, –exclude-dir flags could be used for efficient searching:

This will only search through those files which have .c or .h extensions:

grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"

This will exclude searching all the files ending with .o extension:

grep --exclude=*.o -rnw '/path/to/somewhere/' -e "pattern"

For directories it’s possible to exclude a particular directory(ies) through –exclude-dir parameter. For example, this will exclude the dirs dir1/, dir2/ and all of them matching *.dst/:

grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/somewhere/' -e "pattern"

For more options check man grep

Syn – config automysqlbackup

by
Config Automysqlbackup 

config automysqlbackup.conf
edit  automysqlbackup and set /path/to/automysqlbackup.conf

MySQL aliases
Instead of extending the path variable, you can create a symbolic link to mysql, mysqldump, mysqlshow
cd /usr/local/bin

sudo ln -s /volume1/@appstore/MariaDB10/usr/local/mariadb10/bin/mysql /usr/local/bin/mysql
sudo ln -s /volume1/@appstore/MariaDB10/usr/local/mariadb10/bin/mysqldump /usr/local/bin/mysqldump
sudo ln -s /volume1/@appstore/MariaDB10/usr/local/mariadb10/bin/mysqlshow /usr/local/bin/mysqlshow
reference:

Postfix Queue commands

by

Goal: To find which mails are stuck in mail queue and why?

If emails are getting delayed, its better to inspect postfix mail queues, coupled with postfix mail log.

Read more

Protected: streaming-rpl

by

This content is password protected. To view it please enter your password below:

MySQL – change the collation for database and all table columns

by

Changing the collation for a table will only set the collation for the next column that’s added. To change all of the existing columns to the new collation :

ALTER TABLE tablename CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci

ALTER DATABASE dbname COLLATE utf8_general_ci