I installed MariaDB 10.6.12 with tar.gz file. (/MARIA/mariadb/bin)
I modified mysql.server file and copy to '/etc/init.d/mariadb'

basedir=/MARIA/mariadb

datadir=/MARIA/DATA

I created 'my.cnf' in '/MARIA/mariadb' and I expected '/etc/init.d/mariadb' use '/MARIA/mariadb/my.cnf' when starting MariaDB server.
(I refered " if test -r "$basedir/my.cnf" " in 'mysql.server' file.)

When I excuted 'service mariadb start' I faced error, so I found something with output of 'sh -x /etc/init.d/mariadb start'

if test -r "$basedir/my.cnf"

then

  extra_args="--defaults-extra-file= $basedir/my.cnf"

else

  if test -r "$datadir/my.cnf"

  then

    extra_args="--defaults-extra-file= $datadir/my.cnf"

  fi

fi

'--defaults-extra-file' option cannot load the configuration because of 'space' between '= $basedir'.

After I fixed I executed again, I faced new error.

/etc/init.d/mariadb: line 278: log_failure_msg: command not found

There is not 'log_failure_msg' function in this file.
Please check this.