my_print_defaults: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/my_print_defaults - from package: mysql55w
/usr/bin/my_print_defaults - from package: mysql

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/my_print_defaults - from package: mariadb-server-10.0
/usr/bin/my_print_defaults - from package: mysql-server-core-5.5

You may install the required package with command apt-get install {package}

Error in other languages:
my_print_defaults: bevel nie gevind nie
my_print_defaults: comandă negăsită
my_print_defaults: comando não encontrado
my_print_defaults: commande introuvable
my_print_defaults: command not found
my_print_defaults: käsku ei ole
my_print_defaults: không tìm thấy lệnh
my_print_defaults: komanda nerasta
my_print_defaults: Kommando nicht gefunden.
my_print_defaults: kommandot finns inte
my_print_defaults: komut yok
my_print_defaults: nie znaleziono polecenia
my_print_defaults: níor aimsíodh an t-ordú
my_print_defaults: no se encontró la orden
my_print_defaults: no s'ha trobat l'ordre
my_print_defaults: opdracht niet gevonden
my_print_defaults: parancs nem található
my_print_defaults: perintah tidak ditemukan
my_print_defaults: príkaz nenájdený
my_print_defaults: příkaz nenalezen
my_print_defaults: команда не найдена
my_print_defaults: командата не е открита
my_print_defaults: 命令找不到
my_print_defaults: コマンドが見つかりません