php-fpm: 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/sbin/php-fpm - from package: php54w-fpm
/usr/sbin/php-fpm - from package: php55w-fpm
/usr/sbin/php-fpm - from package: php56w-fpm
/usr/sbin/php-fpm - from package: php70w-fpm
/usr/sbin/php-fpm - from package: php-fpm

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

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