php: 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/php - from package: php54w-cli
/usr/bin/php - from package: php55w-cli
/usr/bin/php - from package: php56w-cli
/usr/bin/php - from package: php70w-cli
/usr/bin/php - from package: php-cli

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

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