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

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

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