createlang: 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/createlang - from package: postgresql

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

On Debian possible default full paths are:

/usr/bin/createlang - from package: postgresql-client-common
/usr/lib/postgresql/9.4/bin/createlang - from package: postgresql-client-9.4

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

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