env: 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:

/bin/env - from package: coreutils
/usr/bin/env - from package: coreutils

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

On Debian possible default full paths are:

/usr/bin/env - from package: coreutils

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

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