cpaninject: 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 Debian possible default full paths are:

/usr/bin/cpaninject - from package: libcpan-inject-perl

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

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