input: 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/input - from package: yagiuda

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

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