inputplug: command not found

Have You tried accessing the binary with the full path?

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/inputplug - from package: inputplug

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