lcd4linux: 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/sbin/lcd4linux - from package: lcd4linux

You may install the required package with command apt-get install {package}
Error in other languages:
lcd4linux: bevel nie gevind nie
lcd4linux: comandă negăsită
lcd4linux: comando não encontrado
lcd4linux: commande introuvable
lcd4linux: command not found
lcd4linux: käsku ei ole
lcd4linux: không tìm thấy lệnh
lcd4linux: komanda nerasta
lcd4linux: Kommando nicht gefunden.
lcd4linux: kommandot finns inte
lcd4linux: komut yok
lcd4linux: nie znaleziono polecenia
lcd4linux: níor aimsíodh an t-ordú
lcd4linux: no se encontró la orden
lcd4linux: no s'ha trobat l'ordre
lcd4linux: opdracht niet gevonden
lcd4linux: parancs nem található
lcd4linux: perintah tidak ditemukan
lcd4linux: príkaz nenájdený
lcd4linux: příkaz nenalezen
lcd4linux: команда не найдена
lcd4linux: командата не е открита
lcd4linux: 命令找不到
lcd4linux: コマンドが見つかりません