ippl: 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/lib/debug/usr/sbin/ippl - from package: ippl-dbg
/usr/sbin/ippl - from package: ippl

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