pldes: 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 CentOS possible default full paths are:

/usr/bin/pldes - from package: gnustep-base

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/pldes - from package: gnustep-base-runtime

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