pdsend: 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/pdsend - from package: puredata-utils

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

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