pegasus-gridftp: 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/pegasus-gridftp - from package: pegasus-wms

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

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