edfviewer: 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/edfviewer - from package: pymca

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

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