cdfsections: 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/cdfsections - from package: cdftools

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

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