pfbtops: 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 CentOS possible default full paths are:

/usr/bin/pfbtops - from package: groff

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

On Debian possible default full paths are:

/usr/bin/pfbtops - from package: groff

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

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