pof5: command not found

Have You tried accessing the binary with the full path?

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/share/doc/mh-book/examples/mh/bin/pof5 - from package: mh-book

You may install the required package with command apt-get install {package}
Error in other languages:
pof5: bevel nie gevind nie
pof5: comandă negăsită
pof5: comando não encontrado
pof5: commande introuvable
pof5: command not found
pof5: käsku ei ole
pof5: không tìm thấy lệnh
pof5: komanda nerasta
pof5: Kommando nicht gefunden.
pof5: kommandot finns inte
pof5: komut yok
pof5: nie znaleziono polecenia
pof5: níor aimsíodh an t-ordú
pof5: no se encontró la orden
pof5: no s'ha trobat l'ordre
pof5: opdracht niet gevonden
pof5: parancs nem található
pof5: perintah tidak ditemukan
pof5: príkaz nenájdený
pof5: příkaz nenalezen
pof5: команда не найдена
pof5: командата не е открита
pof5: 命令找不到
pof5: コマンドが見つかりません