pfsgamma: 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/lib/debug/usr/bin/pfsgamma - from package: pfstools-dbg
/usr/bin/pfsgamma - from package: pfstools

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