pammasksharpen: 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/pammasksharpen - from package: netpbm-progs

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

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