pamflip: 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/pamflip - from package: netpbm-progs

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

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