eyuvtoppm: 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/eyuvtoppm - from package: netpbm-progs

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

On Debian possible default full paths are:

/usr/bin/eyuvtoppm - from package: netpbm

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

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