testpattern: 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/testpattern - from package: gutenprint-extras

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

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