jjrun: 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/jjrun - from package: javacc

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

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