isoinfo: 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/isoinfo - from package: genisoimage

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

On Debian possible default full paths are:

/usr/bin/isoinfo - from package: genisoimage

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

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