applydeltaiso: 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/applydeltaiso - from package: deltaiso

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

On Debian possible default full paths are:

/usr/bin/applydeltaiso - from package: deltarpm

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

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