opari: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/bin/opari - from package: opari

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