rabin2: 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 Debian possible default full paths are:

/usr/bin/rabin2 - from package: radare2

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

Error in other languages:
rabin2: bevel nie gevind nie
rabin2: comandă negăsită
rabin2: comando não encontrado
rabin2: commande introuvable
rabin2: command not found
rabin2: käsku ei ole
rabin2: không tìm thấy lệnh
rabin2: komanda nerasta
rabin2: Kommando nicht gefunden.
rabin2: kommandot finns inte
rabin2: komut yok
rabin2: nie znaleziono polecenia
rabin2: níor aimsíodh an t-ordú
rabin2: no se encontró la orden
rabin2: no s'ha trobat l'ordre
rabin2: opdracht niet gevonden
rabin2: parancs nem található
rabin2: perintah tidak ditemukan
rabin2: príkaz nenájdený
rabin2: příkaz nenalezen
rabin2: команда не найдена
rabin2: командата не е открита
rabin2: 命令找不到
rabin2: コマンドが見つかりません