shellinaboxd: 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/sbin/shellinaboxd - from package: shellinabox

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

On Debian possible default full paths are:

/usr/bin/shellinaboxd - from package: shellinabox

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

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