dosbox: 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/dosbox - from package: dosbox

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

On Debian possible default full paths are:

/usr/bin/dosbox - from package: dosbox

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

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