ark: 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/ark - from package: kdeutils

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

On Debian possible default full paths are:

/usr/bin/ark - from package: ark

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

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