wmk: 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/wmk - from package: wml

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

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