wdwrite: command not found

Have You tried accessing the binary with the full path?

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/wdwrite - from package: WindowMaker

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

On Debian possible default full paths are:

/usr/bin/wdwrite - from package: wmaker

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