wcap-decode: 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/wcap-decode - from package: weston

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

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