wcshead: 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/wcshead - from package: wcstools

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

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