edhead: 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/edhead - from package: wcstools

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

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