ahcpd: 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/sbin/ahcpd - from package: ahcpd

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

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