chirpw: 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/chirpw - from package: chirp

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

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