cpan2doap: 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/cpan2doap - from package: librdf-doap-lite-perl

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

Error in other languages:
cpan2doap: bevel nie gevind nie
cpan2doap: comandă negăsită
cpan2doap: comando não encontrado
cpan2doap: commande introuvable
cpan2doap: command not found
cpan2doap: käsku ei ole
cpan2doap: không tìm thấy lệnh
cpan2doap: komanda nerasta
cpan2doap: Kommando nicht gefunden.
cpan2doap: kommandot finns inte
cpan2doap: komut yok
cpan2doap: nie znaleziono polecenia
cpan2doap: níor aimsíodh an t-ordú
cpan2doap: no se encontró la orden
cpan2doap: no s'ha trobat l'ordre
cpan2doap: opdracht niet gevonden
cpan2doap: parancs nem található
cpan2doap: perintah tidak ditemukan
cpan2doap: príkaz nenájdený
cpan2doap: příkaz nenalezen
cpan2doap: команда не найдена
cpan2doap: командата не е открита
cpan2doap: 命令找不到
cpan2doap: コマンドが見つかりません