any2djvu: 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 CentOS possible default full paths are:

/usr/bin/any2djvu - from package: djvulibre

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/any2djvu - from package: djvulibre-bin

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

Error in other languages:
any2djvu: bevel nie gevind nie
any2djvu: comandă negăsită
any2djvu: comando não encontrado
any2djvu: commande introuvable
any2djvu: command not found
any2djvu: käsku ei ole
any2djvu: không tìm thấy lệnh
any2djvu: komanda nerasta
any2djvu: Kommando nicht gefunden.
any2djvu: kommandot finns inte
any2djvu: komut yok
any2djvu: nie znaleziono polecenia
any2djvu: níor aimsíodh an t-ordú
any2djvu: no se encontró la orden
any2djvu: no s'ha trobat l'ordre
any2djvu: opdracht niet gevonden
any2djvu: parancs nem található
any2djvu: perintah tidak ditemukan
any2djvu: príkaz nenájdený
any2djvu: příkaz nenalezen
any2djvu: команда не найдена
any2djvu: командата не е открита
any2djvu: 命令找不到
any2djvu: コマンドが見つかりません