fetch-ebook-metadata: 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/fetch-ebook-metadata - from package: calibre

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

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