gdcmgendir: 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/gdcmgendir - from package: libgdcm-tools

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

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