gdcminfo: 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/gdcminfo - from package: libgdcm-tools

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

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