gnome-specimen: 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/gnome-specimen - from package: gnome-specimen

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

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