eboard-addtheme: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/eboard-addtheme - from package: eboard

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